Subjects: Biology >> Botany >> Applied botany submitted time 2023-07-26 Cooperative journals: 《广西植物》
Abstract： Shiwandashan is one of the hotspots of biodiversity in Guangxi, and its main vegetation type is the mountain evergreen broad-leaved forest. In order to understand the current community status and the development status of dominant species population structure of mountainous evergreen broad-leaved forests in the region; This study was conducted in a fixed monitoring sample plot of 1 hm2 established within the evergreen broad-leaved forest community in the Shiwandashan. Woody plants with a diameter at breast height ≥ 1 cm in the sample plot community were used as the research object to analyze their species composition, diameter class structure, tree height structure, and the spatial distribution pattern of dominant species using the g(r) function. The results indicate that: (1) There are 153 species of woody plants with a diameter at breast height ≥ 1 cm in the community, belonging to 52 families and 108 genera. The individual density of the sample plot community is 7 517 plants/hm2; The dominant species in the community are Clethra delavayi, Schima argentea, Hartia villosa, Castanopsis hystrix, Engelhardtia roxburghiana, Ardisia quinquegona, Itea chinensis, Symplocos adenophylla, Eurya subintegra, Ilex pubescens; But the dominant position of dominant species is not obvious. (2) The overall average diameter at breast height of the community is 5.51 cm, and the distribution of diameter class and tree height is approximately an inverted "J" shape. The diameter class distribution of dominant species is mostly an inverted "J" or "L" shape, and the community has a large number of small and medium-sized diameter class standing trees, indicating a strong self-renewal ability of the community. (3) Dominant species coexist stably in the community; The dominant species exhibit aggregated distribution in the sample plot, but there are differences in the location of aggregated distribution among dominant species. Overall, the community is currently in a good state of renewal, with the existence of dominant species in the top level community. However, the community has certain secondary characteristics and has not yet reached a stable top level community state. The dominant species can coexist stably and have the potential to inherit towards a stable top level community. Therefore, it is necessary to continue to strengthen management and promote the renewal and survival of the evergreen broad-leaved forest community in the Shiwandashan areas.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-08-05 Cooperative journals: 《广西植物》
Abstract： In order to explore the photosynthetic physiological adaptation mechanism of karst plant, Li-6400XT portable photosynthesis system were used to detect the leaf photosythetic parameters of eight karst adaptable plants in Pingguo City, Guangxi, including net photosynthetic rate (Pn), stomatal conductivity (Gs), intercellular CO2 concentration (Ci), transpiration rate (Tr), water use efficiency (WUE) and stomatal limitation value (Ls). Statistical methods, such as Pearson correlation analysis, principal component analysis (PCA), and permutational multivariate analysis of variance (PERMANOVA) were used in this study. The results showed the six photosynthetic parameters had different variation within and between species, and all the intraspecific variations were greater than the interspecific. Change of Gs and Tr mainly originated from interspecific variation (46.72% - 49.76%), while that of Pn 、Ci 、WUE and Ls mainly from intraspecific variation (48.66% - 64.50%). At the life form level, the intraspecific variations of Pn、Gs and Tr of evergreen plants were less than those of deciduous plants, but the intraspecific variation of Ci、WUE and Ls of evergreen plants was higher. Interspecific variations of all the parameters of deciduous plants were greater than those of evergreen plants. Gs variation was the greatest both at the intraspecific and the interspecific level, followed by Tr and Pn, while Ls and WUE, and Ci variation were the least. There were significant positive correlations among Pn、Gs and Tr (P<0.01). Ls was significantly positively correlated with WUE (P<0.05), but negatively with Gs and Ci (P<0.05). The correlations among these photosynthetic parameters are basically consistent with the global scale, which reflects the diverse trade-off strategies of plants to environment resources. The results also verified the leaf economics spectrum (LES) of karst plant. Evergreen plants were located at the slow investment-return end of the LES with high values of Ls, WUE and low values of Gs、Tr、Ci and Pn. On the contrary, deciduous plants were located at the quick investment-return end of the LES with low value of WUE and high value of Pn and Tr. The results reflect karst plant adapt to changing environment with different adaptation strategies by trade-offs or co-ordinations among traits, and provide scientific basis for selecting adaptive tree species and accelerating the succession process of vegetation restoration in the karst area.
Subjects: Biology >> Botany >> Applied botany submitted time 2020-08-02 Cooperative journals: 《广西植物》
Abstract：植物叶功能性状可直接或间接地反映植物对环境变化的响应与适应策略。采用野外气体交换测量和实验室分析相结合的方法，以桂西南典型喀斯特灌丛常见种龙须藤和黄荆为对照，对该区域 5 种优势木本经济植物的叶功能性状指标及其关系进行研究。结果表明：11 个叶功能性状指标种内均存在不同程度的变异，除胞间 CO2 浓度和水分利用效率外，其余指标均存在显著差异。比叶面积与叶干物质含量、叶组织密度呈极显著负相关，净光合速率与气孔导度、蒸腾速率呈极显著正相关，叶绿素与净光合速率、胞间 CO2 浓度和蒸腾速率呈显著或极显著负相关。结合叶经济谱理论分析，毛葡萄、长穗桑和黄荆属快速投资-收益型物种，趋向于选择光合能力强、比叶面积大但寿命短的生存策略；而柠檬、山黄皮、枇杷和龙须藤属缓慢投资-收益型物种，趋向于选择光合能力弱、比叶面积小和寿命长的生存策略。其中，枇杷和龙须藤的功能性状又发生了趋异分化，枇杷具有较高的水分利用效率，而龙须藤具有较高的叶干物质含量。结果说明桂西南喀斯特地区 5 种优势木本植物通过叶功能性状间的权衡采取了不同的适应策略，对于喀斯特退化生态系统植被恢复与重建具有重要的理论指导意义。
Subjects: Biology >> Botany >> Applied botany submitted time 2018-12-04 Cooperative journals: 《广西植物》
Abstract：通过对 29 个红锥优树二代家系苗光合碳氮同化过程关键物（叶绿素、硝酸还原酶活性、谷氨酰胺合成酶活性、总 ATP 酶含量、PEP 羧化酶含量和 RUBP 羧化酶含量）进行测定，运用主成分分析及隶属函数法进行优良家系的筛选和评价。结果表明：9 个生理指标 29个家系间均存在显著差异。叶绿素 a 含量为 0.13~0.72 mg·g-1Fw，叶绿素 b 含量为 0.01~0.27mg·g-1Fw，叶绿素 a+b 含量为 0.18~0.98 mg·g-1Fw，类胡萝卜素含量为 0.03~0.32 mg·g-1Fw，硝 酸 还 原 酶 活 性 为 1.16~10.26 µg··g-1··h-1 ， 谷 氨 酰 胺 合 成 酶 活 性 为 0.30~1.24A··mg-1protein·h-1，总 ATP 酶含量为 0.37~3.55 U·mg-1 prot，PEP 羧化酶含量为 8.42~21.24IU·L-1，RUBP 羧化酶含量为 2.09~9.12 ng·mL-1。其中总 ATP 酶含量变异最大，其次为硝酸还原酶活性；变异最小的为 RUBP 羧化酶含量。采用主成分分析及隶属函数法分别多指标的综合评价方法筛选出 10 个红锥优树二代优良家系，重复率达到了 90%，分别为 B2、B5、P5、A6、P3、P6、R3、D2、R4 家系。说明主成分分析法和隶属函数法均可用于评价红锥二代优良家系。其中家系 B2、B5 表现最佳.
Hits
Hits
Downloads
Comment