广州长岗山森林凋落物土壤动物群落结构及季节变化

为了解华南地区城市森林凋落物土壤动物群落结构特征及季节变化,对广州市长岗山自然保护区森林凋落物层土壤动物群落进行了为期1年的逐月采样调查,共采获凋落物土壤动物21 817头,隶属于3门9纲22类群,其中蜱螨目和弹尾目为优势类群,二者占全年土壤动物个体总数的70.3%;蠕形马陆亚纲、等足目、蜘蛛目、缨翅目、鞘翅目、膜翅目、鳞翅目幼虫和双翅目幼虫为常见类群,它们的个体数占全年土壤动物总个体数的27.0%.这些主要类群的相对多度和密度随采样季节而改变并与凋落物的湿度存在着一定的相关性.蜱螨目的密度高峰期出现在降雨量最多的5-8月;弹尾目的密度高峰出现在2-7月;缨翅目的密度高峰在8-12月,凋落物湿度过高或过低均使缨翅目密度降低;鞘翅目的密度高峰分别出现在5-8月、11月和翌年2月,而蠕形马陆亚纲的密度高峰期集中在5-6月,而其余月份的密度维持在低水平.蜱螨目(A)和弹尾目(C)个体数之比的大小不一定能反映同一气候带土壤动物的分布特征和规律,因为即使在同一地点,不同的采样时间也会造成A/C值差异悬殊.保留城市森林凋落物对提高城市森林土壤动物的多样性具有重要意义.

Community structure and its seasonal change of litter invertebrates in Changgangshan Natural Reserve of Guangzhou,China

To understand the community structure and its seasonal change of litter invertebrates in urban forests of Southern China,the litter invertebrates in Changgangshan Natural Reserve of Guangzhou were sampled monthly from July 2004 to June 2005.A total of 21817 invertebrate individuals belonging to 22 orders in 9 classes under 3 phyla were collected.Acarina and Collembola,the dominant groups of the litter invertebrates,had the individuals accounting for 70.3% of the total,and the individuals of the ordinary groups Helminthomorpha,Araneae,Isopoda,Thysanoptera,Coleoptera,Hymenoptera,Lepidoptera larvae,and Diptera larvae occupied 27.0% of the total.The relative abundance and density of these 8 groups changed with seasons,and correlated with litter humidity to a certain degree.The highest density of Acarina occurred in heavy rainy seasons,i.e.,from May to August,and that of Collembola appeared from February to July.Thysanoptera showed a high density from August to December,but the higher or lower litter humidity caused its low density in rest months.Coleoptera showed three density peaks,i.e.,May-August,November,and next February.Helminthomorpha had the highest density in May and June,but very low density in the other months.The individuals ratio of Acarina to Collembola(A/C value) varied with sampling season significantly even at the same sampling site,and did not necessarily reflect the distribution characteristics of litter invertebrates in the same climate zone.To remain urban forest litter would be of significance in improving the invertebrate diversity in urban forest soil.