【作者】 李凯；

【导师】 李镇宇；

【作者基本信息】 北京林业大学 ， 野生动植物保护与利用， 2010， 博士

【摘要】 本文以冀中北部的廊坊市固安县为试验点,对田间最常见的天敌节肢动物——瓢虫、草蛉、蜘蛛的生物生态学、及生存对策进行了为期多年的研究,对农田防护林在农林复合生态系统中的生态调控地位与作用进行评价：1)揭示了农田防护林带对天敌节肢动物具有提供栖息地、繁育地等重要生态作用；首次明确量化出防护林对农田系统的生态作用辐射范围及阈值；得出农田防护林带是天敌节肢动物越冬以及躲避不利环境因子的重要庇护场所。2)通过对天敌节肢动物生活史等重要生物学信息进行系统的研究,以量化的形式揭示出林带——天敌——害虫关系中天敌节肢动物对农田害虫的作用范围。3)多数天敌节肢动物在其生活史的某些阶段有明显的抑制害虫种群增长的作用；天敌对害虫的抑制作用受种群增长的驱动在不同作物间是移动的。4)提出了如何最大限度的保护田间天敌节肢动物种群的方案,如科学规划农田布局,合理构建农田小环境等。在农区常见天敌节肢动物种类及动态方面的研究发现,1)所在研究地区,草蛉、瓢虫、蜘蛛由于其种群数量大、活动能力强成为研究农区最常见的天敌节肢动物；2)在草蛉成虫期,丽草蛉(Chrysopa formosa)是田间优势种；瓢虫的优势种为龟纹瓢虫(Propylea japonica),次优势种为异色瓢虫(Harmonia axyridis);蜘蛛的优势种为中华狼蛛(Lycosa sinensis)和中华平腹蛛(Gnaphosa sinensis);3)各生境优势种组成随季节更替而发生变化：①作物耕种前及耕种早期异色瓢虫及七星瓢虫(Coccinellase ptempunctata)为优势种群,主要分布于林带；②作物生长中后期龟纹瓢虫为优势种群,主要分布于作物生境,且龟纹瓢虫在发生面积、数量及发生时间等方面均占据绝对优势；③蜘蛛在时间序列上有明显的增殖初期,高峰期,衰落期。通过对农林复合体不同栖息生境内的天敌数量对比和空间分布型分析,揭示了天敌对栖息地的选择趋向。草蛉的田间草地带分布密度与草地带宽度非正相关关系显示,宽度在1m左右的草地带有更高的草蛉密度,该结论从农田规划和布局角度有助于提高农田使用效率。草蛉密度在邻近道路区域内呈现出距道路距离越远密度越高的分布规律,说明道路环境对草蛉栖息分布有显著影响；瓢虫种群在不同生境斑块间的迁移现象与林木生长和作物的种植收获有直接关系,甚至在不同时期呈现出不同的空间分布类型；蜘蛛在复杂生境的密度和群落多样性指数均高于比较简单的生境,生境的复杂程度是制约蜘蛛种群密度的一个重要因素。林带对天敌空间分布的影响研究揭示了非作物生境在作物栽种空档期、天敌越冬和种群重建过程中对天敌的支撑功能。研究显示,邻近林带处的草蛉和蜘蛛数量明显更多。林带对天敌的这种效应范围因林带结构不同表现各异,本试验中林带对草蛉的效应范围最大为20m,对蜘蛛的效应范围30m。作物耕种前与生长早期,林带是本土物种得以栖息的重要的、甚至是唯一的生境,成为一些天敌向农田扩展的“种库”,它同时也是许多物种在作物收获后最重要栖息和越冬场所。天敌应对干扰时的生存对策和能力的研究显示,土著物种有非凡的适应性。蜘蛛(中华狼蛛)遇险时的避险策略(逃离90%、钻穴10%)、避险方式(跑-停-望)、避险能力(耕地环境平均逃离速度≧0.26±0.175 m／s,最长跳跃距离可达0.12m,最远逃离距离为13.1±0.444 m)能够有效躲避传统农作活动产生的危害,而本研究展示的仅仅是一个侧面。更多还原

【Abstract】 In this paper, Gu’an County, which is situated in Langfang City, North Hebei Province, is selected as sample field. The most common arthropod natural enemies in the crop field include ladybugs, lacewings, spiders, whose biological ecology and survival strategies are studied over many years. We evaluate the status and role of forestry belts in the agroforestry ecosystem. The main conclusions are followed:1) Revealing the ecological role of forestry belts in providing the habitat and breeding surrounding for arthropod natural enemies; firstly explicit quantifying the scope and threshold of radiation scope, which is the ecological role of forestry belts for agricultural system; forestry belts are important shelters for the arthropod natural enemies to avoid the cold winter and adverse environmental factors.2) Through studying the life history and biological information of arthropods, using the quantifying form to reveal the relationship between forest, natural enemies and pests, and also the effective scope of arthropod natural enemies to prey the pests.3) Most arthropod natural enemies in certain stages of life cycle could inhibit the growth of pest population. Effective inhibition on pest population is driven by the population growth of natural enemies and moving between different crop fields.4) We propose how to maximize the protection of arthropod natural enemies in the fields, such as scientifically planning the field mode, reasonably constructing the small surroundings.After systematically studied the common arthropod species and dynamic state, we draw the following conclusions:1) In the sample fields, the lacewings, ladybugs and spiders, which are with large population and strong activities, are the common arthropod natural enemies.2) The Chrysopa formosa, Propylea japonica, Harmonia axyridis, Lycosa sinensis and Gnaphosa sinensis are the dominant species.3) The composition of dominant species in different habitats change with seasons:①Before and early cultivation, the Harmonia axyridis and Coccinella septempunctata are dominant species and mainly distribute in the forestry belts;②in the mid and late period, the Propylea japonica is the dominant species and mainly distribute in the crop field;③the spiders in the time series show three periods: proliferation, peak and declineThrough contrasting the quantities of natural enemies in different habitats and spatial distribution analysis, we reveal the trends of natural enemies in habitat choice. The density of lacewings in the grass belts of crop field is non-positive correlation with the width of grass belts. The width of grass belt is approximately lm with a higher density of lacewings. This conclusion, from the view of farm planning and layout, help us to improve the field efficiency. The lacewing density in the surroundings of adjacent road shows the farther from the road the higher lacewing density. This reveals that the road environment has a significant effect on the lacewing habitat. Ladybug populations moving in different habitat patches is directly related with tree growth and harvesting crops, even in different period shows different spatial types. The spider density and species diversity in complex habitat were higher than simple habitat. The complicated degree of spider habitat is one of the important restrict factors for spider density.After studying how dose forestry belt to affect the space distribution of natural enemies, it shows that this kind of non-crop habitat, especially in the gap of planting crops, winter and population renewal process for natural enemies, provide support function to the natural enemies. It also shows that adjacently forestry belts the number of lacewings and spiders are distinctly added. The effect of forestry belt on natural enemies is differed for different forest structure. In this test, the foresty effect on lacewings is up to 20m, and the effect scope for spiders is 30m. In the early time of crop cultivation and growth, forestry belts is the most important habitat for native species, and becomes the "species pool" for the natural enemies to expand to crop fields. Forestry belt also provides important habitat for most species after harvest and in winter.The survival abilities of natural enemies to respond the interference shows that native species has the remarkable adaptability. When the spiders (Lycosa sinensis) happen to distress, its hedging strategy, hedging approach and hedging ability can effectively avoid the harm of the traditional farming activities. This part of study was done only from the side.更多还原