森林经营单位级系统群团抽样设计比较

Comparison of cluster systematic sampling at management unit level

【目的】在分析国内外森林资源调查现状的基础上,结合我国森林资源监测中存在的问题,对森林经营单位级群团系统抽样设计不同方式进行分析比较,为森林资源调查和样地复查时样地的布设提供技术指导。【方法】以森林经营单位级监测群团样地(1km×1km样地布设)的实际调查数据为基础,设计模拟了1km×1km、1km×2km、2km×1km和2km×2km 4种抽样样地布设模式,对4种抽样设计方案的模拟数据,从调查成本、蓄积、地类面积、方差和标准差等方面进行比较分析。【结果】在模拟的4种样地布设方式中,调查成本由大到小的顺序是1km×1km、2km×1km、1km×2km、2km×2km;总蓄积量标准差由小到大的顺序是1km×1km、2km×1km、1km×2km、2km×2km;各地类面积标准差由小到大的顺序是1km×1km、1km×2km、2km×1km、2km×2km。【结论】在一类和二类资源调查体系耦合以及调查经费充足时,选择1km×1km布设样地;经费不充足或样地复查时,选择2km×1km或1km×2km样地布设方案。

【Objective】This paper compared cluster systematic sampling at forest management unit level to provide technical support for survey and monitoring layout of forest resources.【Method】Based on practical survey data on cluster system sampling design,four circles plots(1km×1km,1km×2km,2km×1km,2km×2km)were simulated and compared from the perspective of survey cost,growing stock,area,variance and standard deviation.【Result】The orders of the four different sampling plots distribution design types were 1km×1km>2km×1km>1km×2km>2km×2km by survey cost,1km×1km>2km×1km>1km×2km>2km×2km by total stock standard deviation,and 1km×1km>1km×2km>2km×1km>2km×2km by land type area standard deviation,respectively.【Conclusion】'1km×1km'plots were best for setting sampling plots with enough fund from system coupling of National Forest Inventory and Forest Resources Survey while'1km×2km'or'2km×1km'were good for setting sampling plots with insufficient survey fund.