Growing season water balance of an inner alpine Scots pine (Pinus sylvestris L.) forest

Abstract

We estimated components of the water cycle of a 150-year-old forest in an inner Alpine dry valley of the Tyrol, Austria throughout five growing seasons. Forest canopy transpiration () was measured by sap flow measurements scaled to the stand canopy level. Estimates of understory transpiration and forest floor evaporation () were derived from the soil water budget method, while interception () was modelled. Growing season cumulative evapotranspiration ( = + + ) varied between 256 and 322 mm or 51 to 79% of the growing season precipitation. The contribution of, , and to were 33, 40 and 27% respectively. Although these values of each layer (evapo)-transpiration are in good agreement with studies carried out in other European Scots pine forests, our estimated growing season total forest water use ( = +) of 200-244 mm is at the lower end of values reported for coniferous forest ecosystems, and thus reflects an adaptation to the low shallow soil water availability. We conclude that Scots pine forests in inner alpine dry valleys are able to cope with high evaporative demand, even when shallow soil water availability is limited.

Water content in soil afforested with a mixture of broadleaves or Scots pine

“…Changes of volumetric water content on the same plots and at the same depths were studied by Vopravil et al (2021) -the period from April to the beginning of November 2020. As stated in different publications, changes in volumetric water content vary between individual years (Tužinský 2005;Wieser et al 2018). In this study, we hypothesised that afforestation of agriculturally used land will lead to lower volumetric water content in soil (Hiltbrunner et al 2013;Vopravil et al 2021).…”

“…Contrary to the plot with broadleaves, understorey vegetation occurs on the plot afforested with Scots pine and can use water for transpiration (and interception). According to Poleno et al (2011) or Wieser et al (2018), understorey transpiration plus forest floor evaporation can form a significant part of total evapotranspiration (Gobin et al 2015). For example, Wieser et al (2018) estimated that forest canopy transpiration, understorey transpiration plus forest floor evaporation and interception formed 33%, 40%, and 27% of growing season cummulative evapotranspiration; understorey transpiration can form 19-90% of total evapotranspiration in temperate and boreal forests [see the Introduction of the publication by Gobin et al (2015)].…”

Monitoring the electrical potential difference of pine tree

“…The potential difference along the pine trunk is formed by physical and biological processes. The physiological process that determines the daily peaks (Figure 1(b, c)) is transpiration -the movement of liquid from the roots up the plant and its evaporation through the stomata into the environment [13]. By pumping and evaporating liquid, the plant regulates the temperature and flow of products into the photosynthetic zone.…”

Technology of Balanced Identification for Selection of Pine Transpiration Mathematical Model

“…Функции, определяющие динамику воды: устьичная проводимость (Ust) как функция радиации (Q) и дефицита упругости водяного пара (VPD), функция регулирования устьичной проводимости стволе (Reg) в зависимости от дефицита воды в стволе (WD), функция скорости поступление воды из почвы (FWF) в зависимости от дефицита воды в стволе (WD). Построенная в итоге модель соответствует современным представлениям о регуляции влаги в растении [10][11][12][13][14][15][16][17][18][19][20]22], она показала хорошее качественное совпадение с независимыми экспериментальными данными.…”

“…Прогноз реакции растений на эти факторы имеет первостепенное значение для прогнозирования последствий воздействия глобальных климатических процессов [10,11]. Надежными индикаторами состояния природных экосистем и растений, позволяющими оценить не только динамику их изменения и развития, но также и охарактеризовать их устойчивость, являются составляющие водного баланса растений, в частности, транспирации [12,13]. Технология применяется к нескольким моделям различной сложности и позволяет сравнить их соответствие экспериментальным данным.…”