Effects of land use on trophic states and multi-taxonomic diversity in Japanese farm ponds

Abstract

Farm ponds are among the most biodiverse anthropogenic freshwater habitats because of their small size, shallow water depth, and aquatic vegetation. Land-use changes, such as converting riparian vegetation to human use or changing the management practices of farm ponds, are assumed to be major factors that change such ecosystems from a clear-water state to a turbid state, leading to deterioration of water quality and biodiversity in such ponds. Using the database of a large-scale pond survey, we evaluated the effects of surrounding land use (landscape factors and modern pond management practices), fish abundance, and other environmental variables on total phosphorus concentration and taxonomic richness patterns of six biological indicators associated with changes in the trophic state. Local-and landscape-level vegetation structure associated with land use and total fish abundance were among the factors influencing the total phosphorus concentration of farm ponds, a main driver of trophic state changes. In addition, a transition from a clear-water state to a turbid state was associated with lower taxonomic richness of aquatic plants, macroinvertebrates, and adult Odonata, and a higher taxonomic richness of phytoplankton and fish. Based on these results, we discuss potential land-use and pond management strategies for conserving and/or restoring the water quality and biodiversity of farm ponds through maintenance of a clear-water state.

Artificial agri‐environment scheme ponds do not replicate natural environments despite higher aquatic and terrestrial invertebrate richness and abundance

“…Ponds with complex aquatic vegetation structure support increased richness and abundance of macroinvertebrates through provision of refuges and more abundant prey populations (Deacon et al, 2018; Zelnik, Gregorič, & Tratnik, 2018). Artificial ponds were surrounded by taller vegetation that can act as a buffer for surface run‐off and aid improved water quality (Usio et al., 2017). High sward in close proximity to the pond can benefit Odonata species by providing suitable roosting areas and shelter (Rouquette & Thompson, 2007).…”

Evaluación de humedales someros tropicales semiáridos asociados al botulismo aviar

“…También la herbivoría por parte de las aves acuáticas puede disminuir la biomasa de los macrófitos, de forma que favorece el cambio de un estado claro a un estado turbio (van Altena et al, 2016). Estos cambios se han asociado a una disminución de la diversidad tanto de zooplancton como de macroinvertebrados (Usio et al, 2017).…”

Pond chironomid communities revealed by molecular species delimitation reflect eutrophication

“…The association of chironomid community ordination with rice paddy land use may suggest the effect, while no pesticides were monitored in this study. As discussed by Imai et al (2016) and Usio et al (2013), Usio et al (2017), the style of pond management and people's (farmers and nonfarmers) concerns on the activity is also worth considering for the conservation of pond biodiversity. In both points, monitoring the status of biodiversity in ponds is a key in assessing and making a feedback to the conservation.…”

“…vertebrates like fishes, annulans, and frogs (Fukumori et al, 2016;Iwai et al, 2017;Natsumeda et al, 2015;Usio et al, 2017). In such studies, most of the taxa studied are sensitive to environmental deterioration, now in progress among farm ponds, and thus they can be indicators of well-conserved waters.…”