At Skogaryd Research Catchment (SRC), the flow and balance of nutrients are studied in various ecosystems and across the whole catchment. Since January, deposition of nutrients has been measured, inching towards complete nutrient budgets.
Nutrient budgets comprise of inputs, outputs and the internal cycling. The base measurement program at SRC includes quantifying nutrient export from specific ecosystems via streams based on stream flow and nutrient measurements in water samples. Moreover, nutrient export via the gaseous phases is estimated by various chamber and micrometeorological techniques. To study the nutrient balance, and changes over time, it is important to understand, for example, the progressive development of ecosystem nutrient limitation or the capacity of ecosystem carbon storage for climate change mitigation. Full nutrient budgets require, in addition to the output pathways, knowledge on nutrient inputs. For most nutrients, the main pathway of input to ecosystems is via deposition from the air.
Since January 2024, SRC is participating in the measurement program of the Swedish Throughfall Monitoring Network (SWETHRO), coordinated by the Swedish Environmental Research Institute (IVL). Within the network, bulk deposition in open areas and throughfall deposition inside forest stands is monitored. At SRC, equipment was installed during autumn 2023, and the first measurement is this month (January 2024). Bulk and dry deposition is measured at the rewetted area of Följemaden, and the throughfall deposition measured at the Central Forest area, within the selectively cut stand. The measurements include, pH, conductivity, alkalinity, NH4-N, Cations (Ca, Mg, Na, K, Mn) and Anions (P, SO4-S, and Cl). These new measurements are crucial in studying the nutrient balance of the catchment.
Picture: Samplers for bulk and dry deposition in open field (Följemaden). In the background one of several eddy-covariance systems within SRC (Photo: David Allbrand).