Drivers of plant species composition of ecotonal vegetation in two fishpond management types

Abstract

Plants play an important role in fishpond littorals, but little is known about factors influencing their presence and growth patterns. We surveyed vegetation of reed bed and exposed bottom zones in ponds used for rearing of common carp fry (nursery pond) and ongrowing to market size (main pond). Plant species diversity and functional diversity and plant species cover and functional cover were assessed. We found no significant differences in spring and summer surveys. When data of the analysed vegetation zones were combined, nursery and main ponds showed significant differences in plant species diversity and species cover. Analysis of the vegetation zones revealed that (i) regardless of fishpond management type, exposed bottoms and reed beds significantly differed in plant species cover and functional cover; (ii) plant species diversity and species cover of exposed bottom zones differed between nursery and main ponds; and (iii) no assessed characteristics differed significantly between nursery pond reed bed and main pond reed bed zones. Zone width and shoreline slope exerted greatest impact on development of reed beds, whereas fishpond management type and surrounding land use were the most important factors determining vegetation of exposed bottoms. Partial summer drainage supported plant species diversity and functional diversity as well as cover of typical species of reed beds and exposed bottoms in both fishpond types. Our results are applicable to preservation of fishpond biodiversity as well as to the management and conservation of other shallow water bodies.