The Akazu Research Forest is the main research forest where much research related to ecohydrology and relevant research fields is conducted. The following topics are of particular importance. 1) For more than 80 years, the rainfall-runoff processes at two different watersheds of Shirasaka and Ananomiya have been investigated. By continuing the long-term hydrological measurement, the effects of ongoing climate change around AKRF and sporadically occurring forest disturbance e.g. forest decline due to disease, on water yield from the three forested watersheds can be analyzed. 2) The paired watershed method is applied to a small watershed in Shirasaka Experimental Watershed in order to evaluate directly the effect of anthropogenic manipulation on runoff and evaporation processes in the treated watershed. 3) To understand the longterm dynamics and succession of a secondary broadleaved forest and accompanying avifauna, long-term ecological research (LTER) in a permanent plot in the AKRF is being conducted.