内蒙古东北段森林衰退现状及种群竞争对其生长的影响

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 内蒙古东北段森林衰退现状及种群竞争对其生长的影响 DOI: 10.5846/stxb202106101549 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 内蒙古自治区科技重大专项（2021ZD0011）；国家自然科学基金委优秀青年科学基金项目（41922001）；国家自然科学基金面上项目（4217010260） The status quo of forest decline and the impact of population competition on its growth in the northeast of the Inner Mongolia Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:随着气候变化加剧，中国半干旱区东段发现大量森林衰退现象，威胁到社会生产和环境保护的可持续发展。种群竞争是森林动态的内在驱动因子，当前对该区域森林种群竞争与森林衰退关系的研究尚缺乏足够的依据。选取内蒙古大兴安岭典型森林作为研究对象，依据Hegyi单木竞争指数模型计算个体水平上和样地水平上的竞争指数，利用树木个体树轮指数(TRI)年表作为个体水平上的衰退指标，利用样地年表(TRI)和胸高断面积增量(BAI)来分析样地水平上的衰退指标，探讨不同尺度上森林衰退状况。探讨个体水平上和样地水平上竞争指数与不同尺度上森林衰退指标之间的关系，分析研究区森林衰退的内因特征。主要结论如下：第一，样地年表与树木个体年表所指示的衰退时段基本一致，结合两者的重合结果，可以得出各样地的衰退年份。不同样地的生长衰退时段有重合的现象，个体年表中超过阈值50%的样地的严重衰退时期年份基本在2001-2005年间，而在样地年表中，样地五岔沟林场(L-WCG1)、五岔沟林场大样地(L-WCG2)、乌尔根(L-WRG)在1989年至1997年都出现生长衰退，样地军达盖林场(L-HDG)、L-WCG1、L-WCG2、L-WRG和s根河(L-GH1)衰退重合期在1998-2003年期间。这是由于这一阶段研究区发生了大规模的干旱事件，导致不同地点的树木生长都受到抑制。第二，各样地中树木个体的五年平均相对胸高断面积增量(rBAI5)与个体竞争指数相关的显著性最高，两者的关系可用指数函数方程表达，即rBAI5随着个体水平竞争指数的上升而下降。这说明了竞争指数对于树木生长存在显著的影响。而样地竞争指数与近2年、5年和10年内样地胸高断面积均值(BAI2、BAI5、BAI10)之间的关系不明显。从种群竞争方面研究中国半干旱区东段的森林衰退影响因素，旨在为森林衰退机理研究提供依据，为半干旱区森林资源可持续发展提供支持。 Abstract:The ecosystem service values and functions of forests are important in the semi-arid region of eastern China. With the increasing of climate change and the degradation of the aridification, forest declines have been monitored in the region in recent years. It eventually changed the species composition, nutrient cycling and biomass accumulation cycle of the ecosystem, and then affected the forest regeneration and structure, caused disturbance to the service function and biodiversity of the forest ecosystem and to a certain extent threatened the human society, culture and ecological function, and promoted the sustainable development of social production and environmental protection. Population competition is an intrinsic driving factor of forest dynamics. But there is still lack of evidences on the relationships between population competitions and forest decline in the area. Using typical forest types in Daxing'anling, the Inner Mongolia as cases, a suitable competition index model was used to analyze the competition status at both individual and population levels; then individual tree chronology (TRI) was selected as an indicator of individual growth reduction; Plot chronology and basal area increment (BAI) were applied to assess forest decline at the plot level. After that, the relationships between the competition indices and the forest decline indicators at different levels were analyzed. Results indicated that the chronology of the plot was basically same as the decay period indicated by the individual chronology of the tree. The decay period of each plot could be concluded by combining the coincidence results. There was also a coincidence between periods of growth decline in different plots. At the individual chronology, most plots had similar periods of 2000-2005, with serious decline over the threshold defined by that the percentage of trees with growth decline exceeding 50%. At the plot chronology, plots L-WCG1, L-WCG2, and L-WRG had the same period of growth decline from 1989 to 1997, and plots L-HDG, L-WCG1, L-WCG2, L-WRG and L-GH1 had the same periods of growth decline from 1998 to 2003. The reason may be that the serious drought events appeared in the stage, causing the growth of trees to be inhibited at a large scale. The individual five-year averagely relative basal area increment (rBAI5) in each plot had the highest correlation with the individual competition index. The relationship between the two can be expressed by an exponential function equation through trend fitting. That is, rBAI5 decreased as the individual level competition index increased. Thus the individual competition index had a significant impact on the growth of trees in five years. The relationships between the competition index at plot level and the mean values of the basal area increment in recent two, five and ten years (BAI2, BAI5 and BAI10) were insignificant. The research explored the factors of forest decline in semi-arid area of eastern China from the perspective of population competition. It aims at providing bases for the analyses of the driving mechanism of forest decline and the sustainable development of forest resources in semi-arid area. 参考文献 相似文献 引证文献