有机种植对农田节肢动物多样性影响的整合分析

Effects of organic planting on arthropod diversity in farmland:A meta-analysis

有机农业是生态环境友好的生产方式,对农业生物多样性保护具有重要意义。个体研究的差异不利于有机农业的生态环境效益评估。本研究利用文献整合分析,以对农田生态环境具有良好指示作用的节肢动物为研究对象,探讨了有机种植对农田生物多样性的保护效果及影响因素。结果表明,相比常规种植,有机种植可使节肢动物的丰富度、多度及均匀度显著提升34.95%、64.95%及12.09%;天敌和害虫的物种丰富度分别显著提升了22.50%和31.03%;同时天敌的个体数量比常规显著增加了71.80%,害虫减少了10.46%。经过3年及以上的有机种植后,节肢动物的丰富度和多度均显著高于常规种植。常规种植化学农药施用频率可显著影响节肢动物丰富度和均匀度指数,施药次数每增加1次,节肢动物丰富度相比有机种植显著降低13.54%,均匀度显著降低2.64%。有机水田对节肢动物多度的提升效果显著优于有机旱地,为后者的4.7倍;但二者的丰富度和均匀度没有显著差异。蔬菜和茶叶种植体系对节肢动物多样性指数的综合提升效果优于其他作物类型,丰富度、多度和均匀度指数分别显著提升了81.46%、74.14%、18.55%和48.86%、49.06%、30.88%。鼓励常规种植减少农药施用频次,加大有机和生态化管理措施的应用程度,是保护农业生物多样性、实现农业绿色高质量发展的有效途径。

Aims:Organic planting is widely considered an environment-friendly agricultural management pattern that plays a crucial role in the protection of agricultural biodiversity.The change of arthropod biodiversity is proposed as a key ecological indicator for agricultural sustainability.However,the effects of organic planting on arthropod biodiversity remain inconsistent in published studies,which may have resulted from the durations of organic planting,land use and cropping systems across the individual studies.The diverse results from previous studies could weaken the practicability of their conclusions in policymaking,which highlighted the necessity of conducting a meta-analysis to provide a generalized understanding of the effects of organic planting on arthropod diversity.This study aims to quantify the impact of organic planting on arthropod biodiversity using meta-analysis and provide scientific support for the formulation of ecological compensation policy under organic planting.Methods:This meta-analysis conducted a literature review of peer-reviewed papers published before the end of 2020 which compared the impacts of organic and conventional planting on arthropod biodiversity.The results from 75 experimental sites,which contained 227 paired valid datasets,were selected for our analysis.To distinguish between the sources of variation for the responses of biodiversity to organic planting,the paired measurements were further subdivided into subgroups according to the factors of duration,land use,crop variety,pesticide application frequency in conventional planting,and arthropod functional groups.Results:The results showed that compared with conventional planting,organic planting significantly improved the richness,abundance,and evenness of arthropods by the rate of 34.95%,64.95%,and 12.09%,respectively.The abundance of the natural enemies of arthropods increased by 71.80%(P<0.05)while the abundance of pests decreased by 10.46%under organic planting.The richness of the natural enemies and pests under organic planting were both increased by 22.50%and 31.03%respectively,relative to conventional planting(P<0.05).The application of pesticides significantly decreased the arthropod biodiversity in conventional planting.Compared with the organic planting,an increase in the time of pesticide application in the conventional planting lead to decreases in the arthropod richness and evenness of arthropods by 13.54%and 2.64%,respectively.The responses of arthropod richness and abundance to organic planting were significantly positive when the duration was equal to or exceeded three years.The positive effect of organic planting on arthropod abundance in paddy fields was 4.7 times higher than that in dryland(P<0.05),but the responses of richness and evenness to organic planting were comparable between paddy and dryland(P>0.05).The responses of arthropod richness,abundance,and evenness to organic planting under the vegetable system were 81.46%,74.14%,and 18.55%,respectively(P<0.05);and under the tea-planting system were 48.86%,49.06%,30.88%(P<0.05),respectively.The benefits of organic planting on arthropod biodiversity under the cropping systems of vegetable and tea were demonstrated to be more significant than that under other cropping systems.Conclusions:Our meta-analysis suggests that organic planting plays an important role in protecting and improving biodiversity in croplands by increasing the abundance of natural enemies and decreasing pests abundance.The frequency of pesticide application was observed to be the key factor which significantly regulates the change of arthropod biodiversity.To promote the positive effects of organic planting on the protection of biodiversity in cropland,policymakers should not only to encourage the implementation of organic planting in regions where necessary conditions are satisfied,but also facilitate the ecological innovation of conventional planting by introducing the principles,concepts,and technologies of organic planting into conventional planting.This will be of more practical significance to agricultural biodiversity conservation in China.