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Laber L, Jandowsky A, Frölich K, Heinrich AP, Düring RA, Donath TW, Eichberg C. Dose-dependent in vivo effects of formulated moxidectin on seedling emergence of temperate grassland species. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167152. [PMID: 37730042 DOI: 10.1016/j.scitotenv.2023.167152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 09/05/2023] [Accepted: 09/15/2023] [Indexed: 09/22/2023]
Abstract
Sheep function as effective endozoochorous seed vectors in grasslands. Recent laboratory-based studies showed that this important function can be impaired by macrocyclic lactone anthelmintics, which are used to control parasites and enter into the environment mainly via faeces; however, there is a lack of in vivo studies. We conducted a seed-feeding experiment with sheep that included four temperate grassland species from four different families (Achillea ptarmica, Asteraceae; Agrostis capillaris, Poaceae; Dianthus deltoides, Caryophyllaceae; Plantago lanceolata, Plantaginaceae). A series of three feeding trials was carried out after one of two groups of sheep received a single administration of a common oral formulation of the macrocyclic lactone moxidectin. Faeces were collected to determine seedling emergence rate and emergence timing as well as moxidectin concentration via HPLC. Seedling emergence differed significantly between the anthelmintic-treated sheep and the control group. This impact depended on time of seed uptake after anthelmintic administration. Number of emerging seedlings was significantly reduced (27.1 %) when faeces moxidectin concentrations were high (on average 3153 ng g-1; 1 d post treatment) and significantly increased (up to 68.8 %) when moxidectin concentrations were low (≤86 ng g-1; 7, 14 d pt). Mean emergence time was significantly lowered at low moxidectin concentrations. These results demonstrate dose-related effects of deworming on seedling emergence which might affect endozoochory and eventually plant population dynamics in grasslands.
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Affiliation(s)
- Lars Laber
- Department of Landscape Ecology, Institute for Natural Resource Conservation, Kiel University, Kiel, Germany.
| | | | - Kai Frölich
- Arche Warder Center for Old and Rare Breeds, Warder, Germany
| | - Andre P Heinrich
- Institute of Soil Science and Soil Conservation, Research Center for Biosystems, Land Use and Nutrition (iFZ), Justus Liebig University, Gießen, Germany
| | - Rolf-Alexander Düring
- Institute of Soil Science and Soil Conservation, Research Center for Biosystems, Land Use and Nutrition (iFZ), Justus Liebig University, Gießen, Germany
| | - Tobias W Donath
- Department of Landscape Ecology, Institute for Natural Resource Conservation, Kiel University, Kiel, Germany
| | - Carsten Eichberg
- Geobotany, Spatial and Environmental Sciences, Trier University, Trier, Germany
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2
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de Souza AC, Donohue K, de Mattos EA. The effect of seed-dispersal timing on seedling recruitment is modulated by environmental conditions that vary across altitude in a threatened palm. ANNALS OF BOTANY 2022; 129:839-856. [PMID: 35325032 PMCID: PMC9292616 DOI: 10.1093/aob/mcac038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 03/22/2022] [Indexed: 05/29/2023]
Abstract
BACKGROUND AND AIMS The timing of seed dispersal determines the environmental conditions that plants face during early life stages. In seasonal environments, selection is expected to favour dispersal timing that is matched to environmental conditions suitable for successful recruitment. Our aim here was to test whether the timing of seed dispersal influences seedling establishment success in two populations of Euterpe edulis that are located at contrasting altitudes, have different seed-dispersal phenologies and are subjected to distinct climatic conditions. METHODS We sowed E. edulis seeds in contrasting altitudes on different dates, and monitored seed germination, emergence and seedling establishment at each altitude over 4 years. At the high-altitude site, five seed-dispersal cohorts were established during the natural dispersal period. At the low-altitude site, three seed-dispersal cohorts were established during natural dispersal, and two were established either before or after natural dispersal. KEY RESULTS At the high-altitude site, seed-dispersal timing did not affect seed germination, seedling emergence or seedling establishment success. In contrast, at the low-altitude site, late seed dispersal near the end of the wet season resulted in a lower probability of seedling establishment, possibly due to the exposure of seeds, germinants and seedlings to unfavourable drought conditions. In addition, at the low-altitude site, the natural seed-dispersal period was poorly matched to favourable environmental conditions for seedling establishment. CONCLUSIONS The greater effect of seed-dispersal timing on seedling establishment at the low-altitude site is probably related to a more seasonal and drought-prone environment that favours a restricted period of seed dispersal. The magnitude of the effect of dispersal timing on seedling establishment success was modulated by environmental conditions that vary across altitude. Furthermore, reproductive phenology appears to be subject to more intense selection at the lower limit of the altitudinal range, due to a more restrictive window of opportunity for successful seedling establishment.
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Affiliation(s)
| | | | - Eduardo A de Mattos
- Departamento de Ecologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
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3
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Salesa D, Baeza MJ, Pérez-Ferrándiz E, Santana VM. Longer summer seasons after fire induce permanent drought legacy effects on Mediterranean plant communities dominated by obligate seeders. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 822:153655. [PMID: 35124057 DOI: 10.1016/j.scitotenv.2022.153655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/30/2022] [Accepted: 01/30/2022] [Indexed: 06/14/2023]
Abstract
The ecological stability of Mediterranean ecosystems is being threatened by climate change. One of the impacts that is expected to be aggravated is the effect of summer drought prolongation toward previous or subsequent seasons by becoming more frequent. This, along with wildfires, could trigger synergistic negative effects on ecosystem regeneration capacity. Here we assessed how extending summer drought in two different ways (to autumn, AutExcl treatment, or bringing it forward to the following spring, SprExcl treatment) would affect plant recovery after an experimental fire carried out in summer in a Mediterranean seeder community. By installing rainout shelters, we assessed differences in seedling emergence, survival and establishment in the main families (Cistaceae, Labiatae, Leguminosae), and the effect on species richness and community composition. We observed that these post-fire dry season extensions reduced the total number of established seedlings and species richness. The most impacting drought treatment was AutExcl. However, the regeneration response was variable depending on the studied family. SprExcl was also determinant for Labiate survival rates. These results suggest that drought events which prolong the usual summer season may have a permanent drought legacy effect on seeder communities as practically all the seeder species populations were established in the first post-fire year. This fact is relevant for Mediterranean ecosystems dominated by seeder species as severer and longer droughts are increasingly recorded and are expected to become more frequent in forthcoming decades.
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Affiliation(s)
- David Salesa
- Fundación de la Comunidad Valenciana Centro de Estudios Ambientales del Mediterráneo (CEAM), C/ Charles Darwin 14, 46980 Paterna, Valencia, Spain.
| | - M Jaime Baeza
- Departamento de Ecología, Universidad de Alicante, Ap. 99, 03080 Alicante, Spain
| | - E Pérez-Ferrándiz
- Fundación de la Comunidad Valenciana Centro de Estudios Ambientales del Mediterráneo (CEAM), C/ Charles Darwin 14, 46980 Paterna, Valencia, Spain
| | - Victor M Santana
- Fundación de la Comunidad Valenciana Centro de Estudios Ambientales del Mediterráneo (CEAM), C/ Charles Darwin 14, 46980 Paterna, Valencia, Spain; Departamento de Ecología, Universidad de Alicante, Ap. 99, 03080 Alicante, Spain
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4
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Fedriani JM, Calvo G, Delibes M, Ayllón D, Garrote PJ. The overlooked benefits of synzoochory: rodents rescue seeds from aborted fruits. Ecosphere 2020. [DOI: 10.1002/ecs2.3298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Jose M. Fedriani
- Centro de Investigaciones sobre Desertificación CIDE CSIC‐UVEG‐GV Carretera de Moncada a Náquera, km 4,5. 46113 Moncada Valencia Spain
- Estación Biológica de Doñana (EBD ‐ C.S.I.C.) c/Americo Vespucio s/n Seville41092Spain
| | - Gemma Calvo
- Estación Biológica de Doñana (EBD ‐ C.S.I.C.) c/Americo Vespucio s/n Seville41092Spain
| | - Miguel Delibes
- Estación Biológica de Doñana (EBD ‐ C.S.I.C.) c/Americo Vespucio s/n Seville41092Spain
| | - Daniel Ayllón
- Department of Biodiversity, Ecology and Evolution Complutense University of Madrid (UCM) c/José Antonio Novais 12 Madrid28040Spain
| | - Pedro J. Garrote
- Centre for Applied Ecology "Prof. Baeta Neves"/InBio Institute Superior of Agronomy University of Lisbon Portugal
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5
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Overcoming germination barriers in four native Malvaceae shrub species of Reunion island to improve restoration in arid habitats. Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2019.e00855] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Bianchi E, Bugmann H, Bigler C. Early emergence increases survival of tree seedlings in Central European temperate forests despite severe late frost. Ecol Evol 2019; 9:8238-8252. [PMID: 31380086 PMCID: PMC6662263 DOI: 10.1002/ece3.5399] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 04/04/2019] [Accepted: 05/15/2019] [Indexed: 01/27/2023] Open
Abstract
Global warming is expected to result in earlier emergence of tree seedlings that may experience higher damages and mortality due to late frost in spring. We monitored emergence, characteristics, and survival of seedlings across ten tree species in temperate mixed deciduous forests of Central Europe over one and a half year. We tested whether the timing of emergence represents a trade-off for seedling survival between minimizing frost risk and maximizing the length of the growing period. Almost two-thirds of the seedlings died during the first growing period. The timing of emergence was decisive for seedling survival. Although seedlings that emerged early faced a severe late frost event, they benefited from a longer growing period resulting in increased overall survival. Larger seedling height and higher number of leaves positively influenced survival. Seedlings growing on moss had higher survival compared to mineral soil, litter, or herbaceous vegetation. Synthesis. Our findings demonstrate the importance of emergence time for survival of tree seedlings, with early-emerging seedlings more likely surviving the first growing period.
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Affiliation(s)
- Eva Bianchi
- Forest Ecology, Department of Environmental Systems Science, Institute of Terrestrial EcosystemsETH ZurichZurichSwitzerland
| | - Harald Bugmann
- Forest Ecology, Department of Environmental Systems Science, Institute of Terrestrial EcosystemsETH ZurichZurichSwitzerland
| | - Christof Bigler
- Forest Ecology, Department of Environmental Systems Science, Institute of Terrestrial EcosystemsETH ZurichZurichSwitzerland
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7
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Kildisheva OA, Erickson TE, Madsen MD, Dixon KW, Merritt DJ. Seed germination and dormancy traits of forbs and shrubs important for restoration of North American dryland ecosystems. PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:458-469. [PMID: 30098068 DOI: 10.1111/plb.12892] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 08/06/2018] [Indexed: 06/08/2023]
Abstract
In degraded dryland systems, native plant community re-establishment following disturbance is almost exclusively carried out using seeds, but these efforts commonly fail. Much of this failure can be attributed to the limited understanding of seed dormancy and germination traits. We undertook a systematic classification of seed dormancy of 26 species of annual and perennial forbs and shrubs that represent key, dominant genera used in restoration of the Great Basin ecosystem in the western United States. We examined germination across a wide thermal profile to depict species-specific characteristics and assessed the potential of gibberellic acid (GA3 ) and karrikinolide (KAR1 ) to expand the thermal germination envelope of fresh seeds. Of the tested species, 81% produce seeds that are dormant at maturity. The largest proportion (62%) exhibited physiological (PD), followed by physical (PY, 8%), combinational (PY + PD, 8%) and morphophysiological (MPD, 4%) dormancy classes. The effects of chemical stimulants were temperature- and species-mediated. In general, mean germination across the thermal profile was improved by GA3 and KAR1 for 11 and five species, respectively. We detected a strong germination response to temperature in freshly collected seeds of 20 species. Temperatures below 10 °C limited the germination of all except Agoseris heterophylla, suggesting that in their dormant state, the majority of these species are thermally restricted. Our findings demonstrate the utility of dormancy classification as a foundation for understanding the critical regenerative traits in these ecologically important species and highlight its importance in restoration planning.
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Affiliation(s)
- O A Kildisheva
- School of Biological Sciences, University of Western Australia, Crawley, WA, Australia
- Chicago Botanic Garden, Glencoe, IL, USA
| | - T E Erickson
- School of Biological Sciences, University of Western Australia, Crawley, WA, Australia
- Kings Park Science, Department of Biodiversity, Conservation and Attractions, Kings Park, WA, Australia
| | - M D Madsen
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, UT, USA
| | - K W Dixon
- Department of Environment and Agriculture, Curtin University, Bentley, WA, Australia
| | - D J Merritt
- School of Biological Sciences, University of Western Australia, Crawley, WA, Australia
- Kings Park Science, Department of Biodiversity, Conservation and Attractions, Kings Park, WA, Australia
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8
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Parra A, Moreno JM. Drought differentially affects the post-fire dynamics of seeders and resprouters in a Mediterranean shrubland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 626:1219-1229. [PMID: 29898529 DOI: 10.1016/j.scitotenv.2018.01.174] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 01/17/2018] [Accepted: 01/17/2018] [Indexed: 06/08/2023]
Abstract
In fire-prone ecosystems, changes in rainfall after fire could differentially affect seeders and resprouters, thus leading to long-lasting impacts on the vegetation. Climate change in the Mediterranean region is projected to reduce precipitation, expand the summer drought and increase fire danger. Understanding the sensitivity to changes in rainfall during the post-fire regeneration stage is critical to anticipate the impacts of climate change on Mediterranean-type areas of the world. Here, we investigated how species differing in post-fire regeneration strategy (seeders vs resprouters) responded to rainfall changes in a Cistus-Erica shrubland of central Spain. Drought treatments were implemented using a system of automatic rainout shelters with an irrigation facility before (one season) and after (four years) burning a set of experimental plots. Treatments applied were: environmental control (natural rainfall), historical control (mimicking the long-term rainfall), moderate drought (-25% rainfall), and severe drought (-45% rainfall). Plant demography and vigour (main woody shrubs), as well as abundance (shrubs and herbs) were monitored during the first four years after fire. The first post-fire year was the key period for the recovery of seeders (Cistus ladanifer and Rosmarinus officinalis), and their recruitment, cover and size significantly decreased with drought. However, density four years after fire was larger than unburned and it was significantly correlated with emergence during the first year, indicating that population controls were more on emergence than on establishment. In contrast, resprouters (Erica arborea, Erica scoparia and Phillyrea angustifolia) were hardly affected by drought. Plant community dynamics in the burned control plots progressively converged with the unburned ones, while that in the drought-treated plots lagged behind them, maintaining a higher cover, richness and diversity of herbs. This post-fire "herbalization" due to drought might facilitate an untimely fire, before seeders would reach sexual maturity, which could have major implications for the maintenance of the community.
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Affiliation(s)
- Antonio Parra
- Universidad de Castilla-La Mancha, Departamento de Ciencias Ambientales, E-45071 Toledo, Spain.
| | - José M Moreno
- Universidad de Castilla-La Mancha, Departamento de Ciencias Ambientales, E-45071 Toledo, Spain.
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9
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Karavani A, Boer MM, Baudena M, Colinas C, Díaz-Sierra R, Pemán J, de Luis M, Enríquez-de-Salamanca Á, Resco de Dios V. Fire-induced deforestation in drought-prone Mediterranean forests: drivers and unknowns from leaves to communities. ECOL MONOGR 2018. [DOI: 10.1002/ecm.1285] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Asaf Karavani
- Master Course Mediterranean Forestry and Natural Resources Management; Universitat de Lleida; E25198 Lleida Spain
| | - Matthias M. Boer
- Hawkesbury Institute for the Environment; Western Sydney University; Richmond New South Wales 2753 Australia
| | - Mara Baudena
- Copernicus Institute of Sustainable Development, Environmental Science Group; Utrecht University; P.O. Box 80115 3508 TC Utrecht The Netherlands
| | - Carlos Colinas
- Department of Crop and Forest Sciences-AGROTECNIO Center; Universitat de Lleida; E 25198 Lleida Spain
| | - Rubén Díaz-Sierra
- Mathematical and Fluid Physics Department; Faculty of Sciences; Universidad Nacional de Educación a Distancia; Madrid 28040 Spain
| | - Jesús Pemán
- Department of Crop and Forest Sciences-AGROTECNIO Center; Universitat de Lleida; E 25198 Lleida Spain
| | - Martín de Luis
- Department of Geography and Regional Planning; University of Zaragoza; 50009 Zaragoza Spain
| | - Álvaro Enríquez-de-Salamanca
- Mathematical and Fluid Physics Department; Faculty of Sciences; Universidad Nacional de Educación a Distancia; Madrid 28040 Spain
| | - Víctor Resco de Dios
- Department of Crop and Forest Sciences-AGROTECNIO Center; Universitat de Lleida; E 25198 Lleida Spain
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10
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Thomson DM, King RA, Schultz EL. Between invaders and a risky place: Exotic grasses alter demographic tradeoffs of native forb germination timing. Ecosphere 2017. [DOI: 10.1002/ecs2.1987] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Diane M. Thomson
- W. M. Keck Science Department The Claremont Colleges 925 N. Mills Avenue Claremont California 91711 USA
| | - Rachel A. King
- W. M. Keck Science Department The Claremont Colleges 925 N. Mills Avenue Claremont California 91711 USA
| | - Emily L. Schultz
- W. M. Keck Science Department The Claremont Colleges 925 N. Mills Avenue Claremont California 91711 USA
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11
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Chamorro D, Luna B, Ourcival JM, Kavgacı A, Sirca C, Mouillot F, Arianoutsou M, Moreno JM. Germination sensitivity to water stress in four shrubby species across the Mediterranean Basin. PLANT BIOLOGY (STUTTGART, GERMANY) 2017; 19:23-31. [PMID: 26998911 DOI: 10.1111/plb.12450] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 03/14/2016] [Indexed: 06/05/2023]
Abstract
Mediterranean shrublands are generally water-limited and fire-driven ecosystems. Seed-based post-fire regeneration may be affected by varying rainfall patterns, depending on species sensitivity to germinate under water stress. In our study, we considered the germination response to water stress in four species from several sites across the Mediterranean Basin. Seeds of species with a hard coat (Cistus monspeliensis, C. salviifolius, Cistaceae, Calicotome villosa, Fabaceae) or soft coat (Erica arborea, Ericaceae), which were exposed or not to a heat shock and smoke (fire cues), were made to germinate under water stress. Final germination percentage, germination speed and viability of seeds were recorded. Germination was modelled using hydrotime analysis and correlated to the water balance characteristics of seed provenance. Water stress was found to decrease final germination in the three hard-seeded species, as well as reduce germination speed. Moreover, an interaction between fire cues and water stress was found, whereby fire cues increased sensitivity to water stress. Seed viability after germination under water stress also declined in two hard-seeded species. Conversely, E. arborea showed little sensitivity to water stress, independent of fire cues. Germination responses varied among populations of all species, and hydrotime parameters were not correlated to site water balance, except in E. arborea when not exposed to fire cues. In conclusion, the species studied differed in germination sensitivity to water stress; furthermore, fire cues increased this sensitivity in the three hard-seeded species, but not in E. arborea. Moreover, populations within species consistently differed among themselves, but these differences could only be related to the provenance locality in E. arborea in seeds not exposed to fire cues.
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Affiliation(s)
- D Chamorro
- Departamento de Ciencias Ambientales, Universidad de Castilla-La Mancha, Toledo, Spain
| | - B Luna
- Departamento de Ciencias Ambientales, Universidad de Castilla-La Mancha, Toledo, Spain
| | - J-M Ourcival
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175 CNRS/Université de Montpellier/Université Paul Valery Montpellier/EPHE, Montpellier, France
| | - A Kavgacı
- Batı Akdeniz Ormancılık Arastirma Enstitüsü, Southwest Anatolia Forest Research Institute, Antalya, Turkey
| | - C Sirca
- DIPNET, Dipartimento di Scienze della Natura e del Territorio, University of Sassari, Sassari, Italy
- IAFES Division of the CMCC, Euro-Mediterranean Centre on Climate Change, Sassari, Italy
| | - F Mouillot
- Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175 CNRS/Université de Montpellier/Université Paul Valery Montpellier/EPHE/IRD, Montpellier, France
| | - M Arianoutsou
- Department of Ecology and Systematics, Faculty of Biology, University of Athens, Athens, Greece
| | - J M Moreno
- Departamento de Ciencias Ambientales, Universidad de Castilla-La Mancha, Toledo, Spain
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Liyanage GS, Ayre DJ, Ooi MKJ. Seedling performance covaries with dormancy thresholds: maintaining cryptic seed heteromorphism in a fire-prone system. Ecology 2016; 97:3009-3018. [PMID: 27870036 DOI: 10.1002/ecy.1567] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 07/12/2016] [Accepted: 08/01/2016] [Indexed: 11/05/2022]
Abstract
The production of morphologically different seeds or fruits by the same individual plant is known as seed heteromorphism. Such variation is expected to be selected for in disturbance-prone environments to allow germination into inherently variable regeneration niches. However, there are few demonstrations that heteromorphic seed characteristics should be favored by selection or how they may be maintained. In fire-prone ecosystems, seed heteromorphism is found in the temperatures needed to break physical dormancy, with seeds responding to high or low temperatures, ensuring emergence under variable fire-regime-related soil heating. Because of the relationship between dormancy-breaking temperature thresholds and fire severity, we hypothesize that different post-fire resource conditions have selected for covarying seedling traits, which contribute to maintenance of such heteromorphism. Seeds with low thresholds emerge into competitive conditions, either after low-severity fire or in vegetation gaps, and are therefore likely to experience selection for seedling characteristics that make them good competitors. On the other hand, high-temperature-threshold seeds would emerge into less competitive environments, indicative of stand-clearing high-severity fires, and would not experience the same selective forces. We identified high and low-threshold seed morphs via dormancy-breaking heat treatments and germination trials for two study species and compared seed mass and other morphological characteristics between morphs. We then grew seedlings from the two different morphs, with and without competition, and measured growth and biomass allocation as indicators of seedling performance. Seedlings from low-threshold seeds of both species performed better than their high-threshold counterparts, growing more quickly under competitive conditions, confirming that different performance can result from this seed characteristic. Seed mass or appearance did not differ between morphs, indicating that dormancy-breaking temperature threshold variation is a form of cryptic heteromorphism. The potential shown for the selective influence of different post-fire environmental conditions on seedling performance provides evidence of a mechanism for the maintenance of heteromorphic variation in dormancy-breaking temperature thresholds.
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Affiliation(s)
- Ganesha S Liyanage
- Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, University of Wollongong, Wollongong, New South Wales, 2522, Australia
| | - David J Ayre
- Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, University of Wollongong, Wollongong, New South Wales, 2522, Australia
| | - Mark K J Ooi
- Centre for Sustainable Ecosystem Solutions, School of Biological Sciences, University of Wollongong, Wollongong, New South Wales, 2522, Australia.,Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, 2052, Australia
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13
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Shikang S, Fuqin W, Yuehua W. Does the passage of seeds through frugivore gut affect their storage: A case study on the endangered plant Euryodendron excelsum. Sci Rep 2015; 5:11615. [PMID: 26109456 PMCID: PMC4479827 DOI: 10.1038/srep11615] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 06/01/2015] [Indexed: 12/01/2022] Open
Abstract
Plant-frugivore mutualism serves an important function in multiple ecological processes. Although previous studies have highlighted the effect of frugivore gut passage on fresh seed germinability, no study has investigated the effect on seed storage after frugivore gut passage. We used the endangered plant, Euryodendron excelsum, to determine the combined effects of frugivore gut passage and storage conditions on the germination percentage and rate of seeds. In particular, three treatments that included storage periods, storage methods, and seed types were designed in the experiment. We hypothesized that seeds that passed through the gut will exhibit enhanced germination capacity and rate during storage. Results showed that the final germination percentage decreased in seeds that passed through the gut, whereas the germination rate increased during seed storage. Germination decreased in most types of seeds under both dry and wet storage after 6 months compared with storage after 1 and 3 months. The results suggest that after frugivore gut passage, E. excelsum seeds cannot form persistent soil seed bank in the field, and were not suitable for species germplasm storage. These finding underscore that seeds that passed through frugivore gut have long-term impact on their viability and germination performance.
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Affiliation(s)
- Shen Shikang
- School of life sciences, Yunnan University, Kunming No. 2 Green lake North road Kunming, Yunnan, 650091, the People’s Republic of China
| | - Wu Fuqin
- School of life sciences, Yunnan University, Kunming No. 2 Green lake North road Kunming, Yunnan, 650091, the People’s Republic of China
| | - Wang Yuehua
- School of life sciences, Yunnan University, Kunming No. 2 Green lake North road Kunming, Yunnan, 650091, the People’s Republic of China
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14
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Delerue F, Gonzalez M, Michalet R, Pellerin S, Augusto L. Weak Evidence of Regeneration Habitat but Strong Evidence of Regeneration Niche for a Leguminous Shrub. PLoS One 2015; 10:e0130886. [PMID: 26098877 PMCID: PMC4476804 DOI: 10.1371/journal.pone.0130886] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 05/26/2015] [Indexed: 11/18/2022] Open
Abstract
The identification of an ecological niche specific to the regeneration phase has mobilised significant attention. However, the importance of the regeneration niche concept remains unclear. Our main objective was to study the existence of such a regeneration niche for a leguminous shrub, Ulex europaeus. This study was carried out in southwest France in the context of water and nutrient stresses (mainly phosphorus limitation) due to the presence of nutrient-poor sandy soils. We analysed the regeneration of the species from the germination of seeds and emergence of new seedlings until the seedlings reached young shrub size. Our design included a P fertilisation treatment. We also investigated microsite characteristics (micro-topography and vegetation development) as they can interact with meteorological conditions and determine water availability for seeds and seedlings. We found that P availability controlled seedling growth and the time necessary to reach young shrub size. Water availability appeared to impact the species germination and seedlings survival. We also found that P and water availability depended on the interactions between microsite characteristics and climatic variations. Finally we found evidence that P and water availability are important ecological factors shaping the regeneration niche of the species, but we found weak evidence that any microsite would be appropriate for the regeneration of the species in the long term. Future studies regarding regeneration niches need to distinguish more clearly the ecological factors important for regeneration (the regeneration niche per se) and the physical world where the seedlings appear and develop (the regeneration habitat).
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Affiliation(s)
- Florian Delerue
- INRA, UMR 1391 ISPA, Villenave d’Ornon F-33140, France
- Bordeaux Science Agro, UMR 1391 ISPA, Gradignan F-33883, France
- Bordeaux INP, G&E, EA 4592, F-33600, Pessac, France
- Univ. Bordeaux Montaigne, G&E, EA 4592, F-33600, Pessac, France
| | - Maya Gonzalez
- INRA, UMR 1391 ISPA, Villenave d’Ornon F-33140, France
- Bordeaux Science Agro, UMR 1391 ISPA, Gradignan F-33883, France
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Pausas JG, Keeley JE. Evolutionary ecology of resprouting and seeding in fire-prone ecosystems. THE NEW PHYTOLOGIST 2014; 204:55-65. [PMID: 25298997 DOI: 10.1111/nph.12921] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
There are two broad mechanisms by which plant populations persist under recurrent disturbances: resprouting from surviving tissues, and seedling recruitment. Species can have one of these mechanisms or both. However, a coherent framework explaining the differential evolutionary pressures driving these regeneration mechanisms is lacking. We propose a bottom-up approach in addressing this question that considers the relative survivorship of adults and juveniles in an evolutionary context, based on two assumptions. First, resprouting and seeding can be interpreted by analogy with annual versus perennial life histories; that is, if we consider disturbance cycles to be analogous to annual cycles, then resprouting species are analogous to the perennial life history with iteroparous reproduction, and obligate seeding species that survive disturbances solely through seed banks are analogous to the annual life history with semelparous reproduction. Secondly, changes in the selective regimes differentially modify the survival rates of adults and juveniles and thus the relative costs and benefits of resprouting versus seeding. Our approach provides a framework for understanding temporal and spatial variation in resprouting and seeding under crown-fire regimes. It accounts for patterns of coexistence and environmental changes that contribute to the evolution of seeding from resprouting ancestors.
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Rowe CLJ, Leger EA. Seed Source Affects Establishment ofElymus multisetusin Postfire Revegetation in the Great Basin. WEST N AM NATURALIST 2012. [DOI: 10.3398/064.072.0410] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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17
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Fedriani JM, Zywiec M, Delibes M. Thieves or mutualists? Pulp feeders enhance endozoochore local recruitment. Ecology 2012; 93:575-87. [DOI: 10.1890/11-0429.1] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Raventós J, Wiegand T, Maestre FT, de Luis M. A resprouter herb reduces negative density-dependent effects among neighboring seeders after fire. ACTA OECOLOGICA 2012. [DOI: 10.1016/j.actao.2011.08.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Raventós J, Wiegand T, Luis MD. Evidence for the spatial segregation hypothesis: a test with nine-year survivorship data in a Mediterranean shrubland. Ecology 2010; 91:2110-20. [DOI: 10.1890/09-0385.1] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Xiang J, Wang Q, Wu G, Wu Y, Han P, Li M, Yu L. Formation of Plant Communities of the Newly Created Wetland in Modern Yellow River Delta. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.proenv.2010.10.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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