围封、浅耕翻改良技术对退化羊草草地植被恢复的影响

为探求华北农牧交错带地区退化草地适宜的改良技术,于2005年在中国农业大学河北沽源草地生态野外试验站研究了围封、浅耕翻改良处理对退化天然羊草(Leymus chinensis(Trin.)Tzvel.)草地地上植被恢复的影响。结果表明:与过度放牧相比,围封、浅耕翻改良均能有效地改善退化羊草草甸草地地上植被的物种组成结构和群落结构,显著提高退化羊草草甸草地地上植被盖度、高度和地上生物产量(P<0.05),其中以浅耕翻改良的效果最为明显;围封、浅耕翻改良导致退化羊草草地植被物种饱和度、物种均匀性指数、物种丰富度指数和物种多样性指数显著下降(P<0.05),其中以浅耕翻的影响效果最明显。从利用的角度看,围封、浅耕翻改良4年后,羊草已占绝对优势,地上植被得到一定程度的恢复,地上生产量也显著提高(P<0.05),草地可以开始有计划地加以利用,其中,浅耕翻改良对促进退化羊草草甸草地地上植被生产力的恢复,尤其是羊草种群的恢复较围封改良效果更好。

Effects of Enclosing and Shallow Ploughing as Improvement Technologies on the Vegetation Restoration of Degraded Leymus chinensis (Trin.) Tzvel.Meadow Grassland

In order to explore the most suitable improving technology on the vegetation restoration of degraded Leymus chinensis(Trin.) Tzvel.meadow grassland in the agriculture and animal husbandry interlace zone in northern China,the effects of two treatments(enclosing and shallow ploughing) on the vegetation restoration of degraded L.chinensis meadow grassland were studied in 2005 at Guyuan Grassland Research Station of China Agricultural University in Hebei province,and.The results show the composition and structure of plant community were both improved,and the vegetation fractional coverage,height,and aboveground biomass were all obviously increased(P<0.05) with both enclosing and shallow ploughing treatments,especially the latter one.However,the species diversity index,species saturation,species richness,and species evenness index were all significantly decreased,especially with shallow ploughing treatment.Four years after the treatments of enclosing or shallow ploughing,the L.chinensis became the dominant species,the vegetation recovered,and aboveground biomass increased significantly(P<0.05);the grassland then could be used in a planned way.Compared with enclosing,shallow ploughing could be a better way for recovering the vegetation productivity(especially the population of L.chinensis) of degraded L.chinensis meadow grassland.