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Rice fields, the major cropland in South Korea, provide an important wetland habitat for a diverse wildlife and contribute to biodiversity conservation. On the other hand, land consolidation conducted to increase agricultural production since the 1960s on a nationwide scale in South Korea has frequently been suggested to be one of the factors in the decline of biodiversity in agricultural ecosystems. Negative effects of habitat manipulation such as land consolidation would have influenced paddy field biodiversity, but the degree has not been clearly measured in South Korea. This study evaluated the impacts of land consolidation on the aquatic invertebrate biodiversity and investigated their patterns across the nation. Field sampling for biodiversity and environmental variables were made from 290 sites of paddy field over the country. Aquatic invertebrate communities were clustered into four major clusters showing land consolidation as the main factor and geographic location as the second factor. Species richness and abundance were significantly lower in the land consolidation fields (mean ± s.e., 12.80 ± 0.28 vs 88.89 ± 0.89 and 2027.15 ± 150.84 vs 2573.54 ± 572.16). Shannon diversity index was also significantly lower in land consolidation fields. Our results suggest that land consolidation and spatial location are important for biodiversity and conservation of the aquatic invertebrate assemblages in Korean rice fields. [ABSTRACT FROM AUTHOR]

1. In the present study, the effects of swimming exercise and soybean supplementation on the immune functions of rats fed a high-fat diet were examined. 2. Thirty-four male rats were randomly divided into four groups: (i) HS, a high-fat diet sedentary group (n = 8); (ii) HE, a high-fat diet exercised group (n = 9); (iii) SS, a soybean diet sedentary group (n = 8); and (iv) SE, a soybean diet exercised group (n = 9). The high-fat diet was composed of 35% carbohydrate, 20% protein and 35% fat. For the soybean diet, 3% crude soybean extract was substituted for the protein, carbohydrate and fat according to the energy content of the diet. In the exercise groups, rats swam for 60 min/day, 5 days/week for 4 weeks. 3. The subpopulation of CD4(+) cells and the CD4(+)/CD8(+) ratio did not differ significantly between the high-fat diet and soybean diet groups. However, the subpopulation of CD8(+) cells in the spleens of SS rats was significantly higher than that in the spleens of HS rats (P < 0.05). In addition, splenic interferon-gamma secretion in the SE group, with or without conconavalin A stimulation, was significantly increased compared with the SS group (P < 0.05 and P < 0.01, respectively). 4. These results show that regular endurance exercise training with soybean supplementation ameliorates splenic T cell-mediated immunity.