Impact of Fast-Growing Trees Planting on Degraded Land from Perspectives of Ecosystem Services—Case Study from Slovakia

The aim of the study was to assess the effect of natural phytoremediation, impact of growing fast-growing trees on contaminated agricultural land on ecosystem services using a Matrix evaluation system. The Matrix system is a table that links an ecosystem to its potential to provide ecosystem services. To determine the monetary price of natural capital for the provision of ecosystem services, we chose the value transfer method, based on which it is possible to assign a price (1 point = 40.7 EUR) to point values. Monitoring of the study site Kuchyňa (Mollic Fluvisol) is running since year 2010. The fast-growing willow was planted (between 2006 to 2018 year) on an area of about 43 hectares. During the monitoring of soil parameters, we observed a slight decrease in the value of the active soil reaction, a negative trend in the content of available phosphorus and a positive trend in the development of the total content risk elements in the soil. The phytoremediation ability of willow regarding risk elements was manifested by an increase in the value and price of production and regulatory ecosystem services at the monitored location. The price of natural phytoremediation of fast-growing willow on the given area was 218762.5 EUR for production services and 171509.8 EUR for regulatory services.

Effect of Afforestation on Soil Properties and Mycorrhizal Formation

A study was conducted on Cambisols in Northern Germany to analyze the effect of fast growing trees （Salix and Populus spp.） used in agroforestry on soil chemical and physical properties and also on endo- and ectomycorrhizal colonization of the fine roots. Representative plots of three trials, Giilzow （GUL）, Vipperow （VIP） and Rostock （ROS）, were used to measure the topsoil inventories at the very beginning and after six （GUL）, seven （VIP） and ten （ROS） years of afforestation with fast growing trees. The effect on soil organic carbon, plant available nutrients, reaction, bulk density, porosity and water conditions was analyzed, Arable soils without tree coppice were used as controls. Additionally, the endoand ectomycorrhizal colonization of two Salix and two Populus clones were investigated at one site （GUL） in 2002. The amounts of organic carbon in the topsoil increased significantly （P 〈 0.01） presumably induced by leaf and root litter and also by the lack of tillage. The soil bulk density significantly decreased and the porosity of the soil increased significantly （both P 〈 0.01）. The proportion of medium pores in the soil also rose significantly （P 〈 0.05 and 0.01）. Generally, afforestation of arable soils improved soil water retention. Ectomycorrhizas dominated the mycorrhizal formation of the Salix and Populus clones, with the accumulation of organic matter in the topsoil suspected of supporting the ectomycorrhizal formation. Thus, agroforestry with Salix and Populus spp. conspicuously affected chemical and additionally physical properties of the top layer of Cambisols within a period of six years.