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The humid forests of Amazonia are experiencing longer and more intense dry seasons, which are predicted to intensify by the end of the 21st century. Although tree species often have long generation times, they may still have the capacity to rapidly respond to changing climatic conditions through adaptive phenotypic plasticity. We, therefore, predicted that Amazonian trees have shifted their leaf morphology in response to the recent drier climate. We tested this prediction by analysing historical herbarium specimens of six Amazonian tree species collected over a 60-year period and comparing changes in leaf morphology with historical precipitation data. Moreover, we explored spatial and temporal biases in herbarium specimens and accounted for their potentially confounding effect in our analysis. We found pronounced biases in herbarium specimens, with nearly 20% of specimens collected in close geographic proximity and around the 1975s. When accounting for such biases, our results indicate a trend of decreasing leaf size after the 1970s, which may have been spurred by an observed reduction in rainfall. Our findings support the hypothesis that (some) Amazonian trees have the capacity to adaptively change their leaf phenotypes in response to the recent drier climate. Nevertheless, the unavoidable spatial and temporal biases in herbarium specimens call for caution when generalizing our findings to all Amazonian trees.

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The last 20 years have seen remarkable progress in monitoring and modelling environmental change in the Amazon region. As a result, scientists and policy makers now have robust and spatially explicit knowledge and forecasts of critical phenomena such as deforestation and bioclimatic uncertainty. However, whether this knowledge is used to support the implementation of policies and initiatives to cope with environmental changes in the Amazon depends on the ability of the political institutions to proactively integrate the scientific evidence into land planning at multiple spatial scales. In Brazil, municipalities are constitutionally responsible for legislating on land planning and therefore have a power to significantly influence the future trajectory of environmental change. Here, we assess the environmental capacity of municipalities in the Brazilian legal Amazon based on data from a self-assessment survey and from the Brazilian Institute of Geography and Statistics database. Municipalities generally have a low level of institutional capacity and there is no evidence that the municipalities most at threat from environmental change are taking proactive measures to reduce their vulnerability. We argue that structural reforms and capacity raising initiatives are urgently needed, especially in smaller, less economically developed municipalities located in areas at high risk of imminent environmental change. [ABSTRACT FROM AUTHOR]

The Caatinga is a botanically unique semi-arid ecosystem in northeast Brazil whose vegetation is adapted to the periodic droughts that characterize this region. However, recent extreme droughts events caused by anthropogenic climate change have challenged its ecological resilience. Here, we evaluate how deforestation and protection status affect the response of the Caatinga vegetation to drought. Specifically, we compared vegetation responses to drought in natural and deforested areas as well as inside and outside protected areas, using a time-series of satellite-derived Normalized Difference Vegetation Index ( NDVI) and climatic data for 2008-2013. We observed a strong effect of deforestation and land protection on overall vegetation productivity and in productivity dynamics in response to precipitation. Overall, deforested areas had significantly lower NDVI and delayed greening in response to precipitation. By contrast, strictly protected areas had higher productivity and considerable resilience to low levels of precipitation, when compared to sustainable use or unprotected areas. These results highlight the importance of protected areas in protecting ecosystem processes and native vegetation in the Caatinga against the negative effects of climate change and deforestation. Given the extremely small area of the Caatinga currently under strict protection, the creation of new conservation areas must be a priority to ensure the sustainability of ecological processes and to avoid further desertification. [ABSTRACT FROM AUTHOR]

Background: Climate change is altering climate patterns, mainly increasing the frequency and intensity of extreme events with potentially serious impacts on natural resources and the people that use them. Adapting to such impacts will require the integration of scientific and local (folk) knowledge, especially the first-hand experiences and perceptions of resource users such as fishers. In this study, we identify how commercial riverine fishers in the Amazon remember extreme climatic events (flood and drought) and how they face the consequences of extreme events on fish availability. Methods: Data were collected from the main Manaus fishery harbor between June and October of 2013. Semi-structured questionnaires and a historical timeline technique were used to gather data from artisanal commercial fishers. Fishers' knowledge of extreme climate events was assessed by their "cultural consensus" for identification of event years and perceived impacts. Fishers' responses were also compared to hydrological data to test their similarity. Results: There was a high level of cultural consensus among fishers about extreme events years. They were able to identify four consecutive unusual droughts, between 2009 and 2012. Elevated levels of fish mortality and decreases in the fishery were perceived as consequences of the drought events, as well as, a reduction in fish size, and disappearance of some species. Extreme flood events were associated with greater difficulties accessing fishing grounds. Conclusions: Extreme climatic events (floods and droughts) were remembered, and the recent increase in their intensity and frequency was also perceived. Moreover, extreme climate event (mainly droughts) impacts on fishery resources were also observed. Such information is potentially valuable for educational programs to further improve adaptation of local Amazonian fishing communities to future climate change, e.g. increasing local ecological knowledge using learning material based on their perception. [ABSTRACT FROM AUTHOR]

Aim Allen's rule posits that the appendages of endothermic organisms will be larger in warmer climates to allow for dumping of heat loads. Given a link between appendage size and climate, we tested the prediction that climate change has driven the evolution of larger bills in birds, resulting in measurable changes over the recent past. Location Australia. Methods We explored geographical and temporal variation in bill surface area of five Australian parrot species to determine whether individuals from warmer climates have larger bills, and whether there have been increases in bill surface area over time, consistent with climatic warming. Measurements were obtained from museum specimens dating from 1871 to 2008. These data were then related to geographical location, collection date and locality-specific climate data, in order to construct and compare models of spatio-temporal and climate-related variation in bill morphology. Results There have been increases in bill surface area in mulga parrots ( Psephotus varius), gang-gang cockatoos ( Callocephalon fimbriatum), red-rumped parrots ( Psephotus haematonotus) and male crimson rosellas ( Platycercus elegans), equating to a c. 4-10% increase in bill surface area since 1871. Average maximum summer temperature in the 5 years prior to specimen collection also positively predicted bill surface area in mulga parrots, red-rumped parrots and crimson rosellas, consistent with Allen's rule. With the exception of red-rumped parrots, however, models with geographical location and year of collection were still better predictors of bill surface area than local climate at the date of collection. Main conclusions Our analysis provides evidence that four species of parrot have exhibited adaptive change in bills over the past century potentially mitigating the thermal stress caused by climatic warming. Although consistent with the predicted effects of climate change, the temporal patterns we observe may have additional causes, however, such as changes in primary productivity, habitat or food availability. [ABSTRACT FROM AUTHOR]

Aim Using survey data for North American birds, we assess how well historical patterns of species richness are explained by stacked species distribution models and macroecological models. We then describe the degree to which projections of future species richness differ, employing both modelling approaches across multiple emissions scenarios. Location USA and Canada. Methods We use Audubon Christmas Bird Count and North American Breeding Bird Survey data to estimate current and future species richness of birds using two distinct approaches. In the first, we model richness by stacking predictions from individual species distribution models. In the second, we model richness directly, ignoring the contributions of specific taxa to richness estimates. Results The two modelling approaches show similar accuracies when validated with historical observations, particularly winter observations, and result in similar patterns of richness when projected onto current and future climate spaces. Patterns of projected change in species richness differed markedly between winter and summer seasons regardless of modelling approach. Our models suggest that bird species richness in winter will increase or remain stable across much of North America. In contrast, species richness in summer is projected to decrease over much of North America, except part of northern Canada, suggesting that climate may constrain many breeding bird species and communities in the future. Main conclusions Stacked species distribution models and macroecological models produce similar estimates of current and future species richness for each of two seasons despite being built on different concepts of community assembly. Our results suggest that, although the mechanisms that shape geographical variation in biodiversity remain uncertain, these limitations do not impede our ability to predict patterns of species richness at broad scales. Congruence of species richness projections across modelling approaches is encouraging for conservation planning efforts that focus on retaining biodiversity into the future. [ABSTRACT FROM AUTHOR]

Aim We analyse the taxonomic status, phylogenetic relationships, distribution and age of a newly discovered ant taxon found in the mountaintops of the island of Mallorca (Spain). We also consider the potential impact of short-term climate change on the survival of this ant and make proposals on its conservation status, risks and management. Location Balearic Islands (Spain). Methods We used morphological, molecular and ecological evidence to assess the specific status of the potential new species. We gathered distribution data to conduct climate-based distribution modelling of present and future occupancy under several SRES emission scenarios. Results The existence of a new non-cryptic species of ant (Lasius balearicus Talavera, Espadaler & Vila, sp. nov.) is described from the island of Mallorca. Its distribution was found to be extremely restricted (Serra de Tramuntana) and elevationally constrained to island summits (between 800 and 1400 m a.s.l.). Molecular dating indicated that this species diverged about 1.51 million years ago from its nearest relatives, from which it can be distinguished based on several morphological traits. Ecological niche modelling shows a dramatic reduction of areas with suitable climatic conditions under the different scenarios studied. Main conclusions Lasius balearicus represents the first endemic ant to be described in the Balearic Islands, as well as the first endemic Lasius species in the Mediterranean islands. Distribution modelling predictions, the low intraspecific genetic diversity observed, and the geographical and elevational isolation of the populations indicated a low probability for the survival of the species in the short term, thus making it a potential model to study real-time climate-based biodiversity loss. As a consequence, we strongly recommend including L. balearicus in the IUCN Red List of Threatened Species under the category 'Endangered'. This case illustrates that a fraction of biodiversity remains unexplored even within Europe, arguably the best-studied region of the planet, and that the available time-window for us to study and protect it may be in some instances notably narrow. [ABSTRACT FROM AUTHOR]

Aim Approximately 32.5% of all amphibian species are globally threatened, and amphibian extinctions have been recorded worldwide. Individual studies rarely give full consideration to multiple potential drivers of observed biological change, instead tending to attribute changes to a single driver. Here, I tested for impacts of land use and climate change on range changes in a community of plethodontid salamanders living from 518 to 2036 m elevation in a global hotspot for amphibian diversity. Location The southern Appalachian Mountains. Methods I resurveyed 18 elevational transects that had originally been surveyed by Nelson Hairston in 1940, 1947 and 1949. I recorded range changes for nine species that Hairston studied and determined the extent to which the recorded expansions or contractions could be attributed to changes in forest stand, climate and competition, singly or in combination. Results 'Montane' species, which occur only on mountaintops, had expanded their lower elevational limits downwards. 'Foothill' species, which occur at lower elevations than montane species, had expanded their upper elevational limits upwards. Main conclusions For montane species these downward expansions appear to be the result of two processes: local cooling of the climate and maturation of forests after the cessation of large-scale logging operations c. 80 years ago. In contrast, changes in upper elevational range limits of foothill species are probably the result of a suite of complex and interacting drivers, including, but not limited to, maturation of forests, changes in climate, and interactions with other species. [ABSTRACT FROM AUTHOR]

Bromeliad phytotelmata are frequently used by several Neotropical amphibian taxa, possibly due to their high humidity, microclimatic stability, and role as a refuge from predators. Indeed, the ability of phytotelmata to buffer against adverse environmental conditions may be instrumental in allowing some amphibian species to survive during periods of environmental change or to colonize sub-optimal habitats. Association between bromeliad traits and salamanders has not been studied at a fine scale, despite the intimate association of many salamander species with bromeliads. Here, we identify microhabitat characteristics of epiphytic bromeliads used by two species of the Bolitoglossa morio group (B. morio and B. pacaya) in forest disturbed by volcanic activity in Guatemala. Specifically, we measured multiple variables for bromeliads (height and position in tree, phytotelma water temperature and pH, canopy cover, phytotelma size, leaf size, and tree diameter at breast height), as well as salamander size. We employed a DNA barcoding approach to identify salamanders. We found that B. morio and B. pacaya occurred in microsympatry in bromeliads and that phytotelmata size and temperature of bromeliad microhabitat were the most important factors associated with the presence of salamanders. Moreover, phytotelmata with higher pH contained larger salamanders, suggesting that larger salamanders or aggregated individuals might modify pH. These results show that bromeliad selection is nonrandom with respect to microhabitat characteristics, and provide insight into the relationship between salamanders and this unique arboreal environment. [ABSTRACT FROM AUTHOR]

Aim Bats are promising candidates for studying morphometric responses to anthropogenic climate or land-use changes. We assessed whether the cranial size of a common bat ( Pipistrellus kuhlii) had changed between 1875 and 2007. We formulated the following hypotheses: (1) if heat loss is an important reaction to climate change, body size will have decreased in response to the increased temperatures, because small bats have a larger surface-to-volume ratio and dissipate heat more effectively; (2) if water loss is the main driver, body size will have increased in response to the temperature increase, because larger bats will lose water more slowly through a reduced surface-to-volume ratio; (3) the energetic benefits provided by urbanization (food concentration at street lamps, warmer maternity roosts in buildings) will lead to a general body size increase in P. kuhlii; and (4) because street lamps impair moth antipredatory manoeuvres, cranial size may have selectively increased as an adaptive response to handle larger prey (moths) in artificially illuminated sites. Ours is the first study to assess temporal trends in bat body size over more than a century and to relate them to urbanization. Location Mainland Italy. Methods We used traditional morphometrics to compare seven variables of skull size in 117 museum specimens (75 female, 42 male). Results Cranial size increased after 1950, but this change was not paralleled by an increase in body size, measured as forearm length. This selective increase matched a rapid increase in electric public illumination in Italy. Main conclusions Street lights are crucial foraging sites for P. kuhlii. The directional change that we found in cranial size might represent microevolutionary adaptive tracking of a sudden shift in food size, making more profitable prey available. [ABSTRACT FROM AUTHOR]

Aim High-latitude ectotherms are predicted to be less physiologically vulnerable to climate warming than tropical species based on their larger thermal safety margins, the distance between ambient temperatures and species' thermal optima. We sought to test the prediction that high latitude amphibians are buffered against the impacts of climate warming. Location British Columbia, Canada. Methods We estimated the risk from climate change for three high-latitude amphibian species ( Spea intermontana, Rana aurora and Pseudacris regilla) by combining thermal performance experiments with species distribution models and predicted changes in maximum summer temperatures through the 2080s, in order to demonstrate temporal and geographical trends in vulnerability to climate warming among and within species. Results We found that species have thermal safety margins of 3.2-3.8 °C based on current maximum summer temperatures. However, by the 2080s (emissions scenario A1B), we estimate that 45-82% of our focal species' current distributions will experience maximum summer temperatures above their thermal optima. We also found that by using long-term average temperatures, as some studies have done, there were almost no scenarios in which populations of any species were experiencing temperatures greater than their thermal optima. Main conclusions Combining spatially explicit species distribution models with performance physiology allows us to predict where limiting temperatures will occur in the coming decades, and can guide climate mitigation and conservation efforts before populations decline. Despite moderate thermal safety margins, high-latitude ectotherms can be highly vulnerable to climate warming when spatio-temporal variation is incorporated into estimates of risk as a result of climate change. [ABSTRACT FROM AUTHOR]

Physical habitat complexity regulates the structure and function of biological communities, although the mechanisms underlying this relationship remain unclear. Urbanisation, pollution, unsustainable resource exploitation and climate change have resulted in the widespread simplification (and loss) of habitats worldwide. One way to restore physical complexity to anthropogenically simplified habitats is through the use of artificial substrates, which also offer excellent opportunities to explore the effects of different components (variables) of complexity on biodiversity and community structure that would be difficult to separate in natural systems. Here, we describe a software program (CASU) that enables users to visualise static, physical complexity. CASU also provides output files that can be used to create artificial substrates for experimental and/or restoration studies. It has two different operational modes: simple and advanced. In simple mode, users can adjust the five main variables of informational complexity (i.e. the number of object types, relative abundance of object types, density of objects, variability and range in the objects’ dimensions, and their spatial arrangement) and visualise the changes as they do so. The advanced mode allows users to design artificial substrates by fine-tuning the complexity variables as well as alter object-specific parameters. We illustrate how CASU can be used to create tiles of different designs for application in a marine environment. Such an ability to systematically influence physical complexity could greatly facilitate ecological restoration by allowing conservationists to rebuild complexity in degraded and simplified habitats. [ABSTRACT FROM AUTHOR]

There are a few patterns in nature that are striking even to casual observers. These include patterns of species richness associated with latitude, elevation, rainfall and area. Current thinking suggests that a number of primary mechanisms determine richness variation and that these differ depending on the type of pattern and the biome to which they apply. Prominent among the many hypotheses that attempt to explain the latitudinal diversity gradient ( LDG) are those based either on climate or on historical factors such as past biome area. Climate-based and historically-based hypotheses have been regarded as competing alternatives, but there is growing acknowledgement that both are important. The evolutionary speed hypothesis ( ESH) is one of several climate-based hypotheses. According to this hypothesis the LDG is generated by thermally mediated asymmetries in evolutionary speed and diversification. Here we identify five relationships predicted by the ESH and survey the literature for empirical evidence for and against these relationships. We find these five relationships are supported by a number of empirical studies. However, there are gaps in this evidence that require further work and, because the relationship between temperature and species richness is negative when water is limited, a modification to the ESH is necessary. Additionally, we suggest that diversity patterns associated with area, temperature and water availability might all be influenced by a common mechanism associated with biologically available energy and its influence on the tempo of evolution. Rates of genetic evolution might also be influenced by spatial heterogeneity and rates of biotic and abiotic environmental change, potentially introducing positive feedbacks between diversification and genetic evolution. [ABSTRACT FROM AUTHOR]

•Remote sensing data are a key tool to assess large forested areas, where limitations such as accessibility and lack of field measurements are prevalent. Here, we have analysed datasets from moderate resolution imaging spectroradiometer (MODIS) satellite measurements and field data to assess the impacts of the 2005 drought in Amazonia. •We combined vegetation indices (VI) and climatological variables to evaluate the spatiotemporal patterns associated with the 2005 drought, and explore the relationships between remotely-sensed indices and forest inventory data on tree mortality. •There were differences in results based on c4 and c5 MODIS products. C5 VI showed no spatial relationship with rainfall or aerosol optical depth; however, distinct regions responded significantly to the increased radiation in 2005. The increase in the Enhanced VI (EVI) during 2005 showed a significant positive relationship ( P < 0.07) with the increase of tree mortality. By contrast, the normalized difference water index (NDWI) exhibited a significant negative relationship ( P < 0.09) with tree mortality. •Previous studies have suggested that the increase in EVI during the 2005 drought was associated with a positive response of forest photosynthesis to changes in the radiation income. We discuss the evidence that this increase could be related to structural changes in the canopy. [ABSTRACT FROM AUTHOR]

Despite the uncertainties associated with forecasts of the possible negative effects of climate change on natural environments, such research is often widely reported in the news media. Here we review the presentation in the UK news media and on the internet of an academic study published in Nature, forecasting future global extinctions as a result of climate change. The results and conclusions of the study were widely misrepresented, especially in the news media, to make the consequences seem more catastrophic and the timescale shorter. Representations of the original article on the internet were more variable, with several sites ranked highly on popular search engines being overtly critical of the underlying science. We suggest that such polarised representations of environmental science are indicative of a 'struggle for legitimacy' between environmentalist and anti-environmentalist groups, with potential negative consequences for public trust in science. [ABSTRACT FROM AUTHOR]

Many organisms will respond to climate change by shifting their ranges while pursuing potential climatically suitable areas. Predicting these area changes is important especially in dry areas such as the Brazilian semiarid biome, the Caatinga. Here we identified which Caatinga areas would be climatically suitable for small mammal species under different climate change scenarios; and quantified how much of these potential suitable areas would be gained or lost for each species under each scenario by 2050 and 2070. The small mammal species fall into two main ecological groups: 1) arid-adapted species with good climatic suitability for most of the Caatinga (four rodents were predicted to experience gain in their total suitable areas, while there was loss of suitable areas for all marsupials and two other rodents) and 2) species with good suitability for highlands or transitions areas with the Atlantic Forest (typically more vulnerable to climate change, experiencing loss of suitable area). These are the first predictions of climatically suitable area potentially lost and gained for the Caatinga small mammals during future climate change scenarios. Our results reinforce the need to ensure that conservation strategies are in place to deal with the unavoidable climate change consequences in this unique biome. [Display omitted] • Predicted reduction of climatically suitable area for 83.3% of 24 modelled species. • Only four arid-adapted rodent species will have climatically suitable area increase. • Suitable areas for small mammals are shrinking or will be practically inaccessible. • Typical mesic-adapted species in the Caatinga are more vulnerable to Climate Change. • There are potential savannization foci in the Atlantic Forest. [ABSTRACT FROM AUTHOR]

Brazil is currently one of the largest soybean and maize producers in the world. A dramatic increase in total production of these grains was possible due to the implementation of double cropping systems (two crops on the same land in the same agricultural calendar) in places where the wet season is sufficiently long. Although several recent studies have assessed soybean productivity change in South America after climate change, they have not considered important factors such as the decision whether or not to adopt double cropping systems and the incidence of diseases—both of which can influence planting dates. Here, we test five cultivars (expressed by total growing degree days) and 10 planting dates using two crop models and four climate models to assess soybean productivity in Brazil after climate change. Our results indicate that soybean productivity will increase in farms that choose to grow only one crop in the agricultural calendar (planting dates occur usually in November–December). However, the productivity of short-cycle cultivars planted in late September, typically sowed by farmers who chose to grow two crops in the same agricultural calendar, may dramatically decrease. While delaying planting dates of early planted cultivars can offset productivity loss, it may also compromise the possibility to plant a second crop. Furthermore, additional deforestation can lead to increased productivity loss due to further reductions in September and October rainfall. Urgent adaptation strategies are needed to maintain highly productive double cropping systems in Brazil in the advent of climate change. [ABSTRACT FROM AUTHOR]