关键词: 兴安落叶松, 时滞效应, 主成分分析, 逐步回归分析, 环境因子

Abstract: A mulberry-silkworm-livestock ecosystem was experimentally established in 1984 at Tai county of Jiangsu province. Winter crops have been interplanted as fodder in mulberry field during leafless seasons. Plant residues left by silkworm and fallen leaves have been used to feed goats. Chickens have fed on weeds and insects in mulberry field in summer and kept in silkworm breeding rooms in winter. The excrements of silkworms, goats and chickens have been applied as manures to mulberry and intercropping crops. Compared with traditional sericulture, this is one of successful homestead agroforestry'system, with better cycling of material and energy and better economic benefits, which is inereasingly practised in China today.

Key words: Larix gmelinii, time lag, principal components analysis, stepwise regression analysis, environmental factor