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Wang Z, Yan J, Martin A, Brunton DH, Qu J, He JS, Ji W, Nan Z. Alpine grassland degradation intensifies the burrowing behavior of small mammals: evidence for a negative feedback loop. Integr Zool 2024; 19:240-252. [PMID: 37243518 DOI: 10.1111/1749-4877.12730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Globally, grassland degradation is an acute ecological problem. In alpine grassland on the Tibetan Plateau, increased densities of various small mammals in degraded grassland are assumed to intensify the degradation process and these mammals are subject to lethal control. However, whether the negative impact of small mammals is solely a result of population size or also a result of activity and behavior has not been tested. In this study, we use plateau pika as a model to compare population size, core area of colony, and the number of burrow entrances and latrines between lightly and severely degraded grassland. We test whether the alleged contribution of pika to grassland degradation is a result of increased population size or increased burrowing activities of individuals in response to lower food abundance. We found that grassland degradation resulted in lower plant species richness, plant height, and biomass. Furthermore, the overall population size of pika was not significantly affected by location in lightly and severely degraded grassland. However, pika core areas in severely grassland degradation were significantly larger and had significantly higher densities of burrows and latrines. Our study provides convincing evidence that habitat-induced changes in the behavior of small, burrowing mammals, such as pika, can exacerbate grassland degradation. This finding has significant implications for managing small mammals and restoring degraded grassland ecosystems.
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Affiliation(s)
- Zaiwei Wang
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Jiawen Yan
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Amy Martin
- Manaaki Whenua-Landcare Research, Lincoln, New Zealand
| | - Dianne H Brunton
- School of Natural Sciences, Massey University (Albany Campus), Auckland, New Zealand
| | - Jiapeng Qu
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
- Qinghai Haibei National Field Research Station of Alpine Grassland Ecosystem, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Jin-Sheng He
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
- Institute of Ecology, College of Urban and Environmental Sciences, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, China
| | - Weihong Ji
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
- School of Natural Sciences, Massey University (Albany Campus), Auckland, New Zealand
| | - Zhibiao Nan
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
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2
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Hogan KFE, Jones HP, Savage K, Burke AM, Guiden PW, Hosler SC, Rowland-Schaefer E, Barber NA. Functional consequences of animal community changes in managed grasslands: An application of the CAFE approach. Ecology 2024; 105:e4192. [PMID: 37878728 DOI: 10.1002/ecy.4192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 08/23/2023] [Accepted: 09/19/2023] [Indexed: 10/27/2023]
Abstract
In the midst of an ongoing biodiversity crisis, much research has focused on species losses and their impacts on ecosystem functioning. The functional consequences (ecosystem response) of shifts in communities are shaped not only by changes in species richness, but also by compositional shifts that result from species losses and gains. Species differ in their contribution to ecosystem functioning, so species identity underlies the consequences of species losses and gains on ecosystem functions. Such research is critical to better predict the impact of disturbances on communities and ecosystems. We used the "Community Assembly and the Functioning of Ecosystems" (CAFE) approach, a modification of the Price equation to understand the functional consequences and relative effects of richness and composition changes in small nonvolant mammal and dung beetle communities as a result of two common disturbances in North American prairie restorations, prescribed fire and the reintroduction of large grazing mammals. Previous research in this system has shown dung beetles are critically important decomposers, while small mammals modulate much energy in prairie food webs. We found that dung beetle communities were more responsive to bison reintroduction and prescribed fires than small nonvolant mammals. Dung beetle richness increased after bison reintroduction, with higher dung beetle community biomass resulting from changes in remaining species (context-dependent component) rather than species turnover (richness components); prescribed fire caused a minor increase in dung beetle biomass for the same reason. For small mammals, bison reintroduction reduced energy transfer through the loss of species, while prescribed fire had little impact on either small mammal richness or energy transfer. The CAFE approach demonstrates how bison reintroduction controls small nonvolant mammal communities by increasing prairie food web complexity, and increases dung beetle populations with possible benefits for soil health through dung mineralization and soil bioturbation. Prescribed fires, however, have little effect on small mammals and dung beetles, suggesting a resilience to fire. These findings illustrate the key role of re-establishing historical disturbance regimes when restoring endangered prairie ecosystems and their ecological function.
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Affiliation(s)
- Katharine F E Hogan
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Holly P Jones
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
- Institute for the Study of the Environment, Sustainability, and Energy, Northern Illinois University, DeKalb, Illinois, USA
| | - Kirstie Savage
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Angela M Burke
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Peter W Guiden
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Sheryl C Hosler
- Department of Biological Sciences, University of Illinois Chicago, Chicago, Illinois, USA
| | - Erin Rowland-Schaefer
- Department of Biological Sciences, Northern Illinois University, DeKalb, Illinois, USA
| | - Nicholas A Barber
- Department of Biology, San Diego State University, San Diego, California, USA
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3
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Palmer JB, Hahn PG, Metcalf EC, Maron JL. Seed size of co‐occurring forb species predicts rates of predispersal seed loss from insects. Ecosphere 2022. [DOI: 10.1002/ecs2.4032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Jakob B. Palmer
- Division of Biological Sciences University of Montana Missoula Montana USA
| | - Philip G. Hahn
- Entomology and Nematology Department University of Florida Gainesville Florida USA
| | | | - John L. Maron
- Division of Biological Sciences University of Montana Missoula Montana USA
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4
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Marás GA, Trucco CE, Nuñez-Reguiro MM, Soledad Andrade-Díaz M, Trigo CB, Flavia Caruso M, Derlindati EJ, Tálamo A. Relationships between livestock grazing intensity and mammal predator-prey: A study case in Copo National Park in the dry Chaco forests. J Nat Conserv 2022. [DOI: 10.1016/j.jnc.2022.126186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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5
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Limited influence of experimentally induced predation risk on granivory in a tropical forest. JOURNAL OF TROPICAL ECOLOGY 2022. [DOI: 10.1017/s0266467422000050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Abstract
Seed predation by rodents can strongly influence plant recruitment and establishment. The extent to which predation risk indirectly alters plant survival in tropical forests via impacts on granivory is unclear, making it difficult to assess the cascading impacts of widespread predator loss on tree recruitment and species composition. Experimental field studies that manipulate predation risk can help address these knowledge gaps and reveal whether antipredator responses among small mammals influence plant survival. We used camera traps and seed predation experiments to test the effects of perceived predation risk (via predator urine gel) on foraging behaviour of and seed removal by murid rodents in an unlogged and unhunted rainforest in Malaysian Borneo. We also explored the influence of seed traits (e.g., seed size) on removal by granivores and assessed whether granivore preferences for particular species were affected by predator urine. Murid visits to seed plots were positively related to overall seed removal, but were not affected by predator scent. Granivory was the lowest for the largest-seeded (>6 g) plant in our study, but was not influenced by predation risk. Predator urine significantly affected removal of one seed taxon (Dimoocarpus, ∼0.8 g), suggesting that removal by granivores may be affected by predation risk for some seed species but not others. This could have implications for plant species composition but may not affect the overall level of granivory.
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6
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Johnson SE, Zettlemoyer MA. Seed predator preferences are associated with seed traits but an unlikely mechanism of local extinction. Restor Ecol 2022. [DOI: 10.1111/rec.13627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sarah E. Johnson
- Kellogg Biological Station Michigan State University Hickory Corners MI 49060‐9505
| | - Meredith A. Zettlemoyer
- Kellogg Biological Station Michigan State University Hickory Corners MI 49060‐9505
- Department of Plant Biology University of Georgia Athens GA 30602‐5004
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7
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Godó L, Valkó O, Borza S, Deák B. A global review on the role of small rodents and lagomorphs (clade Glires) in seed dispersal and plant establishment. Glob Ecol Conserv 2022. [DOI: 10.1016/j.gecco.2021.e01982] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Cazetta TC, Vieira EM. Fire Occurrence Mediates Small-Mammal Seed Removal of Native Tree Species in a Neotropical Savanna. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.793947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Seed dispersal and predation are critical processes for plant recruitment which can be affected by fire events. We investigated community composition of small mammals in gallery forests with distinct burning histories (burned or not burned ∼3 years before) in the Cerrado (neotropical savanna). We evaluated the role of these animals as seed removers of six native tree species, potentially mediated by the occurrence of fire. We sampled four previously burned sites and four unburned ones. Seed removal was assessed using two exclusion treatments: exclusive access of small rodents and access of all seed-removing vertebrates. The previous burning changed the structural characteristics of the forests, increasing the density of the understory vegetation and herbaceous cover, which determined differences in species composition, richness, and abundance of small rodents (abundance in the burned forests was 1/6 of the abundance in the unburnt ones). Seed removal rates across the six species were reduced in burnt forests in both treatments and were higher for the “all vertebrates” treatment. Other vertebrates, larger than small rodents, played a significant role as seed removers for five of the six species. The effects of fire were consistent across species, but for the two species with the largest seeds (Hymenaea courbaril and Mauritia flexuosa) removal rates for both treatments were extremely low in the burned forests (≦5%). The observed decline in small rodent seed predation in the burned forests may have medium to long-term consequences on plant communities in gallery forests, potentially affecting community composition and species coexistence in these forests. Moreover, fire caused a sharp decline in seed removal by large mammals, indicating that the maintenance of dispersal services provided by these mammals (mainly the agouti Dasyprota azarae) for the large-seeded species may be jeopardized by the burning of gallery forests. This burning would also affect several small mammal species that occur in the surrounding typical savanna habitats but also use these forests. Fire events have been increasing in frequency and intensity because of human activities and climate changing. This current scenario poses a serious threat considering that these forests are fire-sensitive ecosystems within the Cerrado.
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Maron JL, Lightfoot DC, Rodriguez‐Cabal MA, Collins SL, Rudgers JA. Climate mediates long‐term impacts of rodent exclusion on desert plant communities. ECOL MONOGR 2021. [DOI: 10.1002/ecm.1497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- John L. Maron
- Division of Biological Sciences University of Montana Missoula MT 59812 USA
| | - David C. Lightfoot
- Museum of Southwestern Biology University of New Mexico Albuquerque NM 87131 USA
| | - Mariano A. Rodriguez‐Cabal
- Grupo de Ecología de Invasiones INIBIOMA ‐ CONICET Universidad Nacional del Comahue Av. de los Pioneros 2350 CP. 8400 Bariloche, Rio Negro Argentina
- Rubenstein School of Environment and Natural Resources University of Vermont Burlington Vermont 05405 USA
| | - Scott L. Collins
- Department of Biology University of New Mexico Albuquerque NM 87131 USA
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10
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Dorigo L, Boscutti F, Sigura M. Landscape and microhabitat features determine small mammal abundance in forest patches in agricultural landscapes. PeerJ 2021; 9:e12306. [PMID: 34820165 PMCID: PMC8603830 DOI: 10.7717/peerj.12306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 09/22/2021] [Indexed: 11/24/2022] Open
Abstract
Intensification of agricultural landscapes represent a major threat for biodiversity conservation also affecting several ecosystem services. The natural and semi-natural remnants, available in the agricultural matrix, represent important sites for small mammals and rodents, which are fundamental for sustaining various ecosystem functions and trophic chains. We studied the populations of two small mammals (Apodemus agrarius, A. sylvaticus) to evaluate the effects of landscape and habitat features on species abundance along a gradient of agricultural landscape intensification. The study was performed in Friuli Venezia Giulia (north-eastern Italy) during 19 months, in 19 wood remnants. Species abundance was determined using Capture-Mark-Recapture (CMR) techniques. In the same plots, main ecological parameters of the habitat (at microhabitat and patch scale) and landscape were considered. Abundance of A. agrarius increased in landscapes with high extent of permanent crops (i.e., orchards and poplar plantations) and low content of undecomposed litter in the wood understory. Instead, A. sylvaticus, a more generalist species, showed an opposite, albeit less strong, relationship with the same variables. Both species were not affected by any landscape structural feature (e.g., patch shape, isolation). Our findings showed that microhabitat features and landscape composition rather than wood and landscape structure affect populations’ abundance and species interaction. The opposite response of the two study species was probably because of their specific ecological requirements. In this light, conservation management of agricultural landscapes should consider the ecological needs of species at both landscape and habitat levels, by rebalancing composition patterns in the context of ecological intensification, and promoting a sustainable forest patch management.
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Affiliation(s)
- Luca Dorigo
- Museo Friulano di Storia Naturale, Udine, Italy
| | - Francesco Boscutti
- Di4A - Department of Agricultural, Food, Environmental and Animal Sciences, Università degli Studi di Udine, Udine, Italy
| | - Maurizia Sigura
- Di4A - Department of Agricultural, Food, Environmental and Animal Sciences, Università degli Studi di Udine, Udine, Italy
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11
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Song X, Corlett RT. Do natural enemies mediate conspecific negative distance‐ and density‐dependence of trees? A meta‐analysis of exclusion experiments. OIKOS 2021. [DOI: 10.1111/oik.08509] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Xiaoyang Song
- CAS Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences Mengla China
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences Mengla China
| | - Richard T. Corlett
- Center of Conservation Biology, Core Botanical Gardens, Chinese Academy of Sciences Mengla China
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences Mengla China
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12
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Anderegg GC, Henn JJ, Orrock JL, Damschen EI. Litter removal reduces seed predation in restored prairies during times when seed predation would otherwise be high. Restor Ecol 2021. [DOI: 10.1111/rec.13550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Genevieve C. Anderegg
- Department of Integrative Biology University of Wisconsin‐Madison, Madison, WI 53706, U.S.A
- CU Museum of Natural History University of Colorado‐Boulder, Boulder, CO 80309, U.S.A
| | - Jonathan J. Henn
- Department of Integrative Biology University of Wisconsin‐Madison, Madison, WI 53706, U.S.A
- Department of Biological and Environmental Sciences University of Gothenburg Gothenburg Sweden
| | - John L. Orrock
- Department of Integrative Biology University of Wisconsin‐Madison, Madison, WI 53706, U.S.A
| | - Ellen I. Damschen
- Department of Integrative Biology University of Wisconsin‐Madison, Madison, WI 53706, U.S.A
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13
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Pearson DE, Ortega YK, Cimino HE, Mummy DL, Ramsey PW. Does active plant restoration passively restore native fauna community structure and function? Restor Ecol 2021. [DOI: 10.1111/rec.13481] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dean E. Pearson
- Rocky Mountain Research Station USDA Forest Service 800 East Beckwith Avenue, Missoula MT 59801 U.S.A
- Division of Biological Sciences University of Montana Missoula MT 59801 U.S.A
| | - Yvette K. Ortega
- Rocky Mountain Research Station USDA Forest Service 800 East Beckwith Avenue, Missoula MT 59801 U.S.A
| | - Hillary E. Cimino
- Division of Biological Sciences University of Montana Missoula MT 59801 U.S.A
| | - Daniel L. Mummy
- MPG Ranch 19400 Lower Woodchuck Road, Florence MT 59833 U.S.A
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14
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Bartel SL, Orrock JL. An omnivorous mesopredator modifies predation of omnivore‐dispersed seeds. Ecosphere 2021. [DOI: 10.1002/ecs2.3369] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Savannah L. Bartel
- University of Wisconsin – Madison 363 Birge Hall, 430 Lincoln Drive Madison Wisconsin53706USA
| | - John L. Orrock
- University of Wisconsin – Madison 363 Birge Hall, 430 Lincoln Drive Madison Wisconsin53706USA
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15
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Small mammals and ungulates respond to and interact with revegetation processes following dam removal. FOOD WEBS 2020. [DOI: 10.1016/j.fooweb.2020.e00159] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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16
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Nicolai N. Rodents' responses to manipulated plant litter and seed densities: implications for restoration. PeerJ 2020; 8:e9465. [PMID: 32704449 PMCID: PMC7346862 DOI: 10.7717/peerj.9465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 06/10/2020] [Indexed: 11/20/2022] Open
Abstract
Rodent populations in arid grasslands do not always track seed production, possibly due to high levels of plant litter. When natural disturbances are suppressed, litter accumulates becoming physically complex, causing rodents to harvest fewer seeds per equivalent time foraging. It also alters security from predation. Restoring natural disturbances may be an important element in conserving rodent communities. The aim of this study was to assess the influence of two levels of plant litter cover and seed densities on nocturnal rodent population characteristics in a semiarid grassland. Specifically, I hypothesized that kangaroo rats, pocket mice, grasshopper mice, and total rodents would be higher in the sparse plant litter treatment than dense litter, whereas deer mice would be lower in sparse plots. I further hypothesized that kangaroo rats and deer mice would be higher in the seed augmented treatment compared to the unseeded treatment. A prescribed fire removed litter in four of eight plots prior to sowing native seeds 1 year postfire into two burned and two unburned plots. Rodents were live-trapped during spring and fall 1 year. Sparse litter treatment had higher total rodent abundance, biomass, and frequency of offspring compared to dense plots indicating use of stored seeds. Banner-tailed kangaroo rats had higher abundance, implying reduced predation risk. Pocket mice body mass was greater in dense plots. After winter, seeded plots had higher kangaroo rat body mass and grasshopper mice abundance than unseeded, reflecting the use of stored seeds. These short term results demonstrate litter's physical complexity may be equivalent to seed pulses on the responses of nocturnal rodents. Managers might positively influence grassland rodents by providing a mosaic of varying levels of plant litter.
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Affiliation(s)
- Nancy Nicolai
- Department of Biology, University of New Mexico, Albuquerque, NM, USA
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17
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Bartel SL, Orrock JL. Past and present disturbances generate spatial variation in seed predation. Ecosphere 2020. [DOI: 10.1002/ecs2.3116] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Savannah L. Bartel
- Department of Integrative Biology University of Wisconsin‐Madison 430 Lincoln Drive Madison Wisconsin 53706 USA
| | - John L. Orrock
- Department of Integrative Biology University of Wisconsin‐Madison 430 Lincoln Drive Madison Wisconsin 53706 USA
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Bjornlie NL, Thompson J. Detection of Preble's Meadow Jumping Mice (Zapus hudsonius preblei) Following Low-Severity Fire. WEST N AM NATURALIST 2019. [DOI: 10.3398/064.079.0414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
| | - Joel Thompson
- Western EcoSystems Technology, Inc., Corvallis, OR 97333
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Maron JL, Hajek KL, Hahn PG, Pearson DE. Seedling recruitment correlates with seed input across seed sizes: implications for coexistence. Ecology 2019; 100:e02848. [PMID: 31351014 DOI: 10.1002/ecy.2848] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 07/11/2019] [Accepted: 07/15/2019] [Indexed: 11/09/2022]
Abstract
Understanding controls on recruitment is critical to predicting community assembly, diversity, and coexistence. Theory posits that at mean fecundity, recruitment of highly fecund small-seeded plants should be primarily microsite limited, which is indicated by a saturating recruitment function. In contrast, species that produce fewer large seeds are more likely to be seed-limited, which is characterized by a linear recruitment function. If these patterns hold in nature, seed predation that disproportionately affects larger-seeded species can limit their establishment. We tested these predictions by comparing recruitment functions among 16 co-occurring perennial forb species that vary by over two orders of magnitude in seed size. We also assessed how postdispersal seed predation by mice influenced recruitment. We added seeds at densities from zero to three times natural fecundity of each species to undisturbed plots and examined spatial variation in recruitment by conducting experiments across 10 grassland sites that varied in productivity and resource availability. Consistent across two replicated years, most species had linear recruitment functions across the range of added seed densities, indicative of seed-limited recruitment. Depending on year, the recruitment functions of only 19-37% of target species saturated near their average fecundity, and this was not associated with seed size. Recruitment was strongly inhibited by rodent seed predation for large-seeded species but not for smaller-seeded species. Proportional recruitment was more sensitive to spatial variation in recruitment conditions across sites for some small-seeded species than for large-seeded species. These results contradict the common belief that highly fecund small-seeded species suffer from microsite-limited recruitment. Rather, they imply that, at least episodically, recruitment can be strongly correlated to plant fecundity. However, proportional recruitment of small-seeded species was inhibited at productive sites to a greater extent than large-seeded species. Results also show that in a system where the dominant granivore prefers larger seeds, low-fecundity large-seeded species can suffer from even greater seed-limited recruitment than would occur in the absence of predators.
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Affiliation(s)
- John L Maron
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812, USA
| | - Karyn L Hajek
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812, USA
| | - Philip G Hahn
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812, USA
| | - Dean E Pearson
- Division of Biological Sciences, University of Montana, Missoula, Montana, 59812, USA.,Rocky Mountain Research Station, U.S. Department of Agriculture Forest Service, Missoula, Montana, 59801, USA
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Vergara-Torres CA, Corona-López AM, Díaz-Castelazo C, Toledo-Hernández VH, Flores-Palacios A. Effect of seed removal by ants on the host-epiphyte associations in a tropical dry forest of central Mexico. AOB PLANTS 2018; 10:ply056. [PMID: 30338050 PMCID: PMC6185717 DOI: 10.1093/aobpla/ply056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 09/21/2018] [Indexed: 06/08/2023]
Abstract
Seed depredation is recognized as a determining factor in plant community structure and composition. Ants are primary consumers of seeds influencing abundance of epiphytes on trees. This study was conducted in two subunits of a tropical dry forest established on different soil substrates in San Andrés de la Cal, Tepoztlán, in Morelos, Mexico, and experimentally tested whether seed removal activity is higher in tree species with smaller epiphyte loads compared to those with greater epiphyte loads. Five trees were selected at random from six species of trees with high (preferred hosts) or low (limiting hosts) epiphyte loads. Seed removal differed among hosts and different soil substrates in the forest. On relating seed removal to the abundance of arboreal ants, the most consistent pattern was that lower seed removal was related to lower ant abundance, while high seed removal was associated with intermediate to high ant abundance. Epiphyte seed removal by ants influences epiphyte abundance and can contribute considerably to a failure to establish, since it diminishes the quantity of seeds available for germination and establishment.
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Affiliation(s)
- Carmen Agglael Vergara-Torres
- Centro de Investigación en Biodiversidad y Conservación (CIByC), Universidad Autónoma del Estado de Morelos, Av. Universidad, Col. Chamilpa, Cuernavaca, Morelos, México
| | - Angélica Ma Corona-López
- Centro de Investigación en Biodiversidad y Conservación (CIByC), Universidad Autónoma del Estado de Morelos, Av. Universidad, Col. Chamilpa, Cuernavaca, Morelos, México
| | - Cecilia Díaz-Castelazo
- Red Ecología Funcional, Instituto de Ecología, A. C. Carretera Antigua a Coatepec, El Haya, Xalapa, Veracruz, México
| | - Víctor Hugo Toledo-Hernández
- Centro de Investigación en Biodiversidad y Conservación (CIByC), Universidad Autónoma del Estado de Morelos, Av. Universidad, Col. Chamilpa, Cuernavaca, Morelos, México
| | - Alejandro Flores-Palacios
- Centro de Investigación en Biodiversidad y Conservación (CIByC), Universidad Autónoma del Estado de Morelos, Av. Universidad, Col. Chamilpa, Cuernavaca, Morelos, México
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von Wettberg EJB, Chang PL, Başdemir F, Carrasquila-Garcia N, Korbu LB, Moenga SM, Bedada G, Greenlon A, Moriuchi KS, Singh V, Cordeiro MA, Noujdina NV, Dinegde KN, Shah Sani SGA, Getahun T, Vance L, Bergmann E, Lindsay D, Mamo BE, Warschefsky EJ, Dacosta-Calheiros E, Marques E, Yilmaz MA, Cakmak A, Rose J, Migneault A, Krieg CP, Saylak S, Temel H, Friesen ML, Siler E, Akhmetov Z, Ozcelik H, Kholova J, Can C, Gaur P, Yildirim M, Sharma H, Vadez V, Tesfaye K, Woldemedhin AF, Tar'an B, Aydogan A, Bukun B, Penmetsa RV, Berger J, Kahraman A, Nuzhdin SV, Cook DR. Ecology and genomics of an important crop wild relative as a prelude to agricultural innovation. Nat Commun 2018; 9:649. [PMID: 29440741 PMCID: PMC5811434 DOI: 10.1038/s41467-018-02867-z] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/04/2018] [Indexed: 12/30/2022] Open
Abstract
Domesticated species are impacted in unintended ways during domestication and breeding. Changes in the nature and intensity of selection impart genetic drift, reduce diversity, and increase the frequency of deleterious alleles. Such outcomes constrain our ability to expand the cultivation of crops into environments that differ from those under which domestication occurred. We address this need in chickpea, an important pulse legume, by harnessing the diversity of wild crop relatives. We document an extreme domestication-related genetic bottleneck and decipher the genetic history of wild populations. We provide evidence of ancestral adaptations for seed coat color crypsis, estimate the impact of environment on genetic structure and trait values, and demonstrate variation between wild and cultivated accessions for agronomic properties. A resource of genotyped, association mapping progeny functionally links the wild and cultivated gene pools and is an essential resource chickpea for improvement, while our methods inform collection of other wild crop progenitor species.
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Affiliation(s)
- Eric J B von Wettberg
- Department of Biological Sciences and International Center for Tropical Botany, Florida International University, Miami, FL, 33199, USA.
- Department of Plant and Soil Science, University of Vermont, Burlington, VT, 05405, USA.
| | - Peter L Chang
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Fatma Başdemir
- Faculty of Agriculture, Dicle University, Diyarbakir, 21280, Turkey
| | | | - Lijalem Balcha Korbu
- Institute of Biotechnology, Addis Ababa University, Addis Ababa, 32853, Ethiopia
- Ethiopian Institute of Agricultural Research, Addis Ababa, P.O. Box 2003, Ethiopia
| | - Susan M Moenga
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616, USA
| | - Gashaw Bedada
- Hawassa University, Hawassa, 005, Ethiopia
- Oromia Agricultural Research Institute (OARI), Addis Ababa, P.O. Box 81265, Ethiopia
| | - Alex Greenlon
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616, USA
| | - Ken S Moriuchi
- Department of Biological Sciences and International Center for Tropical Botany, Florida International University, Miami, FL, 33199, USA
| | - Vasantika Singh
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Matilde A Cordeiro
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
| | - Nina V Noujdina
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
- Department of Applied Mathematics, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, 195251, Russia
| | - Kassaye Negash Dinegde
- Institute of Biotechnology, Addis Ababa University, Addis Ababa, 32853, Ethiopia
- Ethiopian Institute of Agricultural Research, Addis Ababa, P.O. Box 2003, Ethiopia
| | - Syed Gul Abbas Shah Sani
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616, USA
- Department of Plant Sciences, Quaid-i-Azam University Islamabad, Islamabad, 45320, Pakistan
| | - Tsegaye Getahun
- Institute of Biotechnology, Addis Ababa University, Addis Ababa, 32853, Ethiopia
| | - Lisa Vance
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616, USA
| | - Emily Bergmann
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616, USA
| | - Donna Lindsay
- Department of Plant Sciences, University of Saskatchewan, Saskatoon, SK, S7N5A8, Canada
| | - Bullo Erena Mamo
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616, USA
| | - Emily J Warschefsky
- Department of Biological Sciences and International Center for Tropical Botany, Florida International University, Miami, FL, 33199, USA
| | - Emmanuel Dacosta-Calheiros
- Department of Biological Sciences and International Center for Tropical Botany, Florida International University, Miami, FL, 33199, USA
| | - Edward Marques
- Department of Biological Sciences and International Center for Tropical Botany, Florida International University, Miami, FL, 33199, USA
- Department of Plant and Soil Science, University of Vermont, Burlington, VT, 05405, USA
| | | | - Ahmet Cakmak
- Department of Field Crops, Faculty of Agriculture, Harran University, Sanliurfa, 63100, Turkey
| | - Janna Rose
- Department of Biological Sciences and International Center for Tropical Botany, Florida International University, Miami, FL, 33199, USA
| | - Andrew Migneault
- Department of Biological Sciences and International Center for Tropical Botany, Florida International University, Miami, FL, 33199, USA
| | - Christopher P Krieg
- Department of Biological Sciences and International Center for Tropical Botany, Florida International University, Miami, FL, 33199, USA
- Department of Botany, University of Florida, Gainesville, FL, 33181, USA
| | - Sevgi Saylak
- Faculty of Agriculture, Dicle University, Diyarbakir, 21280, Turkey
| | - Hamdi Temel
- Faculty of Agriculture, Dicle University, Diyarbakir, 21280, Turkey
| | - Maren L Friesen
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48823, USA
| | - Eleanor Siler
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48823, USA
| | - Zhaslan Akhmetov
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616, USA
| | - Huseyin Ozcelik
- Black Sea Agricultural Research Institute, Samsun, P.O. Box 39, Turkey
| | - Jana Kholova
- International Crops Research Institute for the Semi-Arid Tropics, Patancheru, 502324, Telangana, India
| | - Canan Can
- Department of Biology, Gaziantep University, Gaziantep, 27310, Turkey
| | - Pooran Gaur
- International Crops Research Institute for the Semi-Arid Tropics, Patancheru, 502324, Telangana, India
| | - Mehmet Yildirim
- Faculty of Agriculture, Dicle University, Diyarbakir, 21280, Turkey
| | - Hari Sharma
- International Crops Research Institute for the Semi-Arid Tropics, Patancheru, 502324, Telangana, India
| | - Vincent Vadez
- International Crops Research Institute for the Semi-Arid Tropics, Patancheru, 502324, Telangana, India
| | - Kassahun Tesfaye
- Institute of Biotechnology, Addis Ababa University, Addis Ababa, 32853, Ethiopia
| | | | - Bunyamin Tar'an
- Department of Plant Sciences, University of Saskatchewan, Saskatoon, SK, S7N5A8, Canada
| | - Abdulkadir Aydogan
- Central Research Institute for Field Crops (CRIFC), Ankara, 06042, Turkey
| | - Bekir Bukun
- Faculty of Agriculture, Dicle University, Diyarbakir, 21280, Turkey
| | - R Varma Penmetsa
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616, USA
| | - Jens Berger
- Commonwealth Scientific and Industrial Research Organization (CSIRO), Agriculture and Food, Perth, 6014, WA, Australia
| | - Abdullah Kahraman
- Department of Field Crops, Faculty of Agriculture, Harran University, Sanliurfa, 63100, Turkey
| | - Sergey V Nuzhdin
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089, USA
- Department of Applied Mathematics, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, 195251, Russia
| | - Douglas R Cook
- Department of Plant Pathology, University of California Davis, Davis, CA, 95616, USA.
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22
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Setterfield SA, Andersen AN. Seed supply limits seedling recruitment of Eucalyptus miniata: interactions between seed predation by ants and fire in the Australian seasonal tropics. Oecologia 2018; 186:965-972. [PMID: 29357030 DOI: 10.1007/s00442-018-4061-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 01/05/2018] [Indexed: 11/30/2022]
Abstract
Seed predation can cause substantial seed losses and influence plant population dynamics, but the impact depends on the extent to which populations are limited by seed availability or favorable microsites for recruitment. Harvester ants are the dominant post-dispersal seed predators in Australia's tropical savannas, and their abundance and foraging efficiency, as well as the availability of seed and microsites, are affected by fire history. We undertook a predator-exclusion experiment to examine the interactive effects of fire history (no fire compared with annual burning over 5 years) and seed predation by ants on seedling establishment of the dominant savanna tree, Eucalyptus miniata, in northern Australia. Despite its large seed size, the rate of removal (~ 20-60%) was similar or higher than typically reported for eucalypts, although it was lower than that recorded for the smaller seeds of the co-occurring E. tetrodonta. Seed predation rates were twice as high in annually burnt compared to unburnt sites, but there was no significant difference in the proportion of seedlings that emerged from the initial seed available. Seedling emergence in both regimes was low, representing < 7% of seed available after harvesting. About one-third of emergent seedlings were still alive during the middle of the following dry season. Our results indicate that seedling recruitment in E. miniata is limited by both seed supply and microsite availability. However, seed predation by ants reduces the likelihood of seedling establishment from low to virtually zero, which suggests that it plays a potentially important role in the population dynamics of savanna eucalypts.
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Affiliation(s)
- Samantha Ann Setterfield
- School of Biological Sciences, University of Western Australia, Crawley, WA, 6009, Australia. .,Charles Darwin University, Darwin, NT, 0909, Australia.
| | - Alan Neil Andersen
- Charles Darwin University, Darwin, NT, 0909, Australia.,CSIRO Tropical Ecosystem Research Centre, PMB 44, Winnellie, Darwin, NT, 0822, Australia
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23
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Ssekuubwa E, Loe LE, Sheil D, Tweheyo M, Moe SR. Comparing seed removal rates in actively and passively restored tropical moist forests. Restor Ecol 2017. [DOI: 10.1111/rec.12629] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Enock Ssekuubwa
- Department of Forestry, Biodiversity and Tourism; Makerere University; PO Box 7062, Kampala Uganda
| | - Leif E. Loe
- Faculty of Environmental Sciences and Natural Resource Management; Norwegian University of Life Sciences; PO Box 5003, 1432 Aas Norway
| | - Douglas Sheil
- Faculty of Environmental Sciences and Natural Resource Management; Norwegian University of Life Sciences; PO Box 5003, 1432 Aas Norway
| | - Mnason Tweheyo
- Department of Forestry, Biodiversity and Tourism; Makerere University; PO Box 7062, Kampala Uganda
| | - Stein R. Moe
- Faculty of Environmental Sciences and Natural Resource Management; Norwegian University of Life Sciences; PO Box 5003, 1432 Aas Norway
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24
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Granados A, Brodie JF, Bernard H, O'Brien MJ. Defaunation and habitat disturbance interact synergistically to alter seedling recruitment. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:2092-2101. [PMID: 28660670 DOI: 10.1002/eap.1592] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 05/31/2017] [Indexed: 06/07/2023]
Abstract
Vertebrate granivores destroy plant seeds, but whether animal-induced seed mortality alters plant recruitment varies with habitat context, seed traits, and among granivore species. An incomplete understanding of seed predation makes it difficult to predict how widespread extirpations of vertebrate granivores in tropical forests might affect tree communities, especially in the face of habitat disturbance. Many tropical forests are simultaneously affected by animal loss as well as habitat disturbance, but the consequences of each for forest regeneration are often studied separately or additively, and usually on a single plant demographic stage. The combined impacts of these threats could affect plant recruitment in ways that are not apparent when studied in isolation. We used wire cages to exclude large (elephants), medium, (sambar deer, bearded pigs, muntjac deer), and small (porcupines, chevrotains) ground-dwelling mammalian granivores and herbivores in logged and unlogged forests in Malaysian Borneo. We assessed the interaction between habitat disturbance (selective logging) and experimental defaunation on seed survival, germination, and seedling establishment in five dominant dipterocarp tree species spanning a 21-fold gradient in seed size. Granivore-induced seed mortality was consistently higher in logged forest. Germination of unpredated seeds was reduced in logged forest and in the absence of small to large-bodied mammals. Experimental defaunation increased germination and reduced seed removal but had little effect on seed survival. Seedling recruitment however, was more likely where logging and animal loss occurred together. The interacting effects of logging and hunting could therefore, actually increase seedling establishment, suggesting that the loss of mammals in disturbed forest could have important consequences for forest regeneration and composition.
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Affiliation(s)
- Alys Granados
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Jedediah F Brodie
- Department of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
- Division of Biological Sciences and Wildlife Biology Program, University of Montana, Missoula, Montana, 59812, USA
| | - Henry Bernard
- Institute for Tropical Biology and Conservation, University Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia
| | - Michael J O'Brien
- Consejo Superior de Investigaciones Científicas, Estación Experimental de Zonas Áridas, Carretera de Sacramento s/n, E-04120, La Cañada, Almería, Spain
- The South East Asia Rainforest Research Partnership, Danum Valley Field Centre, P.O. Box 60282, 91112, Lahad Datu, Sabah, Malaysia
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25
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Campbell DR, Brody AK, Price MV, Waser NM, Aldridge G. Is Plant Fitness Proportional to Seed Set? An Experiment and a Spatial Model. Am Nat 2017; 190:818-827. [PMID: 29166152 DOI: 10.1086/694116] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Individual differences in fecundity often serve as proxies for differences in overall fitness, especially when it is difficult to track the fate of an individual's offspring to reproductive maturity. Using fecundity may be biased, however, if density-dependent interactions between siblings affect survival and reproduction of offspring from high- and low-fecundity parents differently. To test for such density-dependent effects in plants, we sowed seeds of the wildflower Ipomopsis aggregata (scarlet gilia) to mimic partially overlapping seed shadows of pairs of plants, one of which produced twice as many seeds. We tested for differences in offspring success using a genetic marker to track offspring to flowering multiple years later. Without density dependence, the high-fecundity parent should produce twice as many surviving offspring. We also developed a model that considered the geometry of seed shadows and assumed limited survivors so that the number of juvenile recruits is proportional to the area. Rather than a ratio of 2∶1 offspring success from high- versus low-fecundity parents, our model predicted a ratio of 1.42∶1, which would translate into weaker selection. Empirical ratios of juvenile offspring and of flowers produced conformed well to the model's prediction. Extending the model shows how spatial relationships of parents and seed dispersal patterns modify inferences about relative fitness based solely on fecundity.
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26
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Blubaugh CK, Widick IV, Kaplan I. Does fear beget fear? Risk-mediated habitat selection triggers predator avoidance at lower trophic levels. Oecologia 2017; 185:1-11. [DOI: 10.1007/s00442-017-3909-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/08/2017] [Indexed: 11/29/2022]
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27
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Ceradini JP, Chalfoun AD. Species' traits help predict small mammal responses to habitat homogenization by an invasive grass. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:1451-1465. [PMID: 28317278 DOI: 10.1002/eap.1535] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 02/09/2017] [Accepted: 03/03/2017] [Indexed: 06/06/2023]
Abstract
Invasive plants can negatively affect native species, however, the strength, direction, and shape of responses may vary depending on the type of habitat alteration and the natural history of native species. To prioritize conservation of vulnerable species, it is therefore critical to effectively predict species' responses to invasive plants, which may be facilitated by a framework based on species' traits. We studied the population and community responses of small mammals and changes in habitat heterogeneity across a gradient of cheatgrass (Bromus tectorum) cover, a widespread invasive plant in North America. We live-trapped small mammals over two summers and assessed the effect of cheatgrass on native small mammal abundance, richness, and species-specific and trait-based occupancy, while accounting for detection probability and other key habitat elements. Abundance was only estimated for the most common species, deer mice (Peromyscus maniculatus). All species were pooled for the trait-based occupancy analysis to quantify the ability of small mammal traits (habitat association, mode of locomotion, and diet) to predict responses to cheatgrass invasion. Habitat heterogeneity decreased with cheatgrass cover. Deer mouse abundance increased marginally with cheatgrass. Species richness did not vary with cheatgrass, however, pocket mouse (Perognathus spp.) and harvest mouse (Reithrodontomys spp.) occupancy tended to decrease and increase, respectively, with cheatgrass cover, suggesting a shift in community composition. Cheatgrass had little effect on occupancy for deer mice, 13-lined ground squirrels (Spermophilus tridecemlineatus), and Ord's kangaroo rat (Dipodomys ordii). Species' responses to cheatgrass primarily corresponded with our a priori predictions based on species' traits. The probability of occupancy varied significantly with a species' habitat association but not with diet or mode of locomotion. When considered within the context of a rapid habitat change, such as caused by invasive plants, relevant species' traits may provide a useful framework for predicting species' responses to a variety of habitat disturbances. Understanding which species are likely to be most affected by exotic plant invasion will help facilitate more efficient, targeted management and conservation of native species and habitats.
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Affiliation(s)
- Joseph P Ceradini
- Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming, 1000 East University Avenue, Laramie, Wyoming, 82071, USA
| | - Anna D Chalfoun
- U.S. Geological Survey Wyoming Cooperative Fish and Wildlife Research Unit, Department of Zoology and Physiology, University of Wyoming, 1000 East University Avenue, Laramie, Wyoming, 82071, USA
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28
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Larios L, Pearson DE, Maron JL. Incorporating the effects of generalist seed predators into plant community theory. Funct Ecol 2017. [DOI: 10.1111/1365-2435.12905] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Loralee Larios
- Department of Botany and Plant Sciences University of California Riverside CA92507 USA
- Division of Biological Sciences University of Montana Missoula MT59812 USA
| | - Dean E. Pearson
- Division of Biological Sciences University of Montana Missoula MT59812 USA
- Rocky Mountain Research Station U.S.D.A. Forest Service Missoula MT59801 USA
| | - John L. Maron
- Division of Biological Sciences University of Montana Missoula MT59812 USA
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29
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Chacón J, Luebert F, Weigend M. Biogeographic Events Are Not Correlated with Diaspore Dispersal Modes in Boraginaceae. Front Ecol Evol 2017. [DOI: 10.3389/fevo.2017.00026] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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30
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Schneider S, Steeves R, Newmaster S, MacDougall AS. Selective plant foraging and the top-down suppression of native diversity in a restored prairie. J Appl Ecol 2017. [DOI: 10.1111/1365-2664.12886] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stefan Schneider
- Department of Integrative Biology; University of Guelph; Guelph ON N1G2W1 Canada
| | - Royce Steeves
- Department of Integrative Biology; University of Guelph; Guelph ON N1G2W1 Canada
| | - Steve Newmaster
- Department of Integrative Biology; University of Guelph; Guelph ON N1G2W1 Canada
| | - Andrew S. MacDougall
- Department of Integrative Biology; University of Guelph; Guelph ON N1G2W1 Canada
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31
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Wood CM, McKinney ST, Loftin CS. Intraspecific functional diversity of common species enhances community stability. Ecol Evol 2017; 7:1553-1560. [PMID: 28261464 PMCID: PMC5330891 DOI: 10.1002/ece3.2721] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 12/14/2016] [Accepted: 12/18/2016] [Indexed: 11/09/2022] Open
Abstract
Common species are fundamental to the structure and function of their communities and may enhance community stability through intraspecific functional diversity (iFD). We measured among-habitat and within-habitat iFD (i.e., among- and within-plant community types) of two common small mammal species using stable isotopes and functional trait dendrograms, determined whether iFD was related to short-term population stability and small mammal community stability, and tested whether spatially explicit trait filters helped explain observed patterns of iFD. Southern red-backed voles (Myodes gapperi) had greater iFD than deer mice (Peromyscus maniculatus), both among habitats, and within the plant community in which they were most abundant (their "primary habitat"). Peromyscus maniculatus populations across habitats differed significantly between years and declined 78% in deciduous forests, their primary habitat, as did the overall deciduous forest small mammal community. Myodes gapperi populations were stable across habitats and within coniferous forest, their primary habitat, as was the coniferous forest small mammal community. Generalized linear models representing internal trait filters (e.g., competition), which increase within-habitat type iFD, best explained variation in M. gapperi diet, while models representing internal filters and external filters (e.g., climate), which suppress within-habitat iFD, best explained P. maniculatus diet. This supports the finding that M. gapperi had higher iFD than P. maniculatus and is consistent with the theory that internal trait filters are associated with higher iFD than external filters. Common species with high iFD can impart a stabilizing influence on their communities, information that can be important for conserving biodiversity under environmental change.
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Affiliation(s)
- Connor M Wood
- Department of Wildlife, Fisheries, and Conservation Biology University of Maine Orono ME USA; Present address: Department of Forest and Wildlife Ecology University of Wisconsin-Madison Madison WI USA
| | - Shawn T McKinney
- U.S. Geological Survey Maine Cooperative Fish and Wildlife Research Unit Orono ME USA
| | - Cynthia S Loftin
- U.S. Geological Survey Maine Cooperative Fish and Wildlife Research Unit Orono ME USA
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32
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Fischer C, Türke M. Seed preferences by rodents in the agri-environment and implications for biological weed control. Ecol Evol 2016; 6:5796-807. [PMID: 27547355 PMCID: PMC4983592 DOI: 10.1002/ece3.2329] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2016] [Revised: 06/23/2016] [Accepted: 06/28/2016] [Indexed: 11/06/2022] Open
Abstract
Post-dispersal seed predation and endozoochorous seed dispersal are two antagonistic processes in relation to plant recruitment, but rely on similar preconditions such as feeding behavior of seed consumers and seed traits. In agricultural landscapes, rodents are considered important seed predators, thereby potentially providing regulating ecosystem services in terms of biological weed control. However, their potential to disperse seeds endozoochorously is largely unknown. We exposed seeds of arable plant species with different seed traits (seed weight, nutrient content) and different Red List status in an experimental rye field and assessed seed removal by rodents. In a complementary laboratory experiment, consumption rates, feeding preferences, and potential endozoochory by two vole species (Microtus arvalis and Myodes glareolus) were tested. Seed consumption by rodents after 24 h was 35% in the field and 90% in the laboratory. Both vole species preferred nutrient-rich over nutrient-poor seeds and M. glareolus further preferred light over heavy seeds and seeds of common over those of endangered plants. Endozoochory by voles could be neglected for all tested plant species as no seeds germinated, and only few intact seeds could be retrieved from feces. Synthesis and applications. Our results suggest that voles can provide regulating services in agricultural landscapes by depleting the seed shadow of weeds, rather than facilitating plant recruitment by endozoochory. In the laboratory, endangered arable plants were less preferred by voles than noxious weeds, and thus, our results provide implications for seed choice in restoration approaches. However, other factors such as seed and predator densities need to be taken into account to reliably predict the impact of rodents on the seed fate of arable plants.
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Affiliation(s)
- Christina Fischer
- Restoration Ecology Department of Ecology and Ecosystem Management Technische Universität München Emil-Ramann-Str. 6 D-85354 Freising Germany
| | - Manfred Türke
- Terrestrial Ecology Research Group Department of Ecology and Ecosystem Management Technische Universität München Hans-Carl-von-Carlowitz-Platz 2D-85354 Freising Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig Deutscher Platz 5eD-04103 Leipzig Germany; Institute of Biology Leipzig University Johannisallee 21D-04103 Leipzig Germany
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33
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Ricketts AM, Sandercock BK. Patch‐burn grazing increases habitat heterogeneity and biodiversity of small mammals in managed rangelands. Ecosphere 2016. [DOI: 10.1002/ecs2.1431] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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34
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Kildisheva OA, Erickson TE, Merritt DJ, Dixon KW. Setting the scene for dryland recovery: an overview and key findings from a workshop targeting seed-based restoration. Restor Ecol 2016. [DOI: 10.1111/rec.12392] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Olga A. Kildisheva
- School of Plant Biology; The University of Western Australia; Crawley WA 6009 Australia
| | - Todd E. Erickson
- School of Plant Biology; The University of Western Australia; Crawley WA 6009 Australia
- Kings Park and Botanic Garden; Kings Park WA 6005 Australia
| | - David J. Merritt
- School of Plant Biology; The University of Western Australia; Crawley WA 6009 Australia
- Kings Park and Botanic Garden; Kings Park WA 6005 Australia
| | - Kingsley W. Dixon
- School of Plant Biology; The University of Western Australia; Crawley WA 6009 Australia
- Kings Park and Botanic Garden; Kings Park WA 6005 Australia
- Department of Environment and Agriculture; Curtin University; Kent Street, Bentley Perth WA 6102 Australia
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35
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Korell L, Stein C, Hensen I, Bruelheide H, Suding KN, Auge H. Stronger effect of gastropods than rodents on seedling establishment, irrespective of exotic or native plant species origin. OIKOS 2016. [DOI: 10.1111/oik.02696] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lotte Korell
- Inst. of Biology; Martin Luther Univ. Halle-Wittenberg; Am Kirchtor 1 DE-06108 Halle Germany
- Inst. of Biology; Karl-von-Frisch-Straße 8 DE-35043 Marburg Germany
| | - Claudia Stein
- Dept of Environmental Science; Policy and Management, Univ. of California Berkeley; 130 Mulford Hall Berkeley CA 94720-3114 USA
- Biology Dept and Tyson Research Center; Washington Univ. St. Louis; Campus Box 1137, One Brookings Drive, St. Louis MO 63130-4899 USA
| | - Isabell Hensen
- Inst. of Biology; Martin Luther Univ. Halle-Wittenberg; Am Kirchtor 1 DE-06108 Halle Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; Deutscher Platz 5e DE-4103 Leipzig Germany
| | - Helge Bruelheide
- Inst. of Biology; Martin Luther Univ. Halle-Wittenberg; Am Kirchtor 1 DE-06108 Halle Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; Deutscher Platz 5e DE-4103 Leipzig Germany
| | - Katharine N. Suding
- Dept of Environmental Science; Policy and Management, Univ. of California Berkeley; 130 Mulford Hall Berkeley CA 94720-3114 USA
| | - Harald Auge
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig; Deutscher Platz 5e DE-4103 Leipzig Germany
- Dept of Community Ecology; Helmholtz Centre for Environmental Research - UFZ; Theodor-Lieser-Straße 4 DE-06120 Halle Germany
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Stuhler JD, Orrock JL. Past agricultural land use and present-day fire regimes can interact to determine the nature of seed predation. Oecologia 2016; 181:463-73. [PMID: 26905418 DOI: 10.1007/s00442-016-3585-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 02/07/2016] [Indexed: 10/22/2022]
Abstract
Historical agriculture and present-day fire regimes can have significant effects on contemporary ecosystems. Although past agricultural land use can lead to long-term changes in plant communities, it remains unclear whether these persistent land-use legacies alter plant-consumer interactions, such as seed predation, and whether contemporary disturbance (e.g., fire) alters the effects of historical agriculture on these interactions. We conducted a study at 27 sites distributed across 80,300 ha in post-agricultural and non-agricultural longleaf pine woodlands with different degrees of fire frequency to test the hypothesis that past and present-day disturbances that alter plant communities can subsequently alter seed predation. We quantified seed removal by arthropods and rodents for Tephrosia virginiana and Vernonia angustifolia, species of conservation interest. We found that the effects of land-use history and fire frequency on seed removal were contingent on granivore guild and microhabitat characteristics. Tephrosia virginiana removal was greater in low fire frequency sites, due to greater seed removal by rodents. Although overall removal of V. angustifolia did not differ among habitats, rodents removed more seeds than arthropods at post-agricultural sites and non-agricultural sites with low fire frequencies, but not at non-agricultural sites with high fire frequencies. Land-use history and fire frequency also affected the relationship between microhabitat characteristics and removal of V. angustifolia. Our results suggest that historical agriculture and present-day fire regimes may alter seed predation by shifting the impact of rodent and arthropod seed predators among habitats, with potential consequences for the establishment of rare plant species consumed by one or both predators.
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Affiliation(s)
- John D Stuhler
- Department of Zoology, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, WI, 53706, USA.
| | - John L Orrock
- Department of Zoology, University of Wisconsin-Madison, 430 Lincoln Drive, Madison, WI, 53706, USA
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Loayza AP, Gachon PR, García-Guzmán P, Carvajal DE, Squeo FA. Germination, seedling performance, and root production after simulated partial seed predation of a threatened Atacama Desert shrub. REVISTA CHILENA DE HISTORIA NATURAL 2015. [DOI: 10.1186/s40693-015-0039-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
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Maron JL, Auge H, Pearson DE, Korell L, Hensen I, Suding KN, Stein C. Staged invasions across disparate grasslands: effects of seed provenance, consumers and disturbance on productivity and species richness. Ecol Lett 2014; 17:499-507. [PMID: 24467348 DOI: 10.1111/ele.12250] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 09/17/2013] [Accepted: 12/24/2013] [Indexed: 11/28/2022]
Abstract
Exotic plant invasions are thought to alter productivity and species richness, yet these patterns are typically correlative. Few studies have experimentally invaded sites and asked how addition of novel species influences ecosystem function and community structure and examined the role of competitors and/or consumers in mediating these patterns. We invaded disturbed and undisturbed subplots in and out of rodent exclosures with seeds of native or exotic species in grasslands in Montana, California and Germany. Seed addition enhanced aboveground biomass and species richness compared with no-seeds-added controls, with exotics having disproportionate effects on productivity compared with natives. Disturbance enhanced the effects of seed addition on productivity and species richness, whereas rodents reduced productivity, but only in Germany and California. Our results demonstrate that experimental introduction of novel species can alter ecosystem function and community structure, but that local filters such as competition and herbivory influence the magnitude of these impacts.
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Affiliation(s)
- John L Maron
- Division of Biological Sciences, University of Montana, Missoula, MT, 59812, USA
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40
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Hurst ZM, McCleery RA, Collier BA, Silvy NJ, Taylor PJ, Monadjem A. Linking changes in small mammal communities to ecosystem functions in an agricultural landscape. Mamm Biol 2014. [DOI: 10.1016/j.mambio.2013.08.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Germain RM, Johnson L, Schneider S, Cottenie K, Gillis EA, MacDougall AS. Spatial Variability in Plant Predation Determines the Strength of Stochastic Community Assembly. Am Nat 2013; 182:169-79. [DOI: 10.1086/670928] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Rebollo S, Milchunas DG, Stapp P, Augustine DJ, Derner JD. Disproportionate effects of non-colonial small herbivores on structure and diversity of grassland dominated by large herbivores. OIKOS 2013. [DOI: 10.1111/j.1600-0706.2013.00403.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Kulpa SM, Leger EA. Strong natural selection during plant restoration favors an unexpected suite of plant traits. Evol Appl 2013; 6:510-23. [PMID: 23745142 PMCID: PMC3673478 DOI: 10.1111/eva.12038] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 11/05/2012] [Indexed: 01/17/2023] Open
Abstract
RESTORATION IS AN OPPORTUNITY TO STUDY NATURAL SELECTION: One can measure the distribution of traits in source propagules used to found populations, compare this with the distribution of traits in successful recruits, and determine the strength and direction of selection on potentially adaptive traits. We investigated whether natural selection influenced seedling establishment during postfire restoration in the Great Basin, an area where large-scale restoration occurs with a few widely available cultivars planted over a large range of environmental conditions. We collected seeds from established plants of the perennial grass Elymus elymoides ssp. californicus (squirreltail) at two restoration sites and compared the distribution of phenotypic traits of surviving plants with the original pool of restoration seeds. Seeds were planted in common gardens for two generations. Plants grown from seeds that established in the field were a nonrandom subset of the original seeds, with directional selection consistently favoring a correlated suite of traits in both field sites: small plant and seed size, and earlier flowering phenology. These results demonstrate that natural selection can affect restoration establishment in strong and predictable ways and that adaptive traits in these sites were opposite of the current criteria used for selection of restoration material in this system.
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Affiliation(s)
- Sarah M Kulpa
- Department of Natural Resources and Environmental Science, University of Nevada Reno, NV, USA
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Porter SS. Adaptive divergence in seed color camouflage in contrasting soil environments. THE NEW PHYTOLOGIST 2013; 197:1311-1320. [PMID: 23312014 DOI: 10.1111/nph.12110] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 11/20/2012] [Indexed: 06/01/2023]
Abstract
Although adaptive plant population divergence across contrasting soil conditions is often driven by abiotic soil factors, natural enemies may also contribute. Cryptic matching to the native soil color is a form of defensive camouflage that seeds can use to avoid detection by seed predators. The legume Acmispon wrangelianus occurs across a variety of gray-green serpentine soils and brown nonserpentine soils. Quantitative digital image analysis of seed and soil colors was used to test whether genetically based seed color is a closer match to the color of the native soil than to the color of other nearby soils. Lineages bear seeds that more closely match the color of their native serpentine or nonserpentine soil type than the opposing soil type. Further, even within a soil type, lineages bear seeds with a closer color match to the soil at their native site than to other sites. The striking concordance between seed and native soil color suggests that natural selection for locally camouflaged seed color morphs, probably driven by seed predators, may maintain adaptive divergence in pigmentation, despite the opportunity for migration between soil environments.
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Affiliation(s)
- Stephanie S Porter
- The Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA
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Schorr RA. Using a temporal symmetry model to assess population change and recruitment in the Preble's meadow jumping mouse (Zapus hudsonius preblei). J Mammal 2012. [DOI: 10.1644/11-mamm-a-407.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Bricker M, Maron J. Postdispersal seed predation limits the abundance of a long-lived perennial forb (Lithospermum ruderale). Ecology 2012; 93:532-43. [PMID: 22624208 DOI: 10.1890/11-0948.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Loss of seeds to consumers is common in plant communities, but the degree to which these losses influence plant abundance or population growth is often unclear. This is particularly the case for postdispersal seed predation by rodents, as most studies of rodent seed predation have focused on the sources of spatiotemporal variation in seed loss but not quantified the population consequences of this loss. In previous work we showed that seed predation by deer mice (Peromyscus maniculatus) substantially reduced seedling recruitment and establishment of Lithospermum ruderale (Boraginaceae), a long-lived perennial forb. To shed light on how rodent seed predation and the near-term effects on plant recruitment might influence longer-term patterns of L. ruderale population growth, we combined experimental results with demographic data in stage-based population models. Model outputs revealed that rodent seed predation had a significant impact on L. ruderale population growth rate (lambda). With the removal of postdispersal seed predation, the projected population growth rates increased between 0.06 and 0.12, depending on site (mean deltalambda across sites = 0.08). Seed predation shifted the projected stable stage distribution of populations from one with a high proportion of young plants to one in which larger adult size classes dominate. Elasticities of vital rates also changed, with germination and growth of seedlings and young plants becoming more important with the removal of seed predation. Simulations varying the magnitude of seed predation pressure while holding other vital rates constant showed that seed predation could lower lambda even if only 40% of available seeds were consumed. These results demonstrate that rodent granivory can be a potent force limiting the abundance of a long-lived perennial forb.
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Affiliation(s)
- Mary Bricker
- Division of Biological Sciences, University of Montana, Missoula, Montana 59812, USA.
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Knights AM, Firth LB, Walters K. Interactions between multiple recruitment drivers: post-settlement predation mortality and flow-mediated recruitment. PLoS One 2012; 7:e35096. [PMID: 22493734 PMCID: PMC3320868 DOI: 10.1371/journal.pone.0035096] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Accepted: 03/08/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Dispersal is a primary driver in shaping the future distribution of species in both terrestrial and marine systems. Physical transport by advection can regulate the distance travelled and rate of propagule supply to a habitat but post-settlement processes such as predation can decouple supply from recruitment. The effect of flow-mediated recruitment and predation on the recruitment success of an intertidal species, the eastern oyster Crassostrea virginica was evaluated in two-replicated field experiments. Two key crab species were manipulated to test predator identity effects on oyster mortality. FINDINGS Recruitment was ∼58% higher in high flow compared to low flow, but predation masked those differences. Predation mortality was primarily attributed to the blue crab Callinectes sapidus, whilst the mud crab Panopeus herbstii had no effect on recruit mortality. Recruit mortality from predation was high when recruit densities were high, but when recruit density was low, predation effects were not seen. Under high recruitment (supply), predation determined maximum population size and in low flow environments, recruitment success is likely determined by a combination of recruitment and resource limitation but not predation. CONCLUSIONS Four processes are demonstrated: (1) Increases in flow rate positively affect recruitment success; (2) In high flow (recruitment) environments, resource availability is less important than predation; (3) predation is an important source of recruit mortality, but is dependent upon recruit density; and (4) recruitment and/or resource limitation is likely a major driver of population structure and functioning, modifying the interaction between predators and prey. Simultaneous testing of flow-mediated recruitment and predation was required to differentiate between the role of each process in determining population size. Our results reinforce the importance of propagule pressure, predation and post-settlement mortality as important determinants of population growth and persistence, but demonstrate that they should not be considered mutually exclusive.
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Affiliation(s)
- Antony M Knights
- Department of Marine Science, Coastal Carolina University, Conway, South Carolina, United States of America.
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Meng L, Gao X, Chen J, Martin K. Spatial and temporal effects on seed dispersal and seed predation of Musa acuminata in southern Yunnan, China. Integr Zool 2012; 7:30-40. [PMID: 22405446 DOI: 10.1111/j.1749-4877.2011.00275.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Wild bananas are abundant in tropical areas and many ecologists have observed that the succession process is quicker following increased disturbance. This study was conducted to analyze animal-seed interactions and their effects on the seed fate of a wild banana species (Musa acuminata) in tropical southern Yunnan (China) through experiments considering spatial (site and habitat) and temporal (seasons) variation. The largest proportion of fruits (81%) was removed by frugivorous seed dispersers, especially by bats at nighttime. Only 13% of the fruits were removed by climbing seed predators (different species of rats). In the exclosure treatment, rodents accounted for a significantly higher total artificially exposed seed removal number than ants, but with spatial and temporal differences. The highest seed predation rate by rodents (70%) was found in forest with wild banana stands, corresponding with the highest rodent diversity (species numbers and abundance) among the habitat types. In contrast, the seed removal number by ants (57%) was highest in the open land habitats, but there was no close correlation with ant diversity. Seed removal numbers by ants were significantly higher in the dry compared to the rainy season, but rodent activity showed no differences between seasons. The overall results suggest that the largest proportion of seeds produced by wild banana are primarily dispersed by bats. Primary seed dispersal by bats at nighttime is essential for wild banana seeds to escape seed predation.
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Affiliation(s)
- Lingzeng Meng
- Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, China.
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Scott AJ, Morgan JW. Dispersal and microsite limitation in Australian old fields. Oecologia 2012; 170:221-32. [PMID: 22388691 DOI: 10.1007/s00442-012-2285-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 02/09/2012] [Indexed: 11/29/2022]
Abstract
The recovery of native communities after cultivation may be constrained by (a) the failure of species to reach a site or (b) their failure to survive once there. Although seed addition is a common method to test for seed versus microsite limitation, most studies do not follow populations beyond seedling establishment, nor do they measure seed dispersal. We examined dispersal across native grassland/old field boundaries and investigated the relative importance of seed and microsite limitation across multiple life-history stages and generations. Seed trapping showed little movement of native seeds into old fields and that most species had extremely localized dispersal. Consequently, there was no pattern of seed density with distance from boundaries, and similarity between the seed rain and standing vegetation was moderate to high. Seed addition showed that two annual species were able to establish in all, and flower in most, subplots in the first year, and that seedling establishment increased with sowing density, consistent with seed limitation. However, the relative importance of microsite limitation increased over the lifespans of the species. Density dependence reduced the number of flowering plants, resulting in a large decline in seedling density in the following generation. This decline continued so that the initial positive effect of sowing density on seedling numbers disappeared by the fourth generation and hence the persistence of populations is uncertain. Thus, by monitoring seed dispersal and following experimental populations beyond seedling establishment, we showed that dispersal limits species distributions, but microsite plays an important role in limiting population growth and persistence.
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Affiliation(s)
- Andrew J Scott
- Department of Botany, La Trobe University, Bundoora, Melbourne, VIC, 3086, Australia.
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Velho N, Isvaran K, Datta A. Rodent seed predation: effects on seed survival, recruitment, abundance, and dispersion of bird-dispersed tropical trees. Oecologia 2012; 169:995-1004. [PMID: 22327614 DOI: 10.1007/s00442-012-2252-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2011] [Accepted: 01/09/2012] [Indexed: 11/26/2022]
Abstract
Tropical tree species vary widely in their pattern of spatial dispersion. We focus on how seed predation may modify seed deposition patterns and affect the abundance and dispersion of adult trees in a tropical forest in India. Using plots across a range of seed densities, we examined whether seed predation levels by terrestrial rodents varied across six large-seeded, bird-dispersed tree species. Since inter-specific variation in density-dependent seed mortality may have downstream effects on recruitment and adult tree stages, we determined recruitment patterns close to and away from parent trees, along with adult tree abundance and dispersion patterns. Four species (Canarium resiniferum, Dysoxylum binectariferum, Horsfieldia kingii, and Prunus ceylanica) showed high predation levels (78.5-98.7%) and increased mortality with increasing seed density, while two species, Chisocheton cumingianus and Polyalthia simiarum, showed significantly lower seed predation levels and weak density-dependent mortality. The latter two species also had the highest recruitment near parent trees, with most abundant and aggregated adults. The four species that had high seed mortality had low recruitment under parent trees, were rare, and had more spaced adult tree dispersion. Biotic dispersal may be vital for species that suffer density-dependent mortality factors under parent trees. In tropical forests where large vertebrate seed dispersers but not seed predators are hunted, differences in seed vulnerability to rodent seed predation and density-dependent mortality can affect forest structure and composition.
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Affiliation(s)
- Nandini Velho
- Post-graduate Program in Wildlife Biology and Conservation, National Centre for Biological Sciences, GKVK Campus, Bellary Road, Bangalore 560 065, India.
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