连栽红心杉土壤酶活性及其林木生长量研究

为了研究连栽对红心杉林木生长量和土壤酶活性的影响，笔者运用空间替换时间、相关性以及通径分析方法，对比第1(G1)、2(G2)、3(G3)代红心杉人工林的林木生长特性，探讨土壤酶活性对红心杉生长量的影响程度和机理。结果表明：红心杉的生长量随连栽代数的增加而降低；天然林以及第1、2、3 代红心杉林地中的脲酶活性随着土层的加深均显著降低(P＜0.05)；磷酸酶和过氧化氢酶活性分别对红心杉的胸径和树高生长具有强烈的直接作用，直接通径系数分别为1.115 和1.085。连栽导致红心杉林木生长量和土壤酶活性逐代降低，且红心杉林木生长量受磷酸酶和过氧化氢酶活性影响较大。

Successive Planting Generations of Cunninghamia lanceolata: Soil Enzyme Activity and Growth

The paper aims to study the effects of successive planting on the growth and soil enzyme activities of Cunninghamia lanceolata. We compared the growth characteristics of the first (G1), second (G2) and third (G3) generation of C.lanceolata by the methods of space-for-time, the correlation and path analysis and analyzed the effects of soil enzyme activities on the growth of C.lanceolata and its mechanism. The results showed that: with the increase of planting generations, the growth of C.lanceolata showed a decreasing trend; the urease activity of G1, G2, G3 and CK decreased significantly with the soil depth (P<0.05); the activities of phosphatase and catalase had strong direct effects on the DBH and height growth of C.lanceolata; the path coefficients were 1.115 and 1.085, respectively. Soil enzyme activities and the growth of C.lanceolata decrease with the successive planting, and the growth of C.lanceolata is greatly influenced by phosphatase and catalase activity.