ВОЗМОЖНОСТИ ОЦЕНИВАНИЯ БАССЕЙНОВОЙ ТРАНСПИРАЦИИ НА ОСНОВЕ ИЗМЕРЕНИЯ СТВОЛОВОГО СОКОДВИЖЕНИЯ: ПОСТАНОВКА ЗАДАЧИ

Study of seasonal dynamics and evapotranspiration volume of forested catchments (mainly forest stand transpiration) is the relevant objective for fundamental knowledge and practical applications. However, there are many difficulties: labor efforts of direct observations, many factors affecting against each other, observational data scaling and so on. As a result, evapotranspiration during hydrological modeling is determined by the leftover principle and simplified techniques, leading to wrong representation of water balance structure. The presented article deals with the first results of our research group focused on setting up field measurements of xylem sap flow using trunk sap flow measuring sensors as well as development of sap flow assessment methods for individual trees and whole catchment. The investigations were performed for mixed coniferous-broad leaved forests at the territory of the Central Sikhote-Alin’ within Verkhneussuriyskiy biogeocenotical station of FSC of the East Asia Terrestrial Biodiversity FEB RAS. This site is used for water balance measuring surveys from 2011. Sap flow was measured continuously during June-October of 2019 on one of the local dominant tree species. Apparently, such investigations are novel for the Russian Far East region. It is expected that direct sap flow measurements for individual trees refinement methods, data scaling and its integration to the hydrometeorological observations will help to make a comprehensive analysis of catchments water balance and to integrate measured data into hydrological models.