A B S T R A C TFlooded rice fields can provide habitats for wetland species and ecosystem services similar to those of natural wetlands. During the last three decades, however, farming practices and management systems have been intensified in many rice-producing countries. In addition, more recent socioeconomic changes have caused agricultural abandonment in some parts of East and Southeast Asian countries such as Japan. This study reviewed long-term statistics on rice farming, as well as the impact of agricultural intensification and abandonment on farmland biodiversity at multiple spatial scales in Japan. The impact of pesticide use was greatest in the 1950s-1970s, when the use of highly toxic agents had not yet been prohibited. More recently, different components of agricultural intensification have been the largest threat for various taxa, for example, chemical pesticides for aquatic plants and invertebrates and modern efficient irrigation/ drainage systems for amphibians, fishes, and waterbirds. The negative impacts of agricultural abandonment on farmland species have been rapidly increasing with the expansion of abandoned fields and the subsequent vegetation succession and loss of habitat heterogeneity. We also discuss the effectiveness of environmentally friendly farming practices, including the reduced use of pesticides, winter paddy flooding, and installation of fishways, to reduce the negative impacts of agricultural intensification on farmland species in rice-paddy landscapes.

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1. Organic farming has potential for the conservation of global biodiversity and associated ecosystem services. Despite this, knowledge of the effects of organic farming systems on farmland biodiversity is limited in Asia, the worldwide leader in rice production.2. We conducted the first national-scale study to investigate the effects of three different rice farming systems (conventional, low-input and organic) and specific management practices (e.g. herbicide and insecticide applications, crop rotation and levee-vegetation management) on species richness and abundance of multiple taxonomic groups (plants, invertebrates, Pelophylax and Hyla japonica frogs, cobitid loaches and birds) in Japan during 2013-2015.3. Organic fields supported the highest richness and abundance of several taxonomic groups (native/Red List plants, Tetragnatha spiders, Sympetrum dragonflies and Pelophylax frogs), followed by low-input and conventional fields. We also found taxon-specific responses to specific management practices. For instance, plant richness and Tetragnatha and Sympetrum abundance increased with reduced herbicide and/or insecticide applications. Sympetrum and cobitid loach abundance increased in the absence of crop rotation, whereas H. japonica abundance increased with crop rotation. Pelophylax abundance increased with an increased height of levee vegetation.4. At spatial scales larger than single fields, waterbird richness and abundance were positively correlated with the proportion of organic rice fields, presumably due to increased prey abundance. Meanwhile, landbird richness and abundance were positively associated with annual precipitation and annual mean temperature, suggesting that such climate increases food availability. Synthesis and applications.We highlight the positive effects of organic and low-input farming for biodiversity relative to conventional farming in rice paddies. We also provide the scientific basis of the current agri-environmental schemes in Japan, subsidising organic and low-input farming for biodiversity. The | 1971 Journal of Applied Ecology KATAYAMA eT Al. Additional supporting information may be found online in the Supporting Information section at the end of the article. How to cite this article: Katayama N, Osada Y, Mashiko M, et al. Organic farming and associated management practices benefit multiple wildlife taxa: A large-scale field study in rice paddy landscapes.

Drivers of biodiversity at macroscales have long been of interest in ecology, and climate and topography are now considered to be major drivers. Because humans have transformed most of the Earth's land surface, land use may play a significant role as a driver of biodiversity at a macroscale. Here we disentangle the relationships among climate, topography, land use, available energy (measured by the normalized difference vegetation index [NDVI]), and species richness of Japanese forest birds. Species richness was better explained at 40‐ and 80‐km resolutions than at 5‐, 10‐ and 20‐km resolutions; it was explained by climate, topography, and land use, and the effects of land use were fully incorporated into those of climate and topography. As temperature increased and elevation decreased, natural forest area decreased, and this decrease intensified in warm lowland areas. With the loss of natural forest, species richness decreased below a certain threshold. As temperature increased and elevation decreased, species richness and NDVI increased slightly or were unchanged in cool highland areas and decreased in warm lowland areas. Species richness increased linearly with the increase in NDVI. Most effects of climate/topography on species richness in warm lowland areas were shared by those of land use, suggesting that the decrease in species richness in warm lowland areas has been caused by loss of natural forest. Therefore, it is suggested that climate and topography determined land use intensity, which in turn, drove species richness through the depletion of available energy. Increasing temperature and decreasing elevation leads to both benefits (increase in potential available energy) and costs (depletion of energy by human land‐use change) for forest birds. These costs seem to override benefits in warm lowland areas.

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