Caryota obtusa forests are characterized as showy vegetation with rich species diversity and a unique habitat in the Honghe region of China.Due to its food and horticulture value, mature Caryota obtusa individuals have become more rare in the field.Here, we sampled six plots in a deep karst valley of the Honghe region of Yunnan, China.In each 20 m × 20 m plot, our examination focused on species composition of trees via the measure of any trees with DBH ≥ 4 cm.Importance values were produced from datasets of their relative abundance (RA), relative frequency (RF), and relative prominence (RP).On one hand, we analyzed the composition and geographical affinity of the tree species in Caryota obtusa forests based on the two patterns of geographic distributions (areal-type and natural geographic unit), respectively.On the other hand,•研究报告
Crape myrtles are economically important ornamental trees of the genus Lagerstroemia L. (Lythraceae), with a distribution from tropical to northern temperate zones. They are positioned phylogenetically to a large subclade of rosids (in the eudicots) which contain more than 25% of all the angiosperms. They commonly bloom from summer till fall and are of significant value in city landscape and environmental protection. Morphological traits are shared inter-specifically among plants of Lagerstroemia to certain extent and are also influenced by environmental conditions and different developmental stages. Thus, classification of plants in Lagerstroemia at species and cultivar levels is still a challenging task. Chloroplast (cp) genome sequences have been proven to be an informative and valuable source of cp DNA markers for genetic diversity evaluation. In this study, the complete cp genomes of three Lagerstroemia species were newly sequenced, and three other published cp genome sequences of Lagerstroemia were retrieved for comparative analyses in order to obtain an upgraded understanding of the application value of genetic information from the cp genomes. The six cp genomes ranged from 152,049 bp (L. subcostata) to 152,526 bp (L. speciosa) in length. We analyzed nucleotide substitutions, insertions/deletions, and simple sequence repeats in the cp genomes, and discovered 12 relatively highly variable regions that will potentially provide plastid markers for further taxonomic, phylogenetic, and population genetics studies in Lagerstroemia. The phylogenetic relationships of the Lagerstroemia taxa inferred from the datasets from the cp genomes obtained high support, indicating that cp genome data may be useful in resolving relationships in this genus.
Begonia xishuangbannaensis W.G. Wang & L.J. Jiang (Begoniaceae), a new tuberous species from Yunnan, China, is described and illustrated. It belongs to Begonia sect. Diploclinium. Morphologically, it is similar to B. fimbristipula and B. exposita in its tuberous habit and pubescent leaves, but can be distinguished from both by its asymmetrical leaf blade, 16–18 stamens, filaments that are free at base, and pistillate flowers having five tepals.
Ceropegia luzhiensis X.D. Ma & J.Y. Shen, a new species from Yimen, Yunnan, China, is described and illustrated. This species is similar to C. hookeri C. B. Clarke, C. intermedia Wight and C. manoharii Sujanapal, Salim, Anil & Sasidh., but clearly differs in its indumentum, the shape of leaf, the length of peduncle and pedicel, the shape and size of corolla and the shape of interstaminal corona lobe. A table including the morphological characters of related species and a dichotomous key to all 20 species of Ceropegia occurring in China are provided.
The upper montane evergreen broad-leaved forest in Yunnan occurs mainly in the zone of persistent cloud and has a discontinuous, island-like, distribution. It is diverse, rich in endemic species, and likely to be sensitive to climate change. Six 1-ha sampling plots were established across the main distribution area of the upper montane evergreen broad-leaved forest in Yunnan. All trees with d.b.h. > 1 cm in each plot were identified. Patterns of seed plant distributions were quantified at the specific, generic and family levels. The forests are dominated by the families Fagaceae, Lauraceae, Theaceae and Magnoliaceae, but are very diverse with only a few species shared between sites. Floristic similarities at the family and generic level were high, but they were low at the specific level, with species complementarity between plots. Diversity varied greatly among sites, with greater species richness and more rare species in western Yunnan than central Yunnan. The flora is dominated by tropical biogeographical elements, mainly the pantropic and the tropical Asian distributions at the family and genus levels. In contrast, at the species level, the flora is dominated by the southwest or the southeast China distributions, including Yunnan endemics. This suggests that the flora of the upper montane forest in Yunnan could have a tropical floristic origin, and has adapted to cooler temperatures with the uplift of the Himalayas. Due to great sensitivity to climate, high endemism and species complementarity, as well as the discontinuous, island-like, distribution patterns of the upper montane forest in Yunnan, the regional conservation of the forest is especially needed.
Primula longistyla , a new species of Primulaceae from Cangyuan County, Yunnan Province, China, is described and illustrated. This species is similar to P. densa , but differs clearly in that its leaves are densely white villous on both sides, homostylous flowers, exannulate corollas, longer corolla tube (2.5–2.8 cm long, ca 4 times as long as the calyx) and styles often obviously protruding from corolla tube. A comparison table of related species is provided.
The cultivation patterns of Amomum villosum was simply introduced: The virtues and shortcomings of the main patterns were compared. The results showed that the pattern of tropical rainforest+Amomum villosum had a significant bad effect on species diversity protection. The pattern of second forest+Amomum villosum can increase the yield of Amomum villosum fruits. Both the pattern of Chinese fir+Amomum villosum and rubber tree+Amomum villosum can ameliorate the soil fertility and accelerate the growth rate of the intercroping trees. Tropical rainforest is not the necessary condition planting Amomum villosum. There are quite a bit of ruble tree forest and bamboo forest in Xishuangbanna. Therefore,it is necessary and feasible to transfer Amomum villosum from tropical rainforest.
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