Effects of landscape complexity on biodiversity of rice agroecosystems: A meta-analysis

Abstract

Agricultural intensification is one of the primary drivers of landscape simplification and biodiversity loss. Understanding how different taxa respond to landscape complexity is key to address the challenge of enhancing biodiversity while sustaining food production. We performed a global-scale meta-analysis of biodiversity and landscape relationships, yielding 456 effect sizes from 18 papers across 9 countries. We specifically explored the effect across different taxonomic groups (2 vertebrate and 6 invertebrate orders) and landscape complexity dimensions (composition, configuration, heterogeneity). Despite the high heterogeneity among the data, we found a positive effect of landscape complexity on rice-associated biodiversity, yet the magnitude and sign of effects contrasted among specific orders and landscape dimensions. For instance, among vertebrates only amphibians showed a positive response to landscape composition. Among invertebrates, spiders and beetles responded positively to compositional complexity while true bugs responded negatively to configurational complexity. Our results suggest that promoting landscape compositional complexity at large spatial scales overall benefits biological communities in rice agroecosystems, specifically in major rice-producing regions. Yet the negative impact of configurational heterogeneity observed for certain groups of insects (i.e., true bugs) indicate that the spatial arrangement and degree of fragmentation of rice habitats is also an important factor shaping biodiversity outcomes. This highlights the need of considering different landscape dimensions and multiple groups of animals simultaneously when designing large scale habitat management plans to avoid potential trade-offs and maximize biodiversity in rice agroecosystems.