Species distributions are often portrayed as binary representations of where they are present and absent. These are useful as rough guides but boundaries are virtually impossible to delineate accurately as the sampling effort to be certain of absence is prohibitive and populations near boundaries can be sparse and temporally variable. In this article, we highlight the advantages of focusing on relative abundance rather than presence‐absence and demonstrate methods that can be used to convert probabilities of presence to expected abundance. This has implications for climate change predictions and the management of invasive species and land‐use change.

In warming, drying climates, locally wet sites could form hydrologic microrefugia in which species could persist even as the surrounding landscape becomes unsuitable habitat. A wide variety of physical processes could form locally wet sites, which, if they meet physiological and community‐interaction requirements, could act as microrefugia. Identifying these sites could strengthen climate‐cognizant conservation strategies, but requires improved understanding of hard‐to‐observe hydrologic processes such as groundwater flow.

We show that loss of single predator species in isolation can, irrespective of their identity, trigger rapid secondary extinction cascades in natural communities far exceeding those generally predicted by theory. A food web model of our experimental system—a marine rocky shore community—could reproduce these results only when biologically likely and plausible nontrophic interactions, based on competition for space and predator‐avoidance behaviour, were included. Our findings call for a reassessment of the scale and nature of extinction cascades, particularly the inclusion of nontrophic interactions, in forecasts of the future of biodiversity.

Freshwater ecosystems are exposed to many stressors, including toxic chemicals and global warming. We were interested in exploring how these stressors, alone and in combination, propagate across levels of biological organization, including a key ecosystem process. We developed an individual‐based model of a freshwater amphipod, Gammarus pseudolimnaeus, feeding on leaf litter. We then tested, in different warming scenarios (+1–+4 °C), the effects of hypothetical toxicants on suborganismal processes, including feeding, somatic and maturity maintenance, growth, and reproduction. Warming in combination with toxicants had little effect at the individual and population levels, but ecosystem process was impaired in the warmer scenarios.

We investigated the hypothesis that urbanization reduces the global taxonomic and/or evolutionary diversity in birds. We found a strong and globally consistent reduction in taxonomic diversity in urban areas, which is also synchronized with the evolutionary homogenization of urban bird communities. Despite our general patterns, we found some regional differences in the intensity of the effect of cities on bird species richness or evolutionary distinctiveness, suggesting that conservation efforts should be adapted locally.

Assessing biodiversity change is essential to inform monitoring and conservation programs and evaluate implications of biodiversity loss to humans. We provide a comprehensive evaluation of a near‐half century (1969–2013) of changes in avian taxonomic, functional, and phylogenetic diversity across much of North America. We found increases in bird diversity until ca. 2000, followed by a slow decline since, suggesting recent loss of avian diversity. We also found biotic homogenization of avian assemblages in terms of their functional characteristics. Lastly, we found that assemblage changes were greatest at high elevations and latitudes—consistent with purported effects of ongoing climate change on biodiversity.

Bycatch mortality from fisheries is clearly among the most serious global threats for marine ecosystems, especially for top predators. Here we estimate for the first time both bycatch mortality rates and their population‐level effects on three endemic and vulnerable Mediterranean taxa: Scopoli's shearwater, Mediterranean shag, and Audouin's gull, that die in different types of fishing gears. Bycatch mortality was significant for the three species, but varied enormously between types of fishing gear, the species of seabird and even the ages of individuals. Different life‐history traits and compensatory demographic mechanisms between the three species are probably influencing the bycatch impact: especially for shearwaters, urgent conservation actions are required to ensure the viability of their populations.

Based on a new complete database on birds' colour polymorphism, we show that polymorphic species, such as these Parasitic jaeger and Northern fulmar, are at lesser risk of extinction than nonpolymorphic species. The higher genetic variation we detected in polymorphic species might explain this result. In contrast, we could not detect any difference in polymorphic species vulnerability to specific extinction drivers (habitat destruction, direct exploitation, climate change or invasive species).

Land‐use change is one of the main anthropogenic drivers of species loss, yet its consequence on other components of biodiversity is poorly understood. By investigating the trophic associations between primary producers and consumers along a gradient of landscape simplification across Europe, we show a loss of both functional and phylogenetic associations between plants and butterflies in landscapes now dominated by arable land. These processes occurred even without immediate reductions of species richness. This approach significantly advances our understanding of the functional consequences of species associations’ loss for biodiversity in a changing world. It provides an innovative tool for early warning of alteration in ecosystem functioning.

An increased magnitude and duration of winter and spring flooding by rain‐fed streams and rivers are expected, likely affecting riparian plant communities. We experimentally modified the hydrology of five streams across three countries in north‐western Europe during late winter/early spring and assessed the responses in riparian plant species richness, biomass, plant‐available nitrogen and phosphorus and seed deposition to increased flooding depth and duration. After 3 years of increased flooding, there was an overall decline in riparian species richness, while riparian plant biomass, extractable soil nitrogen and phosphorus increased. More seeds of additional species were deposited in the riparian zone, potentially facilitating the shifts in riparian plant species composition we observed. Changes in stream riparian plant communities can occur rapidly following increased winter flooding, leading to reductions in plant species diversity.

Warmer water enhances decomposition of organic matter in streams and rivers, but it is unclear if climate change will result in more carbon emitted to the atmosphere or transported to the ocean. We assembled over 1000 published data points on leaf litter breakdown in streams and rivers globally to assess how rates of breakdown will change with elevated temperature. Across 85 plant genera, we found that rates may increase only half as much as expected should water temperature rise by 1–4 °C. Among 12 plant genera for which temperature sensitivity could be calculated individually, higher sensitivity was correlated with lower quality litter. Similarity in the temperature sensitivity of breakdown mediated by microbes alone or microbes plus detritivores suggests the relative proportions of carbon converted to gas or transported as smaller particles will not change with elevated temperature.

We evaluate vegetation carbon turnover processes in global vegetation models (GVMs) participating in the Inter‐Sectoral Impact Model Intercomparison Project (ISI‐MIP, including HYBRID4, JeDi, JULES, LPJml, ORCHIDEE, SDGVM, and VISIT) using estimates of vegetation carbon turnover rate (k) derived from a combination of remote sensing based products of biomass and net primary production (NPP). We find that current model limitations lead to considerable biases in the simulated biomass and in k (severe underestimations by all models except JeDi and VISIT compared to observation‐based average k), likely contributing to underestimation of positive feedbacks of the northern forest carbon balance to climate change caused by changes in forest mortality. A need for improved turnover concepts related to frost damage, drought, and insect outbreaks to better reproduce observation‐based spatial patterns in k and biomass is identified.

Determining whether the terrestrial biosphere will be a source or sink of carbon (C) under a future climate of elevated CO₂ (eCO₂) and warming requires accurate quantification of gross primary production (GPP), the largest flux of C in the global C cycle. We evaluated 6 years (2007–2012) of flux‐derived GPP data from the Prairie Heating and CO₂ Enrichment (PHACE) experiment, situated in a grassland in Wyoming, USA. The GPP data were used to calibrate a light‐response model whose basic formulation has been successfully used in a variety of ecosystems. Stimulation of cumulative 6‐year GPP by warming (29%, P = 0.02) and eCO₂ (26%, P = 0.07) was primarily driven by enhanced C uptake during spring (129%, P = 0.001) and fall (124%, P = 0.001), respectively, which was consistent across years. Antecedent air temperature (Tair_ant) and vapor pressure deficit (VPD_ant) effects were the most significant predictors of temporal variability in GPP among most treatments.

Wetland sediments recovered from the Prairie Pothole Region of North America host microbial communities catalyzing some of the highest sulfate reduction rates ever measured. Concurrently, these same sediments drive some of the highest methane fluxes to atmosphere ever measured. Together, these data indicate that the PPR may play an oversized role in carbon cycling and greenhouse gas fluxes to the atmosphere.

Experimental air warming increased emissions of all three greenhouse gases (GHGs), including the highly understudied N₂O, clearly demonstrating the need to include N₂O in future Arctic GHG budgets. Increased GHG fluxes were regulated by changes in plant functioning and biogeochemical processes, leading to an enhanced soil input of labile carbon compounds via leaching. Plants were also identified as the main regulator of arctic N₂O emissions. Importantly, we highlight the tight linkages between plant and soil processes, and the interactions between the top‐soil and deeper soil layers, in regulating arctic GHG exchange.

The enhanced winter soil frost did not significantly affect the growing season gross primary production (GPP) and ecosystem respiration (ER) in the short term; however, in the long term (i.e. after 11 consecutive winters with enhanced soil frost treatment), the growing season ER was reduced and seasonal pattern of GPP was changed.

The distribution of dry, extreme dry, and wet years from 1953 to 2014 (Bases: 1950–1980 average precipitation). The shaded area represents the time frame of the oak decline. Dry conditions in forest, forest stand composition and diversity change, net primary production, and oak decline.

Climate warming is expected to increase plant productivity and growth especially in temperature‐limited environments; however, vegetation dynamics considering concurrently both shrubs and trees are still not well explored. We investigated, with a dendroecological approach, the growth trends and climate sensitivity of Juniperus communis L. and coexisting trees to better understand their responses to recent climate in three contrasting biomes, Polar, Alpine and Mediterranean, across the European continent. Shrub and tree growth forms revealed divergent growth trends in all biomes, with juniper performing better than trees at Mediterranean than at Polar and Alpine sites. The post‐1980s decline of tree growth in Mediterranean sites might be induced by drought stress amplified by climate warming and did not affect junipers. This study emphasizes that other climatic drivers, as drought or snow cover, in addition to temperature could play a fundamental role in defining future woody plant growth under the pressure of climate changes.

The highest‐resolution paloeclimatic history yet available from Amazonia reveals a long history of maize agriculture around Lake Sauce, Peru. When agriculture intensified about 3000 years ago, it increased erosion into the lake. The erosion reflected local climatic variability and sediment color analysis revealed a characteristic 2‐ to 8‐year periodicity, a signal associated with El Nino–Southern Oscillation. The ENSO signal had been there prior to human‐induced erosion, but human activity amplified the pattern to make it detectable. Humans can induce climate change, and their activity can also make latent patterns evident.

Fertilizer use is expected to increase by more than an order of magnitude in sub‐Saharan Africa, to increase food production and reduce food insecurity. We measured emissions of nitric oxide, a precursor to tropospheric ozone pollution, over 2 years from experimental maize plots in western Kenya to understand how agricultural intensification may affect air quality and to quantify the relationship between nitrogen inputs and NO emissions. We found evidence that nitric oxide emissions increase as a sigmoidal function of the rate of nitrogen additions, with the highest emissions occurring above recommended fertilization rates. Using an atmospheric chemical transport model, we find that changes in tropospheric ozone pollution driven by increased fertilizer‐induced nitric oxide emissions are unlikely to negatively impact crop production in western Kenya.

We included global pyrogenic carbon (PyC) cycling in a coupled climate–carbon model to assess the role of PyC in historical and future simulations. PyC cycling decreased atmospheric CO₂ only slightly between 1751 and 2000 as PyC‐related fluxes changed little over the period. For 2000 to 2300, PyC cycling will likely reduce the future increase in atmospheric CO₂ if landscape fires become much more frequent; otherwise, PyC cycling might contribute to, rather than mitigate, the future increase in atmospheric CO₂.

We perform a North America continent‐wide (México, United States, Canada) climate change vulnerability assessment to quantify potential patterns of climate relocation within, among, and outside protected areas. Our analysis suggests that the conservation capacity of the North American protection network is likely to be severely compromised by a changing climate as the majority of protected areas might be exposed to high rates of climate displacement. The majority of nearest climatic analogs for protected areas are in nonprotected locations, and therefore, unprotected landscapes could pose additional threats (beyond climate forcing itself) as sensitive biota may have to migrate farther than what is prescribed by the climate velocity to reach a protected area destination.

Boreal forest–wetland landscapes in the lowlands of northwestern Canada store large organic carbon stocks and act as long‐term CO₂ sinks to the atmosphere. Thaw‐induced wetland expansion has negligible effects on net ecosystem CO₂ exchange of these landscapes as indicated by nested eddy covariance flux measurements. In contrast, boreal forest–wetland landscapes may no longer act as net CO₂ sinks in an exceedingly warmer climate as indicated by combining climate projections with a simple CO₂ flux model. These changes in net ecosystem CO₂ exchange are five times smaller for a moderate warming scenario (RCP 4.5) compared to the scenario leading to the strongest warming (RCP 8.5). The fate of organic carbon in these landscapes depends therefore largely on the degree of warming during the 21st century.

We used field surveys and experimental manipulations to examine how warming and fire affect shrub seedling recruitment and growth and survival. We found that warming, coupled with more frequent or severe fires, will likely increase the cover and abundance of evergreen shrubs—a major fuel for alpine fires. As a consequence, warming is likely to strengthen an existing feedback between shrub abundance and fire in these ecosystems.

Assessing how historical processes modulate the response of ecosystems to perturbations is pivotal to understand the effects of global change. Here, using experiments in combination with Stochastic Antecedent Modelling, we asked how ecological memory – the signature of past ecological processes – shapes the response of epilithic microphytobenthos (EMPB) to extreme warming, sediment deposition and grazing events. Our results provide empirical support to the theoretical expectation that stochastic fluctuations promote ecological memory, but also show that contingencies may lead to memory loss.

Phytoplankton form the base of most aquatic ecosystems. We show that when nutrients are low, phytoplankton are less able to tolerate extreme temperatures. The temperature at which they grow most quickly (their optimum temperature) also decreases. This means that hot, low‐nutrient conditions – commonly found in the tropical oceans – are a major challenge to species’ survival. Many species’ ranges may therefore be smaller than previously recognized. In the future, warming will increase the area of the ocean in which these challenging conditions are found, reducing these ranges even further.

Growth at the root collar is much more sensitive to climate than growth of the stem for a widely distributed shrub species, Betula glandulosa. These differences were maintained across common tundra ecosystems in Northern Canada and have important implications for sampling strategies when trying to quantify tundra change at a global scale.

Rising global temperatures are suggested to be drivers of shifts in tree species ranges, but long‐term shifts in tree species ranges remain poorly documented. We test for shifts in the northern range limits of 16 temperate tree species in Quebec, Canada, using forest inventory data spanning three decades, 15° of longitude and 7° of latitude. Tree species ranges shifted predominantly northward; however, species latitudinal velocities were on average <50% of the velocity required to equal the spatial velocity of climate change. Our results add to the body of evidence suggesting limited capacity of tree species to track climate warming, supporting concerns that warming will negatively impact the functioning of forest ecosystems.

Here we provide a framework and application for tree species vulnerability in the eastern US focused on management application. We incorporated climate change exposure, species‐specific sensitivity, and adaptive capacity for 40 tree species at 800 m resolution. Most species were considered vulnerable to climate change, particularly those in the northern states and at high‐elevation, although there were notable cases of resilience.

We use spatiotemporal spring phenology observations for 22 UK plant species to estimate the temperature‐mediated plasticity of each species and the degree to which optimum timing changes with temperature. We find that all species are highly plastic and that in most cases, this plasticity is adaptive (i.e. it partially tracks temperature‐mediated changes in the phenological optimum).

Adult and sapling distributions of dominant tree species in mountains of the northeastern United States suggest a potential upslope shift only for American beech, downslope shifts for sugar maple and red spruce, and no change with elevation for balsam fir. All species exhibited individualistic responses to climate and land use, and the return of red spruce to lower elevations, where past logging originally benefited northern hardwood species, indicates that land use may mask species range shifts caused by changing climate.

The phenology of tree diameter‐growth cessation in autumn is an important process that strongly impacts organism and ecosystem function, but its environmental and genetic drivers are poorly understood, impeding predictions of climate change impacts. As favorable growing conditions shift later into autumn with warming, trees would likely need to delay the timing of growth cessation to track favorable climate. We studied diameter‐growth cessation in coast Douglas‐fir (a foundation species) and found that cool temperatures or short photoperiods can induce cessation, implying that in cool parts of the range low temperatures primarily trigger cessation, while in warm parts short photoperiods are the primary cue. In addition, we found that trees from seed sources with higher frost frequencies tended to cease growth earlier. Thus, climate change will likely lead to strong shifts to later cessation in cool locations, but weak shifts in warm locations, reflecting photoperiod and genetic limitations on phenological responses.

We performed a phylogenetically‐controlled meta‐analysis to assess whether there is a general pattern of differences in invasive and native plant performance under each component of global environmental change, using a database of studies that reported performance measures for 74 invasive alien plant species and 117 native plant species. We found that elevated temperature and CO₂ enrichment increased performance of invasive alien plants more strongly than was the case for native plants. Invasive alien plants tended to also have a slightly stronger positive response to increased N deposition and increased precipitation than native plants, but these differences were not significant. Invasive alien plants tended to have a slightly stronger negative response to decreased precipitation than native plants, although this difference was also not significant.

To investigate how altered nitrogen and rainfall modulate the effect of warming on soil carbon fluxes, we synthesized global data on soil carbon pool, input and loss from experiments simulating nitrogen deposition, drought and increased precipitation and quantified the responses of soil carbon fluxes and equilibrium to the three single factors and their interactions with warming. We found that the positive carbon–warming feedback was modulated by the changing nitrogen and rainfall regimes. Further, we found that simple additive simulation overestimated the ‘real’ effects on soil carbon fluxes, suggesting that more multifactorial experiments should be considered in studying Earth systems.

We find that the old pastures (≥24 years) have a high C storage, explained by a large part of C3 originated by legumes and shrubs and the increased of C4 grass. This carbon is mainly sequestered in the humus of deep soil layers (20–100 cm). Establishing the pasture with a mixture of plant species could provide unlimited accumulation of C in the long‐term.

Path analysis indicated that environmental variables and substrate properties together explained 52% of total variation in temperature sensitivity (Q₁₀) of soil organic matter decomposition across all sites. Soil pH and soil electrical conductivity (EC) explained most variation in Q₁₀.

In normal rainfall years, N fertilization stimulated total soil respiration by increased autotrophic respiration. Soil respiration was unresponsive to N fertilization in a record wet year due to reduction in both autotrophic and heterotrophic respiration by extreme rainfall. Extreme snowfall stimulated nongrowing season soil respiration but reduced its response to N fertilization.

Numerous processes drive the global spatial distribution of phosphorus (P) in agricultural soils, but their relative roles remain unclear. Thanks to a modelling approach, we found that almost all of the global spatial variability in total soil P in cropland soils (P_TOT) could be explained by the distribution of the soil biogeochemical background (that determines the P content of soils at the conversion to agriculture, BIOG), while both BIOG and farming practices (FARM) explained the spatial variability in inorganic labile P (P_ILAB) (~40% and ~60%, respectively).