Tobo is a Swedish demo area with the aim to show ditch cleaning.
Precipitation 564 millimetres
Landowner: Bergvik Skog AB
The actual site is close to 26 hectares. The site is a drained peatland. The ditch system (a squared systematic pattern) has a main ditch in the centre of the stand and side ditches perpendicular to the main ditch with a distance about 180 meters between the side ditches. The peat is a well humified peat (not yet classified). The depth of the peat is 80 centimetres or more at the major part of the site according to the survey conducted in July 2016. The previous stand was a 45-year old almost pure Norway spruce (Picea abies L. Karst.) forest, with less than 10 percent birch admixture (Betula sp.), standing volume 185 m3. The site index was classified as G32 m1. These data were given by the landowner.
The site is easy to reach situated 60 kilometres north of the city of Uppsala, further there is a commuter train station 500 meters from the site, train leaving Uppsala central station every 30 minutes.
The site will be used as a demonstration site showing a site where ditch cleaning has been conducted in conjunction with forest harvest performed as final felling. Also, a water protection construction, in terms of a kind of long-stretched sediment pond, has been installed. The purpose of the pond is to capture suspended solids released at the ditch cleaning, minimizing the transport to downstream waters.
Conduced work and time plan for future activities
Ground water tubes was installed in July 2016 and the depth of ground water table has been recorded.
In the in late summer 2017 (August/September) the stand was harvest according to the conventional cut-to-length system. All logging residues were left on site and used as brash mats on strip roads, to reduce soil compaction and minimise the risk of forming ruts. Later the same year the ditch was cleaned and a so called ‘pipe-controlled flow dam’ was constructed at the outlet.
At the same time as the ditch cleaning, mounding was done by the same excavator in the areas in-between the ditches. In spring 2018, Norway spruce seedlings were planted in the mounds.