基于BCI 50公顷大样地的森林空间结构特征研究

发布时间：2018-04-28 07:41

本文选题：BCI大样地 + 空间结构参数　；参考：《中国林业科学研究院》2017年博士论文

【摘要】：以大型固定样地进行森林生物多样性监测的方法为人们了解物种共存机制,理解生物多样性及其影响提供了可靠、翔实的数据。在森林生态学研究领域采用该方法开展森林生态系统的结构、动态及生态功能研究已经成为该领域的热点和基本方法。基于相邻木关系的林分空间结构参数如角尺度(Uniform angle index,Wi)、混交度(Mingling,Mi)和大小比数(Dominance,Ui)等,在国内外关于林分空间结构的分析、林木的竞争与优势度计算、物种的多样性测度以及结构的恢复重建与优化调整等研究领域中被广泛使用,并取得了良好的效果。但是基于相邻木关系的林分空间结构分析方法在对大型固定样地(Large-scale forest dynamics plot,FDP)的森林空间结构分析中应用较少,其潜力没有得到充分发挥。因此本研究将森林空间结构研究方法(空间结构参数)应用于位于巴拿马的巴罗克罗拉多岛(Barro Colorado Island,BCI)的50 hm2的森林动态监测固定大样地中,通过分析其1982-2010年近30年累计7次的普查数据的空间结构特征的动态变化,探讨空间结构参数在大样地中的应用前景以及对空间结构参数理论体系进行进一步完善和验证。以期为我国森林空间结构的精准分析和森林经营指导提供参考。通过分析,本研究具体取得如下主要的结论:(1)对BCI样地第1-7次普查样地中全部活立木个体(DBH≥5cm)的空间结构和相应的地上生物量(Above ground biomass,agb)空间结构的一元分布特征及二元分布特征进行分析,结果表明:BCI大样地1-7次调查中活立木整体空间结构呈随机分布状态,林分中大部分林木处于强度和极强度混交状态。样地中40%左右林木个体处于随机分布且极强度混交状态。BCI样地整体地上生物量空间结构一元及二元分布则表明样地中少数(20%)的林木个体贡献了样地中80%的地上生物量。(2)对BCI样地第1-7次普查中冠层林木(canopy trees)和下层林木(understory trees)(以DBH≥20cm进行区分)的空间结构以及相应地上生物量的一元分布特征及二元分布特征进行分析,结果表明:冠层的空间结构在总体上呈随机分布,冠层中77%以上的林分处于极强度混交。在随机分布轴(Uniform angle index=0.50)上,冠层林分地上生物量的频率值最高,均占冠层的一半以上。在强度混交和极强度混交等级(Mingling=0.75→1.00)上,几乎整个冠层的全部生物量都集中在这两个等级上。冠层中少数的大树(绝对优势树)贡献了近60%的冠层地上生物量。下层空间结构总体上呈随机分布,下层林木中57%的个体属于随机分布,很均匀分布和很不均匀分布只占下层林木的3%。90%以上的林木处于强度混交和极强度混交状态,最近相邻木为同种个体的情况基本不存在。90%的生物量集中在强度混交和极强度混交等级的林木上,林木的地上生物量随着林木大小比数等级的上升而急剧下降。只占下层林木总数20%的林木,贡献了下层地上生物量的50%。下层生物量分布主要集中在极强度混交和绝对优势的组合上,贡献了样地40%的下层地上生物量。处于随机分布且绝对优势的林木贡献了40%的地上生物量。(3)对BCI样地1-7次调查中的活立木,采用基于大小分化度的林木多样性指数Simpson(DT)、Shannon(HT)及其均值(?T)等指标进行林木大小多样性分析,并对各次调查空间优势度排名前20的树种进行分析比较,结果表明:3个指数在林木株数较少的冠层都能比较一致的判断林木大小多样性,但是在林木株数极多的整体和下层中就出现结果不统一的情形。3个多样性指数在总体上均呈现整体冠层下层的趋势。?T指数能够体现出各次调查的细微差异,这种细微差异在多样性极其复杂的热带森林中具有更高的研究价值和应用意义。对在各次调查中的空间优势度(Dsp)排名前20的树种进行树种空间格局分析,结果说明各次调查中,空间优势种多呈聚集分布。BCI大样地中前20个空间优势种主要集中在木棉科、大戟科、豆科、桑科、楝科、肉豆蔻科、紫葳科、茜草科、夹竹桃科、番荔枝科、樟科、芸香科等。其中以木棉科的Quararibea asterolepis空间优势度最高,其次是大戟科的Hura crepitans(响盒子)。
[Abstract]:The method of monitoring forest biodiversity in large and fixed plots provides reliable and accurate data for understanding the mechanism of species coexistence and understanding biodiversity and its effects. In the field of forest ecology research, the structure, dynamic and ecological function of forest ecosystem has become a hot spot in the field of forest ecology. The spatial structure parameters such as Uniform angle index (Wi), mixed degree (Mingling, Mi) and size ratio (Dominance, Ui) based on the relationship between adjacent trees, the analysis of the spatial structure of the stand, the competition and dominance of the trees, the measure of the species diversity, the restoration and reconstruction of the structure and the optimization of the structure. The whole research field is widely used and has achieved good results. But the spatial structure analysis method based on the relationship of adjacent wood is less applied to the analysis of the spatial structure of Large-scale forest dynamics plot (FDP), and its potential has not been fully exploited. The structure study method (spatial structure parameter) is applied to the 50 hm2 forest dynamic monitoring fixed plots of Barro Colorado Island (BCI) in Panama. By analyzing the dynamic changes in the spatial structure characteristics of the 7 census data accumulated over the past 30 years, the spatial structure parameters are discussed in the large sample plots. The application prospect and the theoretical system of spatial structure parameters are further perfected and verified in order to provide reference for the precise analysis of forest spatial structure and the guidance of forest management guidance in China. Through analysis, the main conclusions are obtained as follows: (1) the space of all living standing trees (DBH > 5cm) in the BCI sample plots at the first 1-7 times of common land inspection The spatial structure of the Above ground biomass (AGB) spatial structure and its two element distribution characteristics were analyzed. The results showed that the overall spatial structure of the living tree was randomly distributed in the 1-7 investigation of BCI, and most of the trees in the stand were in the mixed state of intensity and extreme intensity. About 40% of the plots were in the sample. The one and two yuan distribution of the spatial structure of the overall aboveground biomass of.BCI samples in the random distribution and extreme intensity mixed state shows that a few (20%) of the trees in the sample plots contributed 80% of the aboveground biomass. (2) the canopy forest (canopy trees) and the lower layer (understory trees) of the 1-7 census of BCI samples (D) The spatial structure of BH > 20cm and the one element distribution characteristics of the corresponding aboveground biomass and the two element distribution characteristics are analyzed. The results show that the spatial structure of the canopy is randomly distributed, and more than 77% of the trees in the canopy are in the extreme intensity. The canopy stands on the random distribution axis (Uniform angle index=0.50). The frequency of the biomass is the highest, all of which account for more than half of the canopy. The total biomass of the whole canopy is concentrated on the two grades in the mixed and extreme strength mixed grades (Mingling=0.75 to 1). A few large trees (absolute dominant trees) in the canopy contribute nearly 60% of the aboveground biomass. 57% of the individuals in the lower trees belong to the random distribution. The trees with a very uniform distribution and very uneven distribution of more than 3%.90% of the lower trees are in the state of mixed intensity and extreme intensity, and the nearest neighbouring wood is the same as the same individual, and the biomass of the.90% is not concentrated in the intensity mixed and the extreme intensity mixed forest. On the wood, the aboveground biomass of the trees fell sharply with the rise of the tree size ratio. The trees that only accounted for 20% of the total number of trees in the lower layer, contributed to the lower aboveground biomass 50%. biomass distribution mainly concentrated in the combination of extreme intensity mixing and absolute superiority, contributing to the 40% lower aboveground biomass. The trees with absolute superiority contributed 40% of the aboveground biomass. (3) the tree diversity index based on the size differentiation of tree diversity index Simpson (DT), Shannon (HT) and its mean (? T) were used to analyze tree size diversity in the 1-7 survey of BCI plots, and the tree species of the top 20 of the survey spatial dominance were analyzed. The results show that the 3 indices of the trees with fewer trees can be used to determine the diversity of the tree size, but the results are not uniform in the whole and lower tree number. The.3 diversity index shows the overall downward trend of the canopy on the whole. The T index can reflect the various surveys. The fine differences have higher research value and application significance in the tropical forests with extremely complex diversity. The spatial dominance of the first 20 species of tree species in the spatial dominance (Dsp) in each survey shows that the dominant species of spatial dominant species are mostly in the first 20 empty spaces in the large area of.BCI. The dominant species mainly concentrated in the kapok family, euphordiaceae, Leguminosae, Moraceae, neem, myrisaceae, vladiaceae, alizaraceae, Oleaceae, nevlitaceae, Lauraceae, Rutaceae, etc. among them, the Quararibea asterolepis spatial dominance of the family kapok family was the highest, followed by the Hura crepitans (ringing box) of euphordiaceae.

【学位授予单位】：中国林业科学研究院
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S718.5

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