土地利用变化中地表蚂蚁功能多样性的变化

Changes in the functional diversity of ground-dwelling ants during land use change

【目的】为了揭示土地利用变化中人工林对生态系统功能的保护作用。【方法】使用陷阱法调查了云南省绿春县天然次生林、桉树林、橡胶林、紫胶林、紫胶林-玉米混农林、玉米地和农田7种生境样地的地表蚂蚁群落,测定了82种蚂蚁的头长、头宽、胸长和后足腿节长的功能特征,并计算和比较不同生境蚂蚁功能丰富度、功能均匀度和功能离散度的差异。【结果】不同生境蚂蚁功能丰富度指数FRic有显著差异(雨季:F=4.475,P=0.002;旱季:F=7.717,P<0.001),天然次生林、雨季桉树林和橡胶林以及旱季的紫胶林和紫胶-玉米混农林功能丰富度较高,农田最低;不同生境地表蚂蚁功能均匀度指数FE_(ve)无显著差异(雨季:F=2.106,P=0.078;旱季:F=2.093,P=0.079);不同生境地表蚂蚁功能离散度指数FD_(iv)有显著差异(雨季:F=2.577,P=0.036;旱季:F=3.969,P=0.004),旱雨季橡胶林蚂蚁功能离散度均最高,天然次生林和农田则较低。地表蚂蚁功能丰富度指数与物种丰富度显著相关(雨季:Pearson=0.461,P=0.002;旱季:Pearson=0.854,P<0.001)且为线性模型(雨季:F=10.533,P=0.002;旱季:F=107.387,P<0.001)。地表蚂蚁功能均匀度及功能分散度指数与物种丰富度无显著关系。雨季蚂蚁功能丰富度随枯落物厚度增加而增加;旱季蚂蚁功能丰富度随着空地比例增加而降低,随着枯落物厚度增加先下降再升高,随着植物盖度增加先升高后下降。【结论】土地利用变化及旱季和雨季交替导致的栖境异质性降低能降低蚂蚁群落的功能丰富度,但对功能均匀度和功能离散度影响不明显。土地利用中降低人工林的干扰、人为增加栖境复杂程度将为蚂蚁提供生存空间,降低蚂蚁竞争程度,有利于生态系统功能多样化及功能保护。

【Aim】 To reveal the protection roles of artificial plantations for ecosystem function. 【Methods】 The ground-dwelling ants were investigated in plots of seven habitats, i.e., secondary natural forest, eucalyptus plantation, rubber plantation, lac insect plantation, lac insectcorn agroforest, corn dryland and farmland, by pitfall traps in Lüchun County, Yunnan Province. Head length, head width, Weber＇s length and femur length of hind leg of 82 ant species were measured. Differences in functional richness, functional evenness and functional divergence were compared among different habitats. 【Results】 There were significant differences of ant functional richness FRic among different habitats （rainy season： F=4.475, P=0.002; dry season： F=7.717, P〈0.001）. Secondary natural forest, eucalyptus plantation and rubber plantation during the rainy season and lac insect plantation and lac insect-corn agroforest during the dry season had higher levels of ant functional richness, and farmland had the lowest ant functional richness. There were no significant differences in ant functional evenness FEve among different habitats （rainy season： F=2.106, P=0.078; dry season： F=2.093, P=0.079）. There were significant differences in ant functional divergence FDiv among different habitats （rainy season： F=2.577, P=0.036; dry season： F=3.969, P=0.004）. Rubber plantation had the highest ant functional divergence during both rainy and dry seasons, while secondary natural forest and farmland had the lower ant functional divergence. Functional richness of ground-dwelling ants were significantly correlated with ant species richness （rainy season： Pearson=0.461, P=0.002; dry season： Pearson=0.854, P〈0.001; liner model： rainy season： F=10.533, P=0.002; dry season： F=107.387, P〈0.001）. Functional evenness and functional divergence of ground-dwelling ants were not significantly correlated with ant species richness. In rainy season, ant functional richness increased with increasing of leaf-litter thickness. In dry season, ant functional richness decreased with increasing of bare ground coverage, and first decreased then increased with increasing of leaf-litter thickness, and first increased then decreased with increasing of plant coverage. 【Conclusion】 Reduction of habitat heterogeneity caused by land use change and alternation of rainy and dry seasons can lead to the decrease of ant functional richness but has no significant effect on ant functional evenness and functional divergence. More ant living space will be provided by reducing disturbance to artificial plantation and increasing habitat heterogeneity artificially. This will reduce the competition between different ants, and be helpful to ecosystem function diversity and protection.