Estimation of potential and actual evapotranspiration of boreal forest ecosystems in the European part of Russia during the Holocene

Abstract

A simple regression model for calculating annual actual evapotranspiration (ET) and potential evapotranspiration (PET), as well as annual transpiration (TR) of mature boreal forests grown in the European part of Russia in the Holocene using paleoclimatic and paleobotanical data (air temperature, precipitation, forest species compositions) is presented. The model is based on nonlinear approximations of annual values of ET, TR and PET obtained by the Levenberg-Marquardt method using the results of numerical simulations of ET, TR and PET provided by a process-based Mixfor-SVAT model for forests with different species compositions under various thermal and moistening conditions. The results of ET, TR and PET reconstructions for the Holocene show large variability and high correlation with the air temperature pattern. Minimal values of ET and PET are obtained for the Younger Dryas cold phase (11.0-10.0 14 C kyr BP) when ET varied between 320 and 370 mm yr −1 and PET varied between 410 and 480 mm yr −1 . During the Late Atlantic periods of the Holocene (4.5-5.1 14 C kyr BP), ET and PET reached maximal values (ET: 430-450 mm yr −1 and PET: 550-570 mm yr −1 ).

Solar Energy Transformation Strategies by Ecosystems of the Boreal Zone (Thermodynamic Analysis Based on Remote Sensing Data)

“…At the same time, the amount of precipitation is decreasing in spring and increasing in other periods. It can be assumed that, in terms of its parameters, the climate of the territory shifts towards the Atlantic period (6–7 thousand years ago), which, according to dating, marks the beginning of the formation of raised bogs on the territory of the Reserve [ 86 ]. Our analysis of the dynamics of the Reserve’s vegetation cover in recent years [ 87 ] and field observations show an increase in the renewal of broad-leaved tree species (maple, linden, hazel) in well-drained and warm relief positions and the expansion of sphagnum mosses in well-lit glades and under the forest canopy on flat and concave landforms.…”

Planning for climate change impacts on hydropower in the Far North

“…In the southern-most parts of this region, more precipitation will arrive in liquid form and be available earlier in the season for hydropower generation, rather than stored in the snowpack until spring melt. In the Far North, ET is a relatively small portion of the hydrologic budget and precipitation dominates (Kane et al, 1990), though ET will increase as the growing season continues to lengthen as it has in recent decades (Genet et al, 2013;Olchev and Novenko, 2011;Zeng et al, 2011). Other aspects of the supply side, which include groundwater storage and glacier storage, will be addressed in the next section on regional complexity.…”

Planning for climate change impacts on hydropower in the Far North

“…In the southern-most parts of this region, more precipitation will arrive in liquid form and be available earlier in the season for hydropower generation, rather than stored in the snowpack until spring melt. In the Far North, ET is a relatively small portion of the hydrologic budget and precipitation dominates (Kane et al, 1990), though ET will increase as the growing season continues to lengthen as it has in recent decades (Genet et al, 2013;Olchev and Novenko, 2011;Zeng et al, 2011). Other aspects of the supply side, which include groundwater storage and glacier storage, will be addressed in the next section on regional complexity.…”