Water protection measures in forest management
Published on 28 February 2020
Latvia
This is the good practice's implementation level. It can be national, regional or local.
About this good practice
The practice includes a set of measures implemented in forest management to reduce the harmful effects of logging, site preparation and drainage system maintenance.
Forestry close to water may enhance export of nitrogen (N), phosphorus (P), suspended solids and mercury to the waterbodies.
Riparian buffers (belts of trees retained by the waterbodies) retain sediment and nutrients through both mechanical control and uptake by ground and tree vegetation.
The set of water protection measures in drainage system maintenance includes establishment of sedimentation ponds (size 3-8 m2 for catchment ha), peak flow control (PFC) dams (dam with two runoff regulating pipes, usually combined with sedimentation pond) and overland flow areas or wetland buffers (0,5-1% of the catchment area) before the inlet of the main ditch into waterbody. These measures may be used alone or combined in the catchment of the drainage system to be maintained. Sedimentation ponds improve habitat for amphibians, insects and aquatic birds, thus enhancing biodiversity in the area. Ponds are important in terms of direct water re-use, as they store water for firefighting purposes. Riparian buffers, overland flow areas and PFC dams contribute to the water re-use indirectly, as they reduce the amount of N, P, suspended solids and Hg entering the waterbodies from forest areas.
Main beneficiaries are forest management organizations, water management institutions, nature protection institutions and general society.
Forestry close to water may enhance export of nitrogen (N), phosphorus (P), suspended solids and mercury to the waterbodies.
Riparian buffers (belts of trees retained by the waterbodies) retain sediment and nutrients through both mechanical control and uptake by ground and tree vegetation.
The set of water protection measures in drainage system maintenance includes establishment of sedimentation ponds (size 3-8 m2 for catchment ha), peak flow control (PFC) dams (dam with two runoff regulating pipes, usually combined with sedimentation pond) and overland flow areas or wetland buffers (0,5-1% of the catchment area) before the inlet of the main ditch into waterbody. These measures may be used alone or combined in the catchment of the drainage system to be maintained. Sedimentation ponds improve habitat for amphibians, insects and aquatic birds, thus enhancing biodiversity in the area. Ponds are important in terms of direct water re-use, as they store water for firefighting purposes. Riparian buffers, overland flow areas and PFC dams contribute to the water re-use indirectly, as they reduce the amount of N, P, suspended solids and Hg entering the waterbodies from forest areas.
Main beneficiaries are forest management organizations, water management institutions, nature protection institutions and general society.
Resources needed
Amount of necessary resources depends on establishment conditions in each case, as well as work and material costs in each country. For example, in Latvia building of the PFC dam costs less than 10000 EUR.
Evidence of success
The effectiveness of forest buffers for retaining N was estimated in three studies. In two of them the impact of forest buffers on the levels of P and suspended solids that enter headwater streams after harvesting at mineral soil sites were assessed. The forest buffers retained 15 to 73% of the inflowing N, whereas P and suspended solids were not retained in one study and retained at a rate of 96% and 43%, respectively, in another.
Potential for learning or transfer
Due to the climate change and growing demand for renewable energy, forest management intensification is increasing, and measures targeted to enhance forest growth (including soil preparation, fertilization, drainage system maintenance) are expected to be applied more in the future. Water quality decline in natural waterbodies is a growing concern, and with the climate becoming less stable, threat to water ecosystems will increase. These challenges are not limited to the Baltic Sea region only, and the described practice may be implemented in all countries that rely on intensive forest management and have a dense network of natural waterbodies.
There is an example of transfer of the described practice from the Nordic countries (Sweden and Finland) to Latvia, and the effect is currently under investigation. Preliminary results suggest positive impact on suspended solid and N retention; these will be quantified in the coming years.
There is an example of transfer of the described practice from the Nordic countries (Sweden and Finland) to Latvia, and the effect is currently under investigation. Preliminary results suggest positive impact on suspended solid and N retention; these will be quantified in the coming years.
Further information
Website
Good practice owner
You can contact the good practice owner below for more detailed information.
Organisation
Latvian State Forest Research Institute Silava
Latvia
Latvija
Contact
Project managers