Subjects: Biology >> Botany >> Applied botany submitted time 2023-07-13 Cooperative journals: 《广西植物》
Abstract： Analyzing the community characteristics of tropical monsoon forests with different succession is aiming to provide scientific basis for assessing their community assembly mechanisms and forest structure optimization. In this study, we investigated four different plant communities named A, B, C, and D, respectively, in a typical monsoon forest of E’ huangzhang in Yangchun, Guangdong Province, in attempt to analyze their species composition, biodiversity and spatial structure, determine their maturity levels’ differences, predict succession directions, and make suggestions for optimization. The result were as follows: (1) The forest layers of the four communities were single. Small diameter at breast height (DBH) class trees and lower-layer trees dominated these communities, owning 1~3 obvious dominant species. (2) Their Shannon-Wiener index ranged from 2.72 to 3.74, the Simpson index from 0.90 to 0.97, and the Pielou evenness index from 0.74 to 0.89, suggesting that their diversity characteristics were significant differences. (3) Their dominance ranged from 0.49 to 0.51, uniform angle from 0.56 to 0.61, mingling from 0.54 to 0.83, stand spatial structure index from 60.57 to 71.44, spatial structure distance from 53.15 to 68.53. (4) The analysis of community characteristics, diversity characteristics and spatial structural characteristics indicating that the maturity levels in all community ranked D > A > C > B. The study reveals that all four communities are currently in the pre- or mid-term succession stages and the development space of DBH and tree height is large. The four communities were in the moderate growth state. All trees showed a slight aggregated distribution, and the tree species were moderately, strongly or very strongly mingling. Besides, there was a distance in spatial structure between the four communities and ideal stand With the development of maturity levels, the four communities will continue to succession with intolerant tree species as the main dominant tree species, and gradually and preliminarily have the typical vegetation characteristics of the district forest climax community. With the development of maturity levels, the four communities’ biodiversity and mingling will increase, the spatial structure will be optimized and the stability will be enhanced. In the future, E’ huangzhang tropical monsoon forests should be more regulated and protected , while the ecology of vegetation and biodiversity conservation in the area should be widely monitored and studied in depth.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-05-21 Cooperative journals: 《广西植物》
Abstract： Biondia Schltr., contains about 13 species, is endemic to China, and Merrillanthus Chun & Tsiang is a monotypic genus distributing only in China and Cambodia. These two genera have been included in Vincetoxicum Wolf., but their phylogenetic positions and taxonomic status need further study because of insufficient samples and phylogenetic analysis. We reconstructed the phylogenetic trees of Tylophorinae based on two nuclear ribosomal DNA data (ITS, ETS) and five plastid DNA data (psbA–trnH, trnG, trnL, trnL–F, trnT–L) individually and combined data, which contain two type species samples. The results showed that Biondia and Merrillanthus were nested inside the Vincetoxicum; Biondia was polyphyletic, and the type species B. chinensis Schltr.=V. shaanxiense (Schltr.) Meve & Liede was sister to B. henryi (Warb.) Tsiang & Li=V. henryi (Warb.) Meve & Liede, and formed a clade with V. kawaroense Meve & Liede, but B. insignis Tsiang=V. insigne (Tsiang) Meve, H.H.Kong & Liede belonged to the Subtropical Clade; Merrillanthus formed a clade with V. cissoides (Blume) Kuntze and V. philippicum Meve, Omlor & Liede. Our results support that Biondia and Merrillanthus should be included in Vincetoxicum, but Biondia is polyphyletic, more species samples and data need to be collected and analysed to confirm their systematic positions about Vincetoxicum.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-04-29 Cooperative journals: 《广西植物》
Abstract： Moringa oleifera is a perennial tropical deciduous tree species, which has high economic value and cultivation purpose. In order to investigate the effects of different water (W) and nitrogen (N) additions on the root growth and traits of Moringa oleifera, we explored the response of root growth (e.g., root length, surface area, volume and average diameter of coarse and fine roots) of Moringa oleifera seedlings to the coupling of different soil water and nitrogen availability. There were three soil W gradients including 40% (W1), 60% (W2), 80% (W3) of field saturated water capacity (SWC), and four N application levels N0 (0 g穚lant-1), N1 (0.6 g穚lant-1), N2 (1.8 g穚lant-1), and N3 (3.6 g穚lant-1). The results were as follows: (1) W treatment had no significant effects on the coarse and fine root traits; (2) N treatment significantly affected the coarse root length, surface area, volume,
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