Intercropping is a commonly employed agricultural technique that offers numerous advantages, such as increasing land productivity, enhancing soil health, and controlling soil-borne pathogens. In this study, Artemisia argyi, Dioscorea esculenta, and Arachis pintoi were intercropped with coconuts and compared with naturally growing weeds (Bidens pilosa), respectively. The regulatory mechanism of intercropping was examined by analyzing the variability in soil properties and microbial community structure across different intercropping modes and soil depths (0–20 cm, 20–40 cm, and 40–60 cm). The results indicate that intercropping can increase the diversity of soil bacteria and fungi. Moreover, as soil depth increases, the changes in microbial communities weaken. Intercropping reduced soil SOM and increased pH, which is directly related to the changes in the abundance of Acidobacteria in the soil. In various intercropping systems, the disparities resulting from intercropping with A. pintoi are particularly pronounced. Specifically, intercropping with A. pintoi leads to an increase in soil potassium and phosphorus levels, as well as an enhancement in the abundance of Bacillus sp., which plays a crucial role in the suppression of plant pathogenic fungi within the soil ecosystem. The results of the correlation analysis and structural equation modeling (SEM) suggest that the impacts of three intercropping systems on microbial composition and soil indicators exhibit considerable variation. However, a common critical factor influencing these effects is the soil phosphorus content. Furthermore, our findings indicate that intercropping resulted in lower soil nitrogen levels, exacerbating nitrogen deficiency and masking its impact on the microbial community composition.

The distribution of plant species diversity has long been a major focus on biogeography. Yet, the universality of the popular Rapoport’s rule remains controversial for endemic plants, as previous studies have focused more on broad-ranged species. Here, we collected data for 4418 endemic woody seed plant species across China, including trees, shrubs, and lianas, to explore the latitudinal patterns of species range size and richness, and test the relevant biogeographic law. The species range size distribution was examined for conformity with Rapoport’s rule using four methods (i.e., Steven’s, Pagel’s, the mid-point, and the across-species method). Spatial patterns of species richness along latitudinal gradient were also investigated by parabolic regression. Results showed that species range size increased with latitude for all species as well as by trees, shrubs and lianas, especially assessed by Pagel’s method. Species richness was highest at low latitude, where species range size was smallest, and decreased with increasing latitude. The species range size and richness of shrubs were maximum, followed by trees then lianas. These findings prove that Rapoport’s rule is strongly supported by latitudinal patterns of species distribution in Chinese endemic woody seed plants.

The maximum height of plants is an important trait determining community structure and ecosystem function. However, the variation in maximum plant height along large‐scale environmental gradients is still largely unknown. Here, data of maximum height for 2796 endemic woody seed plant species and 23 environmental variables (climate, space, and soil) were collected in China. Distribution patterns of maximum plant height were detected, and the relative importance of different environmental variables to maximum plant height was also determined. The maximum height of 2439 Chinese endemic woody seed plant species was lower than 16 m. The number of endemic woody seed plant species decreased gradually with increasing maximum plant height. At the county level, the mean maximum plant height (MMPH) of endemic woody seed plant species had an increasing trend from northwest to southeast across China. The environmental factors explained 19% of the variance in MMPH, among which climate explained more variation in MMPH than did space and soil. The most important predictors of MMPH were mean temperature of the warmest quarter, annual mean temperature, temperature seasonality, and altitude. These results demonstrate that the maximum height of endemic woody seed plants across China strongly responds to temperature. Our findings provide the first study elucidating the patterns in maximum height of Chinese endemic woody seed plants and identifying the most influential environmental factors for the variation in this trait, which will contribute to the development of sounder theory on the macropatterns of plant distribution.

Functional traits are pivotal for understanding the functional niche within plant communities. Yet, the relationship between the functional niches of typical forest plant communities across different climatic zones, as defined by functional traits, and their association with community and phylogenetic structures remains elusive. In this study, we examined 215 woody species, incorporating 11 functional traits spanning leaf economy, mechanical support, and reproductive phenology, gathered from forests in four climatic zones from tropical, subtropical, warm-temperate to cold-temperate zones in China and supplemented by the literature. We quantified the functional niche hypervolume (FNH), reflecting the multidimensional functional niche variability. We then probed into the correlation between the FNH and community and phylogenetic structures of forests. Our findings reveal that species richness significantly influences the geographic variance of functional niche space in forest vegetation across different climatic zones. Specifically, a community’s species richness correlates positively with the functional niche breadth occupied by the community species. The FNH of woody plants across diverse forest types shows significant associations with both the mean phylogenetic distance (MPD) and the mean nearest phylogenetic taxon distance (MNTD) of the communities. There is a progressive increase in tropical rainforest (TF), subtropical evergreen deciduous broad-leaved mixed forest (SF), and warm-temperate coniferous broad-leaved mixed forest (WF), followed by a decline in the cold-temperate coniferous forest (CF). This pattern suggests potential environmental filtering in CF, which may constrain the spatial extent of plant functional niches. Our research underscores the substantial variability in the FNH across China’s typical forest vegetation, highlighting the complex interplay between functional traits, community richness, and phylogenetic distance.

Coconut yield and quality are significantly affected by multiple female inflorescences (MFF), which disrupt flower differentiation balance. To elucidate the molecular mechanisms, we compared MFF with normal female inflorescences (NFF) using phenotypic, morphological, physiological, and multi-omics approaches. The results revealed that MFF exhibited altered flower structures. MFF showed elevated iron (Fe), nitrogen (N), sulfur (S), potassium (K), calcium (Ca), zinc (Zn), proline (Pro), catalase (CAT), malondialdehyde (MDA), abscisic acid (ABA), and jasmonic acid (JA), but reduced molybdenum (Mo), soluble sugar (SS), soluble protein (SP), superoxide dismutase (SOD), peroxidase (POD), indole acetic acid (IAA), zeatin riboside (ZR), and gibberellic acid (GA). We detected 445 differentially expressed genes (DEGs) mainly enriched in ABA, ETH, BR, and JA pathways in MFF compared to NFF. We identified 144 differentially accumulated metabolites (DAMs) primarily in lipids and lipid-like molecules, phenylpropanoids and polyketides, as well as organic acids and derivatives in the comparison of MFF and NFF. Integrated analysis linked these to key pathways, e.g., “carbon metabolism”, “carbon fixation in photosynthetic organisms”, “phenylalanine, tyrosine, and tryptophan biosynthesis”, “glyoxylate and dicarboxylate metabolism”, “glycolysis/gluconeogenesis”, “pentose and glucuronate interconversions”, “flavonoid biosynthesis”, “flavone and flavonol biosynthesis”, “pyruvate metabolism”, and “citrate cycle (TCA cycle)”. Based on our results. the bHLH137, BHLH062, MYB (CSA), ERF118, and MADS2 genes may drive MFF formation. This study provides a framework for understanding coconut flower differentiation and improving yield.

Intercropping with peanuts in coconut plantation is a traditional agroforestry model in tropical regions. However, current agricultural practices lack a solid scientific basis. In this study, a four-year field experiment with three treatments (coconut–peanut intercropping, coconut monoculture and peanut monoculture) was conducted in a young coconut plantation in Hainan, China. The regulatory mechanism of intercropping was examined by analyzing the variability in coconut root characteristics (n = 3), soil physicochemical properties (n = 5) and microbial community structure (n = 5) across different treatments. The results indicated that more than 80% of the intercropped coconut roots were concentrated within a horizontal distance of 100 cm from the trunk and at a soil depth of 0–40 cm. Compared to monocropped coconuts, intercropping with peanut significantly promoted the root growth of young coconut palms, increasing their RLD and RAD by 93.70–442.86% and 82.72–358.54%, respectively, in the 0–40 cm soil layers at horizontal 50 cm from the coconut. Intercropping with peanuts also improved soil quality by raising pH, total phosphorus and available phosphorus contents. The improved nutrient levels might result from the long-term fertilization accumulation in soil of peanut intercropping. Compared to the coconut monoculture, the soil bacterial community in the intercropping system showed increases in the Chao1 and Shannon indices by 19.00% and 7.39%, but fungal diversity did not differ significantly between the two treatments. Furthermore, intercropping with peanuts enriched beneficial taxa such as Pseudomonadota, Gemmatimonadota, and Ascomycota. Soil pH, available phosphorus, and available potassium were identified as the primary drivers of microbial community variations. This study highlights that coconut–peanut intercropping improves coconut root growth, soil properties and microbial composition, providing an effective management strategy for young coconut plantations.