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1.
    
As global climate change and variability drive shifts in species’ distributions, ecological communities are being reorganized. One approach to understand community change in response to climate change has been to characterize communities by a collective thermal preference, or community temperature index (CTI), and then to compare changes in CTI with changes in temperature. However, important questions remain about whether and how responsive communities are to changes in their local thermal environments. We used CTI to analyze changes in 160 marine assemblages (fish and invertebrates) across the rapidly‐changing Northeast U.S. Continental Shelf Large Marine Ecosystem and calculated expected community change based on historical relationships between species presence and temperature from a separate training dataset. We then compared interannual and long‐term temperature changes with expected community responses and observed community responses over both temporal scales. For these marine communities, we found that community composition as well as composition changes through time could be explained by species associations with bottom temperature. Individual species had non‐linear responses to changes in temperature, and these nonlinearities scaled up to a nonlinear relationship between CTI and temperature. On average, CTI increased by 0.36°C (95% CI: 0.34–0.38°C) for every 1°C increase in bottom temperature, but the relationship between CTI and temperature also depended on community composition. In addition, communities responded more strongly to interannual variation than to long‐term trends in temperature. We recommend that future research into climate‐driven community change accounts for nonlinear responses and examines ecological responses across a range of temporal and geographical scales.  相似文献   

2.
    
Organisms are projected to face unprecedented rates of change in future ocean conditions due to anthropogenic climate‐change. At present, marine life encounters a wide range of environmental heterogeneity from natural fluctuations to mean climate change. Manipulation studies suggest that biota from more variable marine environments have more phenotypic plasticity to tolerate environmental heterogeneity. Here, we consider current strategies employed by a range of representative organisms across various habitats – from short‐lived phytoplankton to long‐lived corals – in response to environmental heterogeneity. We then discuss how, if and when organismal responses (acclimate/migrate/adapt) may be altered by shifts in the magnitude of the mean climate‐change signal relative to that for natural fluctuations projected for coming decades. The findings from both novel climate‐change modelling simulations and prior biological manipulation studies, in which natural fluctuations are superimposed on those of mean change, provide valuable insights into organismal responses to environmental heterogeneity. Manipulations reveal that different experimental outcomes are evident between climate‐change treatments which include natural fluctuations vs. those which do not. Modelling simulations project that the magnitude of climate variability, along with mean climate change, will increase in coming decades, and hence environmental heterogeneity will increase, illustrating the need for more realistic biological manipulation experiments that include natural fluctuations. However, simulations also strongly suggest that the timescales over which the mean climate‐change signature will become dominant, relative to natural fluctuations, will vary for individual properties, being most rapid for CO2 (~10 years from present day) to 4 decades for nutrients. We conclude that the strategies used by biota to respond to shifts in environmental heterogeneity may be complex, as they will have to physiologically straddle wide‐ranging timescales in the alteration of ocean conditions, including the need to adapt to rapidly rising CO2 and also acclimate to environmental heterogeneity in more slowly changing properties such as warming.  相似文献   

3.
    
Recent observations confirm the rising temperatures of Atlantic waters transported into the Arctic Ocean via the West Spitsbergen Current (WSC). We studied the overall abundance and population structure of the North Atlantic keystone zooplankton copepod Calanus finmarchicus, which is the main prey for pelagic fish and some seabirds, in relation to selected environmental variables in this area between 2001 and 2011, when warming in the Arctic and Subarctic was particularly pronounced. Sampling within a 3‐week time window each summer demonstrated that trends in the overall abundance of C. finmarchicus varied between years, with the highest values in “extreme” years, due to high numbers of nauplii and early copepodite stages in colder years (2001, 2004, 2010), and contrary to that, the fifth copepodite stage (C5) peaking in warm years (2006, 2007, 2009). The most influential environmental variable driving C. finmarchicus life cycle was temperature, which promoted an increased C5 abundance when the temperature was above 6°C, indicating earlier spawning and/or accelerated development, and possibly leading to their development to adults later in the summer and spawning for the second time, given adequate food supply. Based on the presented high interannual and spatial variability, we hypothesize that under a warmer climate, C. finmarchicus may annually produce two generations in the southern part of the WSC, what in turn could lead to food web reorganization of important top predators, such as little auks, and induce northward migrations of fish, especially the Norwegian herring.  相似文献   

4.
    
Sandy ocean beaches are iconic assets that provide irreplaceable ecosystem services to society. Despite their great socioeconomic importance, beaches as ecosystems are severely under‐represented in the literature on climate‐change ecology. Here, we redress this imbalance by examining whether beach biota have been observed to respond to recent climate change in ways that are consistent with expectations under climate change. We base our assessments on evidence coming from case studies on beach invertebrates in South America and on sea turtles globally. Surprisingly, we find that observational evidence for climate‐change responses in beach biota is more convincing for invertebrates than for highly charismatic turtles. This asymmetry is paradoxical given the better theoretical understanding of the mechanisms by which turtles are likely to respond to changes in climate. Regardless of this disparity, knowledge of the unique attributes of beach systems can complement our detection of climate‐change impacts on sandy‐shore invertebrates to add rigor to studies of climate‐change ecology for sandy beaches. To this end, we combine theory from beach ecology and climate‐change ecology to put forward a suite of predictive hypotheses regarding climate impacts on beaches and to suggest ways that these can be tested. Addressing these hypotheses could significantly advance both beach and climate‐change ecology, thereby progressing understanding of how future climate change will impact coastal ecosystems more generally.  相似文献   

5.
Footprints of climate change in the Arctic marine ecosystem   总被引:3,自引:0,他引:3  
In this article, we review evidence of how climate change has already resulted in clearly discernable changes in marine Arctic ecosystems. After defining the term ‘footprint’ and evaluating the availability of reliable baseline information we review the published literature to synthesize the footprints of climate change impacts in marine Arctic ecosystems reported as of mid‐2009. We found a total of 51 reports of documented changes in Arctic marine biota in response to climate change. Among the responses evaluated were range shifts and changes in abundance, growth/condition, behaviour/phenology and community/regime shifts. Most reports concerned marine mammals, particularly polar bears, and fish. The number of well‐documented changes in planktonic and benthic systems was surprisingly low. Evident losses of endemic species in the Arctic Ocean, and in ice algae production and associated community remained difficult to evaluate due to the lack of quantitative reports of its abundance and distribution. Very few footprints of climate change were reported in the literature from regions such as the wide Siberian shelf and the central Arctic Ocean due to the limited research effort made in these ecosystems. Despite the alarming nature of warming and its strong potential effects in the Arctic Ocean the research effort evaluating the impacts of climate change in this region is rather limited.  相似文献   

6.
    
While the effect of weather on reproduction has been studied for many years in avian taxa, the rapid pace of climate change in arctic regions has added urgency to this question by changing the weather conditions species experience during breeding. Given this, it is important to understand how factors such as temperature, rain, snowfall, and wind affect reproduction both directly and indirectly (e.g. through their effects on food availability). In this study, we ask how weather factors and food availability influence daily survival rates of clutches in two arctic‐breeding migratory songbirds: the Lapland longspur Calcarius lapponicus, a circumpolar breeder, and Gambel's white‐crowned sparrow Zonotrichia leucophrys gambelii, which breeds in shrubby habitats across tundra, boreal and continental climates. To do this, we monitored clutch survival in these two species from egg‐lay through fledge at field sites located near Toolik Field Station (North Slope, Alaska) across 5 yr (2012–2016). Our results indicate that snowfall and cold temperatures decreased offspring survival rates in both species; although Lapland longspurs were more susceptible to snowfall. Food availability, quantified by pitfall sampling and sweep‐net sampling methods, had minimal effects on offspring survival. Some climate models predict increased precipitation for the Arctic with global warming, and in the Toolik region, total snow accumulation may be increasing. Placed in this context, our results suggest that changes in snow storms with climate change could have substantial consequences for reproduction in migratory songbirds breeding in the North American Arctic.  相似文献   

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8.
Commercial fishing and climate change have influenced the composition of marine fish assemblages worldwide, but we require a better understanding of their relative influence on long‐term changes in species abundance and body‐size distributions. In this study, we investigated long‐term (1911–2007) variability within a demersal fish assemblage in the western English Channel. The region has been subject to commercial fisheries throughout most of the past century, and has undergone interannual changes in sea temperature of over 2.0 °C. We focussed on a core 30 species that comprised 99% of total individuals sampled in the assemblage. Analyses showed that temporal trends in the abundance of smaller multispecies size classes followed thermal regime changes, but that there were persistent declines in abundance of larger size classes. Consistent with these results, larger‐growing individual species had the greatest declines in body size, and the most constant declines in abundance, while abundance changes of smaller‐growing species were more closely linked to preceding sea temperatures. Together these analyses are suggestive of dichotomous size‐dependent responses of species to long‐term climate change and commercial fishing over a century scale. Small species had rapid responses to the prevailing thermal environment, suggesting their life history traits predisposed populations to respond quickly to changing climates. Larger species declined in abundance and size, reflecting expectations from sustained size‐selective overharvesting. These results demonstrate the importance of considering species traits when developing indicators of human and climatic impacts on marine fauna.  相似文献   

9.
    
The consequences of elevated temperature on body shape were investigated by comparing European perch Perca fluviatilis from the Forsmark area of the Baltic Sea to P. fluviatilis from a nearby Biotest enclosure. The Biotest is a man‐made enclosure within the Baltic Sea that has received warm water from a nuclear power plant since 1980, resulting in temperatures that are elevated 5–10° C relative to the surrounding Baltic Sea. Sampled fish ranged from young‐of‐the‐year to 14 years. Geometric morphometrics and multivariate statistical analysis revealed significant morphological differences between individuals of P. fluviatilis from these two habitats. Most importantly, relative shape changed with size, with small individuals of P. fluviatilis from Biotest being characterized by a deeper body shape and a larger caudal peduncle than the smaller Baltic individuals. In large specimens, smaller differences were found with Biotest individuals being more slender than Baltic individuals. These results show that, in order to have a full understanding of the biological effects of elevated temperatures, studies that cover the entire size range of organisms will be important. Apart from the direct influence of temperature on growth rate and body shape, other ecological factors affected by temperature are discussed as possible contributors to the observed differences between the two populations.  相似文献   

10.
    
  1. Exotic cladoceran Daphnia lumholtzi is a highly invasive species in the north and south American continents and can potentially also invade European freshwaters and outcompete native Daphnia populations. However, European waterbodies are frequently dominated by less edible filamentous cyanobacteria including also invaders such as Raphidiopsis raciborskii, which might affect the fitness of D. lumholtzi. Furthermore, temperature may influence the sensitivity of D. lumholtzi to R. raciborskii filaments.
  2. In this study, we determined whether the presence of R. raciborskii could obstruct the invasion of Europe by D. lumholtzi, through reducing its fitness, and whether this depends on temperature. We compared the population growth rate (r) and the somatic growth rate of D. lumholtzi maintained at two temperatures (20 or 26°C) and fed with two diets: green microalgae alone or green microalgae mixed with filaments of R. raciborskii. Three clones of D. lumholtzi were used to evaluate potential variation in response to the treatments among different clones.
  3. At 20°C, the population growth rate of D. lumholtzi fed with cyanobacterial filaments declined sharply. This reduction was caused by increased egg abortion, egg degeneration, and mortality of newborn daphnids. At 26°C, R. raciborskii lost its harmful effect on the population growth of D. lumholtzi. The presence of cyanobacteria did reduce the somatic growth rate of D. lumholtzi at both temperatures and in all three clones except for one that had a similar somatic growth rate on both diets at 26°C.
  4. The presence of filamentous cyanobacteria does affect growth in D. lumholtzi and may thereby substantially reduce its invasive potential, but only at lower temperatures. Therefore, the presence of filamentous cyanobacteria may not present an obstacle to the invasion of Europe by D. lumholtzi in a warmer future climate.
  相似文献   

11.
    
An experimental life support system (ELSS) was constructed to study the interactive effects of multiple stressors on coastal and estuarine benthic communities, specifically perturbations driven by global climate change and anthropogenic environmental contamination. The ELSS allows researchers to control salinity, pH, temperature, ultraviolet radiation (UVR), tidal rhythms and exposure to selected contaminants. Unlike most microcosms previously described, our system enables true independent replication (including randomization). In addition to this, it can be assembled using commercially available materials and equipment, thereby facilitating the replication of identical experimental setups in different geographical locations. Here, we validate the reproducibility and environmental quality of the system by comparing chemical and biological parameters recorded in our ELSS with those prevalent in the natural environment. Water, sediment microbial community and ragworm (the polychaete Hediste diversicolor) samples were obtained from four microcosms after 57 days of operation. In general, average concentrations of dissolved inorganic nutrients (NO3?; NH4+ and PO4?3) in the water column of the ELSS experimental control units were within the range of concentrations recorded in the natural environment. While some shifts in bacterial community composition were observed between in situ and ELSS sediment samples, the relative abundance of most metabolically active bacterial taxa appeared to be stable. In addition, ELSS operation did not significantly affect survival, oxidative stress and neurological biomarkers of the model organism Hediste diversicolor. The validation data indicate that this system can be used to assess independent or interactive effects of climate change and environmental contamination on benthic communities. Researchers will be able to simulate the effects of these stressors on processes driven by microbial communities, sediment and seawater chemistry and to evaluate potential consequences to sediment toxicity using model organisms such as Hediste diversicolor.  相似文献   

12.
Antarctica and its surrounding islands lie at one extreme of global variation in diversity. Typically, these regions are characterized as being species poor and having simple food webs. Here, we show that terrestrial systems in the region are nonetheless characterized by substantial spatial and temporal variations at virtually all of the levels of the genealogical and ecological hierarchies which have been thoroughly investigated. Spatial variation at the individual and population levels has been documented in a variety of genetic studies, and in mosses it appears that UV-B radiation might be responsible for within-clump mutagenesis. At the species level, modern molecular methods have revealed considerable endemism of the Antarctic biota, questioning ideas that small organisms are likely to be ubiquitous and the taxa to which they belong species poor. At the biogeographic level, much of the relatively small ice-free area of Antarctica remains unsurveyed making analyses difficult. Nonetheless, it is clear that a major biogeographic discontinuity separates the Antarctic Peninsula and continental Antarctica, here named the 'Gressitt Line'. Across the Southern Ocean islands, patterns are clearer, and energy availability is an important correlate of indigenous and exotic species richness, while human visitor numbers explain much of the variation in the latter too. Temporal variation at the individual level has much to do with phenotypic plasticity, and considerable life-history and physiological plasticity seems to be a characteristic of Antarctic terrestrial species. Environmental unpredictability is an important driver of this trait and has significantly influenced life histories across the region and probably throughout much of the temperate Southern Hemisphere. Rapid climate change-related alterations in the range and abundance of several Antarctic and sub-Antarctic populations have taken place over the past several decades. In many sub-Antarctic locations, these have been exacerbated by direct and indirect effects of invasive alien species. Interactions between climate change and invasion seem set to become one of the most significant conservation problems in the Antarctic. We conclude that despite the substantial body of work on the terrestrial biodiversity of the Antarctic, investigations of interactions between hierarchical levels remain scarce. Moreover, little of the available information is being integrated into terrestrial conservation planning, which lags far behind in this region by comparison with most others.  相似文献   

13.
    
Microbes affect the global carbon cycle that influences climate change and are in turn influenced by environmental change. Here, we use data from a long-term whole-ecosystem warming experiment at a boreal peatland to answer how temperature and CO2 jointly influence communities of abundant, diverse, yet poorly understood, non-fungi microbial Eukaryotes (protists). These microbes influence ecosystem function directly through photosynthesis and respiration, and indirectly, through predation on decomposers (bacteria and fungi). Using a combination of high-throughput fluid imaging and 18S amplicon sequencing, we report large climate-induced, community-wide shifts in the community functional composition of these microbes (size, shape, and metabolism) that could alter overall function in peatlands. Importantly, we demonstrate a taxonomic convergence but a functional divergence in response to warming and elevated CO2 with most environmental responses being contingent on organismal size: warming effects on functional composition are reversed by elevated CO2 and amplified in larger microbes but not smaller ones. These findings show how the interactive effects of warming and rising CO2 levels could alter the structure and function of peatland microbial food webs—a fragile ecosystem that stores upwards of 25% of all terrestrial carbon and is increasingly threatened by human exploitation.  相似文献   

14.
Phenological, biogeographic and community shifts are among the reported responses of marine ecosystems and their species to climate change. However, despite both the profound consequences for ecosystem functioning and services, our understanding of the root causes underlying these biological changes remains rudimentary. Here, we show that a significant proportion of the responses of species and communities to climate change are deterministic at some emergent spatio-temporal scales, enabling testable predictions and more accurate projections of future changes. We propose a theory based on the concept of the ecological niche to connect phenological, biogeographic and long-term community shifts. The theory explains approximately 70% of the phenological and biogeographic shifts of a key zooplankton Calanus finmarchicus in the North Atlantic and approximately 56% of the long-term shifts in copepods observed in the North Sea during the period 1958–2009.  相似文献   

15.
    
Carbon and nitrogen isotopes analyses were performed on marine mammal bone collagen from three archaeological sites (ad 1170–1813) on Cape Espenberg (Kotzebue Sound, northwestern Alaska) as well as modern animals harvested from the same area to examine long‐term trends in foraging ecology and sea ice productivity. We observed significant and dramatic changes in ringed seal stable isotope values between the early 19th and early 21st centuries, likely due to changing sea ice productivity and reduced delivery of organic matter to the benthos driven by recent warming in the Arctic. These data highlight the importance of the archaeological record for providing a long‐term perspective on environmental variation and interpreting recent changes driven by anthropogenic processes.  相似文献   

16.
    
The exploration of evolutionary biology and biological adaptation can inform society's adaptation to climate change, particularly the mechanisms that bring about adaptability, such as phenotypic plasticity, epigenetics, and horizontal gene transfer. Learning from unplanned autonomous biological adaptation may be considered undesirable and incompatible with human endeavor. However, it is argued that there is no need for agency, and planned adaptation is not necessarily preferable over autonomous adaptation. What matters is the efficacy of adaptive mechanisms and their capacity to increase societal resilience to current and future impacts. In addition, there is great scope for industrial ecology (IE) to contribute approaches to climate change adaptation that generate system models and baseline data to inform decision making. The problem of “uncertainty” was chosen as an example of a challenge that is shared by biological systems, IE, and climate change adaptation to show how biological adaptation might contribute solutions. Finally, the Coastal Climate Adaptation Decision Support tool was used to demonstrate how IE and biological adaptation approaches may be mainstreamed in climate change adaptation planning and practice. In conclusion, there is close conceptual alignment between evolutionary biology and IE. The integration of biological adaptation thinking can enrich IE, add new perspectives to climate change adaptation science, and support IE's engagement with climate change adaptation. There should be no major obstacles regarding the collaboration of industrial ecologists with the climate change adaptation community, but mainstreaming of biological adaptation solutions depends greatly on successful knowledge transfer and the engagement of open‐minded and informed adaptation stakeholders.  相似文献   

17.
    
Adaptation to changing conditions is one of the strategies plants may use to survive in the face of climate change. We aimed to determine whether plants' leaf morphological and physiological traits/gas exchange variables have changed in response to recent, anthropogenic climate change. We grew seedlings from resurrected historic seeds from ex-situ seed banks and paired modern seeds in a common-garden experiment. Species pairs were collected from regions that had undergone differing levels of climate change using an emerging framework—Climate Contrast Resurrection Ecology, allowing us to hypothesise that regions with greater changes in climate (including temperature, precipitation, climate variability and climatic extremes) would be greater trait responses in leaf morphology and physiology over time. Our study found that in regions where there were greater changes in climate, there were greater changes in average leaf area, leaf margin complexity, leaf thickness and leaf intrinsic water use efficiency. Changes in leaf roundness, photosynthetic rate, stomatal density and the leaf economic strategy of our species were not correlated with changes in climate. Our results show that leaves do have the ability to respond to changes in climate, however, there are greater inherited responses in morphological leaf traits than in physiological traits/variables and greater responses to extreme measures of climate than gradual changes in climatic means. It is vital for accurate predictions of species' responses to impending climate change to ensure that future climate change ecology studies utilise knowledge about the difference in both leaf trait and gas exchange responses and the climate variables that they respond to.  相似文献   

18.
    
In the present framework of global warming, it is unclear whether evolutionary adaptation can happen quick enough to preserve the persistence of many species. Specifically, we lack knowledge about the adaptive potential of the different populations in relation to the various constraints that may hamper particular adaptations. There is evidence indicating that early flowering often provides an adaptive advantage to plants in temperate zones in response to global warming. Thus, the objective of this study was to assess the adaptive potential for advancing flowering onset in Lupinus angustifolius L. (Fabaceae). Seeds from four populations from two contrasting latitudes in Spain were collected and sown in a common garden environment. Selecting the 25% of the individuals that flowered earlier in the first generation, over three generations, three different early flowering selection lines were established, involving both self-crosses and outcrosses. All artificial selection lines advanced their flowering significantly with respect to the control line in the northernmost populations, but not in the southern ones. Selection lines obtained from outcrossing had a greater advancement in flowering than those from self-crossing. No differences were found in the number or weight of the seeds produced between control and artificial selection lines, probably because plants in the common garden were drip irrigated. These results suggest that northern populations may have a greater adaptive potential and that southern populations may be more vulnerable in the context of climate warming. However, earlier flowering was also associated with changes in other traits (height, biomass, shoot growth, specific leaflet area, and leaflet dry matter content), and the effects of these changes varied greatly depending on the latitude of the population and selection line. Assessments of the ability of populations to cope with climate change through this and other approaches are essential to manage species and populations in a more efficient way.  相似文献   

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