Nitrogen (N) and phosphorus (P) are key elements essential for plant growth and development. Due to fertilizer application, rapid urbanization, and fossil fuel combustion, nitrogen deposition has reached relatively high levels in China. However, there is still uncertainty regarding the response of N:P stoichiometry in plants and soil to N deposition across different ecosystems. Therefore, a meta-analysis was conducted using 845 observations from 75 studies to evaluate the response of plant and soil N and P concentrations and N to P ratios across various ecosystems to N addition. The analysis revealed that N concentration and N:P stoichiometry in plants and soil increased under N addition, while P concentration in plants and soil decreased on average. Furthermore, the magnitude of these responses was related to the N input rate and experimental duration. Finally, the effects of N addition on N concentration, P concentration, and N:P in terrestrial ecosystems would alter their allocation patterns, depending on relevant climate factors such as mean annual temperature and mean annual precipitation. This study highlights the ecological impact of N addition on the biogeochemical cycling of major elements (N and P) in terrestrial ecosystems in China. These findings are necessary for improving our understanding of the characteristics of plant ecological stoichiometry and helping to plan measures for increasing N deposition.

The Wuyi Mountains in China are one of the largest and most complete subtropical forest ecosystems at the same latitude in the world. However, our limited understanding of the function of this distinctive ecosystem means that the interrelationship between species diversity and ecosystem functioning needs to be investigated if evergreen broadleaf forests (EBLFs) are to be protected. Here, we calculated species richness, the Shannon–Wiener index, and the Pielou index in large-, medium-, and small-scale (20 m × 20 m, 10 m × 10 m, and 5 m × 5 m) forest dynamics plots (FDPs). We also investigated the interrelationships between species diversity and aboveground biomass (AGB)/productivity in FDPs at the different scales using the generalized linear regression model. The results showed that species diversity and AGB positively interrelated with each other, whereas there was no species diversity-productivity interrelationship in the subtropical BLF on the Wuyi Mountains. The structural equation model (SEM) showed that elevation was a key factor directly affecting AGB. These findings lead to the conclusion that productivity is not solely correlated with species diversity and that abiotic factors probably mediate the positive interrelationship between species diversity and ecosystem functioning. This study provides theoretical basis that can be used to protect EBLFs in subtropical areas and the results can be used to improve the construction of artificial forest communities and vegetation restoration at the same latitude.

Species diversity (SD) and genetic diversity (GD) are the two basic levels of biodiversity. In general, according to the consensus view, the parallel effects of environmental heterogeneity, area, and connectivity on two levels, can drive a positive correlation between GD and SD. Conversely, a negative correlation or no correlation would be expected if these effects are not parallel. Our understanding of the relationships between SD and GD among different ecosystems, sampling methods, species, and under climate change remains incomplete. In the present study, we conducted a hierarchical meta-analysis based on 295 observations from 39 studies and found a positive correlation between genetic diversity and species diversity (95% confidence interval, 7.6–22.64%). However, significant relationships were not found in some ecosystems when we conducted species–genetic diversity correlation analysis based on a single ecosystem. Moreover, the magnitudes of the correlations generally decreased with the number of sampling units and the annual average the temperature of sampling units. Our results highlight the positive correlation between GD and SD, thereby indicating that protecting SD involves protecting GD in conservation practice. Furthermore, our results also suggest that global increases in temperature during the 21st century will have significant impacts on global biodiversity.

Plant ecological strategies are essential for assessing habitat stress and disturbance and evaluating community productivity. These strategies provide theoretical frameworks for maintaining the natural state of vegetation and enhancing productivity. The functional traits of leaves reflect a plant’s responses to environmental changes and contribute to understanding ecosystem stability, providing a basis for species diversity maintenance and effective conservation efforts. The Wuyishan National Park, a biodiversity hotspot in China, is a focal point for ecological research. Its evergreen, broad-leaved forest, the zonal vegetation of Mt. Wuyi, underpins plant diversity protection in the region. This study investigates the CSR (competitor, stress-tolerator, ruderal) strategy of 126 species on Wuyi Mountain to elucidate prevalent ecological strategies. The main ecological strategy of plants in the study area is the CS (competitor, stress-tolerator) strategy. The species exhibit nine categories. The most abundant ecological strategy is S/CS (plants from Fagaceae), accounting for 38%, followed by S/CSR at 23% (plants from Theaceae), CS at 20% (plants from Fagaceae and Theaceae), and the remaining strategies collectively at 19%. The different growth habit categories showed variations in the CSR strategies. The trees clustered around a CS median strategy, with no R-selected trees observed. Shrubs and lianas centered around an S/CSR strategy, while grasses and understory shrubs clustered around CS/CSR. Redundancy analysis results indicate that leaf functional traits are primarily influenced by temperature, suggesting that temperature is the key environmental factor driving the differentiation of plant functional traits. This study provides insights into the ecological strategies of plant species in the Mt. Wuyi region, highlighting the importance of considering both biotic and abiotic factors in maintaining biodiversity and ecosystem stability.

Subtropical high-elevation mountain ecosystems are crucial for regional climate regulation and biodiversity conservation. However, the patterns of conifer radial growth in response to climate change in these regions remain unclear, significantly hindering the development of effective adaptive forest management strategies. This study examined Pinus taiwanensis and Cryptomeria fortunei, two dominant species in the Wuyi Mountains, using dendroclimatological methods to systematically analyze their long-term climate–growth relationships. The main findings include the following: (1) P. taiwanensis radial growth was significantly and positively associated with summer mean and maximum temperatures (in both the current and previous year), with no significant correlation to precipitation or minimum temperatures. In contrast, C. fortunei growth showed a positive relationship with previous autumn precipitation and a negative correlation with previous winter precipitation; (2) moving-window analysis revealed that P. taiwanensis maintained consistent temperature sensitivity, with an increasing response to summer warming in recent decades. Meanwhile, C. fortunei displayed phase-specific responses driven by precipitation and minimum temperatures. These results demonstrate divergent climate-response strategies among subtropical conifers in a warming climate: P. taiwanensis exhibits temperature-sensitive growth, whereas C. fortunei is primarily regulated by moisture availability. The findings provide critical insights for the adaptive management of subtropical montane forests, highlighting the need for species-specific strategies to maintain ecosystem services under future climate change.

Understanding the population dynamics and interspecific interactions in subtropical forests is crucial for uncovering the underlying mechanisms of species coexistence and community stability. Two censuses were conducted between 2018 and 2023 in a 9.6 ha subtropical evergreen broad-leaved forest dynamics plot situated in Mount Wuyi, southeastern China. Utilizing co-occurrence networks and long-term data, we examined the relationship between species interactions and their contributions to community assembly. Our findings reveal that high mortality rates among small-diameter individuals have created ecological niches, facilitating the establishment of 12 new species between 2018 and 2023. A generalized linear mixed-effects model showed positive relationships between sapling abundance and conspecific neighbor density. Co-occurrence networks demonstrated a shift toward higher positive interactions but reduced modularity, indicating a more integrated yet less stable community structure. Despite their low abundance, rare species demonstrated significant roles in network connectivity and stability, underscoring their status as keystone species. Additionally, the significant correlations between topographic factors and species richness highlighted the role of environmental filtering in shaping community composition. Our findings contribute to a deeper understanding of subtropical forest community dynamics, emphasizing the importance of long-term monitoring to unravel the complex interactions between populations and their environmental conditions. This study represents the first long-term observational experiment conducted in a subtropical secondary forest, providing valuable insights into the dynamics of forest community assembly in this region.