Effect of different tree species on soil quality parameters in forest plantations of Kyrgyzstan

Abstract

The forest area in Kyrgyzstan covers only 4 % of the land area, but it plays a significant role in soil, water and landslide protection. An effective and efficient way to enhance forest unit area productivity and stop erosion processes is to increase afforestation by the introduction of other tree species among Kyrgyzstan fir (Picea shrenkiana) mono-species forest. The main objective of the present research work was to investigate the influence of different forest plantations on soil processes including statements to site productivity and sustainability. The investigations were carried out in birch (Betula pendula), fir (Picea shrenkiana), pine (Pinus silvestris) and larch (Larix sibirica) plantations in the Jylandy boundary during 2000-2002. The results of this work revealed that the forest litter, especially under coniferous plantations, have favourable physico-chemical properties, are rich in chemical elements and play a main role in supporting the fertility of forest soils. Also data showed that under the influence of trees the meadow-steppe vegetation on soils becomes more mesophilous. Coniferous plantations under natural conditions in Kyrgyzstan improved soil quality parameters and favourably influence the microbial activity of soils. However, investigations on the biochemical “forest-soil” cycle should be evaluated within site-specific characteristics. Forest plantations can be an efficient indicator for assessing the erosion risk in mountain areas of Kyrgyzstan. Thus, it will be economically more profitable to create mixed plantations pine/fir or larch/birch on the northern expositions. A very important task in future is to avoid the creation of mono-species birch plantation.