周边不同生境条件对茶园蜘蛛群落及叶蝉种群时空结构的影响

Effects of the surrounding habitat on the spider community and leafhopper population in tea plantations

为利用天敌实施害虫生态控制,田间调查了周边不同生境条件对茶园蜘蛛及叶蝉种群结构的影响。结果表明:小乔木生境茶园(Ⅰ)和相思树生境茶园(Ⅲ)影响下茶园蜘蛛及叶蝉聚集程度较强,茶园Ⅰ叶蝉聚集数最多,为692头,但与其他生境茶园间差异不显著(P>0.05);茶园Ⅲ蜘蛛聚集数量最多,为1155头,并与稻田生境茶园(Ⅱ)、生活区生境茶园(Ⅳ)的差异达到显著水平(P<0.05);从蜘蛛功能群聚集情况来看,结网型蜘蛛相对较少,为295头;游猎型蜘蛛最多,为2957头;其中,茶园Ⅰ与茶园Ⅲ蜘蛛多样性指数和丰富度数值较大,对叶蝉的跟随效应明显,并与Ⅱ、Ⅳ茶园有显著差异(P<0.05)。多元数据分析结果显示,茶园Ⅰ和茶园Ⅲ均能够明显提高蜘蛛群落聚集的时空分布水平;蜘蛛群落的聚集密度时空分布大小表现为:茶园Ⅰ>茶园Ⅲ>茶园Ⅳ>茶园Ⅱ。由此可知周边生境结构植物丰富和相对稳定的茶园能通过和谐的生态过程影响蜘蛛和叶蝉的时空格局,提高蜘蛛对害虫叶蝉的自然控制能力。

The issue of carbon emissions from tea plantations is currently the focus of global attention. The agricultural field ecosystem is a major factor in maintaining a balance, and plays a significant role in counteracting emissions. Our aim was to explore the aggregation indices, individual number, spatial distribution, dynamic occurrence, and principal component of arthropods, and their effects on tea plantations. Field experiments were conducted at the Drinkable Plants Research Institute, Guangdong Academy of Agricultural Sciences, Yingde County, Guangdong, China. Sampling was carried out continuously from January to December, 2009. In order to develop more effective pest control on tea plantations, four plantations were surveyed to quantify the effects of different surrounding habitats on both the pest （the leafhopper, Empoasca vitis Gothe） and predatory spider populations. No pesticides were used on the plantations. The results showed that： （ 1 ） The biggest aggregation occurred in the tea plantations surrounded by mixed natural woodland （ plantation Ⅰ ） or pure Acacia confusa communities （ plantation Ⅲ）. The greatest numbers of leafhoppers （692） occurred in plantation I ; however, this value was not significantly different from that found in the other three tea plantations （P〉0.05）. The number of predatory spiders in plantation Ⅲ （1155） was significantly higher than that found in the other three tea plantations （ P 〈 0.05 ）. （2） Analysis of the behavior of all aggregated spider species showed that the number of spiders that remained in their webs was relatively small （ 295 ）, which is significantly less than the 2957 spiders that were observed moving. The diversity index and species-rich value were both highest in plantationsⅠ and Ⅲ. This had an obvious effect on leafhopper numbers, which were significantly higher than those found in plantations close to paddy fields （plantation Ⅱ） or to a village （plantation Ⅳ）. Both predatory spiders and leafhoppers showed aggregated distribution, caused by their own biological habits and the common environment; different ways of managing habitats lead to significant differences in the size and diversity of the spider communities and the size of the lea/hopper population. （3） Multivariate data analysis showed that the comprehensive distribution characteristics of the spider communities--both in time and space--had the potential for significant improvement in plantations I and III, over those in plantations I1 and IV （P〈0.05）. These data enabled the behavior of predatory spiders in tracking their leafhopper prey to be examined. The aggregation density of spiders in the tea plantations was： plantation Ⅰ （close to mixed natural woodland） 〉 plantation Ⅲ （ close to pure Acacia confusa communities） 〉 plantation Ⅳ （ close to a village） 〉 plantation Ⅱ（close to paddy fields）. These results indicate that the habitat surrounding a tea plantation, being a relatively stable and complex structure, affects the spatial and temporal pattern of both leafhopper and spider populations through ecological processes. This leads to an increase in the quantity of spiders moving about on the tea trees, which creates a synergistic effect of leafhopper capture, hence improving the ability of predatory spiders to control leafhopper numbers.