Mohsen Zare: Betreute Abschlussarbeiten
Masterarbeiten | |
| Fabian Wankmüller |
A stomatal regulation algorithm consistent with abscisic acid (ABA) signaling predicts the concomitance of hydraulic loss and transpiration reduction during drought The thesis of Fabian Wankmüller presents a new model and concept of stomata regulation that links soil and plant hydrological principles ( soil-plant hydraulic conductance) to plant physiological evidence of stomata regulation (chemical signaling -i.e., abscisic acid, photosynthesis rate). The model developed here includes simulations of leaf water potential based on plant transpirational demand, soil water potential, and variable hydraulic conductances of the soil-plant-atmosphere continuum, and a function that links stomatal conductance to photosynthesis rate. This model reproduces a flexible stomatal behavior in response to various air moisture and soil-hydraulic conditions and casts light on new aspects of stomata regulation under variable environmental conditions such as soil drying, increasing vapor pressure deficit in the air, and day and night cycles. mehr Betreuer: Andrea Carminati, Mohsen Zare |
| Ursula Elisabeth Bundschuh |
Water repellency of beech forest soils measured with sessile drop and capillary rise method Betreuer: Andrea Carminati, Pascal Benard, Mohsen Zare |
| Andreas Cramer (2020) |
Biogenic Si and its effect on soil hydraulic properties The submitted thesis presents the effect of biogenic amorphous silica (BSi) on the retention and flow of water in the soil. It was hypothesized that the BSi due to its highly porous structure and high surface area could hold a large volume of water in the soil and therefore it could significantly contribute to retention and flow of water in the soil. The thesis tests its hypothesis in two directions: i) a synthetic pyrogenic amorphous silicic acid (ASi) was taken as an analog of BSi. The water holding capacity of pure ASi and soil mixed with different ASi contents were experimentally determined and a conceptual model was developed to describe the effect of ASi on water retention in soil, ii) in parallel, a set of different substrates and soils were selected and their water-holding capacities and Bsi contents were determined in order to relate the retention of water to the Bsi content. Betreuer: Mohsen Zare, Jörg Schaller |
| Judith Schepers (2019) |
Biophysical properties of root exudates and their impact on the shape of water in soil Mucilage is a polymeric gel that is exuded at the root tips and that maintains the rhizosphere moist Betreuer: Pascal Benard, Andrea Carminati, Mohsen Zare |
| (2019) |
Effects of soil heterogeneity on root water uptake under drying conditions and varying transpiration rates Der Wasserfluss in Böden ist in vielen Bereichen heterogen. In einem gegebenen repräsentativen Elementarvolumen können diese Heterogenitäten durch eine effektive hydraulische Leitfähigkeit beschrieben werden. Übliche Wurzelwasseraufnahmemodelle stützen sich im Allgemeinen auf diese repräsentative hydraulische Leitfähigkeit und gehen davon aus, dass die hydraulische Leitfähigkeit des Bodenzylinders um die Wurzeln derjenigen entspricht, die in Bodenproben gemessen wird, die repräsentativ für den Boden sind. Hier argumentieren wir, dass diese effektive Leitfähigkeit sich aus hydrologischen und biologischen Gründen von derjenigen unterscheidet, die die Wurzelwasseraufnahme steuert. mehrBetreuer: Andrea Carminati, Mohsen Zare |