This article emphasizes on biological interactions as an important overlooked criterion to better assess the chance of target marine species in potential refugia to survive climate change. It proposes future climate change refugia studies must consider the reciprocal interactions among climate change, biological factor, and conservation strategies.

Hierarchy levels and building units of micro- and macroaggregates and related separation methods. The hierarchy levels (left arrow) are inversely related to the energy necessary for the disruption (right arrow).

We reprocessed existing amino sugar data, published between 1996 and 2018 from global agricultural, grassland, and forest ecosystems in temperate zones, by scaling them up to microbial necromass carbon. On average, microbial necromass abundance increased in the order agricultural < grassland < forest, while its contribution to soil organic carbon (SOC) storage was lowest in the forest ecosystem. Fungal necromass abundance and its contribution to SOC were consistently higher than bacterial necromass. Microbial necromass can make up more than half of SOC pool, suggesting the need to understand microbial necromass conservation in the context of soil management and climate change mitigation.

Plant phenology offers insight into plant biology and plant-mediated ecosystem processes. However, many plant phenological processes are “cryptic” in that they are hidden (e.g., root production) or undistinguishable based on common measurements at typical scales of examination (e.g., leaf turnover in evergreen forests). Here, we offer a framework for cryptic phenology and synthesize literature with a focus on whether terrestrial biosphere models currently capture cryptic phenology. We illustrate how capturing cryptic phenological processes can advance scientific understanding and vegetation modeling with two case studies: wood phenology in a temperate deciduous forest and leaf phenology in tropical evergreen forests of Amazonia.

As countries advance in greenhouse gas (GHG) accounting for climate change mitigation, consistent estimates of aboveground biomass change (∆AGB) in natural forests are needed. Countries with limited forest monitoring capabilities in the (sub)tropics rely on the 2006 IPCC guidelines for default ∆AGB rates. This study provides refined default ∆AGB rate estimates based on forest plot data in younger secondary forests, older secondary forests and old-growth forests, located in 42 countries across (sub)tropical ecozones. These new estimates contribute towards the 2019 IPCC Refinement and can be used for large-scale GHG accounting by governmental bodies, nongovernmental organizations and in scientific research.

The understorey in temperate forests is an important biodiversity reservoir that can influence ecosystem functioning in multiple ways. We here compiled studies that quantify the relative importance of the understorey for temperate forest functioning, focussing on litter production, tree regeneration, nutrient cycling and evapotranspiration and show that the understorey's contribution to temperate forest functioning is significant but varies depending on the ecosystem function and the environmental context. Our review also shows that studies that quantify both overstorey and understorey functioning are still scarce, providing little data to forecast changes in the understorey's relative importance under global change.

The small hive beetle (SHB) is an invasive honey bee pest. We investigated the potential distribution and impact of the small have beetle based on its ability to pupate under current and future climate conditions. The results show many areas yet uninvaded, as suitable for pupation, suggesting considerable invasion risk. Future scenarios of global warming project a vehement increase in climatic suitability for SHBs to pupate. Our study shows that climate change, and global warming in particular, can promote the impact of a honey bee pest on a global scale.

Spatially autocorrelated weather and climate may cause population co-fluctuations over large distances. We show that increasingly frequent rain-on-snow (ROS) and icing events in winter synchronize the annual dynamics of Svalbard reindeer populations, while, paradoxically, spatial variation in ROS trends and density-dependent weather effects cause diverging local population trajectories in the long run. Such decoupling of population dynamics increases species viability under a rapidly warming high-Arctic climate.

Indirect effects of climate change are often mediated by trophic interactions and consequences for individual species depend on how they are tied into the local food web. Here we show that the breeding density of an arctic bird of prey decreased when small rodents, its main prey, experienced a shift from high-amplitude cycles to moderate fluctuations paralleled with a change in species composition toward less lemmings and more voles. At the same time, however, the birds still breeding had on average larger broods, suggesting that the population adapted to a certain degree to the changes in the major resource.

A long-term study on spring-migrating barnacle geese (Branta leucopsis) from the Svalbard-breeding population demonstrates that geese recently have colonized a new, more northerly staging area (Vesterålen, Norway). In this northern area, food conditions have improved due to a warmer climate. The population has doubled in size during the past 25 years, and we argue that this is associated with the northerly area becoming suitable as a foraging ground. The colonization of the northerly area was set in motion by younger individuals. In later years, older birds followed, and increasingly chose to switch to the northerly area.

Despite our growing understanding of the impacts of invasive plants on ecosystem structure and function, important gaps remain, including whether resident native and exotic species respond differently to plant invasion. We found that invasive plants reduced the abundance of native, but not exotic, animals, though this varied by animal phyla, with invasive plants reducing the abundance of native annelids and chordates, but not mollusks or arthropods. We provide an important first insight into how native and exotic species respond differently to plant invasion, the consequences of which may facilitate cascading trophic disruptions further exacerbating the impacts of invasive plants.

New data-driven estimates of cropland-nitrous oxide (N₂O) emissions across China in 1990–2014 improves our understanding of their historical trends and associated drivers. The data illuminate a direct evidence of the nationwide deceleration of cropland-N₂O emissions since 2003, mainly due to policy-driven reduction of nitrogen-fertilizer applied per area. These findings that challenge the traditional views about the continuous increase in cropland-N₂O emissions in China, underline the potential value of local policy interventions for future projections.

Food production in sub-Saharan Africa needs to rise steeply to keep up with food demands. Self-sufficiency can be achieved by either intensifying or expanding agricultural land. Our study provides insights into the consequences of these on greenhouse gas (GHG) emissions towards 2050. We show that GHG emissions from cereal production (including emissions from fertilizer use and land use change) will increase in all scenarios. Intensifying cereal cropping with efficient use of nutrients will lead to less GHG emissions than expanding cereal cropping into forest areas.

NIR_V, a new remote sensing product, provides a robust basis for estimating photosynthesis at the global scale. Bottom-up and top-down estimates of global GPP disagree by over 50 Pg C/year. NIR_v offers an opportunity for studying and bridging this disconnect.

This study showed a large uncertainty in accounting carbon fluxes (E_luc) from land use and land cover change (LULCC) in the conterminous United States. We compared the E_luc from model simulations by using a commonly used global land use database (LUH2) and a US-specific, multisource harmonized land use data (YLmap). Simulation results showed that the LUH2-based LULCC data resulted in a C accumulation of 1,121.0 ± 90.9 Tg from 1980 to 2016, while YLmap-based LULCC led to a carbon source of 501.5 ± 130.8 Tg during the same period. The opposite estimates may be attributed to the aggregated land conversion signals in coarse resolution database of LUH2.

In a 19 year study in California, compost + cover crops in a maize–tomato rotation increased soil carbon by 12% to 2 m, whereas cover crops alone resulted in cumulative soil carbon losses when considering the entire 2 m profile. Reliance on synthetic inputs alone resulted in no soil carbon changes to a 2 m depth in maize–tomato, and wheat–fallow rotations showed little potential to increase soil carbon. Measuring soil carbon in only the surface would have resulted in over- and underestimates of soil carbon changes; therefore, the entire soil profile should be considered when estimating the potential for soil carbon sequestration.

This is the first dynamic vegetation model that simulates lianas. We predict a strong impact on the carbon stocks, especially for younger (secondary) forests where liana density is higher.

There is an urgent need to assess the specific responses of trees to both drought and spring frost to provide solid bases for decision-making regarding the selection of tree species matching the ongoing environmental change. Using tree-ring width series from 2,844 trees from 104 Swiss sites ranging from 400 to 2,200 m a.s.l. for the period 1930–2016, we found strong disparities in the species resistance and resilience to extreme droughts and spring frosts. Oak, fir, and to a lower extent beech could moderately cope with severe droughts whereas spruce and larch only poorly resist and recover after such events.

Drought-induced tree mortality is projected to increase due to climate change, yet predictions of tree mortality remain limited, in part because within-species variations in ecophysiology and ecosystem adjustments could buffer mortality in dry locations. Here, we conduct a meta-analysis of 50 studies spanning >100 woody plant species globally to quantify how populations within species vary in vulnerability to drought mortality. We find that climate stress has exceeded physiological and ecosystem-level tolerance or compensating mechanisms by triggering extensive mortality at dry range edges, providing a foundation for future mortality projections in empirical distribution and mechanistic vegetation models.

We quantified the impact of repeated or multi-year drought, that is, drought occurring during the recovery from previous drought, upon growth in ponderosa pine in the western US. Consistent with expectation, we found more droughts had greater impacts on growth, but unexpectedly, differences in responses among regions suggested regional adaptations to frequent drought. We argue considering the long memory of tree response to climate is critical.

Extreme climatic and weather events are increasing in frequency and intensity across the world causing episodes of widespread tree mortality. We investigated the effects of two major local factors, topography and forest successional type, on climate-induced tropical tree mortality patterns in northwestern Mexico using an observational and modeling approach. Elevation is the main factor modulating frost effects. Holding elevation constant, the probability of frost-induced tree mortality in mature forests was twice that of secondary forests but severity showed the opposite pattern, suggesting a cautious use of occurrence probabilities of tree mortality to infer climate-driven disturbance severity.

Fire refugia (i.e. unburnt patches) are important for the persistence of fire-sensitive species in forests, though the fate of fire refugia under climate change is unknown. Quantification of the relative effects of climate and landscape factors on refugia patterns across Australian temperate forests revealed that fire weather and drought override the effect of topography and fuel age on fire refugia, with less refugia being present under severe fire weather and intense drought. Climate change is likely to lead to the contraction and loss of persistent fire refugia across temperate forests of southern Australia.

As human impact on natural processes grows, species distributions are increasingly overridden by anthropogenic influence, such as altered wildfire regimes and ecological restoration. Incorporating these anthropogenic variables into species distribution models is a research need that is complicated by the scale mismatch between regional distributions and fine-scale variation in anthropogenic impacts. Our study demonstrates how novel datasets and spatial models can resolve this challenge. We apply our modeling framework to understand the distribution of big sagebrush across the Great Basin of North America. We found that wildfire and restoration treatment history have effects that are comparable to climate and topography.

Sphagnum photosynthesis supports carbon (C) assimilation in peatlands—a major C pool. New research shows that Sphagnum primary productivity resists climate warming over the growing season. Species phenotypic plasticity is the key to maintain C assimilation under climate warming. The conservation of the full peat bog species pool appears as the chief priority in the mitigation of peatland impacts on climate change.

We test a new proxy for ecological network deformation caused by external stress, using diatom (algal) assemblages across China. We link species through shared habitats (top-left panel, upper part) to obtain a network of associations (top-left, lower). We argue that undisturbed lakes will have positively skewed distributions in their degree of species associations (top-right, upper), while disturbed lakes will shift towards negative skew (top-right, lower). Field data show the frequency distributions of species associations that switch from positive to negative skew across a west–east gradient of increasing disturbance (bottom panel map) linked to human population density (bottom graph).

Globally, freshwater megafauna populations declined by 88% from 1970 to 2012, with the highest declines in the Indomalaya and Palearctic realms (−99% and −97%, respectively). Among taxonomic groups, mega-fishes exhibited the greatest global decline (−94%). In addition to population declines, major range contractions of freshwater megafauna have been observed, which is more pronounced in Europe than in the United States.

Upper thermal limits were reduced by exposure to infectious disease; and depended on the severity of infection, the type of thermal stress encountered and the specific genotype of both the host and pathogen. We observed that pathogens could reduce thermal limits at a magnitude equivalent in scale to the natural variation in thermal limits seen within species over large geographic and ecological ranges.

Ocean warming has rapidly expanded the amount of thermally suitable bottom habitat for settling American lobster postlarvae in the Gulf of Maine. Local oceanography, coupled with nonlinear responses to warming, may have led to a demographic expansion disproportionate to the relatively small change in bottom temperature. Habitat expansion offshore may explain population increases northeastward and decreases in inshore settlement densities.

High-latitude region has been heralded as potential climate change refugia for many species. However, our findings highlight that high-latitude coral assemblages are critically threatened by the effects of ocean warming as endemic and high-latitude specialist species are particularly prone to punctuated heat stress.

Analysis of 124 coral cores collected across the Belize Mesoamerican Barrier Reef System indicates that nearshore corals have historically grown faster than their offshore counterparts, but that growth rates of nearshore corals are in decline while offshore growth rates remain stable. For both species, individual mass coral bleaching events were correlated with low rates of skeletal extension within specific reef environments, but no single bleaching event was correlated with low skeletal extension rates across all reef environments. We postulate that the decline in skeletal extension rates for nearshore corals is driven primarily by the combined effects of long-term ocean warming and increasing exposure to higher levels of land-based anthropogenic stressors, with acute thermally induced bleaching events playing a lesser role.

Predicted phytoplankton response to increased non-chlorophyll light attenuation. In this study, we present evidence suggesting a centennial increase in non-chlorophyll light-attenuating substances in the North Sea. This implies a reduction of the euphotic zone, leading to a delayed, intensified, and prolonged spring bloom. While climate warming is suggested to advance the spring bloom due to earlier shoaling of the mixed layer, it also causes browning in lakes and rivers due to increases in terrestrial greening, ultimately reducing water clarity in downstream coastal areas. These contrasting responses highlight the importance of including water transparency in analyses of phytoplankton phenology and primary production.

We conducted a trait-based climate vulnerability assessment for groundfish, salmon, and crab stocks in the eastern Bering Sea, a data-rich region, and leveraged existing downscaled climate projections, species distribution models, and (for some stocks) detailed biological studies. The vulnerability ranged from “low” to “moderate”; however, comparison with more detailed studies indicates that water temperature may have important effects on climate vulnerability for some stocks. We also demonstrate how several types of uncertainties (climate projections, biological, and model structure) can be analyzed and communicated, including bootstrapping of the results.

We compared the spatio-temporal dynamics of species and trait structure in North Sea fish communities over 33 years. Both species and trait structure changed significantly over time; however, communities in the southern and northern North Sea diverged towards different species, becoming taxonomically more dissimilar over time, yet they converged towards the same traits regardless of species differences. In particular, communities shifted towards smaller, faster growing species with higher thermal preferences and pelagic water column position. Our findings suggest that global environmental change, notably climate warming, will lead to convergence towards traits more adapted for novel environments regardless of species composition.

Emissions from forest fires in the western United States are often vastly overestimated due to the misconception that mature forests can “burn to the ground.” In fact, the largest pool of aboveground carbon in western US forests—live, mature trees—negligibly combusts during fire and remains as standing, dead stems for years to centuries. Using realistic combustion coefficients from new field observations and an improved ecosystem model that represents dead, standing trees, we demonstrate that model simulations can double realistic fire-event emissions estimates in the western United States by assuming 30%–80% live tree combustion, with overestimates increasing in carbon-dense forests.