Asa High-yield Experimental Forest is a world-unique large-scale research arena on intensive forestry. Production possibilities together with effects on the environment are being measured and evaluated. The goal is to increase forest growth by 50%.
Forests play a critical role in sustainable development. The view of what services the forest should provide is changing and demands are increasing. Forests supply wood that is used for building houses, making paper, furniture, energy, textiles, etc. At the same time, there is a demand from society to provide recreational services and protect biodiversity. Simultaneously forests play a key role in mitigaiting climate change. Does this sound like an impossible equation? One solution may be to significantly increase forest growth in certain areas.
The purpose of Asa High-yield Experimental Forest is to create an arena where studies of the effects of signigficantly increased forest growth at the landscape level are made possible.
Various silvicultural practices and management programs are used to increase growth, eg.:
Forest growth, vegetation changes, water chemistry and runoff are being monitored at the Asa High-yield Experimental Forest.
Water is sampled monthly in 12 catchment areas, and samples are analysed with an extensive water chemistry program. Water flow is continuously measured and the hourly average value is recorded. The water control program is further expanded after every fertilisation.
Vegetation changes are monitored through airborne laser scanning and a network of permanent sample plots where trees as well as ground- and field-layer vegetation are inventoried.
The High-yield Experimental Forest in Asa is an unique arena for research on increased forest growth, timber production and environmental effects. Our infrastructure enables studies of eg.:
If you have questions or research ideas, do not hesitate to contact us!
Climate data at Asa climate station includes:
Data from Asa climate station and stations at other experimental forests is available here
For data, contact:
Magdalena Zuchlinska Steen, Experiment Technician
Unit for Field-based Forest Research; Asa
magdalena.steen@slu.se, +46 472-263181
The analysis includes 23 parameters since mid-2010: pH, alkalinity, conductivity, two different absorbance values, suspended material content, turbidity (from mid-2010 to 2014), total organic carbon, total nitrogen, ammonium, nitrite nitrate, total phosphorus, phosphate phosphorus, sulphate, chlorine, fluorine, calcium, magnesium, sodium, potassium, iron, manganese, silicon, aluminium
Water sampling is additionally extended after every fertilisation in all catchment areas affected by the fertilisation and also in two control areas. After fertilisation water is sampled every- or every second day after fertilisation (4-5 times) and also during the coming summer at high water flow.
Water chemistry data from extended sampling after fertilizations includes: total nitrogen, ammonium, nitrite nitrate, phosphate phosphorus, total phosphorus.
Water sampling from our two reference catchment areas took place twice a month.
Monthly water analysis from our two reference catchment areas included the following heavy metals: arsenic, cadmium, cobalt, chromium, nickel, copper, lead, vanadium, zinc, uranium, methylmercury (IVL), total mercury (IVL).
Manual measurements (control):
once a month from mid-2010 to mid-2015
twice a month from mid-2015
Automatic measurements (logger) - hourly average value from mid-2012 (except for winter periods, read more below)
Manual measurements of water flow are made at weirs, the distance from the weir’s edge to the water surface is measured on both sides (see picture below). It is also noted whether water flow is influenced.
For automatic level measurements, Level Troll 7 loggers are used. Loggers measure the water flow and temperature every two seconds and save the hourly average value. Data is loaded twice a month (data cannot be viewed in real time).
During three winters 2017/2018, 2018/2019 and 2019/2020, the loggers were stored inside - for those periods, data is only available from one reference stream (weir equipped with a shed and infrared heating).
Quality control of water flow data is in progress.
For data, contact:
Magdalena Zuchlinska Steen, Experiment Technician
Unit for Field-based Forest Research; Asa
magdalena.steen@slu.se, +46 472-263181
Airborne laser scanning data
Asa Experimental Forest and Asa High-yield Experimental Forest were scanned with airborne laser in 2009 and 2019. On both occasions, it was high point density scanning, approx. 20 points/m2, which enables the identification of individual trees. In connection with the scans, the areas have also been photographed aerially.
For data, contact:
Mikael Andersson, Group Manager
Unit for Field-based Forest Research; Asa
mikael.andersson@slu.se, +46 472263170
Tree inventories within a network of 234 permanent sample plots within Asa Experimental Forest and Asa High-Yield Experimental Forest constitute reference data for the two laser scanning carried out in 2009 and 2019. The network was established and GPS-positioned in connection with the 2009 scanning when all stands within area were divided into five layers depending on tree species and age. The size of the sample plot varies depending on age and condition of each stand.
The variables measured/registered at every sample plot:
For data, contact:
Mikael Andersson, Group Manager
Unit for Field-based Forest Research; Asa
mikael.andersson@slu.se, +46 472263170
In 2018, vegetation was inventoried on all samples plots used for tree inventory (234) and on additional 40 sample plots distributed over fertilised stands. On the subplot area of 1m² all occurring species and their percent of cover were registered in three layers: bottom layer (e.g. mosses), field vegetation layer (grass, herbaceous plants) and shrub layer. Tree canopy cover above the sample plot was also registered.
For data, contact:
Mikael Andersson, Group Manager
Unit for Field-based Forest Research; Asa
mikael.andersson@slu.se, +46 472263170