鄂西南鹅掌楸天然林林分结构特征

structuraICharacteristicsofLiriodendronchinenseNaturaIForestinsouthwestChina

摘要:

以鄂西南鹤峰县鹅掌楸天然林为研究对象,通过对林分空间结构(角尺度、大小比、混交度)和林分非空间结构 (径级结构、树高结构、重要值)的研究与分析,直观地反映其林分结构的特征,查清该区鹅掌楸种群的发展现状,为鹅掌楸 天然林的合理保护与科学经营提供依据 。在鹅掌楸天然林集中生长的代表性地段建立 17个 20mx20m调查样地,进行 每木定位与检尺调查,应用 Excel2019、Winkelmas2.0软件对样地调查数据进行处理与分析 。结果表明:研究区鹅掌楸 天然林中共 73个树种,鹅掌楸为该群落的优势种,生长处优势地位( =0.17),种群整体呈轻微聚集分布(为 0.56),同 时该种群在林分中呈现极强度混交状态( =0.85):种群整体径级、树高分布都呈右偏正态分布,小径级林木株数很少, 种群整体呈现稳定型一衰退型 。FSI均值为 0.82,FSD 均值为 0.30,林分空间结构为接近于理想状态(41.18%)或达 到理想状态(58.82%)。鹅掌楸天然林处于演替后期,林分结构整体上较为理想,可对处于聚集分布的林木进行适当调整, 辅以 一定人为促进更新的措施,促使鹅掌楸林分结构更加合理。

Abstract:

Abstract: Improving the carbon sequestration capacity of forests through afforestation and vegetation restoration has become one of the main ways to mitigate climate change. It is of great significance for regional forest sink management to estimate forest carbon sequestration potential by defining the change of carbon sequestration capacity of specific stands. In this paper, 74 fixed plots were set up according to different ages of poplar plantations in Jianghan Plain, Hubei Province. The growth pattern of poplar plantations was monitored continuously and dynamically by using the method of forest traffic regulation investigation. Then we constructed a growth model of poplar plantation to study the carbon sequestration potential of poplar plantation. The results showed that the age of artificial stand was positively correlated with average DBH, and negatively correlated with stand density in Jianghan Plain. The carbon density of mature poplar forest with 25 years of stand age is 97.13 t C/hm2, the maximum vegetation carbon density is 167.50 t C/hm2, and the theoretical average carbon sequestration potential is 1474.73 millon tons. In order to improve the carbon sequestration function of poplar plantation in Jianghan Plain, it is suggested that poplar forest should be managed continuously to play the carbon sink function, prolong the forest management cycle, strengthen the management and management, rationally allocate tree species, build mixed forest and reduce the biomass loss of forest.