Climate Change Ecology最新文献

Following the near-eradication of the American chestnut (Castanea dentata) over the last century by an invasive fungal pathogen, progress has been made in recent decades towards generating blight-resistant varieties for restoration in its former native range in the Eastern US. Maximum Entropy species distribution modeling software was used with known surviving specimen locations and environmental data to determine optimal present-day habitat characteristics. Model projection was used to estimate shifts in ideal habitat under moderate and extreme carbon-emission climate scenarios over several time horizons ranging between present day and 2100. Sites with suitable habitat across all scenarios were identified and suggested as restoration targets, most notably lowland New England and high-elevation Southern and Mid-Atlantic Appalachian regions. The current study builds upon previous work by combining fine-resolution data, regional-scale breadth, future climate models, and a different source of chestnut location data to produce a species distribution model that is concurrently useful to local sample collectors, state-level planners and long-term restoration managers.

Seagrass meadows are among the most valuable habitats in the world as they are used by a wide range of marine organisms and provide important ecosystem services. With increasing human populations and coastal development, seagrasses are under increased stress and coverage is declining worldwide. This is the first experiment to test the effects of two known seagrass stressors, increased temperature and reduced light availability, on the composition of seagrass blade surface microbial communities, which is a relatively understudied community. Analysis of 16S rRNA amplicon (iTag) sequence data revealed that both of these stressors significantly altered microbial community structure, including both taxonomy and abundance, on the blade surfaces of the tropical seagrass Thalassia testudinum. The highest temperature and lowest light treatments showed higher abundances of phyla not commonly reported as indigenous members of seagrass phyllosphere communities, including members of the bacterial phyla Ca. PAUC34f, Ca. Modulibacteria, and Chlamyidae. Despite these compositional difference among treatments, no significant differences in overall microbial diversity or richness were found. These results suggested seagrass phyllosphere microbial communities have the capacity to change significantly and relatively quickly in response to changing environmental conditions due to anthropogenic activity. Further studies are needed to determine if these direct environmental effects on the microbial community or indirect effects that feedback through the seagrass host.

Climate change will affect the timing of natural features of recreational interest, like fall colors, salmon migration, and wildflower blooms; and may therefore alter social-ecological relationships. For example, if fewer recreational visits are aligned with seasonal events of interest, visitor satisfaction could be affected. To explore this possibility at Mount Rainier National Park, we combined data from a community science program (MeadoWatch – MW) with hiking trip reports posted to a hiking organization (Washington Trails Association – WTA). We first explored how peak flowering, WTA trip reports, and visitation varied across years that differed in snow disappearance, a climatic factor that correlates with flowering phenology. We found that wildflower blooms tracked snow disappearance more closely than did trip reports and park visitation, implying a decreasing proportion of future visitors will experience peak wildflower blooms. We next extracted sentiment related to specific trail-experiences (e.g., wildflowers, views) and overall hike satisfaction from WTA trip reports. While wildflowers were a positive component in overall hiker satisfaction, other non-seasonal trail experiences also had positive effects. In all, a shifting wildflower season that is less accessible to visitors could alter perceptions of natural areas like Mount Rainier National Park. Countering negative social-ecological impacts could be achieved by highlighting non-seasonal aspects of the visitor experience, or alternatively, communicating the altered timing of the peak wildflower season while also increasing accessibility during this time. Such actions likely require partnerships between managers of natural areas, interpretive staff, and scientists that study seasonal phenomena of recreational interest.

Our changing climate is affecting predator-prey interactions in different ways. Increasing atmospheric CO₂ is acidifying the ocean and disrupting the chemosensation of several species. Here, we evaluated a risk-induced trait response to a potential predator under an acidified scenario. Using planktonic crab larvae as a prey model, we first analysed their swimming avoidance response to different potential fish predators and conspecific odours. Prey intensified their avoidance response to conspecific and predator odours, but not to all predators, with no maternal effect. Then, larvae were exposed to a responsive predator odour under a predicted acidified scenario. A similar response was observed for both saltwater and predator odour under low pH conditions. Thus, acidification seems to affect the chemosensation of planktonic larvae, leading them to not distinguish between a non-harmful stimulus and a potential predator and potentially bringing a cascade of ecological impairments.

One characteristic of global change is an increase in the frequency and magnitude of algae blooms. Although a large body of work has documented severe ecological impacts, such as mortality due to toxins or hypoxia, less research has described sublethal effects that may still affect population dynamics. Here, we focus on blooming Sargassum macroalgae in the North Atlantic and describe effects on nesting sea turtles. Since 2011, large masses of the algae have been inundating Atlantic nesting habitats. We documented the accumulation of Sargassum at Long Island, Antigua, and quantified effects on a rookery of hawksbill sea turtles (Eretmochelys imbricata). Using monitoring data from 2010 to 2019, we analyzed population- and individual-level patterns in nesting. Our results suggest that sea turtles respond to Sargassum at nesting beaches by shifting space use away from heavily impacted areas. We also tested for an effect on nesting success, but found no change in the years and areas most impacted by Sargassum. The algae may not increase the energetic costs of nesting after a turtle has emerged onto the beach, but we speculate that costs are imposed in algae-filled waters as turtles initially seek to emerge. As the Sargassum “invasion” continues, sea turtles at impacted sites will need to exhibit plasticity when choosing nesting sites, and nest densities may increase in areas with less Sargassum present. Individuals may also be required to expend more energy per nesting season. More broadly, this work demonstrates that algae blooms can have sublethal effects on fauna that affect population dynamics.

Climate change will accelerate the extinction rate of wildlife species in the Anthropocene. Identifying which species exhibit the capacity to be flexible in their activity patterns to avoid heat stress will help direct conservation effort to those species that lack resilience. We propose a framework for using photo capture data sets from camera trapping surveys to make conservation management decisions based on a combination of population trends and activity pattern shifts. After summarizing the basic design of typical camera trap surveys, we conduct a literature review of camera-trap-based activity pattern studies for select large tropical forest mammals. Based on our literature review we identified problems with data form and availability, data capture and image sampling, and sampling area and period, which may impede the application of camera trap technology to investigate behavioral resilience to climate warming. We conclude with eight important research questions that must be answered before our monitoring and management framework could be adopted to guide conservation efforts for large tropical mammals.

Species Distribution Models (SDMs) are a cornerstone of climate change conservation research but temporal extrapolations into future climate scenarios cannot be verified until later this century. One way of assessing the robustness of projections is to compare their consistency between different modelling approaches, placing more confidence on consistent rather than inconsistent predictions, especially if they are consistent with recent population trajectories. We compared predicted climate change impacts on nine bat species throughout their European ranges (using SDMs) and their activity (using GLMMs) within Ireland as a focal study region. Five species (N. leisleri, P. nathusii, P. pipistrellus, P. pygmaeus and P. auritus) were predicted to have stable ranges throughout the 21^st century with projected increases in activity consistent with recently observed population increases. M. daubentonii and R. hipposideros are also likely to have stable European ranges throughout the 21^st century but models predicted a negative impact of climate change on activity in Ireland, contrasting with a stable population trend in M. daubentonii and an increasing trend in R. hipposideros over recent decades. M. nattereri was predicted to maintain its range extent while M. mystacinus was predicted to undergo range contraction by the end of the 21st century under a high greenhouse gas emissions scenario. We propose there is utility in comparing predicted trajectories from climate change impact models using different parameters (e.g. range versus activity). Our predictions should inform government and conservation organisations when creating future climate change conservation policy.

Tropical ecosystems are expected to experience climate warming, with predicted increases in drying and heat extremes in the coming years. Understanding how these changes will affect terrestrial vertebrates such as amphibians is limited. The Tropical Responses to Altered Climate Experiment in the Luquillo Experimental Forest in northeastern Puerto Rico allows us to study how the tropical forest responds to warming within a replicated plot design. From September 2018 to August 2019, we used mark-recapture sampling to investigate how the spatial population ecology of the common coqui frog (Eleutherodactylus coqui) is impacted by experimentally increasing surface temperatures by 4 °C above ambient. We compared estimates of baseline detection, space use, and the density of frogs in control and warmed plots. Coqui space use and population density did not differ between control and warmed plots. However, coqui detection probabilities were higher in warmed plots, suggesting an increased level of activity relative to individuals in the control (unwarmed) plots. Frog detection increased in all plots with increased precipitation. Our results suggest that, at least in the short-term, the density of an ecological generalist frog like E. coqui does not change as a response to increased surface temperatures. However, short-term responses to warming such as changes in behavior may lead to changes in population dynamics in the long-term. Our research highlights the need to consider mutiple repsonses in order to understand the effects of climate warming on tropical vertebrates.

Organic matter (OM) dynamics determine how much carbon is stored in ecosystems, a service that modulates climate. We synthesized research from across the US Long-Term Ecological Research (LTER) Network to assemble a conceptual model of OM dynamics that is consistent with inter-disciplinary perspectives and emphasizes vulnerability of OM pools to disturbance. Guided by this conceptual model, we identified unanticipated patterns and long-term trends in processing and transport of OM emerging from terrestrial, freshwater, wetland, and marine ecosystems. Cross-ecosystem synthesis combined with a survey of researchers revealed several themes: 1) strong effects of climate change on OM dynamics, 2) surprising patterns in OM storage and dynamics resulting from coupling with nutrients, 3) characteristic and often complex legacies of land use and disturbance, 4) a significant role of OM transport that is often overlooked in terrestrial ecosystems, and 5) prospects for reducing uncertainty in forecasting OM dynamics by incorporating the chemical composition of OM. Cross-fertilization of perspectives and approaches across LTER sites and other research networks can stimulate the comprehensive understanding required to support large-scale characterizations of OM budgets and the role of ecosystems in regulating global climate.