L.N. ROZHKOV

Wetlandforest ecosystem

of Belarusian catchment

area of the River Neman

Wetland forests are currently in focus of particular attention of scientists and

general public as they are a unique ecological system possessing rich diversity of

plant resources, a depository of biological diversity, large natural filter of fresh water,

an important accumulating link of the balance between carbon dioxide sinks and

emissions.

Especially important is the role of wetland forests in Belarusian catchment area of

the River Neman, which is situated on the hilly plain belonging to the Minsk

Elevation.

Wetlands took 7.5% of the total Neman’s catchment area until the beginning of

the large-scale draining amelioration activities in Belarus in 1960s, today – only

1.9%. 74% of natural bogs were subject to draining amelioration. In general bogs and

overwetted lands were drained on 12.4% of the Neman’s catchment area.

Today on the Belarusian catchment area of the River Neman there are 88.5

thousand ha of natural bogs and 245 thousand ha of wetland forests, what makes

7.3% of the catchment area. 92.5% of these lands belong to the state forest fund.

Wetland forests of Belarusian catchment area of the River Neman 5,0% from its

area and are situated on bogs

– of raised type – 0.3%,

– of transitional – 13.5%,

– of lowland type – 86.2%.

Forests of lowland bog type prevail.

Wetland forests of Belarusian catchment area of the River Neman are

represented in the following forest formations (% of area):

– birch (Betuleta pendula) – 40.5%;

– black alder (Alneta glutinosae) – 40.2%;

– pine (Pineta silvestriae) – 12.9%;

– spruce (Piceeta abiestiae) – 3.3%;

– grey alder (Alneta incanae) – 0.9%;

– other species and shrubs – 2.2%.

Typological diversity of wetland forests on Neman’s catchment area is

represented by 57 forest types, which are united in 12 forest type series:

– fern (Betuletum filicosum – 16.9%, Glutinoso-alnetum filicosum –

11.0%, Piceetum filicosum – 2.7% and other) – 32.1% from the forest covered area

of wetland forest lands on Neman’s catchment area.

– sedge (Betuletum cariсosum – 12.1%, Glutinoso-alnetum caricosum –

9.5%, Pinetum caricosum – 1.8% and other) – 25.0%;

– meadowsweet (Glutinoso-alnetum filipendulosum – 11.0% and other) –

15.3%; – edge-sphagnum (Pinetum caricoso-sphagnosum – 4.4% and other) –

7.2%; – wild rosmary (Pinetum ledosum) – 5.8%;– other – 14.6%.

The following bog forest types are fragmentarily on Neman’s catchment area and

should be considered as “rare” or “single”: pine forest of sphagnum type (Pinetum

sphagnosum) – 0.29%, spruce forest of stream grass type (Piceetum fontinale-

herbosum) – 0.30%, birch forest of iris type (Betuletum iridosum) – 0.11%, birch

forest of sphagnum type (Pubescentio-Betuletum sphagnosum) – 0.03%, ash

forest of meadowsweet type (Fraxinetum filipendulosum) and some other. It is

worth mentioning that these forest types are relatively common for Belarus in general.

Productivity of wetland forests is characterized with the following indices:

– total stock – 29 994,7 thousand m3;

– average stock – 130 m3/ha;

– average yield class – 2.5;

– average density – 0.66.

Wetland forests on Neman’s catchment area take highly productive lands.

Secondary (not indigenous) species take nearby 21.2% of their area. Along with

unsatisfactory density structure it indicates of low (less than 50%) use of

productive capacity of wetland forests.

In wetland forests considerable wood resources are concentrated, including

mature stands of coniferous species – ≈ 0.8 million m3, black alder –

≈ 0.15 million m3, birch – 0.12 million m3.

In Fig. 1 there is shown carbon budget of wetland forests on catchment area of the River Neman basin.

Thousand t С

11 146

1 043

396

816

56 340

184 870

Figure 1 – Component structure of carbon resource of forest covered lands in wetland forests on catchment area of the River Neman basin

Total carbon resources in wetland forests on catchment area of the River Neman basin (wetland forest carbon pool) make 254.6 million t С. Main carbon stocks (94.7%) are accumulated in soil of wetland forests. The share of phytomass carbon makes only 4.8% wetland forest carbon pool.

over earth phytomass

dead wood

forest floor

small biological cycle

preserve carbon (peat)

under earth phytomass

Wetland forests are notable for heightened carbon productivity and prospects

for potential sequestration of atmospheric carbon dioxide in form of peat, removed

from biological cycle. Wetland forests take 14.06% of area, but their carbon

sequestration amounts 48,55% from forest carbon pool on forest covered lands on

catchment area of the River Neman (Fig. 2). Average carbon productivity of wetland

forests makes 1104.6 t С/ha, while upland forests – 191.0 t С/ha or lower by a

factor of 5,78. It is caused by slower mineralization of soil humus in wetland forests

in comparison to upland forests. As a result only 23.4% of organic carbon are

included in small biological cycle, while for upland forests it amounts 92.6%.

Figure 2 – Comparative carbon budget of forests on catchment area of the River Neman, including wetland and upland forests (forest covered lands)

72.6% of carbon resources sequestrated by wetland forests are removed from exchange zone

(cycle) between animate and inanimate components of forest ecosystem and are preserved in form of

peat. This figure for upland forests amounts 3.6%, that is twenty times lower. This is an important

function of wetland forests on catchment area of the River Neman – preservation of atmospheric carbon

dioxide in form of peat (184.9 million t С or 35.3% from its total stock on forest covered lands).

million t C thousand ha

organiccarbon 30 cm soil layer

phyto-mass

wetland forests

upland forests

forest covered lands

forest carbon pool

preserve carbon (peat)

small biological cycle

56.3 million t С in soil layer ≤ 30 cm of wetland forests form the closest reserve

of organic soil carbon which can be involved into biological cycle by rapid

mineralization of soil humus for example after forest draining, clear cutting of stand

etc. In this connection moderate exploitation of wetland forests is preferable, since

carbon of phytomass, detritus and upper soil layer is included in emission link first.

When cutting wetland forests or transforming them to agricultural purposes there can

happen the intensification of organic matter decomposition in upper soil layer, what

causes the emission of active soil carbon. Emission volume can amount ≈2 million t

СО2/year. Preservation of wetland forests is one of the ways to avoid additional

greenhouse emissions.

In the forest fund of Neman’s catchment area 30 kinds of specially protected

forest parcels were defined, which fulfill important social, environmental, historico-

cultural functions and have high importance.

Wetland forests are present in 21 (from 30) kinds of Objects of

socioecological and historico-cultural significance. Wetland forests take 14.06% of

forest land area in Neman’s catchment area and 26.4% of area of specially

protected forest parcels in the forest fund of catchment area. It indicates their high

conservation value. Wetland forest prevail among Specially protected parts of

zakazniks, Forest parcels with rare birds, wild animals and plants, along rivers

populated by beavers, around mating places of wood grouse. Shrub thicket as key

objects for wildlife corridors and habitats are for 95.3% bog plant associations.

Wetland forests on Neman’s catchment area belong to the Ist and the IId forest

groups – 69.5% and 30.5% of their area respectively. Main fellings are allowed on

32.0% of the wetland forests area.

Forestry production is profitable on ≈54% of the area of wetland forests under

consideration. Amelioration with a view to transform wetland forests to lands of

agricultural use is possible on 70% of their area.

It may be deduced that that there exist preconditions for intensification of forest

resources utilization, as well as for transferring of wetland forests on Neman’s

catchment area to other land use types. It will undoubtedly worsen the water

protective and water regulation components on the whole catchment area territory.

It is necessary to find ways for economically sound and environmentally friendly

sustainable management of wetland forests on Neman’s catchment area. As one of

such ways could serve the involvement of wetland forests in market of ecosystem

services on the basis of carbon sequestration potential and increased biological

diversity of wetland forests.

Taking into account high environmental significance and economic accessibility

for exploitation there are recommended directions of utilization of the wetland forest

resources: specially protected, protection and production, production economy types

were defined.

Оn catchment area of the River Neman, with the view to preserve their

typological diversity it is reasonable to establish special protection regime for wetland

pine and birch forests of sphagnum type, ash forests of bog motley grass type and

for all stands of osier forest type series (birch, black alder forests and other)

regardless their protection group and category. Parcels of these forests remained on

small area, but their function as shelter and habitat of wild animals and birds is very

important.

Taking into account the above mentioned we suggest the following utilization directions of wetland forests (Table 1).

Table 1 – Utilization directions of wetland forests on the catchment area of the River Neman

Economy typeForest protection category On the basis of forest types Utilization direction Felling methods

Specially protected

Forests of natural monuments and zakazniks of republican importance, green belts, zones of sanitary protection of water supply sources and health resorts, specially protected forest parcels

All types of wetland forests.Forests of sphagnum, bog motley grass and osier forest type series belonging to all protection categories of forests of Ist and IId groups.

Preservation of valuable natural areas

Maintenance fellings, selective sanitary fellings according to the Rules of forest felling in the Republic of Belarus

Protection and production

Forest shelter belts along railways and highways, waterside restricted forest belts, production forests

All types of wetland forests excepting sphagnum, bog motley grass and osier forests type series in Forest shelter belts along railways and highways, waterside restricted forest belts; forests of sedge-sphagnum type series in production forests.

Preservation and improvement of protection свойств of forests, harvesting and regeneration of wood raw material and fuel, obtaining of forest by-products, recreation

Maintenance fellings, selective sanitary fellings, рубки regeneration и reformation, gradual and selective main fellings according to the Rules of forest felling in the Republic of Belarus

Production Production forests All types of wetland forests excepting sedge-sphagnum, sphagnum, bog motley grass and osier forests type series

harvesting and regeneration of wood raw material and fuel under preservation of protection forest functions, obtaining of forest by-products, recreation

Maintenance fellings, selective fellings, main fellings according to the Rules of forest felling in the Republic of Belarus

State of wetland forests and forestry activities there should be subject to

monitoring. To estimate the state and occurring changes in wetland forests caused by

natural and anthropogenic factors the following we suggest:

– to realize regular observation for the state of and ameliorated wetland forests,

working forest hydromelioration systems using the network of permanent observation

posts;

– to research influence of economic activities on hydrological regime of the

territory, soil cover, composition and productivity of forest vegetation;

– to estimate the state and sustainability of wetland forests, to forecast expected

changes in forest growing conditions depending on parameters of draining network and

time of its construction, forms and methods of fellings and other economic activities;

– to elaborate advices for improvement of forestry activities in wetland forests;

– to communicate monitoring data to the National Information and Analytic Center

of Forest Vegetation Monitoring.

Main goal of bog ecosystem monitoring is preservation and rational use,

reproduction and protection of natural resources potential of wetland forests.