1
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Graham OJ, Harvell D, Christiaen B, Gaeckle J, Aoki LR, Ratliff B, Vinton A, Rappazzo BH, Whitman T. Taking the Pulse of Resilience in Conserving Seagrass Meadows. Integr Comp Biol 2024; 64:816-826. [PMID: 39066484 DOI: 10.1093/icb/icae120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 07/09/2024] [Accepted: 07/13/2024] [Indexed: 07/28/2024] Open
Abstract
Foundational habitats such as seagrasses and coral reefs are at severe risk globally from climate warming. Infectious disease associated with warming events is both a cause of decline and an indicator of stress in both habitats. Since new approaches are needed to detect refugia and design climate-smart networks of marine protected areas, we test the hypothesis that the health of eelgrass (Zostera marina) in temperate ecosystems can serve as a proxy indicative of higher resilience and help pinpoint refugia. Eelgrass meadows worldwide are at risk from environmental stressors, including climate warming and disease. Disease outbreaks of Labyrinthula zosterae are associated with recent, widespread declines in eelgrass meadows throughout the San Juan Islands, Washington, USA. Machine language learning, drone surveys, and molecular diagnostics reveal climate impacts on seagrass wasting disease prevalence (proportion of infected individuals) and severity (proportion of infected leaf area) from San Diego, California, to Alaska. Given that warmer temperatures favor many pathogens such as L. zosterae, we hypothesize that absent or low disease severity in meadows could indicate eelgrass resilience to climate and pathogenic stressors. Regional surveys showed the San Juan Islands as a hotspot for both high disease prevalence and severity, and surveys throughout the Northeast Pacific indicated higher prevalence and severity in intertidal, rather than subtidal, meadows. Further, among sites with eelgrass declines, losses were more pronounced at sites with shallower eelgrass meadows. We suggest that deeper meadows with the lowest disease severity will be refuges from future warming and pathogenic stressors in the Northeast Pacific. Disease monitoring may be a useful conservation approach for marine foundation species, as low or absent disease severity can pinpoint resilient refugia that should be prioritized for future conservation efforts. Even in declining or at-risk habitats, disease surveys can help identify meadows that may contain especially resilient individuals for future restoration efforts. Our approach of using disease as a pulse point for eelgrass resilience to multiple stressors could be applied to other habitats such as coral reefs to inform conservation and management decisions.
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Affiliation(s)
- Olivia J Graham
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Drew Harvell
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Bart Christiaen
- Washington State Department of Natural Resources, Olympia, WA 47027, USA
| | - Jeff Gaeckle
- Washington State Department of Natural Resources, Olympia, WA 47027, USA
| | - Lillian R Aoki
- Department of Environmental Studies, University of Oregon, Eugene, OR 97403-1245, USA
| | - Baylen Ratliff
- College of the Environment, University of Washington, Seattle, WA 98105, USA
| | - Audrey Vinton
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Brendan H Rappazzo
- Department of Computer Science, Cornell University, Ithaca, NY 14853, USA
| | - Tina Whitman
- Department of Computer Science, Cornell University, Ithaca, NY 14853, USA
- Friends of the San Juans, Friday Harbor, WA 98250, USA
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2
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Lee BR, Ibáñez I. Improved phenological escape can help temperate tree seedlings maintain demographic performance under climate change conditions. GLOBAL CHANGE BIOLOGY 2021; 27:3883-3897. [PMID: 33977598 DOI: 10.1111/gcb.15678] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 06/12/2023]
Abstract
Phenological escape, a strategy that deciduous understory plants use to access direct light in spring by leafing out before the canopy closes, plays an important role in shaping the recruitment of temperate tree seedlings. Previous studies have investigated how climate change will alter these dynamics for herbaceous species, but there is a knowledge gap related to how woody species such as tree seedlings will be affected. Here, we modeled temperate tree seedling leaf-out phenology and canopy close phenology in response to environmental drivers and used climate change projections to forecast changes to the duration of spring phenological escape. We then used these predictions to estimate changes in annual carbon assimilation while accounting for reduced carbon assimilation rates associated with hotter and drier summers. Lastly, we applied these estimates to previously published models of seedling growth and survival to investigate the net effect on seedling demographic performance. Our models predict that temperate tree seedlings will experience improved phenological escape and, therefore, increased spring carbon assimilation under climate change conditions. However, increased summer respiration costs will offset the gains in spring under extreme climate change leading to a net loss in annual carbon assimilation and demographic performance. Furthermore, we found that annual carbon assimilation predictions depend strongly on the species of nearby canopy tree that seedlings were planted near, with all seedlings projected to assimilate less carbon (and therefore experience worse demographic performance) when planted near Quercus rubra canopy trees as opposed to Acer saccharum canopy trees. We conclude that changes to spring phenological escape will have important effects on how tree seedling recruitment is affected by climate change, with the magnitude of these effects dependent upon climate change severity and biological interactions with neighboring adults. Thus, future studies of temperate forest recruitment should account for phenological escape dynamics in their models.
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Affiliation(s)
- Benjamin R Lee
- School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, USA
| | - Inés Ibáñez
- School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, USA
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3
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Forsmoo J, Anderson K, Macleod CJA, Wilkinson ME, DeBell L, Brazier RE. Structure from motion photogrammetry in ecology: Does the choice of software matter? Ecol Evol 2019; 9:12964-12979. [PMID: 31871623 PMCID: PMC6912889 DOI: 10.1002/ece3.5443] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 05/13/2019] [Accepted: 05/15/2019] [Indexed: 11/06/2022] Open
Abstract
Image-based modeling, and more precisely, Structure from Motion (SfM) and Multi-View Stereo (MVS), is emerging as a flexible, self-service, remote sensing tool for generating fine-grained digital surface models (DSMs) in the Earth sciences and ecology. However, drone-based SfM + MVS applications have developed at a rapid pace over the past decade and there are now many software options available for data processing. Consequently, understanding of reproducibility issues caused by variations in software choice and their influence on data quality is relatively poorly understood. This understanding is crucial for the development of SfM + MVS if it is to fulfill a role as a new quantitative remote sensing tool to inform management frameworks and species conservation schemes. To address this knowledge gap, a lightweight multirotor drone carrying a Ricoh GR II consumer-grade camera was used to capture replicate, centimeter-resolution image datasets of a temperate, intensively managed grassland ecosystem. These data allowed the exploration of method reproducibility and the impact of SfM + MVS software choice on derived vegetation canopy height measurement accuracy. The quality of DSM height measurements derived from four different, yet widely used SfM-MVS software-Photoscan, Pix4D, 3DFlow Zephyr, and MICMAC, was compared with in situ data captured on the same day as image capture. We used both traditional agronomic techniques for measuring sward height, and a high accuracy and precision differential GPS survey to generate independent measurements of the underlying ground surface elevation. Using the same replicate image dataset (n = 3) as input, we demonstrate that there are 1.7, 2.0, and 2.5 cm differences in RMSE (excluding one outlier) between the outputs from different SfM + MVS software using High, Medium, and Low quality settings, respectively. Furthermore, we show that there can be a significant difference, although of small overall magnitude between replicate image datasets (n = 3) processed using the same SfM + MVS software, following the same workflow, with a variance in RMSE of up to 1.3, 1.5, and 2.7 cm (excluding one outlier) for "High," "Medium," and "Low" quality settings, respectively. We conclude that SfM + MVS software choice does matter, although the differences between products processed using "High" and "Medium" quality settings are of small overall magnitude.
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Affiliation(s)
- Joel Forsmoo
- Environment and Sustainability InstituteUniversity of ExeterPenrynUK
- James Hutton InstituteAberdeenUK
| | - Karen Anderson
- Environment and Sustainability InstituteUniversity of ExeterPenrynUK
| | | | | | - Leon DeBell
- Environment and Sustainability InstituteUniversity of ExeterPenrynUK
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4
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Rodríguez‐Buriticá S, Winkler DE, Webb RH, Venable DL. Local temporal trajectories explain population‐level responses to climate change in saguaro (
Carnegiea gigantea
). Ecosphere 2019. [DOI: 10.1002/ecs2.2844] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Susana Rodríguez‐Buriticá
- Department of Ecology and Evolutionary Biology University of Arizona Tucson Arizona 85721 USA
- Instituto de Investigación de Recursos Biológicos Alexander von Humboldt Bogotá D.C. Colombia
| | - Daniel E. Winkler
- U.S. Geological Survey Southwest Biological Science Center Moab Utah 84532 USA
| | - Robert H. Webb
- School of Natural Resources University of Arizona Tucson Arizona 85721 USA
| | - D. Lawrence Venable
- Department of Ecology and Evolutionary Biology University of Arizona Tucson Arizona 85721 USA
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5
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Chen L, Wang Y, Mi X, Liu X, Ren H, Chen J, Ma K, Kraft NJB. Neighborhood effects explain increasing asynchronous seedling survival in a subtropical forest. Ecology 2019; 100:e02821. [PMID: 31310665 DOI: 10.1002/ecy.2821] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 05/07/2019] [Accepted: 06/13/2019] [Indexed: 01/30/2023]
Abstract
Biotic interactions play a critical role in mediating community responses to temporal environmental variation, but the importance of these effects relative to the direct effects of environmental change remains poorly understood, particularly in diverse forest communities. Here we combine a neighborhood modeling approach with insights from coexistence theory to assess the effects of temporal variation in species interactions and environmental conditions (e.g., precipitation, temperature, and understory light availability) on seedling survival over nine census years in a subtropical forest. We find significant temporal shifts in the magnitude of neighborhood effects on both community-wide and species-level seedling survival (statistically significant random effects of neighborhood × year and neighborhood × species × year interactions). These results are consistent with the idea that environmental change will play a fundamental role on forest regeneration dynamics by altering biotic interactions at the neighborhood scale. Moreover, differences among species in response to neighbors over time contribute to a pattern of temporal decoupling of seedling survival between species, which can help to promote diversity in certain contexts. In separate analyses of multiple regression on distance matrices (MRM), altered interactions with neighbors are much stronger predictors of asynchronous seedling survival among species than the pure effects of climate and plant functional traits, explaining twice as much variation (43.9% vs. 22.2%). In sum, these results reveal that divergent species responses to interannual environmental variability detected are driven primarily by indirect effects mediated by changing biotic environments. This highlights the importance of including indirect effects from local biotic (neighborhood) interactions in forecasts of forest community responses to global change.
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Affiliation(s)
- Lei Chen
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.,Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095, USA
| | - Yunquan Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China.,Key Laboratory for Biodiversity Science and Ecological Engineering of Ministry of Education, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Xiangcheng Mi
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Xiaojuan Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Haibao Ren
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Jianhua Chen
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004, China
| | - Keping Ma
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Nathan J B Kraft
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, California, 90095, USA
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6
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Using naturally occurring climate resilient corals to construct bleaching-resistant nurseries. Proc Natl Acad Sci U S A 2019; 116:10586-10591. [PMID: 31061118 PMCID: PMC6535031 DOI: 10.1073/pnas.1721415116] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Coral reefs are threatened by global bleaching, spurring a need to improve upon reef restoration practices. Yet the strong capacity for corals and their symbionts to acclimatize to their local environment has brought into question whether or not corals that are temperature tolerant in one setting will lose that tolerance elsewhere. We show that variation in bleaching resilience among intraspecific colonies is maintained in novel environments for four species, and can be used to construct bleaching-resistant coral nurseries for restoration. By focusing on the host genotype and symbiont genus and its importance in stock selection, we demonstrate a path forward for reef restoration in the face of climate change. Ecological restoration of forests, meadows, reefs, or other foundational ecosystems during climate change depends on the discovery and use of individuals able to withstand future conditions. For coral reefs, climate-tolerant corals might not remain tolerant in different environments because of widespread environmental adjustment of coral physiology and symbionts. Here, we test if parent corals retain their heat tolerance in nursery settings, if simple proxies predict successful colonies, and if heat-tolerant corals suffer lower growth or survival in normal settings. Before the 2015 natural bleaching event in American Samoa, we set out 800 coral fragments from 80 colonies of four species selected by prior tests to have a range of intraspecific natural heat tolerance. After the event, nursery stock from heat-tolerant parents showed two to three times less bleaching across species than nursery stock from less tolerant parents. They also retained higher individual genetic diversity through the bleaching event than did less heat-tolerant corals. The three best proxies for thermal tolerance were response to experimental heat stress, location on the reef, and thermal microclimate. Molecular biomarkers were also predictive but were highly species specific. Colony genotype and symbiont genus played a similarly strong role in predicting bleaching. Combined, our results show that selecting for host and symbiont resilience produced a multispecies coral nursery that withstood multiple bleaching events, that proxies for thermal tolerance in restoration can work across species and be inexpensive, and that different coral clones within species reacted very differently to bleaching.
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7
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Warren II RJ, Bayba S, Krupp KT. Interacting effects of urbanization and coastal gradients on ant thermal responses. JOURNAL OF URBAN ECOLOGY 2018. [DOI: 10.1093/jue/juy026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- R J Warren II
- Department of Biology, SUNY Buffalo State, 1300 Elmwood Avenue, Buffalo, NY, USA
| | - S Bayba
- Department of Biology, SUNY Buffalo State, 1300 Elmwood Avenue, Buffalo, NY, USA
| | - K T Krupp
- Department of Biology, SUNY Buffalo State, 1300 Elmwood Avenue, Buffalo, NY, USA
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8
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Ibáñez I, Katz DSW, Lee BR. The contrasting effects of short-term climate change on the early recruitment of tree species. Oecologia 2017; 184:701-713. [PMID: 28573380 DOI: 10.1007/s00442-017-3889-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2017] [Accepted: 05/23/2017] [Indexed: 11/26/2022]
Abstract
Predictions of plant responses to climate change are frequently based on organisms' presence in warmer locations, which are then assumed to reflect future performance in cooler areas. However, as plant life stages may be affected differently by environmental changes, there is little empirical evidence that this approach provides reliable estimates of short-term responses to global warming. Under this premise, we analyzed 8 years of early recruitment data, seed production and seedling establishment and survival, collected for two tree species at two latitudes. We quantified recruitment to a wide range of environmental conditions, temperature, soil moisture and light, and simulated recruitment under two forecasted climatic scenarios. Annual demographic transitions were affected by the particular conditions taking place during their onset, but the effects of similar environmental shifts differed among the recruitment stages; seed production was higher in warmer years, while seedling establishment and survival peaked during cold years. Within a species, these effects also varied between latitudes; increasing temperatures at the southern location will have stronger detrimental effects on recruitment than similar changes at the northern locations. Our simulations illustrate that warmer temperatures may increase seed production, but they will have a negative effect on establishment and survival. When the three early recruitment processes were simultaneously considered, simulations showed little change in recruitment dynamics at the northern site and a slight decrease at the southern site. It is only when we considered these three stages that we were able to assess likely changes in early recruitment under the predicted conditions.
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Affiliation(s)
- Inés Ibáñez
- School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Daniel S W Katz
- School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Benjamin R Lee
- School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI, 48109, USA
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9
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Stuble KL, Zefferman EP, Wolf KM, Vaughn KJ, Young TP. Outside the envelope: rare events disrupt the relationshipbetween climate factors and species interactions. Ecology 2017; 98:1623-1630. [DOI: 10.1002/ecy.1820] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 03/01/2017] [Accepted: 03/09/2017] [Indexed: 11/09/2022]
Affiliation(s)
- Katharine L. Stuble
- Department of Plant Sciences University of California Davis California 95616 USA
- The Holden Arboretum Kirtland Ohio 44094 USA
| | - Emily P. Zefferman
- Department of Plant Sciences University of California Davis California 95616 USA
| | - Kristina M. Wolf
- Department of Plant Sciences University of California Davis California 95616 USA
| | - Kurt J. Vaughn
- Department of Plant Sciences University of California Davis California 95616 USA
| | - Truman P. Young
- Department of Plant Sciences University of California Davis California 95616 USA
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10
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Stevens JT, Latimer AM. Snowpack, fire, and forest disturbance: interactions affect montane invasions by non-native shrubs. GLOBAL CHANGE BIOLOGY 2015; 21:2379-2393. [PMID: 25482316 DOI: 10.1111/gcb.12824] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 11/15/2014] [Indexed: 06/04/2023]
Abstract
Montane regions worldwide have experienced relatively low plant invasion rates, a trend attributed to increased climatic severity, low rates of disturbance, and reduced propagule pressure relative to lowlands. Manipulative experiments at elevations above the invasive range of non-native species can clarify the relative contributions of these mechanisms to montane invasion resistance, yet such experiments are rare. Furthermore, global climate change and land use changes are expected to cause decreases in snowpack and increases in disturbance by fire and forest thinning in montane forests. We examined the importance of these factors in limiting montane invasions using a field transplant experiment above the invasive range of two non-native lowland shrubs, Scotch broom (Cytisus scoparius) and Spanish broom (Spartium junceum), in the rain-snow transition zone of the Sierra Nevada of California. We tested the effects of canopy closure, prescribed fire, and winter snow depth on demographic transitions of each species. Establishment of both species was most likely at intermediate levels of canopy disturbance, but at this intermediate canopy level, snow depth had negative effects on winter survival of seedlings. We used matrix population models to show that an 86% reduction in winter snowfall would cause a 2.8-fold increase in population growth rates in Scotch broom and a 3.5-fold increase in Spanish broom. Fall prescribed fire increased germination rates, but decreased overall population growth rates by reducing plant survival. However, at longer fire return intervals, population recovery between fires is likely to keep growth rates high, especially under low snowpack conditions. Many treatment combinations had positive growth rates despite being above the current invasive range, indicating that propagule pressure, disturbance, and climate can all strongly affect plant invasions in montane regions. We conclude that projected reductions in winter snowpack and increases in forest disturbance are likely to increase the risk of invasion from lower elevations.
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Affiliation(s)
- Jens T Stevens
- Graduate Group in Ecology, University of California, Davis, CA, 95616, USA; Department of Plant Sciences, University of California, Davis, CA, 95616, USA
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11
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Ehrlén J, Morris WF. Predicting changes in the distribution and abundance of species under environmental change. Ecol Lett 2015; 18:303-14. [PMID: 25611188 PMCID: PMC4674973 DOI: 10.1111/ele.12410] [Citation(s) in RCA: 209] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/03/2014] [Accepted: 12/17/2014] [Indexed: 01/22/2023]
Abstract
Environmental changes are expected to alter both the distribution and the abundance of organisms. A disproportionate amount of past work has focused on distribution only, either documenting historical range shifts or predicting future occurrence patterns. However, simultaneous predictions of abundance and distribution across landscapes would be far more useful. To critically assess which approaches represent advances towards the goal of joint predictions of abundance and distribution, we review recent work on changing distributions and on effects of environmental drivers on single populations. Several methods have been used to predict changing distributions. Some of these can be easily modified to also predict abundance, but others cannot. In parallel, demographers have developed a much better understanding of how changing abiotic and biotic drivers will influence growth rate and abundance in single populations. However, this demographic work has rarely taken a landscape perspective and has largely ignored the effects of intraspecific density. We advocate a synthetic approach in which population models accounting for both density dependence and effects of environmental drivers are used to make integrated predictions of equilibrium abundance and distribution across entire landscapes. Such predictions would constitute an important step forward in assessing the ecological consequences of environmental changes.
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Affiliation(s)
- Johan Ehrlén
- Department of Ecology, Environment and Plant Sciences, Stockholm UniversityStockholm, Sweden
| | - William F Morris
- Department of Ecology and Genetics, Uppsala UniversityUppsala, Sweden
- Department of Biology, Duke UniversityDurham, NC, USA
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12
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Pelini SL, Diamond SE, Nichols LM, Stuble KL, Ellison AM, Sanders NJ, Dunn RR, Gotelli NJ. Geographic differences in effects of experimental warming on ant species diversity and community composition. Ecosphere 2014. [DOI: 10.1890/es14-00143.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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13
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Jin Y, Hilker FM, Steffler PM, Lewis MA. Seasonal invasion dynamics in a spatially heterogeneous river with fluctuating flows. Bull Math Biol 2014; 76:1522-65. [PMID: 24889133 DOI: 10.1007/s11538-014-9957-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 03/27/2014] [Indexed: 11/26/2022]
Abstract
A key problem in environmental flow assessment is the explicit linking of the flow regime with ecological dynamics. We present a hybrid modeling approach to couple hydrodynamic and biological processes, focusing on the combined impact of spatial heterogeneity and temporal variability on population dynamics. Studying periodically alternating pool-riffle rivers that are subjected to seasonally varying flows, we obtain an invasion ratchet mechanism. We analyze the ratchet process for a caricature model and a hybrid physical-biological model. The water depth and current are derived from a hydrodynamic equation for variable stream bed water flows and these quantities feed into a reaction-diffusion-advection model that governs population dynamics of a river species. We establish the existence of spreading speeds and the invasion ratchet phenomenon, using a mixture of mathematical approximations and numerical computations. Finally, we illustrate the invasion ratchet phenomenon in a spatially two-dimensional hydraulic simulation model of a meandering river structure. Our hybrid modeling approach strengthens the ecological component of stream hydraulics and allows us to gain a mechanistic understanding as to how flow patterns affect population survival.
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Affiliation(s)
- Yu Jin
- Centre for Mathematical Biology, Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton, AB , T6G 2G1, Canada,
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14
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Roth T, Plattner M, Amrhein V. Plants, birds and butterflies: short-term responses of species communities to climate warming vary by taxon and with altitude. PLoS One 2014; 9:e82490. [PMID: 24416144 PMCID: PMC3885385 DOI: 10.1371/journal.pone.0082490] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 10/25/2013] [Indexed: 11/19/2022] Open
Abstract
As a consequence of climate warming, species usually shift their distribution towards higher latitudes or altitudes. Yet, it is unclear how different taxonomic groups may respond to climate warming over larger altitudinal ranges. Here, we used data from the national biodiversity monitoring program of Switzerland, collected over an altitudinal range of 2500 m. Within the short period of eight years (2003–2010), we found significant shifts in communities of vascular plants, butterflies and birds. At low altitudes, communities of all species groups changed towards warm-dwelling species, corresponding to an average uphill shift of 8 m, 38 m and 42 m in plant, butterfly and bird communities, respectively. However, rates of community changes decreased with altitude in plants and butterflies, while bird communities changed towards warm-dwelling species at all altitudes. We found no decrease in community variation with respect to temperature niches of species, suggesting that climate warming has not led to more homogenous communities. The different community changes depending on altitude could not be explained by different changes of air temperatures, since during the 16 years between 1995 and 2010, summer temperatures in Switzerland rose by about 0.07°C per year at all altitudes. We discuss that land-use changes or increased disturbances may have prevented alpine plant and butterfly communities from changing towards warm-dwelling species. However, the findings are also consistent with the hypothesis that unlike birds, many alpine plant species in a warming climate could find suitable habitats within just a few metres, due to the highly varied surface of alpine landscapes. Our results may thus support the idea that for plants and butterflies and on a short temporal scale, alpine landscapes are safer places than lowlands in a warming world.
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Affiliation(s)
- Tobias Roth
- Hintermann & Weber AG, Reinach, Switzerland
- University of Basel, Zoological Institute, Basel, Switzerland
- Research Station Petite Camargue Alsacienne, Saint-Louis, France
- * E-mail:
| | | | - Valentin Amrhein
- University of Basel, Zoological Institute, Basel, Switzerland
- Research Station Petite Camargue Alsacienne, Saint-Louis, France
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15
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Anderson RP. A framework for using niche models to estimate impacts of climate change on species distributions. Ann N Y Acad Sci 2013; 1297:8-28. [DOI: 10.1111/nyas.12264] [Citation(s) in RCA: 162] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Robert P. Anderson
- Department of Biology, City College of New York, Graduate Center and Cooperative Remote Sensing Science and Technology (CREST) Center, City University of New York, and Division of Vertebrate Zoology (Mammalogy); American Museum of Natural History; New York New York
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16
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Godbold JA, Solan M. Long-term effects of warming and ocean acidification are modified by seasonal variation in species responses and environmental conditions. Philos Trans R Soc Lond B Biol Sci 2013; 368:20130186. [PMID: 23980249 DOI: 10.1098/rstb.2013.0186] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Warming of sea surface temperatures and alteration of ocean chemistry associated with anthropogenic increases in atmospheric carbon dioxide will have profound consequences for a broad range of species, but the potential for seasonal variation to modify species and ecosystem responses to these stressors has received little attention. Here, using the longest experiment to date (542 days), we investigate how the interactive effects of warming and ocean acidification affect the growth, behaviour and associated levels of ecosystem functioning (nutrient release) for a functionally important non-calcifying intertidal polychaete (Alitta virens) under seasonally changing conditions. We find that the effects of warming, ocean acidification and their interactions are not detectable in the short term, but manifest over time through changes in growth, bioturbation and bioirrigation behaviour that, in turn, affect nutrient generation. These changes are intimately linked to species responses to seasonal variations in environmental conditions (temperature and photoperiod) that, depending upon timing, can either exacerbate or buffer the long-term directional effects of climatic forcing. Taken together, our observations caution against over emphasizing the conclusions from short-term experiments and highlight the necessity to consider the temporal expression of complex system dynamics established over appropriate timescales when forecasting the likely ecological consequences of climatic forcing.
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Affiliation(s)
- Jasmin A Godbold
- Ocean and Earth Science, National Oceanography Center Southampton, University of Southampton, Waterfront Campus, European Way, Southampton SO14 3ZH, UK.
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Zelikova TJ, Hufbauer RA, Reed SC, Wertin T, Fettig C, Belnap J. Eco-evolutionary responses of Bromus tectorum to climate change: implications for biological invasions. Ecol Evol 2013; 3:1374-87. [PMID: 23762522 PMCID: PMC3678490 DOI: 10.1002/ece3.542] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 02/15/2013] [Accepted: 02/26/2013] [Indexed: 11/23/2022] Open
Abstract
How plant populations, communities, and ecosystems respond to climate change is a critical focus in ecology today. The responses of introduced species may be especially rapid. Current models that incorporate temperature and precipitation suggest that future Bromus tectorum invasion risk is low for the Colorado Plateau. With a field warming experiment at two sites in southeastern Utah, we tested this prediction over 4 years, measuring B. tectorum phenology, biomass, and reproduction. In a complimentary greenhouse study, we assessed whether changes in field B. tectorum biomass and reproductive output influence offspring performance. We found that following a wet winter and early spring, the timing of spring growth initiation, flowering, and summer senescence all advanced in warmed plots at both field sites and the shift in phenology was progressively larger with greater warming. Earlier green-up and development was associated with increases in B. tectorum biomass and reproductive output, likely due early spring growth, when soil moisture was not limiting, and a lengthened growing season. Seeds collected from plants grown in warmed plots had higher biomass and germination rates and lower mortality than seeds from ambient plots. However, in the following two dry years, we observed no differences in phenology between warmed and ambient plots. In addition, warming had a generally negative effect on B. tectorum biomass and reproduction in dry years and this negative effect was significant in the plots that received the highest warming treatment. In contrast to models that predict negative responses of B. tectorum to warmer climate on the Colorado Plateau, the effects of warming were more nuanced, relied on background climate, and differed between the two field sites. Our results highlight the importance of considering the interacting effects of temperature, precipitation, and site-specific characteristics such as soil texture, on plant demography and have direct implications for B. tectorum invasion dynamics on the Colorado Plateau.
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Affiliation(s)
- Tamara J Zelikova
- Southwest Biological Science Center, U.S. Geological Survey Moab, Utah, 84532 ; Botany Department, Berry Biodiversity Conservation Center, University of Wyoming Laramie, Wyoming, 82071
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