Understanding why some, but not other, plant communities are vulnerable to alien invasive species is essential for predicting and managing biological invasions. Darwin proposed two seemingly contradictory hypotheses on how native‐invader relatedness influences invasion success, emphasizing, respectively, the importance of environmental filtering and competition between natives and invaders. Despite much recent empirical research on this topic, reconciling these two hypotheses, known as Darwin's naturalization conundrum, remains a challenge. Using plot‐level data from natural forests along elevational transects covering strong environmental gradients, we examined whether the invasion of the globally invasive species crofton weed (Ageratina adenophora) can be explained by environmental filtering and/or competition from closely related species linked to environmental gradients. Abundant precipitation, warm temperatures, open canopies and postfire environments facilitatedA. adenophorainvasion, whereas resident taxonomic richness suppressed its invasion. Importantly, we found that invader‐resident relatedness had a strong negative effect on invader cover under resource scarcity conditions (e.g. low water availability), but not under non‐resource environmental stress gradients (e.g. low temperature). Synthesis and applications.Our results suggest that the impact of species phylogenetic relatedness on invasion success varies distinctly along resource versus non‐resource environmental gradients. These results help to reconcile Darwin's naturalization conundrum, thereby improving the ability to predict the success of alien plant invasions in a changing world. Our study stresses the need to consider adjusting forest species composition to strengthen their resistance to invasion, while taking into account resource and non‐resource environmental gradients, particularly after wildfires.

Traditionally, investigations into the climatic response of various tree species have spanned different regions. However, dendrochronological studies within a single region, characterized by minor climatic differences, have received comparatively less attention. Therefore, this study collected 230 tree cores from four prevalent conifer species (P. yunnanensis, A. forrestii, P. likiangensis, and T. dumosa) in the Lugu Lake Wetland Nature Reserve of southwestern China, a region undergoing climate warming and drying. This study employed dendrochronological methods to investigate tree growth–climate static responses, individual tree responses to climate, and dynamic tree–climate interactions. Our findings revealed that as the trend of warming and drying persists, tree growth exhibits an initial increase followed by a subsequent decrease. Dynamic response analyses, along with standardized assessments, indicate that in the early stages of warming, tree growth benefits from elevated temperatures. However, in the later stages of warming, the combined effects of warming and drying become more pronounced. During this phase, the facilitating impact of temperature diminishes, while the controlling influence of moisture conditions intensifies. Looking ahead, with the ongoing intensification of warming and drying, tree growth in the region is anticipated to become increasingly reliant on the water supply. This shift may lead to the decline or mortality of tree species intolerant to drought, such as T. dumosa.

The knowledge concerning the relationship between vegetation restoration and soil microorganisms is limited, especially at high altitudes. In order to evaluate the restoration efficacy of the reforestation on the soil microbial community, we have examined vegetation composition, edaphic properties and structure and function of different soil microbial groups in two different aged (25- and 40-year-old) Picea likiangensis var. rubescens Rehder & E. H. Wilson (P. rubescens) plantations and the primeval coniferous forest (PCF) dominated by Abies squamata Masters by plot-level inventories and sampling in western Sichuan Province, China. Our results suggested that only the fungal samples in 25-year-old P. rubescens plantation could be distinguished from those in the PCF in both structure and function. The structure and function of the fungal community recovered relatively slowly compared with bacterial and archaeal communities. In addition to the soil chemical properties and tree species composition, the shrub composition was also a key factor influencing the soil microbial community. The P. rubescens plantations were conducive to restoring the soil microbial community in both structure and function. However, there were uncertainties in the variations of the bacterial and archaeal communities with increasing the P. rubescens plantation age.

The Hengduan Mountains, a biodiversity hotspot on the Tibetan Plateau, are undergoing rapid elevation-dependent warming, profoundly altering alpine forest dynamics. Larix species in this region dominate high-altitude treelines and represent the world’s lowest-latitude natural populations of larch forests. However, climate-growth relationships of Larix species at the whole regional scales have received little attention. To address this gap, we investigated the spatiotemporal variability of radial growth in Larix species and their climatic sensitivity across this region using a network of 26 tree-ring chronologies spanning 1960–2022. Hierarchical clustering identified three distinct geographical clusters (southwestern, central, and northeastern), revealing divergent growth trajectories and climate responses. Results demonstrated that growing-season temperature was the primary climatic driver of Larix radial growth, but its influence varied spatially: southwestern populations correlate strongly with May–August mean temperatures, central populations with May–August mean temperatures, and northeastern populations with April–June maximum temperatures. Each cluster exhibited unique growth trends and thermal sensitivities before and after the rapid warming since 1990. Meanwhile, an inter-individual response divergence became apparent under warming, reflecting intensified competition and microhabitat-scale stress, which highlights the limitations of traditional population-level climate response models that assume a uniform response. Spatial heterogeneity in climate-growth relationships reflected synergistic thermal-hydrological effects and species-specific adaptations, with warming enhancing carbon sequestration in moisture-sufficient areas but threatening high-elevation ecosystems through growth suppression and treelines instability. These findings underscore the need for regionally tailored conservation strategies to address climate-driven ecological imbalances in alpine forests.

Forests are widely distributed in terrestrial ecosystems, covering about one-third of the global land area. They play a key role in sequestering carbon, releasing oxygen, mitigating climate change, and maintaining ecosystem balance. The ecology of the Tibetan Plateau is very fragile, but the impact of environmental change on regional forest ecosystems is not yet clear. Located in the Eastern Tibetan Plateau, the Shaluli Mountain has the richest biodiversity and the widest distribution of forests on the Tibetan Plateau. Assessing the dynamics of forest change is the basis for correctly formulating forest management measures, and is important for regional biodiversity conservation. However, traditional field surveys have the shortcomings of high cost, being time-consuming, and having poor regional coverage in forest dynamics monitoring. Remote sensing methods can make up for these shortcomings. Therefore, in this study, satellite remote sensing images were used to extract forest information from 2000 to 2020 in Shaluli Mountain, and the main drivers of forest change were analyzed with full consideration of the Spatially Stratified Heterogeneity (SSH) of environmental factors. The results found that the forest area increased from 23,144.20 km² in 2000 to 28,429.53 km² in 2020, and the average Percentage of Forest Cover (PFC) increased from 19.76% to 21.67%, with significant improvement in forest growth. The annual minimum temperature (TMN), altitude, annual maximum temperature (TMX), and annual precipitation (PRE) were the main driving factors of forest change, with an average driving power (q-value) of 0.4877, 0.2706, 0.2342, and 0.2244, and TMN was the primary limiting factor for forest growth. In addition, the driving power of all environmental factors on forest change increased from 2000 to 2020. The results of this study can provide a basis for the development of forest management strategies, and provide reference materials for regional biodiversity conservation.

Seed wings are widely recognized for facilitating dispersal and influencing germination in angiosperms, but their functional role in gymnosperm germination is poorly understood. To assess the effect of seed wings on the germination ecology of Smith fir (Abies georgei var. smithii), we evaluated the germination of three seed treatments—intact seeds, mixed seeds (de-winged seeds mixed with detached wings), and de-winged seeds—under varying light and temperature conditions. Results showed that de-winged seeds achieved a final germination percentage of 48.5 ± 5.0%, which was significantly higher than that of intact seeds (26.0 ± 2.4%) and mixed seeds (32.5 ± 3.5%) (p < 0.001), confirming that seed wings significantly inhibit germination. There was no significant difference between intact and mixed seeds, and both were significantly lower than de-winged seeds (p < 0.001), suggesting that germination inhibition is likely mediated by chemical inhibitors in the wings rather than mechanical restriction. Optimal germination occurred at 15/2 °C–25/5 °C, while light significantly enhanced germination under cold conditions (5/1 °C), indicating conditional dormancy. These findings suggest that seed wings optimize the regulation of germination timing by imposing chemical inhibition that, combined with conditional dormancy, delays germination until favorable spring conditions, reflecting an adaptive strategy to seasonal environmental cues in subalpine ecosystems.