Plant-insect partnership in wetland ecosystems

Nakaikemi沼泽位于福井县，是日本西部仅存的少数天然低地沼泽之一，是许多濒危沼泽动植物的栖息地。1994- 1995年对湿地35科64种植物的开花物候和喜花昆虫群落进行了研究。4月中旬至10月中旬，在花上采集了8目昆虫215种936只。昆虫群落以双翅目昆虫占58%，膜翅目昆虫占26%，半翅目昆虫占6%，鳞翅目昆虫占5%，鞘翅目昆虫占5%。粉虱科是数量最多的科，可能也是最重要的传粉媒介。蜜蜂群落以地上筑巢蜂属（Colletidae）为主，种类最多的是一种微小的、罕见的、记录较少的物种。中池沼被认为是一个罕见的重要湿地栖息地，不仅是许多濒危植物和植物昆虫物种的栖息地，而且还孕育了独特的虫花关系。一些原本由在森林地面筑巢的大黄蜂授粉的植物物种的存在表明，沼泽地应该作为一个完整的生态系统来保护，将沼泽地和邻近的林地结合起来。在不同类型的湿地，如日本的盐沼、潮滩和红树林，也研究了植物与昆虫的相互作用。

Nakaikemi marsh, located in Fukui Prefecture, is one of only a few natural lowland marshlands left in western Japan, and harbors many endangered marsh plants and animals. Flowering phenology and anthophilous insect communities on 64 plant species of 35 families were studied in the marsh in 1994-95. A total of 936 individuals of 215 species in eight orders of Insecta were collected on flowers from mid April to mid October. The anthophilous insect community was characterized by dominance of Diptera (58% of individuals) and relative paucity of Hymenoptera (26%), Hemiptera (6%), Lepidoptera (5%), and Coleoptera (5%). Syrphidae was the most abundant family and probably the most important pollination agents. Bee community was characterized by dominance of an abovegroud nesting bee genus, Hylaeus (Colletidae), the most abundant species of which was a minute, rare little-recorded species. Nakaikemi marsh is regarded as a rare, important wetland habitat not only harboring many endangered plant and anthophilous insect species but also fostering unique insect-flower relationships. The presence of some plant species originally pollinated by bumblebees nesting at forest floor suggests that the marshland should be conserved as a whole ecosystem uniting the marshland and the neighboring woodlands.Plant-insect interactions were studied also in various types of wetlands, e.g., salt marshes, tidal flats and mangroves in Japan.