Global Change Biology最新文献

Anthropogenic nitrogen (N) deposition alters forest functioning and their capacity to sequester carbon (C), yet its contribution to the forest C sink depends on N retention and allocation between plant biomass and soil pools. Despite high N deposition across China, the magnitude and drivers of N retention and contribution to forest C sequestration remain unclear due to a lack of systematic regional synthesis. Here, we synthesized data from decades of ¹⁵N tracer experiments spanning boreal to tropical regions of China to quantify the retention of deposited N, distribution among plant and soil pools, and contribution to forest C sequestration. On average, Chinese forests retained ~65% of the deposited N, with about two-thirds stored in the soil. Total retention and partitioning of N varied with climate, successional stage, and N forms. Soil organic layer retention declined, while mineral soil retention increased along a north–south gradient in mean annual temperature. Chronically N-saturated and disturbed forests exhibited low plant retention, whereas other forests showed substantial uptake across climate zones. Total ecosystem retention efficiency generally declined from boreal to tropical forests. Across successional stages, retention did not differ significantly; however, primary forests retained more deposited N in mineral soils, whereas plantations favored retention in the organic layer. Stoichiometric scaling indicates that CN response (kg C sequestered per kg deposited N) varies among forest types, ranging from ~7 to 40 kg C kg⁻¹ N, with boreal forests and plantations exhibiting the strongest C response due to greater N limitation. This suggests that over the past decade, N deposition enhanced C sequestration by approximately 0.11 Pg C year⁻¹, accounting for 20%–30% of China's forest C sink. Overall, these findings advance understanding of the drivers of deposited N retention and its contribution to C sequestration, with implications for predicting forest N and C dynamics under global change.

Over the last decades, climate change biology has become a central field in global science, yet knowledge production and its inclusion in global strategies remain profoundly unequal. Our bibliometric analysis of over 580,000 records shows that ~80% of author affiliations come from Global North institutions, meaning that research agendas, theoretical frameworks, and priorities are still largely shaped outside the regions with the highest biodiversity and greatest vulnerability to climate change. This imbalance reflects structural and historical inequalities that limit the ability of Global South countries to conduct autonomous research and sustain long-term monitoring. When research and funding originate abroad, local scientists are often excluded, leading to the loss of traditional knowledge, regional perspectives, and long-term capacity building. These dynamics leave tropical and subtropical bioregions (generally in the Global South) underrepresented in global climate knowledge. To address this imbalance, we propose six actions: invest in infrastructure and monitoring, strengthen local research networks, link funding to capacity building, promote open and equitable data access, connect science with regional policies, and foster intersectoral collaboration. We argue that truly effective climate change biology must be global, equitable, and diverse.

The symbioses between corals and microorganisms, including the endosymbiotic dinoflagellates (family Symbiodiniaceae) and bacteria, are central to coral health and functioning. Certain species of Symbiodiniaceae in the genus Durusdinium are known to confer enhanced thermotolerance to corals and could therefore be beneficial under global climate change. However, association with thermotolerant algal symbionts may come with trade-offs that affect long-term coral persistence, and this study reports on one potentially consequential trade-off. We exposed colonies of the coral Galaxea fascicularis hosting Symbiodiniaceae in the genus Cladocopium (C-corals) or Durusdinium (D-corals) to elevated temperature equivalent to ~9.5 degree heating weeks. While C-corals were heat-sensitive, as evidenced by reduced Symbiodiniaceae cell density, photochemical efficiency and tissue pigmentation, they were resilient to tissue loss, maintained a stable bacterial community under elevated temperature, and showed limited mortality (12.5%) at the end of the 15-week recovery. Conversely, D-corals showed limited Symbiodiniaceae photodamage or tissue pigmentation loss under elevated temperature and initially demonstrated heat resilience. However, D-corals exhibited tissue loss and a significant reduction in newly formed polyps under elevated temperature, which occurred in parallel with a shift in their bacterial community composition toward taxa linked to bleaching, disease or algal overgrowth (e.g., Sphingomonas). Most D-corals died at the end of the recovery period. The intracellular bacterial communities in Cladocopium and Durusdinium freshly isolated from the experimental corals revealed symbiont-specific patterns, where Durusdinium showed strong affiliation with the diazotroph Ruegeria sp. Our findings show that G. fascicularis associating with the thermally tolerant Durusdinium may have higher susceptibility to tissue loss relative to corals with Cladocopium symbionts. If this trade-off occurs across corals that can associate with both Cladocopium and Durusdinium, it can have profound implications for reef persistence under global climate change, and further study is critical to inform conservation strategies aiming to build resilient reefs.