Climate Change Ecology最新文献

Describing patterns of plant phenology through models has been critical for quantifying species responses to climate change and forecasting future vegetation impacts. However, many species remain unincluded in large analyses because they are poorly represented in the large public or citizen science datasets that form the foundation of these efforts. Botanical living collections are often key resources that facilitate study of rare and sparsely observed species, but alone are insufficient to predict species phenology throughout their observed ranges. We investigate whether predictions for rare and data-poor species observed at a single site can be improved by leveraging observations of similar taxa observed at multiple locations. We combined observations of oak (Quercus) budburst and leaf out from one botanical garden with a subset of congeneric species observed in the USA-NPN citizen science dataset using Bayesian hierarchical modeling. We show that including USA-NPN observations into a simple thermal time model of budburst and leaf out did not reduce geographic bias in model predictions over models parameterized only with single-site observations. However, using USA-NPN data to add non-taxonomic spatial covariates to the thermal time model improved model performance for all species, including those only observed at a single site. Living collections at botanical gardens provide valuable opportunities to observe rare or understudied species, but are limited in geographic scope. National-scale citizen science observations that capture the spatial variability of related or ecologically similar taxa can be combined with living collections data to improve predictions of species of conservation concern across their native range.

Prior exposure to variable environmental conditions is predicted to influence the resilience of marine organisms to global change. We conducted complementary 4-month field and laboratory experiments to understand how a dynamic, and sometimes extreme, environment influences growth rates of a tropical reef-building crustose coralline alga and its responses to ocean acidification (OA). Using a reciprocal transplant design, we quantified calcification rates of the Caribbean coralline Lithophyllum sp. at sites with a history of either extreme or moderate oxygen, temperature, and pH regimes. Calcification rates of in situ corallines at the extreme site were 90% lower than those at the moderate site, regardless of origin. Negative effects of corallines originating from the extreme site persisted even after transplanting to more optimal conditions for 20 weeks. In the laboratory, we tested the separate and combined effects of stress and variability by exposing corallines from the same sites to either ambient (Amb: pH 8.04) or acidified (OA: pH 7.70) stable conditions or variable (Var: pH 7.80-8.10) or acidified variable (OA-Var: pH 7.45–7.75) conditions. There was a negative effect of all pH treatments on Lithophyllum sp. calcification rates relative to the control, with lower calcification rates in corallines from the extreme site than from the moderate site in each treatment, indicative of a legacy effect of site origin on subsequent response to laboratory treatment. Our study provides ecologically relevant context to understanding the nuanced effects of OA on crustose coralline algae, and illustrates how local environmental regimes may influence the effects of global change.

Food web rewiring is becoming more likely as climate change continues, yet few experimental studies have focused on it and even fewer have examined the effects of two or more climate variables simultaneously. To help fill this gap the current study examined the effects of warming and drought, both alone and in combination, on herbivore feeding behaviors in a well-known old field food web consisting of two plants (grass and goldenrod), one grasshopper herbivore (Melanoplus femurrubrum), and one arachnid predator (Pisaurina mira). Drought had much stronger effects than warming on goldenrod mortality and flowering, goldenrod nutrient content, herbivore feeding preferences, and live goldenrod biomass remaining at the end of the experiment, while grass was largely unaffected. Drought combined with warming to almost completely suppress goldenrod because of increased goldenrod mortality rates and the drought-stressed grasshoppers’ clear preference for consuming goldenrod with high foliar carbon concentrations. When compared with previous studies that have focused on warming in this system, the current study suggests that food web rewiring is very likely in old fields but the type of rewiring that may occur will be dependent on which climate variables shift more strongly.

Identification of important habitats of charismatic marine megafauna is essential to enhance our conservation capacity. Still, for species such as sea turtles that have a long-life span, a complex life history and a highly migratory nature, spatially delineating important marine areas is not a simple task. Even in the case that such areas are identified, our ability to draw effective measures and propose conservation prioritization schemes faces additional challenges, due to the dynamic climate-driven redistribution of habitats. Here, we compile a database on foraging locations of loggerhead sea turtles across the Mediterranean Sea and use climatic niche models to predict the distribution of foraging grounds for juvenile and adult life stages. We explore potential shifts due to future changes in ocean temperature and identify sites, considered as important for both life stages, that will persist under climate change. We found extensive areas which could host foraging sites for juvenile loggerheads, distributed at the central and western Mediterranean, while adults’ foraging grounds had a more sparse and patchy distribution, mostly at the central and eastern part of the basin. Under future changes, expansions prevail over contractions, but projected redistribution of foraging space for both life stages will probably lead to remarkable losses of climatic suitability at certain sites. The coverage of important areas, hosted primarily at the neritic zone, will be extended in the future. Our analyses add a missing dimension to conservation efforts, related to the basin-wide distribution of important areas, offering novel insights towards incorporating climate change into conservation planning.

Environmental changes can affect an animal's activity pattern and influence fitness. Our goal was to understand the influence of weather on daily activity pattern and assess potential impacts of climate change on activity. We used the Organ Mountains Colorado chipmunk (Neotamias quadrivittatus australis) as a case study. To record activity, we deployed 19 remote cameras at locations occupied by the chipmunk for one year. First, we estimated seasonal variation in daily activity pattern using circular kernel density. Second, we tested if weather influenced activity in each season using Poisson regression in a model selection framework. Third, we predicted the impacts of future climate (RCP8.5 high-emissions scenario) on activity using the best weather model for each season. We found that times and modality of peak activity varied seasonally. Temperature influenced intensity of daily activity in late spring, early summer, monsoon, late fall, and winter, while precipitation influenced intensity of daily activity in early spring and early fall and relative humidity influenced intensity of daily activity in early and late fall. Intensity of daily activity was predicted to increase by 89% in winter and decrease by 51% in early summer under future (2050) climate. The predicted future increase in daily activity in winter may negatively affect fitness because small mammals have higher survival while hibernating. The predicted future decrease in daily activity in early summer may negatively affect fitness due to reduced reproductive output. Losing or gaining time for activity because of shifting climatic conditions could have severe consequences to fitness.

Shifting flowering seasons is a global effect of climate change that can have important long-term evolutionary and demographic effects on plant communities. Life history optimization theory can be a valuable tool to assert the adaptive value and fitness effects of observed phenological shifts, but takes plant-plant competition rarely into account. Here we combine energy allocation models with evolutionary game theory to assess how size-asymmetric competition for light can influence phenological adaptations and fitness responses to a changing climate – here represented as changes of the start, end and intensity of the growing season. We focus on annual plants which, due to their short generation times, are particularly likely to exhibit rapid demographic and evolutionary responses to environmental change. We find that while light competition favors late flowering times, it does not affect the direction of selection in the climate changes scenarios considered here. We predict, however, that plants adapted to light competition face more detrimental fitness consequences if the growing season advances, becomes shorter or less intense. We also show that adaptation to changing growing seasons under light competition can favor increased investment in vegetative growth with the counterintuitive side effect that seed production is reduced at the same time. In sum, our study highlights several effects of light competition that may help to interpret phenological trends and idiosyncratic fitness effects of climate change in wild plant communities.

Environmental change often causes decreased food availability and/or increased foraging costs, putting wild animals at risk of starvation. Body-fat reserves can enable individuals to resist (buffer) periods of weather-driven food scarcity, improving their chances of survival and subsequent reproductive success. This capacity, however, is constrained by life-history factors and fixed long-term differences between individuals. Here, we use 29 years of data from a population of wild European badgers (Meles meles) to test how weather and population density affect individual body condition indices (BCIs), how BCI mediates survival rate and reproductive success, and whether long-term BCI phenotypes (fat vs. thin) provide life-history advantages. Maintaining body condition above a certain threshold was key to survival (reflecting a nonlinear relationship), especially when temperatures varied more between seasons (requiring greater tactical foraging and BCI adjustments) and following excessive rainfall (causing thermoregulative stress). BCI also affected survival more strongly in older individuals. Female reproductive success increased linearly with autumn BCI, and consistently fatter badgers (of both sexes) had higher lifetime reproductive success; however, substantial intra-individual body-condition variation remained after accounting for weather and individual factors, and 84% of individuals varied BCI substantially from year to year. Modelling BCI responses according to projected climate change through 2080 (Emissions Scenario RCP 8.5) revealed that even strong warming (as one-off events) would produce < 5% survival probability reductions, pushing few individuals below the BCI risk threshold. We thus demonstrate that life-history factors and individual body-condition tactics are fundamental to understanding population resilience under anthropogenic climate change.

Black locust (Robinia pseudoacacia L.) has been widely used to restore degraded land in northern China for many decades, and the forest has become an important ecosystem in China. However, there is still knowledge gap about how the range shift of black locust in response to future climate change, which is the first step for adaptive management of black locust. Here, a global niche model of black locust was established by means of maximum entropy model (MaxEnt), 1174 global occurrences data, as well as 13 climatic variables. Then, the global niche model was projected to China under current climate (2000) and four future climate scenarios (2080). The results showed that the range of black locust is mainly controlled by temperature related variables rather than precipitation related variables. The latitude of potential range of black locust is mainly between 23° and 40° in China with the area of occupation being about 26.7% (25.7 × 10⁵ km²) of China's total land area. Future climate is conducive to the northward expansion of black locust in China with a speed of 21 km/decade, as well as an upward shift with a speed of 9.6 m/decade across climate scenarios. Relatively high stable ranges (87–94%) and quick range shift speed implies that little vulnerability of black locust in response to climate change, as well as little risk of extinction in China.

The Galapagos Islands are one of the most productive marine ecosystems in the world. The convergence of four ocean currents and the isolation of these islands create a variety of ecosystems that host unique biodiversity. Many of the endemic species are particularly vulnerable to disturbances in their environment, as most of them are unable to migrate or adapt in response to changing climatic conditions. Due to climate change, there is an increase in extreme weather patterns (El Niño-Southern Oscillation [ENSO] and La Niña events) and climate variability. These affect the productivity of marine and terrestrial ecosystems on the Galapagos Islands and ultimately disrupt natural processes and ecosystem dynamics. Here we conduct a systematic review on the impact on the increase of extreme weather events (ENSO and La Niña events) and climate variability on the biodiversity of the Galapagos Islands. We demonstrate that the increase in the frequency of ENSO events poses a major threat to endemic marine biodiversity, while it has positive impacts on many terrestrial species due to increase rainfall and food availability. In contrast, La Niña provides sometimes positive conditions for marine species allowing them to recover, while for many terrestrial species La Niña years result in worse conditions causing adverse effects. Therefore, the increased frequency of ENSO and La Niña years under climate change poses significant threats to the Galapagos biodiversity. Also, increased climate variability (not related to ENSO and La Niña events) has adverse impacts on marine and terrestrial species, putting biodiversity under even more pressure. The results of our review are key to understand the far-reaching implications of climate change on the Galapagos Islands and can be used to understand impacts on other archipelagos worldwide, which are often areas with high levels of (endemic) biodiversity.

Coastal deoxygenation is poorly documented in the tropics. When the Isthmus of Panama separated the Caribbean from the Pacific, sister lineages diverged and adapted to changing oxy-thermal conditions along both coasts. This provides unique insight into the ecological consequences of ocean warming and deoxygenation. We find deoxygenated, or hypoxic, waters shoal to the shallow depths of 10 m on both sides of the Isthmus, with Caribbean waters generally warmer than those in the Pacific. We tested the performance of two Caribbean Echinometra sea urchin species and their Pacific sister species under different warming and oxygen scenarios. Performance, measured as righting ability, was reduced by 50–100% under hypoxia compared to normoxia in one species from each coast. Only one Caribbean species performed well under hypoxia and did so at ambient temperatures (≤ 29 °C) but not under warming. This tolerant species, E. viridis, appears to be specialized for living on protected Caribbean reefs, unlike its two sister species that occur on well-oxygenated reefs. Our results emphasize the danger of shoaling hypoxia compressing well-oxygenated habitat from beneath and the importance of evolved hypoxia tolerance. This highlights the underappreciated risk deoxygenation poses for shallow tropical ecosystems.