模拟氮沉降对杨树人工林土壤动物类群结构的影响

Effect of nitrogen deposition on the composition of soil fauna communities in poplar plantation

氮沉降过量会导致一系列严重的全球性生态问题,研究氮沉降对土壤动物群落结构的影响,对于明晰土壤动物群落受大气氮沉降加剧产生的响应机理有重要意义。通过模拟氮沉降试验,研究了不同氮沉降浓度下土壤动物群落特征的变化规律。试验结果表明:甲螨亚目(Oribatida),前气门亚目(Prostigmata),弹尾纲(Collembola),寡毛纲(Oligocllaeta),膜翅目(Hymenoptera)及盲蜘目(Opiliones)6个类群在不同龄级,不同氮沉降梯度下所占比例较高,为典型的优势类群;土壤动物类群丰富度及数量在不同氮沉降梯度下呈现先升后降的趋势;幼龄林土壤动物多样性指数普遍较高,且随氮沉降浓度的增加波动明显,老龄林与之相反;土壤甲螨随着氮沉降增加呈现先增后减的趋势,具有环境指示作用。

Excess nitrogen deposition will cause a series of global serious ecological problems. Our research on effects of nitrogen deposition on soil animal community structure is significant to clarify the mechanism of the community in response to atmospherically increased nitrogen deposition. The simulated nitrogen deposition experiments were committed to reveal variation of the soil animal community characteristics in this study. The results showed that Oribatida, Prostigmata, Collembola, Oligocllaeta, Hymenoptera and Opiliones were 6 dominant communities in different poplar age-classes and nitrogen deposition gradients; soil animal taxa richness and quantity presented a rise after decline tendency in different nitrogen deposition gradients ; the soil animal diversity index of young forest was generally high and increased with the gradients of nitrogen deposition obviously, but in old forests the case was in the opposite; and especially, soil mites（Oribatida） showing a fall-thenrise tendency with increasing of the nitrogen deposition, could be seen as an environmental indicator.