Freshwater ecosystems of the southern region of the Russian far east are undergoing extreme environmental change

Abstract

The freshwater ecosystems of the Southern Region Of the Russian Far East (SRORFE) are subject to the influence of environmental extremes (especially heavy floods and droughts). Within forested areas, extreme floods do not destroy the ecosystems of rivers and floodplain lakes; in contrast, periodic medium and small floods alternating with low-flow periods are beneficial to these ecosystems. In the 21st century, the natural flood cycles will change, likely increasing the peaks of floods but decreasing the probability of rain during the dry season. Extreme floods can lead to the rapid depletion of river phytoplankton and zoobenthos and can cause long-term water hyper-eutrophication. Droughts will increase the probability of forest fires. The loss of forest cover due to logging and fires will intensify the unsteadiness of hydrological regimes of water bodies. In the SRORFE global environmental change, accompanied by increasing anthropogenic pressures and a lack of protective measures will cause a significant loss of biodiversity among freshwater biota. Meanwhile, forest preservation will ease the negative effects on the biodiversity and productivity of freshwater ecosystems in the SRORFE.