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Halsch CA, Shapiro AM, Thorne JH, Rodman KC, Parra A, Dyer LA, Gompert Z, Smilanich AM, Forister ML. Thirty-six years of butterfly monitoring, snow cover, and plant productivity reveal negative impacts of warmer winters and increased productivity on montane species. Glob Chang Biol 2024; 30:e17044. [PMID: 37994481 DOI: 10.1111/gcb.17044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 10/28/2023] [Accepted: 11/05/2023] [Indexed: 11/24/2023]
Abstract
Climate change is contributing to declines of insects through rising temperatures, altered precipitation patterns, and an increasing frequency of extreme events. The impacts of both gradual and sudden shifts in weather patterns are realized directly on insect physiology and indirectly through impacts on other trophic levels. Here, we investigated direct effects of seasonal weather on butterfly occurrences and indirect effects mediated by plant productivity using a temporally intensive butterfly monitoring dataset, in combination with high-resolution climate data and a remotely sensed indicator of plant primary productivity. Specifically, we used Bayesian hierarchical path analysis to quantify relationships between weather and weather-driven plant productivity on the occurrence of 94 butterfly species from three localities distributed across an elevational gradient. We found that snow pack exerted a strong direct positive effect on butterfly occurrence and that low snow pack was the primary driver of reductions during drought. Additionally, we found that plant primary productivity had a consistently negative effect on butterfly occurrence. These results highlight mechanisms of weather-driven declines in insect populations and the nuances of climate change effects involving snow melt, which have implications for ecological theories linking topographic complexity to ecological resilience in montane systems.
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Affiliation(s)
- Christopher A Halsch
- Department of Biology, Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, Nevada, USA
| | - Arthur M Shapiro
- Center for Population Biology, University of California, Davis, California, USA
| | - James H Thorne
- Department of Environmental Science and Policy, University of California, Davis, California, USA
| | - Kyle C Rodman
- Ecological Restoration Institute, Northern Arizona University, Flagstaff, Arizona, USA
| | - Adriana Parra
- Department of Natural Resources and Environmental Science, University of Nevada, Reno, Nevada, USA
| | - Lee A Dyer
- Department of Biology, Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, Nevada, USA
| | | | - Angela M Smilanich
- Department of Biology, Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, Nevada, USA
| | - Matthew L Forister
- Department of Biology, Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, Nevada, USA
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Hidalgo-Triana N, Solakis A, Casimiro-Soriguer F, Choe H, Navarro T, Pérez-Latorre AV, Thorne JH. The high climate vulnerability of western Mediterranean forests. Sci Total Environ 2023; 895:164983. [PMID: 37353024 DOI: 10.1016/j.scitotenv.2023.164983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/31/2023] [Accepted: 06/16/2023] [Indexed: 06/25/2023]
Abstract
Understanding the effects of climate change is one of the most challenging goals for biodiversity conservation. The forests of Andalusia, in Southern Spain, are part of an important Mediterranean Basin biodiversity hotspot. However, great changes in climate are expected to occur in this region, and there is an increasing need to assess the vulnerability of its vegetation. We assess the vulnerability of twelve forest types in the region that are included in the European Directive 92/43/EEC as Habitats of Community Interest (HCI). HCI are natural habitat types which are in danger, have a small natural range, or present an outstanding example of a biogeographical regions in the European Union. We assessed vulnerability by analyzing the climate exposure level of each forest type under two global climate models (MRI-CGCM3, which predicts warmer and wetter conditions, and MIROC-ESM which predicts hotter and drier conditions), two emission scenarios (RCP4.5, a representative concentration pathway that predicts stable emissions of CO2, and RCP8.5, that predicts the highest CO2 emissions) by the mid- and end-century time periods. The vulnerability analysis also includes the sensitivity and adaptive capacity of the dominant tree species which compose each forest type. An overall vulnerability score was calculated for each forest type, model, scenario and time period. High-elevation forest types and those with high moisture requirements were more vulnerable to climate change, while forest types dominated by more thermophilic species were less vulnerable and more resilient. The worst climate impacts were predicted in the MIROC-ESM model and RCP8.5 scenario by the end of the century (2070-2100), while the least climatic stress was obtained in the MRI-CGCM3 model and RCP4.5 scenario by the mid-century (2040-2070), which still shows high potential stress for most forest types. By the end of the century, the climate exposure of the entire forest domain will range between 32 % in the least stressful situation (MRI-CGCM3 and RCP4.5), and 98 % in the most climatically stressful situation (MIROC-ESM and RCP8.5). However, the effects of climate change will be perceptible by the mid-century, with most of the HCI forest types suffering climate stress. The "Andalusian oak forest" and the "Corylus wet forest" types were the most vulnerable to climate change, while the "Mediterranean pine forest", the "Olea and Ceratonia forests" and the "oak forests" were the least vulnerable. This assessment identifies the vulnerable forest types to climate change in the south of the Iberian Peninsula, and provides context for natural resource managers in making decisions about how to adapt forests to the impacts of climate change.
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Affiliation(s)
- N Hidalgo-Triana
- Department of Botany and Plant Physiology (Botany Area), Faculty of Science, University of Málaga, Málaga 29010, Spain.
| | - Andros Solakis
- Department of Botany and Plant Physiology (Botany Area), Faculty of Science, University of Málaga, Málaga 29010, Spain
| | - Federico Casimiro-Soriguer
- Department of Botany and Plant Physiology (Botany Area), Faculty of Science, University of Málaga, Málaga 29010, Spain
| | - Hyeyeong Choe
- Department of Agriculture, Forestry and Bioresources, Seoul National University, Seoul 08826, Republic of Korea
| | - Teresa Navarro
- Department of Botany and Plant Physiology (Botany Area), Faculty of Science, University of Málaga, Málaga 29010, Spain
| | - Andrés V Pérez-Latorre
- Department of Botany and Plant Physiology (Botany Area), Faculty of Science, University of Málaga, Málaga 29010, Spain
| | - James H Thorne
- Department of Environmental Science and Policy, University of California, Davis 95616, USA
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Hidalgo-Triana N, Pérez-Latorre AV, Adomou AC, Rudner M, Thorne JH. Adaptations to the stressful combination of serpentine soils and Mediterranean climate drive plant functional groups and trait richness. Front Plant Sci 2023; 14:1040839. [PMID: 36993858 PMCID: PMC10040603 DOI: 10.3389/fpls.2023.1040839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 02/15/2023] [Indexed: 06/19/2023]
Abstract
INTRODUCTION Plant functional traits (FTs) are important for understanding plant ecological strategies (e.g., drought avoidance), especially in the nutrient-poor soils of serpentine ecosystems. In the Mediterranean areas, such ecosystems are characterized by climatic factors (e.g., summer drought) that exert a filtering effect. MATERIAL AND METHODS In our study, we analyzed 24 species with varying serpentine affinity, from strictly serpentine plants to generalist plants, from two ultramafic shrublands in southern Spain, considering four FTs: plant height (H), leaf area (LA), specific leaf area (SLA), and stem specific density (SSD). Additionally, we also identified the species' dominant strategies to avoid drought and those strategies' relationship to serpentine affinity. We used principal component analysis to identify combinations of FTs, and cluster analysis to define Functional Groups (FGs). RESULTS AND DISCUSSION We defined eight FGs, which suggests that such Mediterranean serpentine shrublands are composed of species with wide-ranging of FTs. Indicator traits explained 67-72% of the variability based on four strategies: (1) lower H than in other Mediterranean ecosystems; (2) middling SSD; (3) low LA; and (4) low SLA due to thick and/or dense leaves, which contribute to long leaf survival, nutrient retention, and protection from desiccation and herbivory. Generalist plants had higher SLA than obligate serpentine plants, whereas the obligate serpentine plants showed more drought avoidance mechanisms than the generalists. Although most plant species inhabiting Mediterranean serpentine ecosystems have shown similar ecological adaptations in response to the Mediterranean environment, our results suggest that serpentine obligate plant species could present greater resilience to climate change. Given greater number and more pronounced drought avoidance mechanisms in these species compared with generalists, and the high number of FGs identified, the serpentine plants have shown adaptation to severe drought.
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Affiliation(s)
| | | | | | - Michael Rudner
- Faculty of Environmental Engineering, Weihenstephan-Triesdorf University of Applied Sciences, Weidenbach, Germany
| | - James H. Thorne
- Department of Environmental Science and Policy, University of California, Davis, Davis, CA, United States
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Thorne JH, Choe H, Dorji L, Yangden K, Wangdi D, Phuntsho Y, Beardsley K. Species richness and turnover patterns for tropical and temperate plants on the elevation gradient of the eastern Himalayan Mountains. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.942759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Understanding species’ elevational distributions in mountain ecosystems is needed under climate change, but remote biodiverse mountain areas may be poorly documented. National Forest Inventories (NFIs) offer a potential source of data. We used NFI records from Bhutan to ask three questions about elevational richness patterns of Himalayan woody plant species. First, does the mean elevation for all species differ from those species whose entire elevational distribution is recorded in the survey? Second, how does the elevation of maximum richness differ when combining species originating from temperate and tropical regions vs. analyzing them separately? And third, do the highest species turnover rates adjoin elevation zones of maximum species richness? We used 32,198 species records from 1685 forest plots along a 7570 m gradient to map species elevation ranges. Species whose entire range was documented were those whose lowest records are located above 400 m, while bare rock defined all species’ upper limits. We calculated species richness and turnover using 400 m elevation bands. Of 569 species, 79% of temperate and 61% of tropical species’ elevation ranges were fully sampled within the NFI data. Mean elevation of tree and shrub species differed significantly for temperate and tropical species. Maximum combined species richness is from 1300 to 1700 m (277 species), differing significantly from maximum tropical (900–1300 m, 169) and temperate species richness (2500–2900 m, 92). Temperate tree turnover rate was highest in the bands adjoining its maximum species richness (2500–2900 m). But turnover for tropical trees was highest several bands above their maximum species richness, where turnover and decrease in richness interact. Shrub species turnover patterns are similar, but rates were generally higher than for trees. Bhutan’s NFI records show that woody plant species are arrayed on the Himalaya in part according to floristic origins, and that combining temperate- and tropical-originating floras for gradient-based studies such as species richness and turnover obscures actual elevational patterns. In addition, species whose ranges extend below the Himalayan elevation gradient should be accounted for in future studies that correlate climate and environment factors with elevational species richness patterns.
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Balantic C, Adams A, Gross S, Mazur R, Sawyer S, Tucker J, Vernon M, Mengelt C, Morales J, Thorne JH, Brown TM, Athearn N, Morelli TL. Toward climate change refugia conservation at an ecoregion scale. Conservat Sci and Prac 2021. [DOI: 10.1111/csp2.497] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Cathleen Balantic
- Northeast Climate Adaptation Science Center, Department of Environmental Conservation University of Massachusetts Amherst Amherst Massachusetts USA
| | - Andrea Adams
- Earth Research Institute University of California Santa Barbara Santa Barbara California USA
| | - Shana Gross
- Ecology Program USDA Forest Service, Region 5 South Lake Tahoe California USA
| | - Rachel Mazur
- Division of Resources Management and Science Yosemite National Park El Portal California USA
| | - Sarah Sawyer
- USDA Forest Service, Pacific Southwest Region Vallejo California USA
| | - Jody Tucker
- USDA Forest Service, Pacific Southwest Region Vallejo California USA
| | - Marian Vernon
- Point Blue Conservation Science Petaluma California USA
| | - Claudia Mengelt
- U.S. Fish and Wildlife Service Science Applications Sacramento California USA
| | - Jennifer Morales
- Climate Change Program California Department of Water Resources Fresno California USA
| | - James H. Thorne
- Department of Environmental Science and Policy University of California Davis California USA
| | - Timothy M. Brown
- Department of Ecology and Evolutionary Biology University of California Santa Cruz California USA
| | - Nicole Athearn
- Division of Resources Management and Science National Park Service El Portal California USA
| | - Toni Lyn Morelli
- U.S. Geological Survey, Northeast Climate Adaptation Science Center, Department of Environmental Conservation University of Massachusetts Amherst Amherst Massachusetts USA
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Huesca M, Ustin SL, Shapiro KD, Boynton R, Thorne JH. Detection of drought‐induced blue oak mortality in the Sierra Nevada Mountains, California. Ecosphere 2021. [DOI: 10.1002/ecs2.3558] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Affiliation(s)
- Margarita Huesca
- Center for Spatial Technologies and Remote Sensing (CSTARS) John Muir Institute of the EnvironmentUniversity of California Davis Davis California95616USA
- Department of Environmental Science and Policy University of California Davis Davis California95616USA
- Natural Resources Department Faculty of Geo‐information Science and Earth Observation University of Twente Enschede The Netherlands
| | - Susan L. Ustin
- Center for Spatial Technologies and Remote Sensing (CSTARS) John Muir Institute of the EnvironmentUniversity of California Davis Davis California95616USA
| | - Kristen D. Shapiro
- Center for Spatial Technologies and Remote Sensing (CSTARS) John Muir Institute of the EnvironmentUniversity of California Davis Davis California95616USA
- Department of Environmental Science and Policy University of California Davis Davis California95616USA
| | - Ryan Boynton
- Department of Environmental Science and Policy University of California Davis Davis California95616USA
| | - James H. Thorne
- Department of Environmental Science and Policy University of California Davis Davis California95616USA
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Stewart JAE, van Mantgem PJ, Young DJN, Shive KL, Preisler HK, Das AJ, Stephenson NL, Keeley JE, Safford HD, Wright MC, Welch KR, Thorne JH. Effects of postfire climate and seed availability on postfire conifer regeneration. Ecol Appl 2021; 31:e02280. [PMID: 33331069 DOI: 10.1002/eap.2280] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 07/21/2020] [Accepted: 08/17/2020] [Indexed: 06/12/2023]
Abstract
Large, severe fires are becoming more frequent in many forest types across the western United States and have resulted in tree mortality across tens of thousands of hectares. Conifer regeneration in these areas is limited because seeds must travel long distances to reach the interior of large burned patches and establishment is jeopardized by increasingly hot and dry conditions. To better inform postfire management in low elevation forests of California, USA, we collected 5-yr postfire recovery data from 1,234 study plots in 19 wildfires that burned from 2004-2012 and 18 yrs of seed production data from 216 seed fall traps (1999-2017). We used these data in conjunction with spatially extensive climate, topography, forest composition, and burn severity surfaces to construct taxon-specific, spatially explicit models of conifer regeneration that incorporate climate conditions and seed availability during postfire recovery windows. We found that after accounting for other predictors both postfire and historical precipitation were strong predictors of regeneration, suggesting that both direct effects of postfire moisture conditions and biological inertia from historical climate may play a role in regeneration. Alternatively, postfire regeneration may simply be driven by postfire climate and apparent relationships with historical climate could be spurious. The estimated sensitivity of regeneration to postfire seed availability was strongest in firs and all conifers combined and weaker in pines. Seed production exhibited high temporal variability with seed production varying by over two orders of magnitude among years. Our models indicate that during droughts postfire conifer regeneration declines most substantially in low-to-moderate elevation forests. These findings enhance our mechanistic understanding of forecasted and historically documented shifts in the distribution of trees.
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Affiliation(s)
- Joseph A E Stewart
- Western Ecological Research Center, U.S. Geological Survey, Arcata, California, 95521, USA
- Department of Environmental Science and Policy, UC Davis, Davis, California, 95616, USA
| | - Phillip J van Mantgem
- Western Ecological Research Center, U.S. Geological Survey, Arcata, California, 95521, USA
| | - Derek J N Young
- Department of Plant Sciences, UC Davis, Davis, California, 95616, USA
| | - Kristen L Shive
- Western Ecological Research Center, U.S. Geological Survey, Arcata, California, 95521, USA
| | - Haiganoush K Preisler
- Pacific Southwest Research Station, U.S. Forest Service, Albany, California, 94710, USA
| | - Adrian J Das
- Western Ecological Research Center, U.S. Geological Survey, Three Rivers, California, 93271, USA
| | - Nathan L Stephenson
- Western Ecological Research Center, U.S. Geological Survey, Three Rivers, California, 93271, USA
| | - Jon E Keeley
- Western Ecological Research Center, U.S. Geological Survey, Three Rivers, California, 93271, USA
| | - Hugh D Safford
- Department of Environmental Science and Policy, UC Davis, Davis, California, 95616, USA
- Pacific Southwest Region, U.S. Forest Service, Vallejo, California, 94592, USA
| | - Micah C Wright
- Western Ecological Research Center, U.S. Geological Survey, Arcata, California, 95521, USA
| | - Kevin R Welch
- California Department of Forestry and Fire Protection, Sacramento, California, 94244, USA
| | - James H Thorne
- Department of Environmental Science and Policy, UC Davis, Davis, California, 95616, USA
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Affiliation(s)
- Mark W Schwartz
- Department of Environmental Science & Policy, University of California, Davis, Davis, CA 95616, USA.
| | - James H Thorne
- Department of Environmental Science & Policy, University of California, Davis, Davis, CA 95616, USA
| | - Brandon M Collins
- Center for Fire Research and Outreach, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Peter A Stine
- Retired, Pacific Southwest Research Station, U.S. Department of Agriculture Forest Service, Richmond, CA 94804, USA
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Morelli TL, Barrows CW, Ramirez AR, Cartwright JM, Ackerly DD, Eaves TD, Ebersole JL, Krawchuk MA, Letcher BH, Mahalovich MF, Meigs GW, Michalak JL, Millar CI, Quiñones RM, Stralberg D, Thorne JH. Climate-change refugia: biodiversity in the slow lane. Front Ecol Environ 2020; 18:228-234. [PMID: 33424494 PMCID: PMC7787983 DOI: 10.1002/fee.2189] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Climate-change adaptation focuses on conducting and translating research to minimize the dire impacts of anthropogenic climate change, including threats to biodiversity and human welfare. One adaptation strategy is to focus conservation on climate-change refugia (that is, areas relatively buffered from contemporary climate change over time that enable persistence of valued physical, ecological, and sociocultural resources). In this Special Issue, recent methodological and conceptual advances in refugia science will be highlighted. Advances in this emerging subdiscipline are improving scientific understanding and conservation in the face of climate change by considering scale and ecosystem dynamics, and looking beyond climate exposure to sensitivity and adaptive capacity. We propose considering refugia in the context of a multifaceted, long-term, network-based approach, as temporal and spatial gradients of ecological persistence that can act as "slow lanes" rather than areas of stasis. After years of discussion confined primarily to the scientific literature, researchers and resource managers are now working together to put refugia conservation into practice.
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Affiliation(s)
- Toni Lyn Morelli
- Northeast Climate Adaptation Science Center, US Geological Survey (USGS), Amherst, MA
| | - Cameron W Barrows
- Center for Conservation Biology, University of California–Riverside, Riverside, CA
| | - Aaron R Ramirez
- Department of Biology and Environmental Studies, Reed College, Portland, OR
| | | | - David D Ackerly
- Department of Integrative Biology and Department of Environmental Science, Policy, and Management, University of California–Berkeley, Berkeley, CA
| | - Tatiana D Eaves
- Krieger School of Arts and Sciences, Johns Hopkins University, Baltimore, MD
| | - Joseph L Ebersole
- Pacific Ecological Systems Division, Office of Research and Development, US Environmental Protection Agency, Corvallis, OR
| | - Meg A Krawchuk
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR
| | | | - Mary F Mahalovich
- Northern, Rocky Mountain, Southwestern, and Intermountain Regions, US Department of Agriculture (USDA) Forest Service, Moscow, ID
| | - Garrett W Meigs
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR
| | - Julia L Michalak
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA
| | | | | | - Diana Stralberg
- Department of Renewable Resources, University of Alberta, Edmonton, Canada
| | - James H Thorne
- Department of Environmental Science and Policy, University of California–Davis, Davis, CA
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Ramírez-Bautista A, Thorne JH, Schwartz MW, Williams JN. Trait-based climate vulnerability of native rodents in southwestern Mexico. Ecol Evol 2020; 10:5864-5876. [PMID: 32607196 PMCID: PMC7319118 DOI: 10.1002/ece3.6323] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/05/2020] [Accepted: 04/07/2020] [Indexed: 11/09/2022] Open
Abstract
AIM Incorporate species' trait information together with climate projections for associated habitat to assess the potential vulnerability of rodent taxa to climate change. LOCATION Oaxaca State, Mexico. METHODS We used a trait-based approach together with climate exposure models to evaluate the vulnerability of rodent species to projected climate conditions in the study region. Vulnerability was estimated based on three factors: (a) Level of climatic exposure that species are projected to experience across their current statewide range; (b) inherent species-specific sensitivity to stochastic events; and (c) species' capacity to cope with climate change effects. We defined species as inherently sensitive if they had any of the following: restricted geographic distribution in Mexico; narrow altitudinal range; low dispersal ability; or long generation length. RESULTS Vulnerability varied depending on the climate change scenario applied. Under the MPI general circulation model and current emissions trends, by 2099, all species evaluated were projected to have some level of threat (vulnerable for at least one factor), with 4 out of 55 species vulnerable for all three factors, 29 for two factors, and 22 for one factor. Six out of ten rodent species endemic to Oaxaca were vulnerable for two or more factors. We found that species with narrow and restricted-range distributions combined with low adaptive capacity were projected to be particularly vulnerable. MAIN CONCLUSIONS By including species-specific trait information in climate exposure assessments, researchers can contextualize and enhance their understanding about how climate change is likely to affect individual taxa in an area of interest. As such, studies like this one provide more relevant threat assessment information than exposure analyses alone and serve as a starting point for considering how climatic changes interact with an array of other variables to affect native species across their range.
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Affiliation(s)
- Arturo Ramírez-Bautista
- Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional Unidad Oaxaca (CIIDIR-OAX) Instituto Politécnico Nacional Oaxaca Mexico
| | - James H Thorne
- Department of Environmental Science & Policy University of California Davis CA USA
| | - Mark W Schwartz
- Department of Environmental Science & Policy University of California Davis CA USA
| | - John N Williams
- Centro Interdisciplinario de Investigación para el Desarrollo Integral Regional Unidad Oaxaca (CIIDIR-OAX) Instituto Politécnico Nacional Oaxaca Mexico
- Department of Environmental Science & Policy University of California Davis CA USA
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Park CY, Yoon EJ, Lee DK, Thorne JH. Integrating four radiant heat load mitigation strategies is an efficient intervention to improve human health in urban environments. Sci Total Environ 2020; 698:134259. [PMID: 31514036 DOI: 10.1016/j.scitotenv.2019.134259] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 09/02/2019] [Accepted: 09/02/2019] [Indexed: 06/10/2023]
Abstract
Increasing heat in urban areas raises heat-related health risks. Green infrastructure and managing surface albedo can reduce the radiation exposure of pedestrians. However, selecting options among various radiant fluxes mitigation strategies is challenging, particularly due to potential interactions among options such as planting vegetation or changing surface albedos. We used a multi-strategies model for determining optimal design combinations for reducing mean radiant temperature (MRT) in urban environments across a range of costs and benefits. The solutions are developed by a non-dominated sorting genetic algorithm II (NSGA II) with a MRT simulator. We selected four MRT reduction strategies: tree planting, grass planting, albedo reduction of building walls, and albedo reduction of sidewalks. Model test results for a simulated street canyon show a wide range of optimal alternative plans considering the combination effects of the four strategies. While previous studies have focused on single options to reduce heat load, we found benefits were higher by using a combination of these strategies, which can provide synergistic benefits. These results provide useful information for decision makers confronting real world problems such as heat related mortality. Thermal-friendly design methods and green infrastructure will help the urban environment become sustainable and improve human health and well-being.
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Affiliation(s)
- Chae Yeon Park
- Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Eun Joo Yoon
- Center for Social and Environmental Systems Research, National Institute for Environmental Studies, 305-8506, 16-2 Onogawa, Tsukuba, Ibaraki, Japan
| | - Dong Kun Lee
- Research Institute of Agriculture Life Science, Seoul National University, Seoul 08826, Republic of Korea; Dept. of Landscape Architecture & Rural System Engineering, College of Agriculture Life Sciences, Seoul National University, Seoul 08826, Republic of Korea.
| | - James H Thorne
- Dept. of Environmental Science and Policy, University of California, One Shields Ave, Davis, CA 95616, United States of America
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Nice CC, Forister ML, Harrison JG, Gompert Z, Fordyce JA, Thorne JH, Waetjen DP, Shapiro AM. Extreme heterogeneity of population response to climatic variation and the limits of prediction. Glob Chang Biol 2019; 25:2127-2136. [PMID: 30770601 DOI: 10.1111/gcb.14593] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 02/04/2019] [Indexed: 06/09/2023]
Abstract
Certain general facets of biotic response to climate change, such as shifts in phenology and geographic distribution, are well characterized; however, it is not clear whether the observed similarity of responses across taxa will extend to variation in other population-level processes. We examined population response to climatic variation using long-term incidence data (collected over 42 years) encompassing 149 butterfly species and considerable habitat diversity (10 sites along an elevational gradient from sea level to over 2,700 m in California). Population responses were characterized by extreme heterogeneity that was not attributable to differences in species composition among sites. These results indicate that habitat heterogeneity might be a buffer against climate change and highlight important questions about mechanisms maintaining interpopulation differences in responses to weather. Despite overall heterogeneity of response, population dynamics were accurately predicted by our model for many species at each site. However, the overall correlation between observed and predicted incidence in a cross validation analysis was moderate (Pearson's r = 0.23, SE 0.01), and 97% of observed data fell within the predicted 95% credible intervals. Prediction was most successful for more abundant species as well as for sites with lower annual turnover. Population-level heterogeneity in response to climate variation and the limits of our predictive power highlight the challenges for a future of increasing climatic variability.
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Affiliation(s)
- Chris C Nice
- Department of Biology, Population and Conservation Biology Program, Texas State University, San Marcos, Texas
| | - Matthew L Forister
- Department of Biology, Program in Ecology, Evolution and Conservation Biology, University of Nevada, Reno, Nevada
| | | | | | - James A Fordyce
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, Tennessee
| | - James H Thorne
- Department of Environmental Science and Policy, University of California, Davis, California
| | - David P Waetjen
- Department of Environmental Science and Policy, University of California, Davis, California
| | - Arthur M Shapiro
- Center for Population Biology, University of California, Davis, California
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Kang W, Thorne JH, Kim G, Lee D, Song Y. Conserving terrestrial linkages that connect natural landscapes of the Korean Peninsula. Environ Monit Assess 2019; 191:385. [PMID: 31111242 DOI: 10.1007/s10661-019-7520-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 05/03/2019] [Indexed: 06/09/2023]
Abstract
Human-induced land degradation fragments natural ecosystems, hinders ecological processes, and threatens biodiversity. Maintaining or restoring ecological flows across landscapes through landscape linkages may provide a solution. Here, we identify a peninsula-wide ecological connectivity network for the Korean Peninsula using two linkage mapping models. We found three major north-south axes of connectivity traversing the Demilitarized Zone (DMZ), which emerged as an important east-west linkage. Only 7% of the highest-ranked connections are currently secured by protected areas. We found 120 linkages in North and South Korea that are intersected by road networks consisting of motorways and trunk roads under both models. These locations should be the focus of immediate attention for conservation planners, as well as 274 and 1130 additional road-impacted linkages under one model or the other. The results can be used for policy support, and potentially as a basis for the two countries to engage in discussions about ecosystem health and climate change adaptation. The approach presented here can also be efficiently used to assess and map natural landscape linkages.
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Affiliation(s)
- Wanmo Kang
- Department of Human Environment Design, Cheongju University, 298 Daeseong-ro, Cheongwon-gu, Cheongju-si, Chungcheongbuk-do, 28503, Republic of Korea
| | - James H Thorne
- Department of Environmental Science and Policy, University of California, Davis, CA, 95616, USA
| | - GoWoon Kim
- O-Jeong Eco-Resilience Institute, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Dongkun Lee
- Department of Landscape Architecture and Rural Systems Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Youngkeun Song
- Department of Landscape Architecture, Graduate School of Environmental Studies, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea.
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14
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Choe H, Thorne JH. Omnidirectional connectivity of urban open spaces provides context for local government redevelopment plans. Landscape Ecol Eng 2019. [DOI: 10.1007/s11355-019-00377-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Choe H, Thorne JH, Hijmans R, Seo C. Integrating the Rabinowitz rarity framework with a National Plant Inventory in South Korea. Ecol Evol 2019; 9:1353-1363. [PMID: 30805165 PMCID: PMC6374650 DOI: 10.1002/ece3.4851] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 11/17/2018] [Accepted: 11/28/2018] [Indexed: 11/10/2022] Open
Abstract
Increasingly large presence-only survey datasets are becoming available for use in conservation assessments. Potentially, these records could be used to determine spatial patterns of plant species rarity and endemism. We test the integration of a large South Korean species record database with Rabinowitz rarity classes. Rabinowitz proposed seven classes of species rarity using three variables: geographic range, habitat specificity, and local population size. We estimated the range size and local abundance of 2,215 plant species from species occurrence records and habitat specificity as the number of landcover types each species' records were found in. We classified each species into a rarity class or as common, compared species composition by class to national lists, and mapped the spatial pattern of species richness for each rarity class. Species were classed to narrow or wide geographic ranges using 315 km, the average from a range size index of all species (D max), based on maximum distance between observations. There were four classes each within the narrow and wide range groups, sorted using cutoffs of local abundance and habitat specificity. Nationally listed endangered species only appeared in the narrow-range classes, while nationally listed endemic species appeared in almost all classes. Species richness in most rarity classes was high in northeastern South Korea especially for species with narrow ranges. Policy implications. Large presence-only surveys may be able to estimate some classes of rarity better than others, but modification to include estimates of local abundance and habitat types, could greatly increase their utility. Application of the Rabinowitz rarity framework to such surveys can extend their utility beyond species distribution models and can identify areas that need further surveys and for conservation priority. Future studies should be aware of the subjectivity of the rarity classification and that regional scale implementations of the framework may differ.
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Affiliation(s)
- Hyeyeong Choe
- Department of Ecological Landscape Architecture DesignKangwon National UniversityChuncheonSouth Korea
| | - James H. Thorne
- Department of Environmental Science and PolicyUC DavisDavisCalifornia
| | - Robert Hijmans
- Department of Environmental Science and PolicyUC DavisDavisCalifornia
| | - Changwan Seo
- Division of Ecological AssessmentNational Institute of EcologySeocheonSouth Korea
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16
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Keeley ATH, Basson G, Cameron DR, Heller NE, Huber PR, Schloss CA, Thorne JH, Merenlender AM. Making habitat connectivity a reality. Conserv Biol 2018; 32:1221-1232. [PMID: 29920775 DOI: 10.1111/cobi.13158] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 06/12/2018] [Accepted: 06/13/2018] [Indexed: 05/21/2023]
Abstract
Although a plethora of habitat-connectivity plans exists, protecting and restoring connectivity through on-the-ground action has been slow. We identified challenges to and opportunities for connectivity conservation through a literature review of project implementation, a workshop with scientists and conservation practitioners, 3 case studies of connectivity projects, and interviews with conservation professionals. Connectivity challenges and solutions tended to be context specific, dependent on land-ownership patterns, socioeconomic factors, and the policy framework. Successful connectivity implementation tended to be associated with development and promotion of a common vision among diverse sets of stakeholders, including nontraditional conservation actors, such as water districts and recreation departments, and with communication with partners and the public. Other factors that lead to successful implementation included undertaking empirical studies to prioritize and validate corridors and the identification of related co-benefits of corridor projects. Engaging partners involved in land management and planning, such as nongovernmental conservation organizations, public agencies, and private landowners, is critical to effective strategy implementation. A clear regulatory framework, including unambiguous connectivity conservation mandates, would increase public resource allocation, and incentive programs are needed to promote private sector engagement. Connectivity conservation must move more rapidly from planning to implementation. We provide an evidence-based solution composed of key elements for successful on-the-ground connectivity implementation. We identified the social processes necessary to advance habitat connectivity for biodiversity conservation and resilient landscapes under climate change.
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Affiliation(s)
- Annika T H Keeley
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, 130 Mulford Hall #3114, Berkeley, CA, 94720, U.S.A
| | - Galli Basson
- Santa Clara Valley Open Space Authority, 33 Las Colinas Lane, San Jose, CA, 95119, U.S.A
| | - D Richard Cameron
- The Nature Conservancy, 201 Mission Street 4th Floor, San Francisco, CA, 94105, U.S.A
| | - Nicole E Heller
- Peninsula Open Space Trust, 222 High Street, Palo Alto, CA, 94022, U.S.A
| | - Patrick R Huber
- Agricultural Sustainability Institute, University of California, Davis, One Shields Avenue, Davis, CA, 95616, U.S.A
| | - Carrie A Schloss
- The Nature Conservancy, 201 Mission Street 4th Floor, San Francisco, CA, 94105, U.S.A
| | - James H Thorne
- Department of Environmental Science and Policy, University of California, Davis, One Shields Avenue, Davis, CA, 95616, U.S.A
| | - Adina M Merenlender
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, 130 Mulford Hall #3114, Berkeley, CA, 94720, U.S.A
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17
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Jeong S, Kim HG, Thorne JH, Lee H, Cho YH, Lee DK, Park CH, Seo C. Evaluating connectivity for two mid-sized mammals across modified riparian corridors with wildlife crossing monitoring and species distribution modeling. Glob Ecol Conserv 2018. [DOI: 10.1016/j.gecco.2018.e00485] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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18
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Forister ML, Fordyce JA, Nice CC, Thorne JH, Waetjen DP, Shapiro AM. Impacts of a millennium drought on butterfly faunal dynamics. ACTA ACUST UNITED AC 2018. [DOI: 10.1186/s40665-018-0039-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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19
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Thorne JH, Choe H, Boynton RM, Bjorkman J, Albright W, Nydick K, Flint AL, Flint LE, Schwartz MW. The impact of climate change uncertainty on California's vegetation and adaptation management. Ecosphere 2017. [DOI: 10.1002/ecs2.2021] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Affiliation(s)
- James H. Thorne
- Department of Environmental Science and Policy University of California Davis California 95616 USA
| | - Hyeyeong Choe
- Department of Environmental Science and Policy University of California Davis California 95616 USA
| | - Ryan M. Boynton
- Department of Environmental Science and Policy University of California Davis California 95616 USA
| | - Jacquelyn Bjorkman
- Department of Environmental Science and Policy University of California Davis California 95616 USA
| | - Whitney Albright
- California Department of Fish and Wildlife 1416 Ninth Street, Suite 1221 Sacramento California 95814 USA
| | - Koren Nydick
- Sequoia and Kings Canyon National Parks Three Rivers California 93271 USA
| | - Alan L. Flint
- US Geological Survey Placer Hall, 6000 J Street Sacramento California 95819‐6129 USA
| | - Lorraine E. Flint
- US Geological Survey Placer Hall, 6000 J Street Sacramento California 95819‐6129 USA
| | - Mark W. Schwartz
- Department of Environmental Science and Policy University of California Davis California 95616 USA
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20
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Forister ML, Cousens B, Harrison JG, Anderson K, Thorne JH, Waetjen D, Nice CC, De Parsia M, Hladik ML, Meese R, van Vliet H, Shapiro AM. Increasing neonicotinoid use and the declining butterfly fauna of lowland California. Biol Lett 2017; 12:rsbl.2016.0475. [PMID: 27531159 DOI: 10.1098/rsbl.2016.0475] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 07/25/2016] [Indexed: 11/12/2022] Open
Abstract
The butterfly fauna of lowland Northern California has exhibited a marked decline in recent years that previous studies have attributed in part to altered climatic conditions and changes in land use. Here, we ask if a shift in insecticide use towards neonicotinoids is associated with butterfly declines at four sites in the region that have been monitored for four decades. A negative association between butterfly populations and increasing neonicotinoid application is detectable while controlling for land use and other factors, and appears to be more severe for smaller-bodied species. These results suggest that neonicotinoids could influence non-target insect populations occurring in proximity to application locations, and highlights the need for mechanistic work to complement long-term observational data.
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Affiliation(s)
| | - Bruce Cousens
- Western Purple Martin Foundation, Nanaimo, British Columbia, Canada
| | | | | | - James H Thorne
- Department of Environmental Science and Policy, University of California, Davis, USA
| | - Dave Waetjen
- Department of Environmental Science and Policy, University of California, Davis, USA
| | - Chris C Nice
- Department of Biology, Texas State University, San Marcos, TX, USA
| | - Matthew De Parsia
- US Geological Survey, California Water Science Center, Sacramento, CA, USA
| | - Michelle L Hladik
- US Geological Survey, California Water Science Center, Sacramento, CA, USA
| | - Robert Meese
- Department of Environmental Science and Policy, University of California, Davis, USA
| | - Heidi van Vliet
- Biology Department, York University, Toronto, Ontario, Canada
| | - Arthur M Shapiro
- Department of Evolution and Ecology, Center for Population Biology, University of California, Davis, USA
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21
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Santos MJ, Smith AB, Thorne JH, Moritz C. The relative influence of change in habitat and climate on elevation range limits in small mammals in Yosemite National Park, California, U.S.A. ACTA ACUST UNITED AC 2017. [DOI: 10.1186/s40665-017-0035-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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22
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Pérez-García N, Thorne JH, Domínguez-Lozano F. The mid-distance dispersal optimum, evidence from a mixed-model climate vulnerability analysis of an edaphic endemic shrub. DIVERS DISTRIB 2017. [DOI: 10.1111/ddi.12574] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Nora Pérez-García
- Department of Plant Biology; University of Barcelona; Barcelona Spain
| | - James H. Thorne
- Department of Environmental Science and Policy; University of California, Davis; Davis CA USA
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Affiliation(s)
- Hyeyeong Choe
- Department of Environmental Science and Policy; University of California, Davis; Davis CA 95616 USA
| | - James H. Thorne
- Department of Environmental Science and Policy; University of California, Davis; Davis CA 95616 USA
| | - Robert Hijmans
- Department of Environmental Science and Policy; University of California, Davis; Davis CA 95616 USA
| | - Jiyoen Kim
- Monitoring and Analysis Division; Yeongsan River Basin Environmental Office; Ministry of Environment; Gwangju 61945 South Korea
| | - Hyuksoo Kwon
- Division of Ecosystem Services & Research Planning; National Institute of Ecology; Seocheon-gun 33657 South Korea
| | - Changwan Seo
- Division of Ecosystem Services & Research Planning; National Institute of Ecology; Seocheon-gun 33657 South Korea
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Copeland SM, Harrison SP, Latimer AM, Damschen EI, Eskelinen AM, Fernandez‐Going B, Spasojevic MJ, Anacker BL, Thorne JH. Ecological effects of extreme drought on Californian herbaceous plant communities. ECOL MONOGR 2016. [DOI: 10.1002/ecm.1218] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Stella M. Copeland
- Department of Environmental Science and Policy University of California DavisCalifornia 95616USA
| | - Susan P. Harrison
- Department of Environmental Science and Policy University of California DavisCalifornia 95616USA
| | - Andrew M. Latimer
- Department of Plant Sciences University of California DavisCalifornia 95616USA
| | - Ellen I. Damschen
- Department of Zoology University of Wisconsin MadisonWisconsin 53706USA
| | - Anu M. Eskelinen
- Department of Environmental Science and Policy University of California DavisCalifornia 95616USA
- Department of Ecology University of Oulu Oulu Finland
- Department of Physiological Diversity Helmholtz Center for Environmental Research – UFZ German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Deutscher Platz 5e D‐04103 Leipzig Germany
| | - Barbara Fernandez‐Going
- Department of Ecology, Evolution, and Marine Biology University of California Santa BarbaraCalifornia 93106USA
| | - Marko J. Spasojevic
- Department of Biology and Tyson Research Center Washington University in St. Louis St. Louis, Missouri USA
| | - Brian L. Anacker
- Open Space and Mountain Parks Department, City of Boulder BoulderColorado 80303USA
| | - James H. Thorne
- Department of Environmental Science and Policy University of California DavisCalifornia 95616USA
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Esralew RA, Flint L, Thorne JH, Boynton R, Flint A. A Framework for Effective Use of Hydroclimate Models in Climate-Change Adaptation Planning for Managed Habitats with Limited Hydrologic Response Data. Environ Manage 2016; 58:60-75. [PMID: 26141222 PMCID: PMC4887534 DOI: 10.1007/s00267-015-0569-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 06/15/2015] [Indexed: 06/04/2023]
Abstract
Climate-change adaptation planning for managed wetlands is challenging under uncertain futures when the impact of historic climate variability on wetland response is unquantified. We assessed vulnerability of Modoc National Wildlife Refuge (MNWR) through use of the Basin Characterization Model (BCM) landscape hydrology model, and six global climate models, representing projected wetter and drier conditions. We further developed a conceptual model that provides greater value for water managers by incorporating the BCM outputs into a conceptual framework that links modeled parameters to refuge management outcomes. This framework was used to identify landscape hydrology parameters that reflect refuge sensitivity to changes in (1) climatic water deficit (CWD) and recharge, and (2) the magnitude, timing, and frequency of water inputs. BCM outputs were developed for 1981-2100 to assess changes and forecast the probability of experiencing wet and dry water year types that have historically resulted in challenging conditions for refuge habitat management. We used a Yule's Q skill score to estimate the probability of modeled discharge that best represents historic water year types. CWD increased in all models across 72.3-100 % of the water supply basin by 2100. Earlier timing in discharge, greater cool season discharge, and lesser irrigation season water supply were predicted by most models. Under the worst-case scenario, moderately dry years increased from 10-20 to 40-60 % by 2100. MNWR could adapt by storing additional water during the cool season for later use and prioritizing irrigation of habitats during dry years.
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Affiliation(s)
- Rachel A. Esralew
- />U.S. Fish and Wildlife Service, Pacific Southwest Region Refuges Inventory and Monitoring Initiative, 3020 State University Drive East Suite 2007, Sacramento, CA 95819 USA
| | - Lorraine Flint
- />U.S. Geological Survey, California Water Science Center, Placer Hall, 6000 J Street, Sacramento, CA 95819 USA
| | - James H. Thorne
- />Information Center for the Environment, Department of Environmental Science and Policy, University of California – Davis, One Shields Avenue, Davis, CA 95616 USA
| | - Ryan Boynton
- />Information Center for the Environment, Department of Environmental Science and Policy, University of California – Davis, One Shields Avenue, Davis, CA 95616 USA
| | - Alan Flint
- />U.S. Geological Survey, California Water Science Center, Placer Hall, 6000 J Street, Sacramento, CA 95819 USA
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26
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Burge DO, Thorne JH, Harrison SP, O'Brien BC, Rebman JP, Shevock JR, Alverson ER, Hardison LK, RodrÍguez JD, Junak SA, Oberbauer TA, Riemann H, Vanderplank SE, Barry T. PLANT DIVERSITY AND ENDEMISM IN THE CALIFORNIA FLORISTIC PROVINCE. ACTA ACUST UNITED AC 2016. [DOI: 10.3120/madr-63-02-3-206.1] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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27
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Choe H, Thorne JH, Seo C. Mapping National Plant Biodiversity Patterns in South Korea with the MARS Species Distribution Model. PLoS One 2016; 11:e0149511. [PMID: 26930289 PMCID: PMC4773094 DOI: 10.1371/journal.pone.0149511] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2015] [Accepted: 02/02/2016] [Indexed: 11/25/2022] Open
Abstract
Accurate information on the distribution of existing species is crucial to assess regional biodiversity. However, data inventories are insufficient in many areas. We examine the ability of Multivariate Adaptive Regression Splines (MARS) multi-response species distribution model to overcome species’ data limitations and portray plant species distribution patterns for 199 South Korean plant species. The study models species with two or more observations, examines their contribution to national patterns of species richness, provides a sensitivity analysis of different range threshold cutoff approaches for modeling species’ ranges, and presents considerations for species modeling at fine spatial resolution. We ran MARS models for each species and tested four threshold methods to transform occurrence probabilities into presence or absence range maps. Modeled occurrence probabilities were extracted at each species’ presence points, and the mean, median, and one standard deviation (SD) calculated to define data-driven thresholds. A maximum sum of sensitivity and specificity threshold was also calculated, and the range maps from the four cutoffs were tested using independent plant survey data. The single SD values were the best threshold tested for minimizing omission errors and limiting species ranges to areas where the associated occurrence data were correctly classed. Eight individual species range maps for rare plant species were identified that are potentially affected by resampling predictor variables to fine spatial scales. We portray spatial patterns of high species richness by assessing the combined range maps from three classes of species: all species, endangered and endemic species, and range-size rarity of all species, which could be used in conservation planning for South Korea. The MARS model is promising for addressing the common problem of few species occurrence records. However, projected species ranges are highly dependent on the threshold and scale criteria, which should be assessed on a per-project basis.
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Affiliation(s)
- Hyeyeong Choe
- Geography Graduate Group, University of California Davis, Davis, California, United States of America
- * E-mail:
| | - James H. Thorne
- Department of Environmental Science and Policy, University of California Davis, Davis, California, United States of America
| | - Changwan Seo
- Division of Ecosystem Services & Research Planning, National Institute of Ecology, Seocheon-gun, Choongnam, South Korea
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28
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Schwartz MW, Butt N, Dolanc CR, Holguin A, Moritz MA, North MP, Safford HD, Stephenson NL, Thorne JH, van Mantgem PJ. Increasing elevation of fire in the Sierra Nevada and implications for forest change. Ecosphere 2015. [DOI: 10.1890/es15-00003.1] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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29
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Thorne JH, Boynton RM, Flint LE, Flint AL. The magnitude and spatial patterns of historical and future hydrologic change in California's watersheds. Ecosphere 2015. [DOI: 10.1890/es14-00300.1] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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30
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Wathen S, Thorne JH, Holguin A, Schwartz MW. Estimating the spatial and temporal distribution of species richness within Sequoia and Kings Canyon National Parks. PLoS One 2014; 9:e112465. [PMID: 25469873 PMCID: PMC4254294 DOI: 10.1371/journal.pone.0112465] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 10/15/2014] [Indexed: 11/18/2022] Open
Abstract
Evidence for significant losses of species richness or biodiversity, even within protected natural areas, is mounting. Managers are increasingly being asked to monitor biodiversity, yet estimating biodiversity is often prohibitively expensive. As a cost-effective option, we estimated the spatial and temporal distribution of species richness for four taxonomic groups (birds, mammals, herpetofauna (reptiles and amphibians), and plants) within Sequoia and Kings Canyon National Parks using only existing biological studies undertaken within the Parks and the Parks' long-term wildlife observation database. We used a rarefaction approach to model species richness for the four taxonomic groups and analyzed those groups by habitat type, elevation zone, and time period. We then mapped the spatial distributions of species richness values for the four taxonomic groups, as well as total species richness, for the Parks. We also estimated changes in species richness for birds, mammals, and herpetofauna since 1980. The modeled patterns of species richness either peaked at mid elevations (mammals, plants, and total species richness) or declined consistently with increasing elevation (herpetofauna and birds). Plants reached maximum species richness values at much higher elevations than did vertebrate taxa, and non-flying mammals reached maximum species richness values at higher elevations than did birds. Alpine plant communities, including sagebrush, had higher species richness values than did subalpine plant communities located below them in elevation. These results are supported by other papers published in the scientific literature. Perhaps reflecting climate change: birds and herpetofauna displayed declines in species richness since 1980 at low and middle elevations and mammals displayed declines in species richness since 1980 at all elevations.
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Affiliation(s)
- Steve Wathen
- John Muir Institute of the Environment, University of California Davis, Davis, California, United States of America
| | - James H. Thorne
- Information Center for the Environment, University of California Davis, Davis, California, United States of America
| | - Andrew Holguin
- Information Center for the Environment, University of California Davis, Davis, California, United States of America
| | - Mark W. Schwartz
- John Muir Institute of the Environment, University of California Davis, Davis, California, United States of America
- Department of Environmental Science & Policy, University of California Davis, Davis, California, United States of America
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31
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Dolanc CR, Safford HD, Thorne JH, Dobrowski SZ. Changing forest structure across the landscape of the Sierra Nevada, CA, USA, since the 1930s. Ecosphere 2014. [DOI: 10.1890/es14-00103.1] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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32
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Thorne JH, Seo C, Basabose A, Gray M, Belfiore NM, Hijmans RJ. Alternative biological assumptions strongly influence models of climate change effects on mountain gorillas. Ecosphere 2013. [DOI: 10.1890/es13-00123.1] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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33
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Thorne JH, Santos MJ, Bjorkman JH. Regional assessment of urban impacts on landcover and open space finds a smart urban growth policy performs little better than business as usual. PLoS One 2013; 8:e65258. [PMID: 23755204 PMCID: PMC3673918 DOI: 10.1371/journal.pone.0065258] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Accepted: 04/27/2013] [Indexed: 11/29/2022] Open
Abstract
Assessment of landscape change is critical for attainment of regional sustainability goals. Urban growth assessments are needed because over half the global population now lives in cities, which impact biodiversity, ecosystem structure and ecological processes. Open space protection is needed to preserve these attributes, and provide the resources humans need. The San Francisco Bay Area, California, is challenged to accommodate a population increase of 3.07 million while maintaining the region’s ecosystems and biodiversity. Our analysis of 9275 km2 in the Bay Area links historic trends for three measures: urban growth, protected open space, and landcover types over the last 70 years to future 2050 projections of urban growth and open space. Protected open space totaled 348 km2 (3.7% of the area) in 1940, and expanded to 2221 km2 (20.2%) currently. An additional 1038 km2 of protected open space is targeted (35.1%). Urban area historically increased from 396.5 km2 to 2239 km2 (24.1% of the area). Urban growth during this time mostly occurred at the expense of agricultural landscapes (62.9%) rather than natural vegetation. Smart Growth development has been advanced as a preferred alternative in many planning circles, but we found that it conserved only marginally more open space than Business-as-usual when using an urban growth model to portray policies for future urban growth. Scenarios to 2050 suggest urban development on non-urban lands of 1091, 956, or 179 km2, under Business-as-usual, Smart Growth and Infill policy growth scenarios, respectively. The Smart Growth policy converts 88% of natural lands and agriculture used by Business-as-usual, while Infill used only 40% of those lands. Given the historic rate of urban growth, 0.25%/year, and limited space available, the Infill scenario is recommended. While the data may differ, the use of an historic and future framework to track these three variables can be easily applied to other metropolitan areas.
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Affiliation(s)
- James H Thorne
- Information Center for the Environment, University of California Davis, Davis, California, United States of America.
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Thorne JH. update: Of refugia and colonization, an innovative use of biogeography for climate studies. Frontiers of Biogeography 2012. [DOI: 10.21425/f5fbg12258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Dobrowski SZ, Thorne JH, Greenberg JA, Safford HD, Mynsberge AR, Crimmins SM, Swanson AK. Modeling plant ranges over 75 years of climate change in California, USA: temporal transferability and species traits. ECOL MONOGR 2011. [DOI: 10.1890/10-1325.1] [Citation(s) in RCA: 136] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Viers JH, Fremier AK, Hutchinson RA, Quinn JF, Thorne JH, Vaghti MG. Multiscale Patterns of Riparian Plant Diversity and Implications for Restoration. Restor Ecol 2011. [DOI: 10.1111/j.1526-100x.2011.00787.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Thorne JH, Girvetz EH, McCoy MC. Evaluating aggregate terrestrial impacts of road construction projects for advanced regional mitigation. Environ Manage 2009; 43:936-948. [PMID: 19219490 DOI: 10.1007/s00267-008-9246-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Revised: 11/10/2008] [Accepted: 12/05/2008] [Indexed: 05/27/2023]
Abstract
This study presents a GIS-based database framework used to assess aggregate terrestrial habitat impacts from multiple highway construction projects in California, USA. Transportation planners need such impact assessment tools to effectively address additive biological mitigation obligations. Such assessments can reduce costly delays due to protracted environmental review. This project incorporated the best available statewide natural resource data into early project planning and preliminary environmental assessments for single and multiple highway construction projects, and provides an assessment of the 10-year state-wide mitigation obligations for the California Department of Transportation. Incorporation of these assessments will facilitate early and more strategic identification of mitigation opportunities, for single-project and regional mitigation efforts. The data architecture format uses eight spatial scales: six nested watersheds, counties, and transportation planning districts, which were intersected. This resulted in 8058 map planning units statewide, which were used to summarize all subsequent analyses. Range maps and georeferenced locations of federally and state-listed plants and animals and a 55-class landcover map were spatially intersected with the planning units and the buffered spatial footprint of 967 funded projects. Projected impacts were summarized and output to the database. Queries written in the database can sum expected impacts and provide summaries by individual construction project, or by watershed, county, transportation district or highway. The data architecture allows easy incorporation of new information and results in a tool usable without GIS by a wide variety of agency biologists and planners. The data architecture format would be useful for other types of regional planning.
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Affiliation(s)
- James H Thorne
- Information Center for the Environment, University of California, 2132 Wickson Hall, 1 Shields Ave., Davis, CA 95616, USA.
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Seo C, Thorne JH, Hannah L, Thuiller W. Scale effects in species distribution models: implications for conservation planning under climate change. Biol Lett 2009; 5:39-43. [PMID: 18986960 PMCID: PMC2657743 DOI: 10.1098/rsbl.2008.0476] [Citation(s) in RCA: 174] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Accepted: 10/16/2008] [Indexed: 11/12/2022] Open
Abstract
Predictions of future species' ranges under climate change are needed for conservation planning, for which species distribution models (SDMs) are widely used. However, global climate model-based (GCM) output grids can bias the area identified as suitable when these are used as SDM predictor variables, because GCM outputs, typically at least 50x50 km, are biologically coarse. We tested the assumption that species ranges can be equally well portrayed in SDMs operating on base data of different grid sizes by comparing SDM performance statistics and area selected by four SDMs run at seven grid sizes, for nine species of contrasting range size. Area selected was disproportionately larger for SDMs run on larger grid sizes, indicating a cut-off point above which model results were less reliable. Up to 2.89 times more species range area was selected by SDMs operating on grids above 50x50 km, compared to SDMs operating at 1 km2. Spatial congruence between areas selected as range also diverged as grid size increased, particularly for species with ranges between 20000 and 90000 km2. These results indicate the need for caution when using such data to plan future protected areas, because an overly large predicted range could lead to inappropriate reserve location selection.
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Affiliation(s)
- Changwan Seo
- University of Seoul, 90 Jeonnong-dong, Dongdaemun-gu, Seoul 130-743, Korea.
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Abstract
Watts et al. (Reports, 6 May 2007, p. 736) introduced a metric of landscape pattern called roadless volume (RV). However, as with most previous metrics, RV does not explicitly address ecological processes. We demonstrate that RV can produce results inconsistent with the notion of landscape connectivity and contend that more ecologically relevant metrics are available.
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Affiliation(s)
- Evan H Girvetz
- Road Ecology Center, University of California, One Shields Avenue, Davis, CA 95616, USA.
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Abstract
Species phenology is increasingly being used to explore the effects of climate change and other environmental stressors. Long-term monitoring data sets are essential for understanding both patterns manifest by individual species and more complex patterns evident at the community level. This study used records of 78 butterfly species observed on 626 days across 27 years at a site in northern California, USA, to build quadratic logistic regression models of the observation probability of each species for each day of the year. Daily species probabilities were summed to develop a potential aggregate species richness (PASR) model, indicating expected daily species richness. Daily positive and negative contributions to PASR were calculated, which can be used to target optimum sampling time frames. Residuals to PASR indicate a rate of decline of 0.12 species per year over the course of the study. When PASR was calculated for wet and dry years, wet years were found to delay group phenology by up to 17 days and reduce the maximum annual expected species from 32.36 to 30. Three tests to determine how well the PASR model reflected the butterfly fauna dynamics were all positive: We correlated probabilities developed with species presence/absence data to observed abundance by species, tested species' predicted phenological patterns against known biological characteristics, and compared the PASR curve to a spline-fitted curve calculated from the original species richness observations. Modeling individual species' flight windows was possible from presence/absence data, an approach that could be used on other similar records for butterfly communities with seasonal phenologies, and for common species with far fewer dates than used here. It also provided a method to assess sample frequency guidelines for other butterfly monitoring programs.
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Affiliation(s)
- James H Thorne
- Department of Environmental Science and Policy, University of California, Davis 95616, USA.
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Abstract
In vitro assimilate uptake and metabolism were evaluated in embryos of known age isolated from seeds at mid-podfilling through physiological maturity. The capacity of isolated Wye soybean embryos to take up exogenous [(14)C]sucrose dropped nearly 4-fold in less than 1 week at incipient cotyledon yellowing. This drop in rate of sucrose uptake coincided with cessation of seed growth as well as rapid decline in leaf photosynthetic rate that preceded leaf yellowing. Conversely, the rate of [(3)H]glutamine uptake by cotyledons increased as they yellowed. Yellow cotyledons also rapidly converted exogenous [(3)H]glutamine to ethanolinsoluble components, but converted little exogenous [(14)C]sucrose to ethanol-insoluble components, primarily because of greatly reduced sucrose uptake. Sustained import and metabolism of amino acids remobilized from senescing leaves may prolong seed growth beyond loss of photosynthetic competency and sucrose availability.
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Affiliation(s)
- C D Vernooy
- Central Research and Development Department, Experimental Station, E. I. Du Pont de Nemours & Company, Wilmington, Delaware 19898
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Gifford RM, Thorne JH. Phloem unloading in soybean seed coats: dynamics and stability of efflux into attached ;empty ovules'. Plant Physiol 1986; 80:464-9. [PMID: 16664644 PMCID: PMC1075136 DOI: 10.1104/pp.80.2.464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The time-course of sucrose efflux from attached seedcoats (having their embryos surgically removed) into aqueous traps placed in the ;empty ovules' had three phases. The first phase lasted 10 minutes and probably was a period of apoplastic flushing. The second lasted 2 to 3 hours and is thought to be a phase of equilibration of seed coat symplast with the frequently refreshed liquid. The third phase of relatively steady efflux was postulated to reflect the continued import of sucrose from the plant, and hence to reflect the rate of sieve tube unloading. The average steady state efflux was equal under most conditions to the estimated rate of sucrose import. Efflux and import were unaffected by 150 millimolar osmoticum (mannitol or polyethylene glycol [molecular weight about 400]), by 0.5 millimolar CaCl(2), or by pretreatments up to 20 minutes with p-chloromercuribenzenesulfonic acid (PCMBS); they were enhanced by 40 micromolar abscisic acid, 40 micromolar indoleacetic acid, 20 micromolar fusicoccin, and 1 millimolar dithiothreitol (DTT) and were inhibited by 100 micromolar KCN, by 0.03% H(2)O(2), by 20 micromolar and 5 micromolar trifluoromethoxy (carbonyl cyamide) phenylhydrazone, by repeated 5 minutes per hour treatments with 5 millimolar PCMBS, and by 5 millimolar DTT. The ;steady state' sucrose efflux was able to account for about half the rate of dry weight growth of the embryo, but stabilization of the system with <1 millimolar DTT taken together with other considerations is likely to give good correspondence between experimental unloading rates and in vivo growth rates.
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Affiliation(s)
- R M Gifford
- CSIRO, Division of Plant Industry, GPO Box 1600, Canberra, A.C.T. 2601, Australia
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Gifford RM, Thorne JH. Sucrose Concentration at the Apoplastic Interface between Seed Coat and Cotyledons of Developing Soybean Seeds. Plant Physiol 1985; 77:863-8. [PMID: 16664151 PMCID: PMC1064620 DOI: 10.1104/pp.77.4.863] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The apoplastic sucrose concentration at the interface between cotyledons and surrounding seed coats of developing soybeans (Glycine max L. Merr. cv Wye) was found by three indirect methods to be in the range of 150 to 200 millimolar. This is an order of magnitude higher than has been reported elsewhere for soybean. It was also higher than the overall sucrose concentrations in the cotyledons and seed coats, each of which was approximately 90 millimolar. By defoliating plants 24 hours before measurement, both the overall sucrose concentration in the cotyledons and the interfacial apoplastic sucrose concentration were reduced by three-fourths. However, there was no day/night difference in overall tissue sucrose concentration of cotyledons or seed coats from intact plants suggesting the existence of a homeostatic mechanism compensating for the diurnal photosynthetic cycle. About 7 hours were required for a tritiated polyethylene glycol-900 solution to fully permeate developing cotyledons (from approximately 220 milligram fresh weight embryos), implying high diffusion resistance through the tissue.These results indicate that a high interfacial sucrose concentration may exist in vivo. They suggest that the saturable carrier-mediated component of sucrose uptake may be of little physiological significance in the outermost cell layers of the cotyledons.
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Affiliation(s)
- R M Gifford
- Central Research and Development Department, Experimental Station, E. I. du Pont de Nemours, and Company, Wilmington, Delaware 19801
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Abstract
The photosynthetic basis for increasing the yield of major field crops is examined in terms of improving the interception of seasonal solar radiation by crop foliage, the efficiency of conversion of intercepted light to photosynthetic assimilates, and the partitioning of photoassimilates to organs of economic interest. It is concluded that, in practice, genetic and chemical manipulation of light interception over the season and of partitioning offer the most potential for achieving further increases in yield. During the history of improvement of genetic yield potential of crops, increase in the partitioning of photoassimilates to harvested organs has been of primary importance.
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Rainbird RM, Thorne JH, Hardy RW. Role of amides, amino acids, and ureides in the nutrition of developing soybean seeds. Plant Physiol 1984; 74:329-34. [PMID: 16663418 PMCID: PMC1066678 DOI: 10.1104/pp.74.2.329] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The various nitrogenous solutes important to embryo development in symbiotic soybean plants were determined during the midpodfilling stage. Glutamine was the principal form of nitrogen, contributing 55% of the embryo nitrogen requirement. Asparagine was the second most important, contributing 20%. The ureides allantoin and allantoic acid directly contributed only insignificantly to the total nitrogen requirement of the embryo. These conclusions were based upon analyses of tissue extracts, translocation studies of radiolabeled solutes, analysis of in vivo seed coat exudate collected from the freespace of attached, surgically altered seeds, and the in vitro culture of isolated immature soybean embryos.
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Affiliation(s)
- R M Rainbird
- E. I. du Pont de Nemours & Company, Central Research and Development Department, Experimental Station, Wilmington, Delaware 19801
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Thorne JH, Rainbird RM. An in vivo technique for the study of Phloem unloading in seed coats of developing soybean seeds. Plant Physiol 1983; 72:268-71. [PMID: 16662976 PMCID: PMC1066209 DOI: 10.1104/pp.72.1.268] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
A technique has been developed which permits mechanistic studies of phloem unloading in developing seeds of soybean (Glycine max cv Clark) and other legumes. An opening is cut in the pod wall and the embryo surgically removed from the seedcoat without diminishing the capacity of that tissue for assimilate import, phloem unloading, or efflux. The sites of phloem unloading were accessible via the seedcoat apoplast and were challenged with inhibitors, solutes, buffers, etc., to characterize the unloading process.Unloading is stimulated by divalent metal chelators and diethylstilbestrol, and inhibited by metabolic uncouplers and sulfhydryl group modifiers. Solutes released from the seed coat had a carbon/nitrogen ratio of 31 milligrams carbon per milligram nitrogen; sucrose represented 90% of the carbon present and various nitrogenous solutes contributed the remaining 10%. Unloading could be maintained for up 8 hours at rates of 0.5 to 1.0 micromoles per hour, providing a valid, convenient in vivo technique for studies of phloem unloading and seed growth mechanisms.
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Affiliation(s)
- J H Thorne
- Central Research and Development Department, Experimental Station, E. I. du Pont de Nemours and Company, Wilmington, Delaware 19898
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Abstract
Immature soybean embryos were isolated from soybean [Glycine max (L.) Merr.] seeds at various stages of development to study their accumulation of [(14)C]sucrose in vitro. Isolated embryos accumulate sucrose at a constant rate over several hours, the label entering large, endogenous pools of sucrose from which starch, protein, and lipid storage products are formed. Accumulation is without extracellular sucrose hydrolysis and occurs predominantly by active transport at physiological sucrose concentrations. A nonsaturable diffusion component, apparently superimposed upon the active saturable component, dominates overall uptake at exogenous concentrations greater than approximately 50 millimolar sucrose. Active transport is sensitive to uncoupling agents and the sulfhydryl-modifying reagent p-chloromecuribenzene sulfonate, is dependent on more than one energy source, and exhibits well-defined requirements for incubation temperature, pH, and oxygen availability. Under optimal incubation conditions of 35 degrees C, saturating illumination (pH 6), and 21% oxygen, the apparent K(m) for sucrose is approximately 8 millimolar and V(max) is approximately 0.6 micromoles per hour per 100 milligrams fresh weight. Embryos readily accumulate sucrose from dilute exogenous solutions and, when preloaded with large amounts of sucrose, maintain the internal sucrose pool against steep outward gradients. These and other observations indicate that, although perhaps fully saturated in vivo, active sucrose transport is a significant component of photosynthate uptake in developing soybean embryos, enhancing uptake at physiological sucrose concentrations 2- to 5-fold over diffusion alone.
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Affiliation(s)
- J H Thorne
- Central Research and Development Department, Experimental Station, E. I. du Pont de Nemours and Company, Wilmington, Delaware 19898
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