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Invasive alien plants (IAPs) pose a significant threat to island biodiversity and severely impact ecosystems. Understanding the species–area relationship and environmental determinants of growth forms for IAP species on subtropical islands is crucial for establishing an IAP’s early warning mechanism, enhancing island ecological management, and protecting the ecosystems of Fujian and other subtropical islands. The study identified significant species–area relationships for IAPs and different life-form plants (trees, shrubs, and herbs), with slopes of 0.27, 0.16, 0.15, and 0.24, respectively. The small island effect does not apply to all species. Isolation has little effect on species richness, and the IAPs on Fujian islands do not conform to the isolation effect in island biogeography. Landscape factors are the main determinants of IAPs and different life-form species richness, with area, shape index, and perimeter–area ratio being the three primary landscape factors. These environmental factors are closely related to habitat heterogeneity. Besides landscape factors, different life forms respond differently to environmental factors. Climate drives the species richness distribution of shrubs and herbs, while trees are mainly influenced by human activities. Overall, landscape, human disturbance, and climate jointly drive the distribution of IAPs, with landscape factors being the most significant.

Plant invasions threaten the biodiversity of islands, causing serious impacts on their ecosystems. To investigate the distribution patterns of invasive alien plants on subtropical islands, the environmental determinants of species richness, and the growth forms of invasive alien plants, this study analyzed the composition and origin of invasive alien plants on 77 islands in Fujian. The similarity in the distribution of invasive alien plants between islands was assessed using the UPGMA. Moreover, feature selection, best-subset regression, and variance decomposition were performed using 19 environmental variables characterizing climate, anthropogenic disturbance, and landscape/geography, as well as the species richness and growth forms of invasive alien plants. Through the analysis, the main environmental factors affecting the species richness and growth forms of invasive alien plants on the Fujian islands were identified. The results showed 142 species of invasive alien plants in 38 families and 102 genera on 77 islands in Fujian. Annual herbs constituted the most representative growth form of invasive alien plants and tropical America was the main origin of invasive alien plants. The distribution of invasive alien plants across the 77 islands in Fujian showed a high degree of similarity, suggesting a nested pattern in their distribution. The proportions of building and farmland area (BFA), island area (A), and maximum elevation (ME) were the main driving factors of species richness and growth forms for invasive alien plants. In particular, BFA played a key role in driving plant invasion. The results of this study can help establish an early warning mechanism for invasive alien plants and better implement island ecological management, which are important for the protection of subtropical island ecosystems.

(1) Background: Islands are relatively independent and fragile ecosystems with unique habitats. Studying the relatively stable semi-natural plant communities on islands can enrich island vegetation data and provide an understanding of the factors affecting species diversity and distribution. (2) Methods: The semi-natural plant communities on Langqi Island (LI) in Fujian Province were sampled, and the redundancy method was used to analyze the correlation between species diversity, community distribution, and environmental factors. (3) Results: (i) There were 432 species of vascular plants, with 306 genera and 110 families; (ii) the semi-natural plant communities consisted of three vegetation types, 10 formations, and 10 clusters; (iii) the species diversity indices of the semi-natural plant communities presented a trend of gradually decreasing along the shrub, tree, and herb layers. Different formations varied in terms of the species diversity index; and (iv) the soil total potassium and nitrogen contents significantly affected the species diversity of the LI semi-natural plant communities, whereas the pH, soil TN content, organic matter content, AK content, and altitude significantly affected the community distribution. (4) Conclusions: Selecting appropriate tree species for mixed forests based on plant characteristics and regional conditions, together with regulating the soil nutrient content, can improve the species diversity of semi-natural plant communities.

Michelia amoena Q.F.Zheng et M.M.Lin is classified in Magnoliaceae and has a high economic value. Herein, we report the complete chloroplast genome of M. amoena using Illumina sequence data. The chloroplast genome is 160,088 bp in length and contains a large single copy (LSC) region of 88,118 bp and a small single-copy (SSC) region of 18,798 bp separated by two inverted repeat (IR) regions of 26,586 bp each. It contained a total of 131 genes, with an overall GC content of 39.26%. The phylogenetic analysis showed that M. amoena is closely related to Michelia figo. This study provides important sequence information for species identification and its phylogenetic relationship in the Magnoliaceae.

Plant clusters planted in urban green spaces have a significant potential to improve the microclimate. To put this potential to the test, eleven plant clusters (20 m × 20 m) in size were selected as sample plots in Haitan Island, China. We measured the microclimate including air temperature, relative humidity, solar radiation, and wind speed on sunny days from 8:00–17:00. The data were collected from July to September 2020. The purpose of this study was to determine the relationship between plant cluster characteristics and microclimate to enhance tourists comfort. The findings indicated that eleven sample plots had eighteen tree species with four distinct plant functional types. The air temperature difference between the interior and exterior of the plant clusters was substantial and the cooling effect dTair ranged from 2.65% to 5.19%, while the reduction of solar radiation dSR was between 58.08% and 98.33%. Crown area, wind speed, relative humidity, and solar radiation all affected air temperature, as determined by Piecewise SEM analysis. The cooling effect was mostly affected by crown area, canopy density, wind speed, and solar radiation showing that canopy structure affected air temperature by altering solar radiation penetration. Meanwhile, leaf transpiration generated water vapor, which increased relative humidity and cooled the air. Quantitative data on the crown area and canopy density were provided so that forestry management practices can improve people’s comfort while in the area.

Casearia glomerata Roxb. is classified in Salicaceae and has a high economic value. Herein, we report the complete chloroplast (cp) genome of C. glomerata using Illumina sequence data. The cp genome is 156,809 bp in length and contains a large single-copy (LSC) region of 84,888 bp and a small single-copy (SSC) region of 17,039 bp separated by two inverted repeat (IR) regions of 27,441 bp each. It contained a total of 123 genes, with an overall GC content of 36.81%. The phylogenetic analysis showed that C. glomerata is closely related to Casearia velutina. This study provides important sequence information for species identification and its phylogenetic relationship in the Salicaceae

Callicarpa siongsaiensis Metcalf is a drought resistance shrub with ornamental potential. In this study, Illumina sequencing data were used to assemble the complete chloroplast genome of Callicarpa siongsaiensis. The length of the circular genome is 154,144 bp. It contains a total of 130 genes, including 87 protein-coding, 36 tRNA, and seven rRNA genes. The GC content of the chloroplast genome of C. siongsaiensis is 38.09%. The phylogenetic analysis fully resolved C. siongsaiensis in a clade with C. formosana.

This study investigated the uptake capacity and bioaccumulation of heavy metal (Cu) in water using eight different aquatic plant species: Juncus effusus, Acorus calamus, Eichhornia crassipes, Sagittaria sagittifolia, Arundina graminifolia, Echinodorus major, Nymphaea tetragona and Pistia stratiotes. The results showed that Eichhornia crassipes and Pistia stratiotes have the best ability for bioaccumulation, while Arundina graminifolia, Nymphaea tetragona, and Acorus calamus also showed good bioaccumulation. However, Juncus effusus, Sagittaria sagittifolia, and Echinodorus major displayed very weak bioaccumulation. The enrichment capacity for Cu2+ in roots and shoots differed among species. Most of the Cu2+ was located in the shoot tissues of Juncus effuses, while for Sagittaria sagittifolia and Acorus calamus it accumulates in their root tissues. However, in the case of Echinodorus major the accumulation of copper content in root and shoot tissues is the same. The adsorption rates of heavy metal Cu in different aquatic plants were different. The adsorption rates of Eichhornia crassipus, Pistia stratiotes, Echinodorus major, and Nymphaea tetragona were higher than for Juncus effusus, Sagittaria sagittifolia, and Acorus calamus. When different aquatic plants reached the adsorption equilibrium, pH values were different. The Cu enrichment amount in aquatic plants was related to the content of lignin in plants, and the higher the content of lignin, the greater the amount of copper. [ABSTRACT FROM AUTHOR]