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.
BackgroundUnderstanding feedback between above- and below-ground processes of biological communities is a key to the effective management of natural and agricultural ecosystems. However, as above- and below-ground food webs are often studied separately, our knowledge of material flow and community dynamics in terrestrial ecosystems remains limited.ResultsWe developed a high-throughput sequencing method for examining how spiders link above- and below-ground food webs as generalist predators. To overcome problems related to DNA-barcoding-based analyses of arthropod–arthropod interactions, we designed spider-specific blocking primers and Hexapoda-specific primers for the selective PCR amplification of Hexapoda prey sequences from spider samples. By applying the new DNA metabarcoding framework to spider samples collected in a temperate secondary forest in Japan, we explored the structure of a food web involving 15 spider species and various taxonomic groups of Hexapoda prey. These results support the hypothesis that multiple spider species in a community can prey on both above- and below-ground prey species, potentially coupling above- and below-ground food-web dynamics.ConclusionsThe PCR primers and metabarcoding pipeline described in this study are expected to accelerate nuclear marker-based analyses of food webs, illuminating poorly understood trophic interactions in ecosystems.Electronic supplementary materialThe online version of this article (10.1186/s40851-018-0088-9) contains supplementary material, which is available to authorized users.
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.
Our results suggest that risk group stratification based on preoperative clinical T stage, voided urine cytology, and WBC counts may be useful for selection of UUT-UC patients for neoadjuvant chemotherapy. Prospective studies with larger numbers of patients and a longer follow-up period are needed to confirm our results.
Aim The phylogeographical history of wide-ranging Palaearctic species is not well understood. Here, we present a range-wide phylogeographical study of the wasp spider, Argiope bruennichi (Scopoli, 1772), a highly dispersive and widely distributed Palaearctic species. We aim to identify glacial refugia and patterns of interglacial gene flow across the Palaearctic. Location Palaearctic region, including the Azores, Madeira, Europe, North Africa and Asia. Methods We conduct a range-wide phylogeographical survey. Our study is based on nuclear and mitochondrial DNA markers, as well as morphological characters. We use species distribution models to predict the species’ current range as well as its historical distribution during and shortly after the Last Glacial Maximum (LGM). Results All analysed genetic markers and morphological characters support the divergence of a lineage in eastern Asia from the remainder of the Palaearctic. Within the Western Palaearctic, a less pronounced divergence into an Azorean and a European clade is found. Species distribution models predict a pronounced loss of suitable habitat for Western Palaearctic lineages during the LGM, whereas the range of East Asian populations remained largely unaffected. Main conclusions Our results highlight the existence of non-European glacial refugia for Palaearctic species, particularly in East Asia. The current genetic structure is best explained by the recent recolonization of the Western Palaearctic from eastern Asia, or repeated interglacial contact of populations
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