Sub Project 03: Forest Resilience and Water

Persons involved:

Harald Biester (PI)
Lina Oskamp (PhD student)

Research outline:
Subproject 03 examines how changes in forest cover and structure - specifically, the transition from spruce monocultures to mixed / beech forests in Lower Saxony - alter litter as well as soil composition and the resulting water quality in forest drainage systems.
In order to do so, litter and soil samples from (disturbed) spruce, mixed and deciduous forests are examined for parameters like nutrients (nitrate, phosphate and carbon) as well as trace element pools - with a particularly focus on heavy metals and mercury, investigating differences in composition related to changes in forest cover.
Key parameters used for the assessment of chemical water quality in the associated drainage systems are conductivity, pH, nutrient levels, dissolved organic carbon quality and quantity and trace metals contents in samples from soil solutions, streams, groundwater and reservoirs.
Mercury is an atmospheric pollutant of concern, whose uptake and storage is controlled by atmosphere-plant interactions, including the uptake of mercury through the stomata of leaves and the consequent transport to soils via litterfall. Thus, in addition to the investigation of mercury concentrations in soil, litter and water samples, atmospheric mercury measurements at varying heights above the forest canopy will be conducted to fully understand the impact of variations in forest cover on mercury distribution and emissions.
These findings will enhance our understanding of how forest disturbances and transformations affect water quality and mercury dynamics, thus informing timely adaptation measures and underscoring the essential role of forests for the preservation of water quality, which is vital for the resilience of forests amid increasing climate pressures.

Contact
Prof. Dr. Harald Biester
TU Braunschweig
Institut für Geoökologie, Abteilung Umweltgeochemie
+49 (0) 531 391-7240
E-mail: h.biester@tu-braunschweig.de