Knowledge of the climatic drivers of a focal ecological system can be used to guide the analytical framework used in climate change impact assessments. We review key aspects of climate model performance and summarize methodological approaches for incorporating projected changes in climatic means and extremes into impact assessments.

The increasing conversion of agricultural and natural areas to urban landscapes is predicted to lead to a major decline in global biodiversity. However, the extent and spatial scale at which these altered conditions shape biotic communities through selection and/or filtering on species traits is poorly understood. We repeatedly sampled carabid beetle communities at three different local-scale urbanization levels in landscapes showing the same variation in urbanization. Urban communities showed a clear turnover of species tolerating higher temperatures and an almost complete depletion of low dispersive species in the most urbanized localities. The observed shifts in community traits were most pronounced at the local scale, although more subtle effects were even observed at the landscape scale. Our results demonstrate that urbanization may consistently alter species composition by exerting a strong filtering effect on species dispersal characteristics and favouring replacement by warm-dwelling species.

The conservation of monarch butterflies requires linking populations across different portions of the annual cycle and understanding how variation in weather and climate influences productivity, recruitment, and patterns of long-distance movement. Tyler Flockhart et al. associate the natal origin of monarch butterflies overwintering in Mexico collected over almost four decades with global oscillation patterns and region-specific temperature and precipitation. The results suggest that ongoing conservation efforts on the breeding grounds should focus on the US Midwest region, but the population will likely remain sensitive to regional and stochastic weather patterns.

Climate change is causing the loss of glaciers and snowfields worldwide, leading to major changes in alpine stream ecosystems. Using a large dataset with high-resolution climate and habitat information, we describe the distribution, status, and key environmental features that limit the distributions of two rare alpine insects, the meltwater and western glacier stoneflies, which were recently recommended for listing under the U.S. Endangered Species Act. Our results clearly link the loss of alpine glaciers and snowfields to the fate of both species, providing a rare direct connection between climate-induced habitat change and mountaintop biodiversity.

Annual variation in the distribution of species within a marine assemblage was explained by winter temperatures. The response of individual species was predictable based on their temperature preference.

Under anthropogenic climate change, living systems in the ocean are experiencing stressors including elevated temperature and decreased productivity. Here, we hypothesize a further stressor: ocean circulation change. This threatens to modify the flow pathways used by marine species for dispersing their larval stages, potentially preventing them from reaching settling grounds. Using a global simulation of an extreme climate scenario, we calculate how dispersal pathways for the entire global coastline may change over the 21st century. We highlight regions with the greatest circulation stress, where pathways run with/against climate change, and where connectivity may weaken, strengthen or alter entirely in the future.

Experimental whole-stream warming altered invertebrate assemblage structure and decreased total invertebrate abundance by 60% relative to a reference stream, while invertebrate biomass was unchanged due to invasions of new taxa and increased proportions of large, warm-adapted species relative to small-bodied, cold-adapted taxa. Community-level energy demand increased due to higher temperatures and was presumably met by increased primary production during warming.

White light-emitting diodes (LEDs) are rapidly replacing conventional outdoor lighting around the world, despite rising concerns over their effects on animals and plants. We compared the efficacy with which alternative lighting strategies reduced the number of ground-dwelling invertebrate taxa aggregating under LEDs. A combination of dimming by 50% and switching lights off between midnight and 04:00 am showed the most promise for reducing the ecological impacts of LEDs, but did not avoid them altogether. Averting the environmental consequences of LEDs and other lighting technologies may ultimately require avoiding their use altogether.

Warmer temperatures are accelerating the phenology of organisms around the world, and temperature sensitivity of phenology might be greater in colder, higher latitude sites than in warmer regions. We tested this hypothesis using phenology data for 47 tundra plant species at 18 high-latitude sites along a climatic gradient. Across all species, the timing of leaf emergence and flowering was more sensitive to a given increase in summer temperature at colder than warmer high-latitude locations. These are among the first results highlighting differential phenological responses of plants across a climatic gradient and suggest the possibility of convergence in flowering times and therefore an increase in gene flow across latitudes as the climate warms. (Photo credit: Anne D. Bjorkman)

Results indicate that a threshold shift to increased permafrost loss occurred following the severe ENSO of 1997/1998. Hydro-climate data indicate significant changes in the timing and amount of snow accumulation, shift warmer air temperatures, and coincident increase in areal run-off after 1998. Morphological changes in permafrost area are demonstrated using multitemporal airborne Light Detection And Ranging (LiDAR) and optical image analogues. Woody vegetation growth in wetlands and tree mortality at thawing plateau/wetland boundaries may be indicative of a tipping point in drainage efficiency and landscape evolution if permafrost loss continues.

This study quantifies the current and future yield responses of US rainfed maize and soybean to climate extremes and for the first time characterizes spatial shifts in the relative importance of high temperature, heat and drought stress.

Global grassland gross primary production (GPP) was first estimated by an improved model tree ensemble approach considering human interventions (grazing and cutting). Global grassland GPP was on average 11 ± 0.31 Pg C per year and exhibited significantly increasing trend at both annual and seasonal scales, with an annual increase of 0.023 Pg C (0.2%) from 1982 to 2011. Arid and semiarid regions dominated the trend and variability of the global grassland gross carbon dioxide uptake at both seasonal and annual time scales.

We used the ecohydrological model SOILWAT to explore the impact of climate change-induced changes in vegetation cover and composition on soil water availability. We found that for many sites, vegetation changes are likely to lead to a decrease in soil water availability. This can lead to more ecological droughts despite higher rainfall. The negative impact of vegetation on soil water availability increases with a higher change in vegetation biomass.

Ecosystem models have widely varying responses to climate and CO₂, including temperature responses that are largely opposite to those seen in tree-ring data. Although models show the greatest differences in response to precipitation, compounding differences in CO₂ response cause increased ensemble uncertainty in change in net primary productivity (NPP) in the past century relative to the presettlement era.

Wetlands are landscape hotspots for greenhouse gas exchange, but their overall climate effects are uncertain due to simultaneous uptake and release of different greenhouse gases and the complexity of regulating processes. We estimated an annual greenhouse gas budget for a restored wetland in the Sacramento Delta California using a suite of complementary techniques to overcome the challenges of wetland complexity. We found that greenhouse gas fluxes produced an overall warming climate effect and were sensitive to aboveground cover type, gas transport pathway, and wetland seasonality.

We analysed and modelled temperature-dependent changes in photosynthetic capacity in 10 wet-forest tree species; six from temperate forests and four from tropical forests. Area-based rates of photosynthetic apacity (V_cmax) linearly declined with increasing growth temperature, linked to a concomitant decline in total leaf protein per unit leaf area and Rubisco as a percentage of leaf nitrogen. A new model is proposed that accounts for the effect of growth temperature-mediated declines in V_cmax on photosynthesis.

• Phenology cycle (changes in vegetation greenness) in urban areas starts earlier and ends later, resulting in a longer growing season length (GSL), when compared to the respective surrounding urban areas.
• The average difference of GSL between urban and rural areas is consistent among different climate zones in the United States, whereas their magnitudes are varying across regions.
• A tenfold increase in urban size could result in an earlier start of season of about 1.3 days and a later end of season (EOS) of around 2.4 days, with a growing season length extended by approximately 3.6 days.

We conducted field experiments where more than 150 000 trees from 116 geographically diverse populations of sessile oak were planted on 23 field sites in six European countries. Population responses for tree growth and survival were modeled for contemporary climate and then projected using data from four regional climate models for years 2071–2100. Overall, results indicated a moderate response of sessile oak to climate variation, with changes in dryness explaining a predominant part of the response. Stronger and more negative future responses are expected for southeastern populations (Turkey, Hungary) than for central and northern populations (Denmark, Norway).

This study evaluates the long-term effects of conservation vs. conventional tillage and residue management on crop yield, soil greenhouse gas (GHG) emissions, soil organic carbon (SOC) change, and global warming potential (GWP) of an irrigated continuous corn production system. Conservation practices reduced GWP, but all systems were net GHG sources due to SOC losses. Although there was no added benefit in pairing conservation practices, other agroecosystem goals to enhance soil health and reduce soil erosion will also affect producer decisions.

The two non-native grasses that have established long-term populations in Antarctica (Poa pratensis and Poa annua) were studied from a global multidimensional thermal niche perspective to address the biological invasion risk to Antarctica. We conclude that several areas across the region are vulnerable to invasions from these and other similar species.

We studied the relationship between fluorescence and photosynthesis at the leaf, canopy, and larger scales using both field-based and satellite remote sensing data across the entire growing season. We found that fluorescence captured the seasonal variations of photosynthesis with a linear relationship over different spatial scales. Our results suggest that fluorescence is a useful proxy to monitor photosynthesis at leaf, canopy, and ecosystem scales.

Droughts are closely related to the reduced growth of trembling aspen in western Canadian boreal forests. Drought indices could be applied to monitor the potential effects of increased drought stress on aspen trees growth, achieving classification of eco-regions and developing effective mitigation strategies to maintain western Canadian boreal forests.

We analyzed dynamics of forest growth and GPP in relation to climate change and [CO₂] across the western Mediterranean. Tree growth was not enhanced in the recent past despite raising [CO₂]. Models suggest that forests would mostly resist an increase in temperature below +2 °C. Further warming over that threshold would result in very negative Mediterranean forest performance. A strong fertilization effect in response to exponentially raising [CO₂] could counteract the negative effect of a warmer climate, but this effect seems unrealistic.