Molecular and morphological evidence support a new species of Rosaceae Prunus subg. Cerasus from Wuyishan National Park, southeast China

Prunus tongmuensis, a new species of cherry blossom, is described and illustrated from Wuyishan National Park, southeast China. This species is characterized by its tubular to nearly bottle-shaped receptacles and dark purple drupes. It can be distinguished from other wild cherry trees by its flowers and leaves, reddish brown young leaves, presence of 1–2 glands at the base of leaves, petioles densely covered with yellowish brown villi, longer pedicels (0.6–2.5 cm), villous pistil, and dark purple drupes. In the present study, we conducted a comprehensive morphological study based on specimens of the new species and its morphologically close species, field observations, and examination of pollen morphology. In addition, our phylogenetic analysis based on the complete plastid genome sequences further confirms the status of the new species and indicates that it is closely related to Prunus clarofolia, however, it notably differs in leaf shape, size, petiole villus color, gland location, timing of flower and leaf openings, and reflexed or spread sepals, as well as drupe color

The complete chloroplast genome of Changnienia amoena S. S. Chien (Orchidaceae) and its phylogenetic implication

Changnienia amoena S. S. Chien is mainly distributed in the mid-subtropical hilly areas of central and eastern China at an altitude of 200–1700 m. It has important academic significance in the orchid phylogeny, and is an excellent wild flower and precious medicinal plant. The species was once abundant but has become rare and endangered in recent years and has been identified as Endangered (EN) under criteria A2c (The IUCN Red List and Threatened Specis) because of the habitat fragmentation and unduly commercial collections. In this study, the complete chloroplast (cp) genome sequence of C. amoena was determined using next-generation sequencing. The entire cp genome was determined to be 156,818 bp in length. It contained large single-copy (LSC) and small single-copy (SSC) regions of 84,847 and 18,141bp, respectively, which were separated by a pair of 26,915 bp inverted repeat (IR) regions. The genome contained 133 genes, including 87 protein-coding genes, 38 tRNA genes, and eight rRNA genes.The overall GC content of the genome is 37.1%. A phylogenetic tree reconstructed by 48 chloroplast single-copy coding gene reveals that C. amoena is closely related with Calypso bulbosa

Spatio-Temporal Patterns of Tree Diversity and Distribution in Urban Resettlement Areas for Displaced Farmers

Resettlement residential areas (RRAs) are a unique product of China’s urbanisation process. Their greening environment is critical to the quality of life and liveable green neighbourhood of the displaced farmers. Our study aimed to (1) interpret the species composition of the landscape trees and their contributions to urban biodiversity in RRAs, and (2) elucidate the structural changes in the tree composition in the last 20 years. Twenty selected RRAs in Changzhou, Jiangsu Province, China, were divided into three categories by completion year. We assessed tree species composition, floristic diversity, tree dimensions, importance value, RRA characteristics, and greening management. The sampled sites accommodated 741 stems and 52 species belonging to 25 families. The three most abundant species were Cinnamomum camphora, Osmanthus fragrans, and Magnolia grandiflora, constituting 45.75% of all trees. The importance values revealed a changing tree planting pattern over time, with persistent domination by a few species. The oldest sites did not harbour the largest trees due to long-term mismanagement and mistreatment by residents. Compared with other housing types and cities, the tree count, importance value, and diversity in RRAs were low. The species diversity was not correlated with RRA completion time, distance from the city centre, and RRA area. The trees were in poor shape with limited trunk diameter and tree height and suffered from frequent and drastic pruning. Residents with lingering farmer mentality commonly exploited the vegetation and green spaces indiscriminately as natural resources. The greenery management could be overhauled by increasing tree number, native species, species diversity, and tree-care quality and engaging residents in a collaborative and participatory mode for a joint maintenance endeavour. The findings offer a scientific basis to improve or design RRA green spaces

Chloroplast Spacer DNA Analysis Revealed Insights into Phylogeographical Structure of <i>Phoebe chekiangensis</i>

Research studies on the conservation genetics of endangered plants play a crucial role in establishing management plans for biodiversity conservation. Phoebe chekiangensis is a precious and scarce tree species resource in the East China region. To comprehend the origin, evolutionary history, geographical, and historical factors that has contributed to the current distribution pattern of Phoebe chekiangensis in the East China region, we conducted a phylogeographic analysis that utilized intergenic spacers of chloroplast DNA (cpDNA). We amplified and sequenced three spacer regions of cpDNA (psbC-trnS, trnL-Intro, and Ycf3) intergenic spacer regions of 306 individuals from 11 populations, encompassing the majority of its geographical range in China. Our analysis revealed a total of 11 haplotypes. The research findings show that the spacer regions of the cpDNA genetic diversity of Phoebe chekiangensis was Hd = 0.423, and the nucleotide diversity was Pi × 10−3 = 0.400. At the species level, the population differentiation index Fst = 0.25610 (p Nm = 0.73. The genetic variation between populations was 29.14%, while within populations, it was 70.86%, with the inter-population genetic variation much lower than the within-population variation. The divergence time between the genera Phoebe and Machilus was estimated to be approximately 37.87 mya (PP = 1; 95%HPD: 25.63–44.54 mya), and the crown group time of the genus Phoebe was estimated to be 21.30 mya (PP = 1; 95%HPD: 9.76–34.94 mya). The common ancestor of the 11 Phoebe chekiangensis haplotypes was 7.85 mya, while the H7, H8, and H10 haplotypes of Phoebe chekiangensis (northern region) differentiated relatively late, with a divergence time of 1.90 mya. Neutrality tests (NTs) and mismatch distribution analysis (MDA) suggest that the time frame for Phoebe chekiangensis to expand southwestward along Wuyishan was relatively short and its adaptability to the environment was low, thereby limiting the formation of new haplotypes. These results suggest that Phoebe chekiangensis exhibited greater adaptation to the northern subtropics than to the central subtropics, offering valuable insights for the conservation and utilization of germplasm resources

The complete chloroplast genome of Osmanthus serrulatus rehd., a natural sweet olive endemic to China

Osmanthus serrulatus is an endemic tree in southwest China. Here, the complete chloroplast genome of this species was assembled and characterised from high-throughput data. The entire circular genome of O. serrulatus was 155,465 bp in size, which composed of large single-copy (LSC) and small single-copy (SSC) regions of 86,545 bp and 17,494 bp, respectively, and separated by a pair of inverted repeat (IR) regions of 25,713 bp each. The genome contained 133 genes, including 88 protein-coding genes, 37 tRNA genes, and eight rRNA genes. The overall GC content of the genome is 37.8%. A phylogenetic tree reconstructed by 35 chloroplast genomes reveals that O. serrulatus is most related with O. yunnanensis

Molecular and morphological evidence support a new species of Rosaceae Prunus subg. Cerasus from Wuyishan National Park, southeast China

Prunus tongmuensis, a new species of cherry blossom, is described and illustrated from Wuyishan National Park, southeast China. This species is characterized by its tubular to nearly bottle-shaped receptacles and dark purple drupes. It can be distinguished from other wild cherry trees by its flowers and leaves, reddish brown young leaves, presence of 1–2 glands at the base of leaves, petioles densely covered with yellowish brown villi, longer pedicels (0.6–2.5 cm), villous pistil, and dark purple drupes. In the present study, we conducted a comprehensive morphological study based on specimens of the new species and its morphologically close species, field observations, and examination of pollen morphology. In addition, our phylogenetic analysis based on the complete plastid genome sequences further confirms the status of the new species and indicates that it is closely related to Prunus clarofolia, however, it notably differs in leaf shape, size, petiole villus color, gland location, timing of flower and leaf openings, and reflexed or spread sepals, as well as drupe color

Inter- and Intra-Population Variation of Foliage Calcium and Magnesium in Two Chinese Pine Species

Calcium and magnesium are major nutrient elements of plants, and both play an important role in plant growth and development. Pinus massoniana and P. hwangshanensis are important afforestation tree species in barren mountains in China. However, observation and research on calcium and magnesium nutrition of dominant forest species in China are still limited. This study determined the concentration of calcium and magnesium in needles for two species from five sites in East China by inductively coupled plasma optical emission spectrometry (ICP-OES). We then explored the inter- and intra-population variation pattern of calcium and magnesium and their relationship with environmental factors. There were significant differences in traits among populations. The strongest factors, which impacted the variation of calcium and magnesium concentration, were elevation and individual differences, respectively. Element concentration was correlated to environmental factors such as longitude, latitude, elevation, and mean annual temperature. The results of this study can be helpful for a better understanding of tree growth, population survival, and forest succession

Scale‐dependent effects of species diversity on aboveground biomass and productivity in a subtropical broadleaved forest on Mt. Huangshan

Abstract The relationship between species diversity and biomass/productivity is a major scientific question in ecology. Exploring this relationship is essential to understanding the mechanisms underpinning the maintenance of biodiversity. Positive, negative, and neutral relationships have been identified in controlled experiments and observational research. However, increasing evidence suggests that the effects of species diversity on aboveground biomass and productivity are influenced by biotic and abiotic factors, but it remains unclear whether scale‐dependent effects affect aboveground biomass and productivity. Herein, we used a generalized linear regression model and a structural equation model to explore relationships between species diversity and productivity/aboveground biomass under different scales and to investigate the effects of topographical factors and species diversity on ecosystem functioning. The results revealed a positive relationship between biodiversity and ecosystem functioning based on species diversity and aboveground biomass. Different sampling scales may impact the relationship between species diversity and ecosystem functioning. A positive relationship was found between species richness and productivity at medium and large scales; however, ambiguous relationships were found in productivity and other species diversity indices. Elevation was a key factor affecting both biomass and productivity. These results suggest that species diversity is not the only factor affecting biomass and productivity, and the positive correlation between species diversity and ecosystem functioning is mediated by abiotic factors