湿地松连作对土壤肥力及其生长量的影响

Effects of Continuous Cropping on Soil Fertility and Stand Productivity of Pinus elliottii Pure Forest

为了研究连作对湿地松纯林土壤肥力及林分生产力的影响,以湖北省荆门市彭场林场中湿地松人工林为研究对象,调查并分析连作林分和非连作林分林地土壤养分含量变化和林木生长量及根系差异。结果表明:0~10 cm土层中非连作林分土壤氮、磷、有机质含量均高于连作林分,>10~20 cm土层中非连作林分土壤的氮和磷含量高于连作林分;非连作林分林木根的长度和表面积均高于连作林分;利用解析木数据拟合林木树高、胸径和单株材积生长曲线,15 a前连作和非连作林分的树高和胸径没有明显差异,但非连作林分的单株材积高于连作林分,而25 a时,非连作林分的胸径和单株材积明显高于连作林分。可见,湿地松连作会导致土壤肥力退化,林分生产力下降,对于连作林分土壤肥力维持至关重要。

In order to Study the effects of continuous cropping on soil fertility and stand productivity in Pinus elliottii pure forests.Taking the artificial P.elliottii forest in Pengchang Forest Farm,Jingmen City,Hubei Province as the research object,this study investigates and analyzes changes in soil nutrient content and differences in tree growth and root system between continuous and non-continuous cropping forest stands.The results showed that soil nitrogen,phosphorus,and organic matter content of non-continuous cropping stand in 0-10 cm soil layer was higher than those of continuous cropping stand.The soil nitrogen and phosphorus content of non-continuous cropping stand in 10-20 cm soil layer was higher than that of continuous cropping stand;The length and surface area of roots in non-continuous cropping stand was higher than those in continuous cropping stand;Using analytical wood data to fit the growth curves of forest tree height,diameter at breast height,and individual volume,there was no significant difference in tree height and diameter at breast height between continuous and non-continuous cropping stands before 15 years.However,the individual volume of non-continuous cropping stand was higher than that of continuous cropping stands.At 25 years,the breast height and individual volume of non-continuous cropping stands were significantly higher than those of continuous cropping stand.Continuous cropping of P.elliottii can lead to soil fertility degradation and a decrease in stand productivity,which is crucial for maintaining soil fertility in continuous cropping forests.