International workshop on

Koli (c) Metla/Erkki Oksanen

Development of Models and Forest Soil Surveys for Monitoring of Soil Carbon

April 5-8, 2006 at Koli, Finland

Forest soil dynamics at different silvicultural regimes: simulation modelling

A. Mikhailov1, A. Komarov1 and O. Chertov2

1 Institute of Physicochemical and Biological Problems in Soil Science of Russian Academy of Sciences, 142292 Pushchino, Moscow Region, Russia, tel. 7 096 773 0755 Fax 7 096 733 0595, e-mail
2 Biological Institute of St. Petersburg State University, 198904, St. Petersburg, Russia

The forest simulation model of the stand/soil system uniting population and balance modelling approaches, EFIMOD, has been used for a long-term forest simulation of different silvicultural regimes. The ROMUL model (Chertov et al., 2001) is a sub model of soil organic matter dynamics based on a concept of the ‘humus types’. It allows for simulation of the carbon and nitrogen pools dynamics in soil taking into account mineralization and humification of soil organic matter. Structure of the model system allows for a use of standard forest inventory data. Output variables are the inventory stand data, pools of carbon and nitrogen in the stand and soil, the dynamics of CO2 emission and some other characteristics. The case study was conducted on a 300-hectare forest area with 108 stands in the experimental forest “Russky Les” 100 km south of Moscow, Russia.

Four strategies of silvicultural regimes were simulated for a 200 year time span: natural development, selective forest harvest, authorised Russian forestry practices according to the forest laws, and unauthorised forest practices that have increased over the last decade in the country.

The naturally developed forest has maximal increase of carbon in soil (22 ton/ha in 200 years) on the simulated forest section. At selective cuttings scenario pool of soil increased on 7.4 ton/ha, at authorized practice scenario it slightly increased on 1.3 ton.ha. Unauthorised practice scenario demonstrates gradual decrease of carbon in soil on 8.2 ton/ha in 200 years). Undecomposed forest floor maintains in the scenario of natural development only. The stable humus stock changes slightly in all scenarios. Scenario of natural development leads to the notable increase of coarse woody debris (30-40 ton/ha), in other scenarios it is two-three times lower.

The results obtained allow for the conclusion on the advantage and shortcomings of different regimes of forest management for their correspondence to the concept of sustainable forest management. Selective forest technology has clear advance over all other regimes. Actually, the simulation of ecosystem development and tree growth at forest territory (enterprise, landscape) level gives also opportunity for a combination of different regimes.

   Päivitetty:   02.03.2006 / EKel Metla : Events   Palaute Metlan etusivulle
. .