Climate Change Ecology最新文献

Anthropogenic climate change may affect the nutritional quality of perennial crops. Wild blueberry is a perennial crop of cultural and economic importance and known for its health-promoting properties. Wild blueberry fields in Maine, USA are experiencing unprecedented warming, which may affect the quality and marketability of the fruit. We examined the biochemistry of wild blueberries grown under active open-top heating that elevated temperatures by 3.3 °C, passive open-top heating by 1.2 °C, and ambient conditions (control). We found that total soluble solids, fructose, total soluble sugars and total soluble protein decreased as temperatures increased. In contrast, anthocyanin, total flavonoid and phenolics were not affected. Additionally, warming weakened the correlation between sugars, total soluble solids, and other components. Our results suggest that future global warming may reduce the nutritional value and marketability of wild blueberries. Potential mitigation techniques will need to be developed for future production.

Climate change is expected to increase the frequency and intensity of winter thaws, which could affect leaf phenology. Phenology could either be advanced through the acceleration of forcing accumulation or chilling completion, or be postponed through a reduction in chilling associated with warming air temperature. We tested the influence of winter thaws on budburst phenology by exposing 300 tree cuttings of sugar maple and yellow birch trees to five different frequencies and durations of winter thaws in the lab. In spring, half of the cuttings were exposed to air temperature in two cities representing an air temperature gradient of + 2.0 °C to mimic the ongoing climate warming and bud phenology was monitored three times a week. Irrespective of thaw treatment, yellow birch bud phenology occurred earlier in the warmer city, showing the importance of spring temperature in triggering budburst. The treatment with the highest frequency and duration of thawing increased bud mortality and delayed the onset of spring budburst whereas low frequency treatments did not, thereby identifying a tipping point (3 days twice a month) in the impact of winter thaws on bud phenology. Past this point, winter thaws could slow down bud phenology induced by warmer spring temperature and limit carbon uptake by delaying the closure of the canopy. Climate change simulations projected by the CMIP6 Canadian downscaled climate scenario show that winter thaws will increase in frequency Hence the expected advance in spring leaf emergence associated with warmer spring is not necessarily as straightforward as previously thought.

In seasonal environments conception is timed such that offspring are born at the peak of resource abundance. Although largely determined by photoperiod, reproductive timing can also be modulated by fluctuating environmental conditions. Some studies show that reproduction is occurring earlier, coinciding with an earlier spring as the climate warms. A failure to synchronize parturition with the advancing spring flush of resources can lower reproductive fitness; on the other hand, a longer growing season could be beneficial to some species. We asked whether breeding phenology of white-tailed deer (Odocoileus virginianus) has changed with changing environmental conditions. Using 29 years of wildlife motor-vehicle accident data (1988–2016) as an index of deer rut behaviour in southern Ontario, Canada, we assessed four deer management areas (DMAs) to determine: 1) whether timing of the white-tailed deer rut has changed; 2) whether the growing season has changed; and 3) whether changes in growing season and rut are correlated. We found that in the southwestern-most DMA the peak of the rut is 9 days earlier than in the northeastern-most DMA. The peak of the rut did not change over three decades. We detected an increase in the number of growing degree days, signifying both an earlier start to spring green-up and a later end to fall. The trend toward a longer growing season could have positive impacts on deer populations throughout the province.

Global sea turtle populations are in decline and so a global network of sea turtle nesting conservation programs have been established worldwide with the goal to protect vulnerable nesting mothers, and their clutches of eggs. Yet researchers have recently estimated that sea turtle nesting habitat is likely to suffer as a result of climate change and associated sea level rise. This study examines nest monitoring data from Costa Rica's Osa Peninsula with the aim to identify clutches located in suitable nesting habitat most susceptible to sea level rise and subsequent inundation. We analyze the impacts of six different sea level rise scenarios (from 0.25 m to 2 m) and discuss nesting inclinations and distributions of threatened Olive Ridley (Lepidochelys olivacea) and Green (Chelonia mydas) sea turtles on two beaches of the peninsula—known locally as Piro and Pejeperro. Sea-level rise scenarios on Piro beach indicated that 28.81% of the entire sample were likely to be inundated under a 0.25 m scenario, and 16.52% on Pejeperro beach. Under a more extreme, 2 m scenario, results indicated that 41.74% of nest sites on Piro and 24.55% on Pejeperro would be impacted. Results suggest that Olive Ridley turtles may be more susceptible to sea-level rise, based on their preferred nesting zones, commonly nesting closer to the tide line, as opposed to Green turtles that prefer to nest further from the tide line in vegetation zones where sea-level rise is likely to have less impact. Ultimately, the methodologies used in this study can support sea turtle conservation programs in assessing the potential effects of sea level rise and understanding nesting distributions on their nesting beaches, while also providing important insight in forecasting nest management and implementing monitoring techniques that may reduce the negative impacts associated with climate change and subsequent sea-level rise.

The global threat of invasive alien species (IAS) being introduced into new habitats is concerning, particularly in agricultural crops as invasive insect species are continuing to expand their distribution through anthropogenic activities and climate changes. Pea aphids (Acyrthosiphon pisum Harris) are an economic threat to numerous legume crops as they can reproduce parthenogenetically, damage crops directly, and vector over 30 plant viruses as the insect's distribution continues to spread. There are no existing pea aphid-specific risk maps that identify the habitat suitability of pea aphids at either a regional or global scale. Here, we used Species Distribution Models (SDMs) to evaluate which climatic variables influence pea aphid distribution, identify regions of potential distribution, and analyze the global distribution of pea aphids under current and future climate change scenarios (SSP 126, 245, and 370) by utilizing presence-only SDMs based on Maximum Entropy (MaxEnt). The modeling results indicate suitable conditions are relevant for pea aphid establishment in six out of seven continents, with significant range expansion in western Canada, the United States of America, and across Europe. We identified human influence to be the most prominent predictor in determining the distribution of pea aphids, supporting the fact that invasive species distributions are heavily impacted by human activities.

Currently, some sea turtle populations are expanding their home range distribution toward higher latitudes at an unprecedented rate. These expansions are associated to factors such as climate change or and increased conservation efforts. Already home to one of the largest loggerhead turtle (Caretta caretta) rookeries in the world, the islands of Cabo Verde Archipelago have recorded sporadic nesting of green (Chelonia mydas), olive ridley (Lepidochelys olivacea) and hawksbill (Eretmochelys imbricata) turtles in recent years. Here, we present the compiled information on these sporadic nesting events that occurred between 2013 and 2022 and discuss possible causes for their occurrence. Throughout the study period, the green turtle was documented on 20 occasions, the olive ridley on 25 occasions and the hawksbill on three occasions. All nesting females were found untagged and were subsequently tagged. Nesting activities occurred on the islands of Santo Antão, Sal, Boa Vista and Maio, most of them within the Sea Turtle Natural Reserve in Boa Vista Island. We suggest introducing new conservation strategies targeting the green, olive ridley, and hawksbill turtles nesting in Cabo Verde. We further suggest the use of genetic studies to determine the population origins of these three species.

For species with complex life histories, climate change can have contrasting effects for different life stages within locally adapted populations and may result in responses counter to general climate change predictions. Using data from two, 14-year demographic studies for a North American montane amphibian, Cascades frog (Rana cascadae), we quantified how aspects of current climate influenced annual survival of larvae and adult stages and modeled the stochastic population growth rate (λ_s) of each population for current (1980–2006) and future periods (2080s). Climate drivers of survival for the populations were similar for larvae (i.e., decreases in precipitation lead to pond drying and mortality), but diverged for terrestrial stages where decreases in winter length and summer precipitation had opposite effects. By the 2080s, we predict one population will be in sharp decline (λ_s = 0.90), while the other population will remain nearly stable (λ_s = 0.99) in the absence of other stressors, such as mortality due to disease. Our case study demonstrates a result counter to many climate envelope predictions in that stage-specific responses to local climate and hydrology result in a higher extinction risk for the more northern population.

While predicting species status into the future is inherently uncertain, it is necessary to properly inform conservation decision-making. Using a triple loop stochastic simulation model with a population viability analysis, we projected populations of the northwestern and southwestern pond turtle (Actinemys marmorata and Actinemys pallida, respectively) to the end of the century. We integrated the future trajectories and demographic or population-level effects of three primary threats (drought, invasive bullfrogs, and habitat loss) into the predictive model. Extinction risk of both species increased into the future, with projected widespread declines in abundance and a consistent, negative population growth. By the end of the century, mean probability of extinction was 50 % for the northwestern pond turtle and 75 % for the southwestern pond turtle. The northwestern pond turtle exhibited a latitudinal trend, with southern population units at greater risk of extinction. The population growth rate of the northwestern pond turtle was sensitive to the threat of invasive bullfrogs, whereas drought most strongly influenced southwestern pond turtle growth rates. Future drought conditions will likely be more stochastic than modeled here, where projection methods were limited by the scale and congruency of drought information in pond turtle studies. The habitat loss threat was negligible for both species, although it is likely underestimated due to lack of relevant information on both its future trajectory and effect on vital rates. This work served as decision support science for the Species Status Assessment of the two species, and ultimately, the listing decision under the U.S. Endangered Species Act.