Abstracts of the Annual Meeting of the Ecological Society of Japan

Show abstractHide abstract

Malaria is one of the world's most devastating diseases. Annually, 300-500 million cases occur and 1 million people die. Traditional prevention efforts focus on controlling the mosquito vector with insecticides. This has often been unsuccessful because of insecticide resistance. It is also problematic because insecticides cause health problems in humans and animals and disturb the natural balance between mosquitoes and their predators. This 1.5-year study addressed the effectiveness of a new community-based "ecosystem management" program to control mosquito vectors in rice ecosystems in Sri Lanka. Farmers in a malaria-prone village were educated and motivated to engage in source reduction and measures that restore and maximize functions of rice ecosystems. For example, pesticide use was discouraged to conserve mosquito predators. This presentation describes the mechanisms by which the program suppressed the density of multiple Anopheles species during the southwest monsoon season. The species composition of mosquitoes and aquatic insects, their niche overlaps in different habitats, and determinants of mosquito density, including biologic and climatic factors, are discussed. The success of the program in the southwest monsoon season shows that environmentally sound ecosystem management can reduce the burden of Anopheles mosquitoes, destabilize malaria transmission, and prevent the destruction of ecosystems.

View full abstract

The combined effects of a mounting number of threatened animal taxa and limited resources for conservation compel priorities setting. Therefore, a unit for conservation must be identified. Although the original concept of a conservation unit (Evolutionary Significant Unit: ESU) was proposed in 1986 (Ryder 1986), various definitions proposed by various authors created confusion. This paper is aimed to examine the inconsistencies with its usage by reviewing ESU papers published from 1996-2004. The number and trend in publication of papers indicate that the ESU concept has gained support, particularly in studies of mammals and fishes. Although the original concept includes two aspects (genetic and ecological), these are often not satisfied. Due to practical difficulties in obtaining ecological data, Moritz's (1994) definition, which is biased to the genetic aspect, is widely used. The main cause of the confusion is that the ESU concept has been applied in cases where populations were examined from only one aspect. Only when sufficient genetic and ecological data are available, should the ESU designation be applied. We propose Genetically Significant Unit (GSU) and Ecologically Significant System (ESS) as aspectual units constituting the ESU. GSU or ESS should be used instead of ESU, when only one of them is examined.

View full abstract

Register with J-STAGE for free!