Serbia Living Lab: NW Serbia

Name of site: NW Serbia

Responsible person: Žaklina Marjanović

Contact e-mail: zaklina@yahoo.com

Climate:  Continental/Sub-Mediterranean

Ecoregion: PA0431 Eastern Europe.

Approximate size (km²) of Living Lab:  Scattered, stands from 0.3-1Ha.

Description of the area:

The border between Balkan Peninsula and Panonnian region is a borderline between different terrain elevations, geological formations of different age and origin as well as climatic zones and floristic regions (Pannonian to sub-Mediterranean). Since the Holocene climatic era started to dominate, it has been transformed it into the agricultural area, why the original forests turn out to be on the edge of extinction. The soils are very fertile and usually neutral to slightly acidic. The natural vegetation types are riparian forests which are strongly influenced by the seasonal fluvial actions, also being exposed to occasional floods. The dominant tree species are mainly ectomycorrhizal: Populus alba, P. nigra, Quercus robur, Tilia spp. and Carpinus betulus, but also include arbuscular mycorrhizal tree species: like Ulmus spp., Acer spp, Fraxinus spp. and Crategus spp. These are biomass-mighty communities, that are defined by the level of fluvial activity/ groundwater vertical dynamics and soil structure. Due to the bulky and diverse shrub and herbaceous layers, these forests are characterized by high plant species richness, density and productivity. Chosen sub- area is in upper Kolubara river basin in Western Serbia, where the remnant forest stands (originally belonging to Populetum albae – Quercetum roboris type) are limited and highly endangered. Majority of tap root forming oaks have been cut and the stands are left with Populus alba and Fraxinus sp. dominating. This way only trees with surface root systems are present, while deep layered water resources cannot be reached and natural soil water capacity dynamics becomes distracted.   

Forest resilience challenges:

Even though the entire microclimate within the stands is changing with every old oak cut, these forests appear to be quite resilient. The main problem is oak reintroduction – poplars spread rapidly by seeds and vegetative growth from root suckers, while oaks need much more time and specific conditions to establish. Large openings in the canopy caused by the ectomycorrhizal oak cut are changing the soil microclimate, giving the arbuscular mycorrhizal plants the advantage to cover the forest floor very quickly. This changes the structure of soil and symbiotic mycobiome drastically.

Soil hydrological regimes in the forests are influenced by the strong seasonality of the rainfall and temperatures, causing high soil conditions and symbiotic mycobiome fluctuations. The climatic changes that are predicted for this part of Europe could lead towards extreme flooding (like in 2014) or drought (like most of the seasons since then).

The big danger for riparian forests in Kolubara river basin is the waste mining activity – the countries’ largest coal mine has destroyed huge forest areas. Also, agricultural activities produce leaching of various chemicals that are causing entire basin pollution.

Another important challenge is the mentality of the local human population – in Serbia waste removal mechanisms are still rudimental and rural population is used to damp municipal waste into the rivers and forests. Riparian forests in entire country therefore became not only the ilegal landfills, but also waste depositing areas after the flooding events. The River Kolubara plain is especially in danger since the landfill of Valjevo City is directly on the river bank on the upper Kolubara plain.

What are the main ecosystem services provided by the forest?

Alluvial forests are important factors in the amortizing floods and river bank erosion, as well as effective excessive soil water evaporators through transpiration. They have very large biomass production, the trees can grow very large and have high economic value. Additionally, in contrast to northern European regions, riparian forests in southern borderline of Pannonia support production of different true truffle species of commercial value. The dominant sporocarp producing species is the world’s most prized and the most endangered truffle species i.e., Tuber magnatum Pico (white truffle of Alba). Unlike some other truffle species, so far this cannot be produced in artificially formed plantations of inoculated trees, why the fast disappearing natural habitats are the only sources for obtaining its ascocarps.

Furthermore, riparian forests in the Kolubara valley are the last islands of biodiversity hosting highly endangered fauna in the area including different game species. In once respected hunting region, with the disappearance of habitats the number of animals has significantly decreased.

Key Stakeholders and their possible role in the project:

  • Truffle hunters society “Dinarica Tartufi” andcTruffle tradi ng company Boma-Elektro d.o.o
  • Hunter clubs “Braća Nedići” (Valjevo) i “Dragan Radović” (Lajkovac)
  • Municipalities of Valjevo and Lajkovac (decision makers)
  • Ministry for Environment Protection,
  • inistry for Agriculture and Forestry of Serbia