Site description The Kangasvaara catchment is one of the research areas of the Finnish Forest Research Institute. It is a small catchment (56 ha), located in North Carelia in Eastern Finland (Figure 1). The main soil types are somewhat thin, weakly developed iron podzols, peaty podzols, and shallow fabric histosols. The soils are developed on shallow, stony to very stony till materials. The whole catchment is covered by a 140 year old unmanaged forest which grew after a forest fire around 1850. Dominant tree species are Norway spruce (56%), Scots pine (30%) and birch (12%). In the winter 1996/97 an area of 17.4 ha was clearcut, and replanting is planned for 1999.
Standard meteorological data were collected at a small meteorological station in the catchment. The Finnish Forest Research Institute has measured precipitation as well as bulk and throughfall deposition of major cations and anions since 1993. The physical and chemical parameters of the soil as well as the vegetation parameters were also collected by the Finnish Forest Research Institute. Results from the pre-treatment calibration period are described in Finer et al. (1997). Further details on the catchment can be found in Table 1
| Variable | Unit | Value |
|---|---|---|
| Latitude | - | 6351'N |
| Longitude | - | 2858'E |
| Elevation | ma.s.l | 187 |
| Area | ha | 56 |
| Peatlands | % | 8 |
| Standing volume | m3ha-1 | 275 (17.2 kg m-2) |
| Soil thickness | m | 2.30 |
| Bulk density | ||
| organic layer | g cm-3 | 0.18 |
| mineral layer | g cm-3 | 1.02 |
| Cation exchange capacity (CEC): | ||
| organic layer | meq kg-1 | 147 |
| mineral layer | meq kg-1 | 6.13 |
| Organic matter content (top soil) | kg kg-1 | 0.11 |
| C:N ratio (top soil) | - | 29 |
| Precipitation (av. 1993-94) | mm a-1 | 540 |
| Bulk deposition (1993): | ||
| SO4-S | meq m-2 a-1 | 15.97 |
| NOx-N | meq m-2 a-1 | 7.45 |
| NH4-N | meq m-2 a-1 | 12.12 |
