不同杉木林类型林地现存凋落物空间分布特征及其取样策略

通过统计学和Arc GIS技术等研究方法,以老龄林(在一代杉木人工林基础上以延长杉木轮伐期,并实施保护和促进天然更新为主要技术而形成的)、萌芽林(老龄林采伐后,以实施天然更新和杉木萌芽更新为主要造林技术而形成的撂荒天然更新林)、93人工林(老龄林采伐后,于1993年按照不炼山造林的栽杉模式而形成的二代杉木人工林)3个不同杉木林类型作为研究对象,深入地探讨不同杉木林类型林地现存凋落物的空间分布特征,并计算得出不同杉木林类型为满足精度要求所需的最少样本数。结果表明:不同杉木林系统凋落物现存量和变异系数存在着明显差异,均表现为萌芽林老龄林93人工林。不同杉木林类型林地现存凋落物量空间分布状况有较大的区别,存在明显的空间异质性。当精度为90%时,老龄林、萌芽林、93人工林所需的最少样方数量分别为48、72和42个;且在相同精度下,不同杉木林类型林地所需的最少样方数量基本上表现出93人工林老龄林萌芽林。这为不同杉木林类型林地研究中取样策略的选择和优化提供一定的参考。

Spatial Distribution of Litter Biomass of Different Chinese Fir and Its Sampling Strategy

Statistics and ArcGIS technology research methods were used to study the space distribution of Chinese fir forest litter and to calculate the minimum number samples which required to meet the accuracy of different types of Chinese fir for old forest (74-year),sprout forest (21-year),93 Plantation (23-year,restablished in 1993) Results showed the litter biomass and variation coefficient of different Chinese fir had a clear difference with an order sprout forest＞old forest＞93 Plantation.The space distribution of forest litter of different types of Chinese fir forest had great difference and obvious spatial heterogeneity.When the accuracy was 90％,the old forest,sprout forest and 93 Plantation required plots at minimum was 48,72 and 42,respectively.And at the same precision,the minimum number of samples required in the different types was in the order 93 Plantation＜ old-growth forest＜sprout forest.This sample selection and optimization strategies for different types of Chinese fir forest could provide a reference to other research.