[Assessment of soil quality under different land use types in the rocky mountain area of northern Hebei Province, China.].

To assess the variations of soil quality among land use types and with altitude in the rocky mountain area of northern Hebei Province is critical for preventing further human-induced degradation of land and vegetation, and for formulating a strategic plan on vegetation restoration after the Beijing Winter Olympics. Taking natural forest, plantation, natural grassland and abandoned cropland as research objects, 13 soil physicochemical indices (., soil bulk density, porosity and soil nutrient content) were measured to compare soil quality among land use types.

[Spatial structure characteristics of plain ecological plantation in Tongzhou District, Beijing, China].

Forest spatial structure (FSS) directly reflects resource competition and growth space distribution among different trees. The characteristics of FSS play an important role in mastering the growth status of ecological forest, formulating stand structure regulation measures, and improving forest quality and ecological services. In this study, seven plain ecological plantations including , , , , , , and in Tongzhou District, Beijing were selected as the research objects.

[Effects of revegetation approach and terrain on plant species diversity as a result of converting croplands to forests in the Loess region of western Shanxi Province, China].

The plant species diversity of stands converted from croplands as affected by revegetation approaches and terrains was studied using the transect line plot sampling. The goal of the study was to provide reference for evaluation reforestation effects and forest management in the Loess region of western Shanxi Province. The results showed that revegetation approach had a great influence on plant species diversity in stands.

[Effects of small hydropower substitute fuel project on forest ecosystem services].

Based on the Forest Ecosystem Services Assessment Standards (LY/T 1721－2008) issued by the State Forestry Administration, this paper evaluated four key functions of forest ecosystems, i.e., water conservation, soil conservation, carbon fixation and oxygen release, and nutrient accumulation.

[Influences of shallow groundwater on sap flow of riparian poplar plantations in northern China.].

Water use strategy in growing seasons plays a great role in the management of riparian poplar plantations in northern China. The research was conducted on a poplar (Populus × euramericana cv. '74/76') plantation located near the floodplain of Chaobai River in the northeastern su-burb of Beijing.

[Soil aggregate stability and soil organic carbon characteristics in Quercus variabilis and Pinus tabulaeformis plantations in Beijing area].

Based on the field survey and laboratory analysis, this paper studied the soil aggregate stability and soil organic carbon characteristics in Quercus variabilis and Pinus tabulaeformis plantations in Beijing area. In the two plantations, the contents of soil macro-aggregates decreased with soil depth. In P.