经济林草措施改造柏木低效林对中小型土壤动物群落结构的影响

Effects of forest-grass modes on the meso-and micro-soil faunal community structure in transforming low-benefit Cupressus funebris Endl. forest

中小型土壤动物的空间分布及群落多样性对于衡量低效林的生态恢复具有重要的意义。为了探索林草措施对柏木低效林中小型土壤动物群落结构的影响,本试验设置核桃+沙打旺、核桃+苏丹草、核桃+草木犀、核桃+黑麦草、核桃+松土和柏木对照组,采用干、湿漏斗法调查不同处理中小型土壤动物群落分布情况。结果表明:所有处理中小型土壤动物群落类群数、密度和多样性均在夏、秋季相对较高,冬、春季相对较低,且不论哪个季节均表现为核桃+牧草>核桃+松土>柏木低效林;在处理的初期,林草措施与柏木低效林土壤动物群落几乎均处于中等不相似水平,随处理时间的延长,其群落基本处于中等相似水平,其中,核桃+松土与柏木林在秋、冬季甚至达到极相似水平;核桃+牧草和柏木林中小型土壤动物无论在哪个季节主要分布在上中层土壤,且在冬季林草措施土壤动物有向中下层土壤迁移的趋势;核桃+松土中小型土壤动物在处理前期主要分布在上中层土壤,随处理时间的延长,其土壤动物会逐渐往中下层迁移。林草措施对中小型土壤动物群落结构的影响较大,且不同林草措施的这种影响效果略有不同,其中,核桃+苏丹草、核桃+草木犀和核桃+黑麦草的效果较好。

The spatial distribution and community diversity of meso- and micro-soil fauna are of great significance to assessing the ecological restoration of low-benefit forests. A field experiment was conducted to explore the effects of forest-grass measures on the mesoand micro-soil faunal diversity in low-benefit Cupressus fanebris Endl. forest. Six treatments were employed, including Juglans regia L.＋Astragalus adsurgens Pall., J. regia＋ Sorghum sudanense （Piper） Stapf, J. regia＋Melilotus officinalis （L.） Pall., J. regia＋Lolium perenne L., J. regia＋soil-loosening, and low-benefit C. funebris forest as control. The meso- and micro-soil faunal communities were investigated by using dry and wet funnel method. The results showed that the group number, density and diversity of the mesoand micro-soil fauna were relatively higher in summer and autumn than in winter and spring in all trestments. Moreover, these variables showed a pattern of J. regia＋ grass 〉 J. regia＋ soil-loosening 〉 low-benefit C. funebris forest in four seasons. The meso- and micro-soil faunal communities of forest-grass and low-benefit C. funebris forest were moderately dissimilar at the beginning of treatment, and moderately similar with time extension. J. regia ＋ soil-loosening and low-benefit C. funebris forest were significantly similar in autumn and winter. The soil fauna in J. regia＋grass and C. funebris forest was mainly distributed in upper and middle layer soil in four seasons, while the meso- and micro-soil fauna in forest-grass had a tendency of moving to subsoil in winter. At the early stage, the soil fauna in J. regia＋soil-loosening was main- ly distributed in upper and middle soil layer; as time went by, the soil fauna was likely to migrate to the middle and lower layers gradually. Forest-grass had a great effect on the meso- and micro- soil faunal community structure, and this effect was better in J. regia＋M, officinalis and J. regia ＋L. perenne than in the other forest-grass measures.