Functional diversity of farmland bees across rural-urban landscapes in a tropical megacity

Urbanization is a major threat to biodiversity and food security, as expanding cities, especially in the Global South, increasingly compete with natural and agricultural lands. However, the impact of urban expansion on agricultural biodiversity in tropical regions is overlooked. Here we assessed how urbanization affects the functional response of farmland bees, the most important pollinators for crop production. We sampled bees across three seasons in 36 conventional vegetable-producing farms spread along an urbanization gradient in Bengaluru, an Indian megacity. We investigated how landscape and local environmental drivers affected different functional traits (sociality, nesting behaviour, body size and specialization) and functional diversity (functional dispersion) of bee communities. We found that the functional responses to urbanization were trait specific with more positive than negative effects of grey area (sealed surfaces and buildings) on species richness, functional diversity...

城市化是生物多样性与粮食安全面临的重大威胁，因为不断扩张的城市（尤其是全球南方（Global South）地区）正日益与自然及农业用地争夺生存空间。然而，目前学界对热带地区城市扩张对农业生物多样性的影响仍存在研究盲区。本研究针对城市化如何影响农田蜂类的功能响应展开评估——蜂类是作物生产中最为关键的传粉昆虫类群。我们以印度特大城市班加罗尔为研究区域，在沿城市化梯度分布的36家常规蔬菜种植农场中，分三个季节开展蜂类采样工作。本研究探究了景观与局域环境驱动因子如何影响蜂类群落的各类功能性状（functional traits，包括社会性、筑巢行为、体型大小与特化程度）以及功能多样性（functional diversity，含功能分散度（functional dispersion））。研究结果显示，蜂类群落对城市化的功能响应具有性状特异性：灰色区域（grey area，即硬化地表与建筑）对物种丰富度、功能多样性的正向影响多于负向影响……