退化红壤不同植被恢复方式对蚯蚓种群的影响

Effects of different vegetation restoration of degraded red soil on earthworm population dynamics.

对 4种人工林 (小叶栎、木荷、马尾松及木荷 马尾松混交林 )和 2种荒草地 (保护荒地、轻度干扰荒地 )及疏草荒地对照进行了蚯蚓种群的季节动态调查 .结果表明 ,退化红壤植被恢复 10年后蚯蚓种群有了明显的发展 ,但仅 1种天锡杜拉蚓存在 .蚯蚓密度和生物量的季节平均值顺序为 :保护荒地 >干扰荒地>小叶栎 >木荷 >马尾松 >混交林 >疏草荒地 ,其中前三者显著高于其余植被类型 (P <0 0 5 ) .蚯蚓种群季节波动明显 ,夏季干热有强烈的抑制作用 .就季节变异系数所体现的种群稳定性而言 ,小叶栎最高 ,而马尾松最低 ,荒草地也较低 .鉴别分析从整体上刻画了不同恢复植被下蚯蚓种群的分异 .由植被类型决定的归还土壤的有机物数量和质量是蚯蚓种群分异的主要驱动因子 .另外 ,联系蚯蚓种群发展 ,讨论了退化红壤恢复中选择适宜植被类型的重要性 .

This study was conducted at the long-term experimental plots in Ecological Experimental Station of Red Soil in Yujiang County (28°15′30″N,116°55′30″E ),Jiangxi Province,subtropical China.Earthworm population was investigated seasonally from May 1999 to February 2000,under different vegetations including four artificial woodlands [deciduous broadleaf woodland (Quercus chenii,Qc),evergreen broadleaf woodland (Schima superba,Ss),coniferous woodland (Pinus massonina,Pm) and mixed woodland (Schima superba-Pinus massonina,Sm)],two grasslands [gently-disturbed grassland (G 1),undisturbed grassland (G 2)] and control wasteland (CK).The results indicated that the population structure was very simple.Only Drawinda gisti characterized by pioneer was found.The seasonal averages of density and biomass were in the order of G 2>G 1>Qc>Ss>Pm>Sm>CK,and those of G 2,G 1 and Qc were significantly higher than those of the latters (P<0.05).Seasonal fluctuations were obvious with dry-hot summer depressing the earthworm population sharply,leading to the aestivation of earthworm.Based on the variation coefficients of density and biomass,Qc had the highest ecosystem stability,followed by Sm and Ss,and G 1,G 2,and Pm had the lowest stability.The overall differentiation of earthworm population could be drawn through canonical discriminant analysis.There were significant correlations between earthworms and some soil properties (P<0.01).Overall,the differentiation of earthworm population was driven by the quantity and quality of soil organic matter returned by the vegetations.Additionally,based on earthworm population,the importance of selecting appropriate vegetation types during the restoration of degraded red soil was emphasized.