农业景观异质性与生物多样性关系的尺度特征及对景观复杂度的响应

Ecosystem service is the frontier and hotspot of global ecology and geography. It is the key to realizing the healthy development of the regional ecosystem and maintaining the sustainable supply of human welfare. Human well-being and their survival depend upon the stability and sustainability of services that are provided by the agricultural landscape. Natural and semi-natural habitats within agricultural landscapes, as well as the associated plant communities thereof, are vitally important for preserving biodiversity and ecosystem services in agro-landscape. The fragmentation and disappearance of natural and semi-natural habitats in agro-landscape are significant, and can cause the serious decline and loss of biodiversity, ecosystem functions and services. The middle and lower reaches of the Yellow River is acknowledged as one of the core grain-growing areas and main grain-producing areas in China. Biodiversity conservation is particularly imperative in this area due to the rapid loss of biodiversity that caused by agricultural activities. Moreover, the characteristics of landscape pattern have significant differences in this area. With different landscape complexity background, what is the difference of biodiversity composition and spatial pattern in different habitats? How is the scale-dependent effect when landscape heterogeneity and environmental factors impact on biodiversity? What is the difference between different species groups? Which conservative strategies should be taken? All these questions must be solved when we talk about the strategies of biodiversity conservation in agro-landscape. The aim of this proposal is to explore the agricultural landscape heterogeneity, the pattern of biodiversity composition in Gongyi and Fengqiu County, which located in the middle and lower reaches of the Yellow River. Then the mechanisms and scale-dependent effects of agricultural heterogeneity and environmental factors on different organisms and its response to landscape complexity were discussed. This proposal may, at regional scale, prove to be a great theoretical and practical significance for sustaining and improving biodiversity conservation, agricultural production and ecosystem services in landscapes that with different complexity backgrounds.

农业景观是人类生活所需资料的最主要来源地，随着农业用地持续扩张、集约程度日益增强，农业景观中自然、半自然生境破碎化和消失严重，进而引起生物多样性与生态系统功能和服务的严重下降与缺失。黄河中下游地区是我国最重要的农业景观区，区域内的生物多样性保护尤为急迫。但区内景观格局特征存在显著的地区差异，在不同景观复杂度背景下：各生境斑块中生物多样性组成及其空间格局有何差异？景观异质性与环境因子等对生物多样性特征影响的尺度效应如何？在不同物种类群（植物、飞行传粉昆虫）间有何不同？应分别采取怎样的保护措施？本项目拟以区域内景观复杂度背景存在显著差异的巩义市和封丘县农业景观为对象，对各景观要素中的植物群落和飞行传粉昆虫进行调查，借助方差分解和广义线性回归模型（GLM），探讨景观异质性和环境因子等与生物多样性间的关系特征及对景观复杂度的响应差异，从而为区域持续农业景观构建策略和措施的提出提供理论依据。

在全球人口激增，粮食需求日益增加，农业用地持续扩张，生物多样性持续快速下降的背景下，如何在维持粮食供给的同时降低人类活动对生态环境的负效应及实现农业景观的持续健康发展是人类面临的最大挑战。本项目以地处黄河中下游的黄淮海平原典型区域的农业景观为研究对象，通过在典型地段样带定点观测和调查的方法，对区域内农业景观中的不同生物类群（植物、传粉昆虫、鸟类）等的多样性及其分布格局进行研究。研究结果发现：（1）农业景观中的植物物种丰富度组成在很大程度上依赖于偶见种，而常见种尽管数量不多，但构成了群落的主体；（2）农业景观中，植物群落结构特征等局地环境因子与植物群落物种多样性的关系更为直接和密切，但随着空间尺度的增大，景观异质性作用将会逐渐增强，成为影响植物群落物种多样性及其组成结构的潜在和间接因素，并通过局地生态因子的变化进而影响到生物多样性的变化，而生物多样性的变化常常会通过beta多样性的变化展现出来；（3）自然、半自然生境是大量传粉者维持年际种群的关键因素，而农田斑块在特定时段通过爆发式食源的提供为传粉昆虫种群的快速爆发式增长意义重大；（4）对于鸟类来说，水域和湿地的存在能有效的提高鸟类多样性，而沟渠等的存在是提高鸟类多度的重要影响因素，同时人类活动不一定就对鸟类呈现负效应，不同功能群对景观异质性的响应模式存在显著差异。结合国内外前人相关研究认为，在农业景观中生物多样性和生态系统服务研究中仍需对以下问题进行深入探讨：（1）不同景观异质性特征对生物多样性和生态系统服务的影响、机制和阈值分析；（2）跨尺度、多因素、多物种类群与多生态系统服务的综合及其交互作用研究；（3）权衡的、综合的观点。不同生物物种多样性、不同生态系统服务间常存在此消彼长的态势；（4）景观异质性与生境面积的权衡。