有机荔枝园、常规荔枝园和天然荔枝园蜘蛛类群的比较

2004～2005年,对珠海市斗门区有机、常规和天然荔枝园的蜘蛛群落进行了系统的调查和分析,结果表明,不同类型荔枝园蜘蛛群落丰富度S值天然＞有机＞常规荔枝园;多样性指数H'值有机＞天然＞常规荔枝园;均匀度E值有机＞天然＞常规荔枝园.说明进行有机管理的荔枝园对蜘蛛群落的多样性影响较小,有利于保护和发挥天敌的自然控制力.有机、常规荔枝园的优势类群均为园蛛科、皿蛛科和球蛛科,而天然荔枝园除这三者外,跳蛛科也明显增加.除天气因素外,更重要的还与人为农事活动干扰程度直接相关.有机荔枝园不使用化学农药,蜘蛛种类多,个体数也较多.而常规荔枝园由于频繁地使用了化学合成物质,蜘蛛种类和数量较少.说明施用大量的化学农药,对蜘蛛的影响较大.

Comparison of structure and dynamics of spider community in organic,abandoned and conventional litchi orchards

The structures and characteristics of spider communities were analyzed based on surveys in organic, abandoned and conventional litchi plantations at Doumen, Zhuhai, Guangdong Province, from July 2004 to June 2005.The results of visual searching indicated that the species richness (S) of the spider communities was in the order abandoned ＞ organic ＞ conventional litchi zone.The diversity (H') was in the order organic ＞ abandoned ＞ conventional litchi region.Evenness (E) was in the order organic ＞ abandoned ＞ conventional litchi plantation.These findings showed that the impact of organic management practices on the diversity of spider communities was less than other two management methods.Three families, Araneidae, Linyphiidae and Theriodiidae, comprised the dominant groups among organic, abandoned and conventional plantations.The richness and number of Salticidae individuals in the abandoned litchi orchard also increased.Besides weather factor, the disturbance level of farming activity was important for diversity of spider community.The number of species and individuals of spiders was high in the organic litchi orchard, where no chemical pesticides were used, but was lower in the conventional litchi orchard, where chemical products were used frequently.These results indicated that the excessive use of pesticides had a negative effect on the spider community.