Overstory and understory vegetation play a vital role in forest ecosystem functionality. However, it is necessary to enhance the knowledge of their diversity and compositional dynamics following cessation of disturbance, which is required to inform restoration approaches and the mechanisms required for maintaining disturbance cessation. We conducted a chronosequence spanning 0–1, 5–6, 11–12, 20–24, and 28–34 years since disturbance cessation, and old-growth forests to investigate the dynamic changes in overstory and understory vegetation diversity and composition, as well as maintenance mechanisms following the cessation of anthropogenic disturbances in subtropical regions of Eastern China. The current study results indicated a decrease in understory cover and periodic fluctuations in the diversity of overstorey and understory vegetation following disturbance cessation efforts. Specifically, the shrub layer exhibited the highest richness in 28–34 years, while the herb layer showed the lowest evenness. Multivariate analysis using multiple-response permutation procedures indicated that the species composition and interspecific quantity ratio of understory plants in the forest at 28–34 years significantly differ from those in the early closure stage. An indicator species analysis revealed that more support was given to sun-loving plants after 0–1 years of the enclosure, while species with shade tolerance and low nutrient requirements were supported after 28–34 years. The structural equation model results show that 38.8% of the impact on herb evenness was related to light and substrate diversity. The ecological restoration time mainly indirectly affects understory vegetation by influencing the upper vegetation, light availability, and substrate heterogeneity. Overall, this study revealed that cessation of anthropogenic disturbance can maintain and care for understorey plant diversity and contribute to the sustainable management of forests.

Ecological restoration and biodiversity are currently hot issues of global environmental concern. However, knowledge about the specific impacts of restoration duration on understory vegetation diversity remains limited. Therefore, this study comprehensive employed a spatial approach to compare the differences in understory plant diversity and species composition among secondary forests with varying ecological restoration ages (0, 10, 30, 60, and 90-year-old stands) in Huangfu Mountain National Forest Park. This methodology allowed us to clarify the key factors affecting the composition of the understory plant community and investigate the regulatory mechanisms influencing changes in understory plant diversity. The results showed that shrub Shannon’s index value, shrub evenness, herb Shannon’s index value, herb richness, and herb evenness were significantly affected by the years of restoration, with 10 years and 90 years being the highest and 60 years being the lowest. Substrate diversity was the main factor influencing plant diversity in the shrub layer. Overstory richness, soil C/N, soil C, soil N, soil bacterial Observed OTUs, soil bacterial Chao1, soil bacterial Pielou_e, and substrate diversity were the drivers of plant diversity in the herb layer. Overstory evenness had a direct effect (0.256) and an indirect effect (0.284) on herb evenness through light availability and fungal Simpson’s index value. Light availability directly negatively affected herb evenness (−0.360). In addition, 52.6% of the factors affecting the herb evenness index were from the arboreal layer evenness, light availability, and fungal Simpson’s index value. To sum up, moderate disturbance of the understory environment of natural secondary forests can be carried out after 10 years of restoration, which is more conducive to the increase of understory plant diversity. This comprehensive study provides a theoretical basis for formulating ecological restoration measures for secondary forests, particularly in understanding the optimal timing and nature of disturbance in the restoration process, reassuring the audience about the validity and reliability of the findings.

Monoculture plantation systems face increasing challenges in sustaining ecosystem multifunctionality (EMF) under intensive management and climate change, with long-term functional trajectories remaining poorly understood. Although biodiversity–EMF relationships are well-documented in natural forests, the drivers of multifunctionality in managed plantations, particularly age-dependent dynamics, require further investigation. This study examines how stand development influences EMF in Castanopsis hystrix L. plantations, a dominant subtropical timber species in China, by assessing six ecosystem functions (carbon stocks, wood production, nutrient cycling, decomposition, symbiosis, and water regulation) of six forest ages (6, 10, 15, 25, 30, and 34 years). The results demonstrate substantial age-dependent functional enhancement, with carbon stocks and wood production increasing by 467% and 2016% in mature stand (34 year) relative to younger stand (6 year). Nutrient cycling and water regulation showed intermediate gains (6% and 23%). Structural equation modeling identified plant diversity and microbial community composition as direct primary drivers. Tree biomass profiles emerged as the strongest biological predictors of EMF (p < 0.01), exceeding abiotic factors. These findings highlight that C. hystrix plantations can achieve high multifunctionality through stand maturation facilitated by synergistic interactions between plants and microbes. Conservation of understory vegetation and soil biodiversity represents a critical strategy for sustaining EMF, providing a science-based framework for climate-resilient plantation management in subtropical regions.

Strigolactones (SLs) have emerged as important regulators of plant adaptation to abiotic stress, functioning not as isolated hormones but as integrative signaling molecules. Beyond stress responses, SLs regulate key biological processes, including shoot branching, root architecture, leaf senescence, nutrient acquisition, rhizosphere communication, flowering-related development, and growth–developmental plasticity. This review synthesizes current knowledge on how SLs modulate plant responses to drought, salinity, heavy metal toxicity, high temperature, and low temperature through crosstalk with abscisic acid, auxin, cytokinin, ethylene, and gibberellin. We examine SL structural diversity, biosynthesis, transport, and signaling together with their roles in growth–stress coordination, hormonal networking, and stress-specific mitigation, while distinguishing endogenous SL functions from responses inferred from exogenous analogs such as GR24. Across stresses, SL-mediated resilience converges on adaptive modules, including water regulation, root–shoot architectural remodeling, redox protection, ion and osmotic homeostasis, photosynthetic maintenance, and rhizosphere-assisted resource acquisition. The mechanistic basis involves transcriptional reprogramming, ROS/RNS-linked redox regulation, metabolic protection, and root–microbe interactions. Translational prospects include SL analogs, genetic manipulation, and breeding for adaptive plasticity, nutrient efficiency, and stress tolerance. However, species specificity, dosage dependence, limited field validation, unclear structure–function relationships, and parasitic-weed stimulation remain major constraints.

This study investigates the effects of stand age on understory plant diversity in Pinus massoniana plantations recovering from fire disturbance, aiming to provide scientific references for urban ecological restoration and forest management. Three stand ages (15, 30, and 60 years) of P. massoniana plantations in Huangfushan National Forest Park, Chuzhou City, China, were selected as research objects. By combining α and β diversity indices with analyses of edaphic factors from different soil layers, we examined understory plant diversity and its influencing factors across different stand ages. Stand age significantly shaped shrub and herb richness and Shannon–Wiener diversity, which peaked in 15-year-old stands. Symplocos tanakana dominated the shrub layer throughout succession, while the herb layer shifted from single- to multi-species dominance; the Godron structural stability index increased with stand age. Soil C, N, and organic matter responded to stand age, soil layer, and their interaction, whereas pH and bulk density showed partial responses. Understory diversity was negatively correlated with 0–10 cm soil C and organic matter, and herb diversity was positively correlated with 20–30 cm soil N. Herb-layer composition was significantly associated with shallow-soil pH, bulk density, and C/N ratio, whereas no soil drivers were detected for the shrub layer. In summary, this study systematically reveals the synergistic evolution of understory plant diversity and soil characteristics in P. massoniana plantations at different stand age stages, providing an important basis for scientific management and sustainable development of plantations.

Assessing the wind resistance of urban coastal trees is crucial for enhancing ecological security in typhoon-vulnerable regions under climate change. This study conducted post-typhoon field investigations in the wake of Typhoon Wipha in Yangjiang and Maoming, China, to evaluate damage to 1,645 trees across 15 common species. Using the Analytic Hierarchy Process (AHP), we developed a weighted wind damage value (WDV) integrating uprooted (weight: 0.637), trunk broken (0.258), and light-moderate damage (including broken branches and defoliation) (0.105). Results showed that 26.50% of surveyed trees suffered typhoon damage. Casuarina equisetifolia L. (WDV = 2.20), Camphora officinarum Nees (2.49), and Plumeria rubra L. (2.30) exhibited the strongest wind resistance, whereas Ceiba speciosa (A.St.-Hil.) Ravenna (11.66), Cassia fistula L. (11.09), and Bauhinia variegata L. (8.12) were most vulnerable. Functional trait analysis revealed that specific leaf area (SLA) (r2 = 0 .59, p<0.01) and leaf force to punch (Fp) (r2 = 0 .82, p<0.01) were the key predictors of WDV. These leaf-level traits mediate whole-tree wind damage through multi-level regulation of canopy wind load, branch mechanical strength, and root-soil interactions. The integrated WDV and trait framework provides a science-based tool for tree species selection and wind damage mitigation in typhoon-prone urban forests, offering a baseline reference for climate-adaptive management in coastal cities with similar environmental contexts.