Variation in biomass and soil carbon stocks across Pääjärvi catchment area – a landscape ecology and GIS approach

Pääjärvi catchment and biomass
sample points

My professional duties and my MSc and PhD topics are all related to forest ecosystems, especially to forest ecology, forest monitoring and GIS as well. The title of my MSc Thesis was: “Variation in biomass and soil carbon stocks across Pääjärvi catchment area – a landscape ecology and GIS approach„ in which I studied the previously done “Processes controlling dissolved organic carbon fluxes in boreal catchments (PRO-DOC)” project in Lammi, and collected forest site attribute data about the area and made my research with new approach.

Pääjärvi catchment and biomass map
created with GIS

I used measured and online data as well meanwhile I created my own GIS maps connected to landscape ecological approach. I picked the most important landscape factors (elevation, slope, aspect, bedrock, soil, site type) and tested their correlation to each other and forest biomass and soil carbon stocks. As results I got that forest ecosystems are very complicated, each factor has impact on every other, but only site type had stronger relations to every factor, especially to tree and soil carbon stocks. Therefore, I felt that we need to study an area for longer period to be able to say precisely what happens in the landscape.

Effects of snow and wind breaks in Bukk mountains from July
 2017 using high-resolution Sentinel NDVI images.

For this reason, we need to develop monitoring systems, this is connected to my PhD topic: “Usage of time-series of satellite images in Hungarian Forest Monitoring”. By the usage of modern technologies, we can monitor constantly the changes of Earth’s state with satellite based remote sensing. Due to the high importance of forest monitoring on vast areas (2 million hectares in Hungary), the satellite technologies became real supporters or alternatives of ground-based monitoring systems by providing data regularly, geographically explicitly and freely. Good example of these in Hungary the Remote-sensing based Forest Health Monitoring System (shortly ‘TEMRE’ in Hungarian; URL: ) of Hungarian Forest Research Institute, which complements well the ground-based monitoring system running by the Institute and the NFCSO. Forestry Department for decades.

In TEMRE the downloading, filtering and presentation of freely available, moderate resolution satellite images happens automatically by algorithms. On the forest maps updated in every 16 days during the vegetation season, it is possible to monitor the photosynthetic activity and health of forests on the website (see NDVI image above). With this system we managed to show the effects of forest damages: ice-breaks, insect gradations, we created supplementary layers in the system such as tree species (oak, beech, spruce, etc.) and site conditions (soil, hydrology, aspect, slope, etc.) to visualize the attributes of the affected area.

In favor of optimization of developments, we endeavor to establish international connections with Finnish, Swedish, American, Canadian or Russian experts where forest areas are even bigger than in Hungary, and satellite-based monitoring is even more suggested.

Tamás Molnár is a research fellow of Hungarian Forest Research Institute and PhD student at the University of Sopron and a 2016 LBAYS grant recipient