Global Change Biology最新文献

Tropical forests harbour the majority of tree species on the planet but are increasingly subjected to deforestation and human-driven disturbances. Understanding how human modifications impact various facets of diversity—i.e., taxonomic, functional, and phylogenetic—is crucial, as their responses can differ significantly. Additionally, the influence of species dominance and individual size class on the recovery trajectories of future forests is often overlooked. Here, we address these knowledge gaps by comparing the taxonomic, functional, and phylogenetic diversities of large (≥ 10 cm DBH) and small (≤ 2 cm DBH < 10 cm DBH) trees in undisturbed and human-modified Amazonian forests, considering different weights of species dominance using Hill Numbers. We sampled 25,313 large and 30,070 small trees across 215 forest plots distributed in two different regions of Eastern Amazonia and representing a range of human modification (i.e., undisturbed, logged, logged-and-burned, and secondary forests). Our findings indicate that human modifications significantly reduce the taxonomic, functional, and phylogenetic diversities of both large and small trees, regardless of dominance weightings. Secondary forests exhibited the lowest alpha-diversity and were the most dissimilar to undisturbed forests, while logged-and-burned forests were as distinct from undisturbed forests as they were from secondary forests across all diversity facets. Taxonomic and functional diversity showed similar sensitivity to human modification, while phylogenetic diversity was the least sensitive in alpha-diversity but equally sensitive in community composition analyses. Overall, we showed that human modification explained 55% of the effect size variation found in alpha-diversity and 42% of that found in community composition, with diversity facet, tree size and dominance weighting explaining either ≤ 5%. Given the deleterious impacts of human modification on the diversity of tropical forests, it is imperative to protect remaining undisturbed areas from selective logging and wildfires. Nevertheless, even disturbed primary forests still harbour more taxonomic, functional and phylogenetic diversity than secondary forests.

Drained cultivated peatlands are recognized as substantial global carbon emission sources, prompting the exploration of water level elevation as a mitigation strategy. However, the efficacy of raised water table level (WTL) in Arctic/subarctic regions, characterized by continuous summer daylight, low temperatures and short growing seasons, remains poorly understood. This study presents a two-year field experiment conducted at a northernmost cultivated peatland site in Norway. We used sub-daily CO₂, CH₄, and N₂O fluxes measured by automatic chambers to assess the impact of WTL, fertilization, and biomass harvesting on greenhouse gas (GHG) budgets and carbon balance. Well-drained plots acted as GHG sources as substantial as those in temperate regions. Maintaining a WTL between −0.5 and −0.25 m effectively reduces CO₂ emissions, without significant CH₄ and N₂O emissions, and can even result in a net GHG sink. Elevated temperatures, however, were found to increase CO₂ emissions, potentially attenuating the benefits of water level elevation. Notably, high WTL resulted in a greater suppression of maximum photosynthetic CO₂ uptake compared to respiration, and, yet caused lower net CO₂ emissions due to a low light compensation point that lengthens the net CO₂ uptake periods. Furthermore, the long summer photoperiod in the Arctic also enhanced net CO₂ uptake and, thus, the efficacy of CO₂ mitigation. Fertilization primarily enhanced biomass production without substantially affecting CO₂ or CH₄ emissions. Conversely, biomass harvesting led to a significant carbon depletion, even at a high WTL, indicating a risk of land degradation. These results suggest that while elevated WTL can effectively mitigate GHG emissions from cultivated peatlands, careful management of WTL, fertilization, and harvesting is crucial to balance GHG reduction with sustained agricultural productivity and long-term carbon storage. The observed compatibility of GHG reduction and sustained grass productivity highlights the potential for future paludiculture implementation in the Arctic.

Phenological plasticity—the ability of organisms to adjust the timing of life-history events in response to environmental variability—is the primary adaptive mechanism for many organisms to changing seasonality (e.g., earlier spring). By enabling alignment between life-history events and resource availability, it helps to maintain fitness despite changing environmental conditions. Theory predicts that phenological plasticity should vary among populations because of heterogeneity in environmental variability, and among species because of differences in life-history (e.g., migration distance) and phylogenetic constraints. However, comprehensive, multi-species, and cross-population analyses of phenological plasticity remain scarce. Here, we address this gap by using a unique, four-decade dataset from Europe-wide monitoring of common songbirds. Our approach reveals how variation in phenological plasticity is structured according to site temperature properties, both within and across species. We found that long-distance migrants generally exhibit lower plasticity than residents or short-distance migrants, highlighting a fundamental constraint tied to migration strategy. Within species, populations inhabiting sites with predictable temperature profiles showed slightly stronger plastic responses, particularly among single-brooded species and those adapted to warmer breeding conditions. Notably, populations from the fastest-warming regions demonstrated marginally greater plasticity, regardless of other ecological traits, suggesting a global tendency for increased responsiveness in rapidly changing climates. These findings confirm and extend patterns previously observed at smaller scales, offering a more nuanced understanding of how local temperature conditions drive phenological plasticity. By demonstrating that the interplay between local environmental conditions and life-history traits underpins variation in breeding phenological responses, our study refines the current framework for predicting adaptive potential across populations and species under climate change.

Soil fungi underpin key ecosystem functions but face increasing threats from climate and land-use changes, with their future impacts remaining unclear. This uncertainty is exacerbated by limited large-scale data and the challenge of quantifying and comparing both factors at comparable spatial scales. By leveraging two continental-scale sampling networks in North America and applying stacked species distribution models combined with countryside species–area relationship frameworks, we assessed the impacts of climate and land-use change on soil fungal diversity and identified regions affected by both factors across four biomes. We projected climate and land-use change by incorporating shared socioeconomic pathways (SSPs) and associated greenhouse gas–induced radiative forcing, focusing on moderate- (SSP2–4.5) and high-emission (SSP5–8.5) scenarios. Climate change typically led to both diversity losses and gains, particularly in coniferous forests and among arbuscular mycorrhizal (AM) fungi. Land-use change predominantly caused diversity losses under SSP2–4.5, especially in broadleaf-mixed forests and for ectomycorrhizal (EM) fungi, with these effects diminished under SSP5–8.5 due to minimal land-use changes. Across emission scenarios, both factors were predicted to cause widespread diversity losses in coniferous forests (whole-community, EM fungi, and soil saprotrophs) and grasslands (AM fungi and plant pathogens) while promoting gains in broadleaf-mixed forests (whole-community, EM fungi, and saprotrophs) and coniferous forests (AM fungi and pathogens). These results support the need for biome- and guild-specific fungal conservation planning under global change.

The symbiosis between the dinoflagellate Symbiodiniaceae family and reef-building corals underpins the productivity of coral reefs. This relationship facilitates the deposition of calcium-carbonate skeletons that build the reef structure thanks to the energy derived from photosynthesis. The loss of Symbiodiniaceae from coral tissues—resulting in coral bleaching—impedes coral growth and can lead to mass mortality if the symbiosis fails to recover. Given that Symbiodiniaceae communities are dynamic and can shift in response to environmental stressors in the decades to centuries-long lifespan of coral colonies, understanding these changes is crucial. Although the reconstruction of Symbiodiniaceae communities from coral skeleton records has recently been demonstrated as feasible, no studies have yet assessed reconstructions across different species and locations. Here, we present an approach to use coral skeletons for reconstructing the Symbiodiniaceae community on decadal and centennial scales and for resolving dynamics related to coral species and the environmental history of sampling locations. For this, we used dated coral skeleton cores from Porites lobata and Diploastrea heliopora, species commonly used as climate archives, sampled in Palau and Papua New Guinea. We also examined the effect of various DNA extraction protocols on community reconstruction. Here we show that the reconstructed Symbiodiniaceae communities significantly varied across all cores and DNA extraction methods, with decalcification-based protocols enhancing the retrieval of skeletal-bound DNA. Moreover, we observed distinct community dynamics related to the specific coral host and sampling location. Notably, associations of Symbiodiniaceae dynamics with past heat stress events were apparent in cores of both species from Palau. Our findings enable a deeper understanding of the temporal and spatial variability in Symbiodiniaceae communities, offering insights that may refine the use of paleobiological proxies in climate studies and reveal broader ecological trends and microbially aided adaptation pathways in corals.

Mouillot, D., Derminon, S., Mariani, G., Senina, I., Fromentin, J.-M., Lehodey, P., & Troussellier, M. (2023). Industrial fisheries have reversed the carbon sequestration by tuna carcasses into emissions. Global Change Biology, 29, 5062–5074. https://doi.org/10.1111/gcb.16823

In the original version of this article, funder information was omitted from the Acknowledgments section. Previously, the text was:

“PL's contribution was partially funded from the European Union's Horizon 2020 research and innovation programme OCEAN-ICU, under grant agreement no.: 101083922. Views expressed in the paper do not necessarily represent the views of these agencies organizations.”

It should be:

“PL's contribution was partially funded by OCEAN-ICU, a research project funded by the European Union under grant agreement no.: 101083922 (OceanICU) and the UK Research and Innovation (UKRI) under the UK government's Horizon Europe funding guarantee (grant numbers: 10054454, 10063673, 10064020, 10059241, 10079684, 10059012, and 10048179). Views and opinions expressed are those of the author(s) only and do not necessarily reflect those of the European Union or European Research Executive Agency. Neither the European Union nor the granting authority can be held responsible for them.”

The Funding section should be:

“PL‘s contribution was partially funded by OCEAN-ICU, a research project funded by the European Union under grant agreement no.: 101083922 (OceanICU) and the UK Research and Innovation (UKRI) under the UK government’s Horizon Europe funding guarantee (grant numbers: 10054454, 10063673, 10064020, 10059241, 10079684, 10059012, and 10048179).

We apologize for this error.

Ecosystem restoration is a global priority for biodiversity recovery. However, many restoration efforts to date focus only on planting target species, without evaluating the resulting ecosystem-level impacts on community development and trophic networks. For example, most of the world's efforts to restore tropical coral reefs have evaluated only the recovery of coral organisms. Here, we investigate the re-establishment of different trophic groups of reef fishes in response to rapid coral recovery at one of the world's largest coral restoration projects. Within 4–6 years of coral restoration starting, coral cover returned to levels found at nearby healthy reference sites. Many groups of fishes recovered similarly quickly; herbivores, planktivores and omnivores recovered abundances equivalent to reference sites within the same time frame. However, although corallivorous fish abundance on 4–6-year-old restored reefs was significantly higher than on degraded reefs, it remained at just half the abundance of nearby healthy reference sites. Feeding observations demonstrated that across both healthy and restored habitat, the system's most abundant obligate corallivore (the butterflyfish Chaetodon octofasciatus) consistently targeted a small subset of corals—82% of all recorded bites were on just seven coral morphotaxa. Several of these targeted coral morphotaxa were significantly less abundant on restored reefs than on healthy reference sites. Despite reduced availability of these comparatively rare corals on restored reefs, butterflyfish maintained their dietary preferences, meaning that they exhibited a higher dietary selectivity and foraged over areas twice as large compared to healthy reefs. This demonstrates that despite a rapid recovery of coral cover and some fish groups, the reduced recovery rates of slower-growing coral morphotaxa limit the speed at which specialist corallivores can re-establish. Restored coral reefs may regain their coral cover within 5 years, but they will require longer time frames to achieve full trophic networks and ecological complexity.

Climate change rapidly drives species range dynamics, prompting many terrestrial organisms to shift northward to higher latitudes and forcing new species–species and species–environment interactions. The blacklegged tick, Ixodes scapularis, a biological vector of human pathogens including Borrelia burgdorferi (the bacteria causing Lyme disease), is undergoing rapid and persistent expansion into Canada, exposing new human populations to zoonotic diseases. Here, we used an ensembled forecasting approach to construct niche models of I. scapularis' current and future distribution and to identify the environmental drivers of habitat range. Georeferenced occurrence points were acquired from community science programs (eTick and iNaturalist) between 2017 and 2022 in Canada and the United States. We also collected high-resolution environmental data using a spacing of approximately 1 km. We carried out 4704 model iterations across two datasets, 12 algorithms, and 10 climate profiles using 40 environmental variables. We extrapolated select models over three time periods, 2011–2040, 2041–2070, and 2071–2100, across two projected climate scenarios, SSP5-8.5 and SSP3-7.0, incorporating 2094 future outcomes of I. scapularis distribution. Our ensembles (AUC: 0.9565 ± 0.0065; TSS: 0.8435 ± 0.0155; Kappa: 0.819 ± 0.014) identified temperature, precipitation, biomass production (NPP), length of the growing season, climate moisture index, and number of yearly degree days as the variables that best explained I. scapularis distribution. Further changes to these climate conditions will result in continued I. scapularis range expansion, with, at the highest estimate, an increased niche area of ~248% (447,532 km² to 1,556,760 km²) and, at the lowest estimate, by ~205% (409,475 km² to 1,247,689 km²) before the turn of the century. These distributional niche changes coincide with a northern latitude limit reaching as far as ~48° N by 2040, ~50° N by 2070, and ~52° N by 2100. These findings highlight the invasive potential of I. scapularis, with implications for public health and changing ecosystem dynamics.