Naito Risa, Sakai Masaru, Natuhara Yosihiro, Morimoto Yukihiro, Shibata Shozo
Graduate School of Global Environmental Studies, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto-city, Japan.
Zoolog Sci. 2013 May;30(5):386-91. doi: 10.2108/zsj.30.386.
In Japan, rice paddies have acted as substitute habitats for pond-breeding frogs. However, frog populations are declining due to the loss of habitat and environmental changes in rice paddy areas. Frogs need both aquatic and terrestrial habitats to complete their life history; in rice paddy areas, levees that surround rice paddies provide terrestrial habitats for basking, foraging, and shelter from predators. Studying microhabitat use at levees is important to elucidating the ecological roles of levees and to properly managing them to support frog populations. In this study, we conducted surveys in lowland modernized rice paddy areas in Shiga Prefecture in which a common species, Hyla japonica, and an endangered species, Pelophylax porosa brevipoda, were found. We captured frogs at levees and recorded environmental factors related to levee vegetation, rice paddy conditions, and weather. We constructed generalized linear mixed models to examine the effects of environmental factors on juvenile and adult H. japonica and on small and large juveniles, females, and males of P. p. brevipoda. Our results showed distinct microhabitat uses at levees in different species, sexes, and body sizes. In general, abundance was high at levees with vegetation that provided shelter. The water depth in rice paddies negatively influenced juvenile H. japonica and large juvenile and small female P. p. brevipoda, and positively influenced small male P. p. brevipoda. The maintenance of a mosaic structure of levees was important not only to support frog populations but also to maintain frog diversity in the area.
在日本，稻田充当了池塘繁殖蛙类的替代栖息地。然而，由于稻田栖息地的丧失和环境变化，蛙类种群数量正在减少。蛙类需要水生和陆地栖息地来完成其生活史；在稻田地区，环绕稻田的田埂为蛙类提供了用于晒太阳、觅食和躲避捕食者的陆地栖息地。研究田埂上的微生境利用对于阐明田埂的生态作用以及妥善管理田埂以支持蛙类种群至关重要。在本研究中，我们在滋贺县的低地现代化稻田地区进行了调查，在那里发现了常见物种日本雨蛙和濒危物种短肢姬蛙。我们在田埂上捕获蛙类，并记录与田埂植被、稻田状况和天气相关的环境因素。我们构建了广义线性混合模型，以研究环境因素对日本雨蛙幼体和成体以及短肢姬蛙的小幼体和大幼体、雌性和雄性的影响。我们的结果表明，不同物种、性别和体型的蛙类在田埂上的微生境利用存在明显差异。一般来说，有提供遮蔽物植被的田埂上蛙类数量较多。稻田水深对日本雨蛙幼体以及短肢姬蛙的大幼体和小雌性有负面影响，而对短肢姬蛙的小雄性有正面影响。维持田埂的镶嵌结构不仅对支持蛙类种群很重要，而且对维持该地区的蛙类多样性也很重要。
