稻鸭鱼共栖生态系统中蜘蛛动态变化规律及其数学模型建立.docVIP

稻鸭鱼共栖生态系统中蜘蛛动态变化规律及其数学模型建立 　　摘要通过田间试验，对稻鸭鱼共栖生态系统中蜘蛛的数量变化进行了详细的记录，并运用Logistic方程，建立了相应生态系统中蜘蛛增长的数学模型。经数据分析，结果表明：稻鸭鱼共栖生态系统中蜘蛛总量参数为：环境容纳量K=893.813 7，自然增长率r=0.137 3，蜘蛛总数量方程为：Nt=；稻鱼共栖生态系统中蜘蛛总量参数为：环境容纳量K=936.371 2，自然增长率r=0.153 2，方程为：Nt=；而常规用药的稻田中蜘蛛由于受药物作用的影响，环境容纳量K值不稳定，K为变化曲线，即：K=444.219 6（t＜41）-0.126 24t3+21.277t2-1 191.4t+222 78（t≥41），自然增长率r=0.063 1，方程为Nt。研究结果表明：常规用药区比稻-鱼区和稻-鸭-鱼区蜘蛛的自然增长率分别低58.8%和54.0%，化学农药在杀灭害虫的同时也杀死了蜘蛛，破坏了稻田生态环境。稻鸭鱼共栖有利于稻田生态系统中蜘蛛的生长。 　　关键词稻鸭鱼共栖；生态系统；蜘蛛；自然增长率；数学模型 　　中图分类号Q141；S435.112文献标识码A文章编号 1007-5739（2011）03-0027-03 　　 　　TheChangingRulesofSpider′sDevelopingandtheEstablishmentofitsMathsModelinRice-Duck-Fish 　　CommensalismsEcosystem 　　ZHANG Yan 1LIU Da 1LIU Da-zhi 1LIU Xiao-yan 2 *HUANG Huang3 　　（1Agricultural Bureau of Taojiang County in Hunan Province，Taojiang Hunan 413400； 2 College of Animal Science and Technology，Hunan Agricultural University； 3 College of Agronomy，Hunan Agricltural University） 　　AbstractThrough farm trial，the quantity of spiders in rice-duck-fish commensalisms ecosystem was recorded detailedly and logistic equation was exerted to establish maths model of spider′s increasing in the connected ecosystem. By analyzing these data， the calculated results showed that the parameter of spiders′ total amount in rice-duck-fish commensalisms ecosystem was environment acceptance K was 893.813 7，ratio of natural increase r=0.137 3，equation of spider′s total amount was Nt=；the parameter of spiders′ total amount in rice-fish commensalisms ecosystem was environment acceptance K=936.371 2，ratio of natural increase r=0.153 2，equation was Nt=；while in paddyfield which were generally used pesticides，the spiders was effected by it and the environment acceptance K was not stable，K was a changed curve，that was K=444.219 6 （t＜41）-0.126 24t3+21.277t2-1 191.4t+222 78（t≥41），the ratio of natural increase r=0.063 1，the equation was Nt=.The research results indicated that the rate of natural increase of the area which generally used pesticides was lo