The role of ditches in agricultural landscapes in conserving the diversity of wetland plants

Abstract

We examined the relationship between species composition and the habitat of wetland plants growing in ditches in agricultural landscapes, re-evaluated the function of ditches as habitat, and considered ditch management methods for conservation. We investigated vegetation and the environment in four types of drainage ditch (terminal, road, and 1^st- to 2^nd-, and 3^rd-class ditches) and revealed the characteristics of ditch environment and species composition. Ditch environment was characterized by the degree of material flow and habitat size. Terminal and road ditches had low flow, were small habitats and mesophytes-rich. 1^st- to 2^nd- and 3^rd-class ditches had various degrees of flow, size, and species composition and were wetland species-rich. The maintenance of running water and regular management when the flow rate is high were conducive to the diversity of wetland plants.