人类活动是导致生物均质化的主要因素

随着全球化和现代化的持续发展，生物均质化（不同地区的生物群落在物种组成、基因库和功能上趋向于相似或简单化）在全球范围内广泛发生，给保护生物多样性和种质资源库带来严峻的挑战。人类活动是当前全球生物均质化最为重要和直接的推动因素。农业耕作活动直接导致了农田生态系统的普遍生物均质化：垦荒可直接导致生物多样性大幅减少，大面积单一化的作物类型、品种和耕作管理模式，农药化肥的大量使用，机械化、集约化和转基因作物的推广所带来生物均质化问题都直接威胁粮食生产和安全。遗憾的是我们对农田生物均质化的现状、发生规律和趋势都一无所知，相关研究任务紧迫，尤其是当前我国农业耕作模式正经历着巨大的变革。城市所带来的普遍相似的高强度人工干扰、交通运输和建设、规划、破坏自然生境等各种人类活动必然驱动全球生物大规模的均质化。人类活动直接导致的少数成功种恶性扩散并迅速取代大量失败种从而导致生物均质化的现象普遍。生物入侵和灭绝、本地种以及新的杂交种的恶性扩散都直接导致生物均质化。一般而言，在大尺度空间范围内外来种容易导致生物均质化，而在较小的空间范围内外来种容易导致生物异质化。生物均质化的隐患严重威胁着我国的环境和经济社会安定发展，然而相关研究在我国尚未起步，当前我国生物均质化研究的具体迫切任务主要有：1）建立有效的均质化评估方法体系；2）研究我国各种主要生态系统类型以及主要生物类群的均质化现状、规律和趋势；3）掌握我国农业生态系统生物均质化的现状、规律和趋势；4）建立和完善均质化长期监测研究的相关数据库资源。

Human activities are the principle cause of biotic homogenization

With the development of globalization and modernization, biotic homogenization (BH, referring to the process by which the taxonomic, genetic or functional similarities of regional biotas increase over time) pervasively occurs worldwide. BH seriously challenges the conservations of biodiversity and germplasm resources. Human activities are the principle cause of current global BH. Agriculture directly cause pervasive BH in agro-ecosystems worldwide. Land reclamation usually results in great decease of biodiversity. And BH caused by large areas of homogenized crop species, varieties and tillage management, heavy use of pesticides and fertilizers, mechanization, intensification and the popularizing of genetically modified crops seriously challenges the crop production and security. Unfortunately, information about BH situation, occurrence and trend in agro-ecosystems is rare. And thus the relative study is very urgent, in particular that the agricultural model in China is undergoing dramatic changes. Urbanization generally leads to large areas of uniform artificial habitats and habitat degradation which directly cause pervasive BH. Human-induced species distributions and extinctions can also directly cause BH, such as biological invasions and extinctions and the serious spread of local generalists and new hybrids. Generally speaking, in large scale, indigenous species lean to cause BH, while in small scale they may cause biotic differentiation. China is undoubtedly suffering from pervasive BH, however, relative research has not initiated. Currently, it is urgent to conduct BH researches in China to: 1) establish effective BH assessing model; 2) understand the BH situations of major ecosystems and species groups; 3) understand situation, regulation and trend of BH in arable lands, and 4) excavate, build and improve the relative database for BH researches.