Effects of nitrogen-fixing and non-nitrogen-fixing tree species on soil properties and nitrogen transformation during forest restoration in southern China

Abstract

The role of different plantation tree species in soil nutrient cycling is of great importance for the restoration of degraded lands. The objective of the present study was to evaluate the potential of N-fixing and non-N-fixing tree species to recuperate degraded land in southern China. The soil properties and N transformations in six forest types (two N-fixing plantations, three non-N-fixing plantations and a secondary shrubland) established in 1984 were compared. The N-fixing forests had 40-50% higher soil organic matter and 20-50% higher total nitrogen concentration in the 0-5 cm soils than the non-N-fixing forests. Soil inorganic N was highest under the secondary shrubland. The N-fixing Acacia auriculiformis plantation had the highest soil available P. There were no significant differences in soil N mineralization and nitrification among the forest types, but seasonal variation in these N processes was highly significant. In the rainy season, the rates of N mineralization (7.41-11.3 kg N ha )1 month )1) were similar to values found in regional climax forests, indicating that soil N availability has been well recovered in these forest types. These results suggest that N-fixing species, particularly Acacia mangium, are more efficient in re-establishing the C and N cycling processes in degraded land in southern China. Moreover, the N-fixing species A. auriculiformis performed better than other species in improving soil P availability.

Effects of vegetation restoration types on soil quality in Yuanmou dry-hot valley, China

“…Relative to the bare soil and Eucalyptus camaldulensis, restoring Leucaena leucocephala to the slope area positively affected SOM content and N content (Table 2). C input and increase in soil N content can enhance the capacity of the system to support more complex community (Macedo et al 2008;F.M. Wang et al 2010).…”

Seasonal dynamics of soil respiration and nitrification in three subtropical plantations in southern China

“…The annual mean temperature is 21 °C, the mean monthly minimum is 12.1 °C, and the mean monthly maximum is 26.3 °C. The soil was formed on granite, classified as red soil in Chinese soil classification, equivalent to Oxisol in USDA Soil Taxonomy (Liang & Wen 1992, Wang et al 2010a, Huang et al 2014. We studied three of the most dominant plantations: one conifer plantation (Pinus massoniana Lamb.)…”

“…Southern China, which is located mostly in the subtropical region, has 25 million hectares of plantations (Wang et al 2010a). Plantations are becoming a key component of the world's forest resources and play an important role in the context of sustainable forest management (Wang et al 2010b).…”

Seasonal changes in soil respiration and microbial biomass in five tropical tree plantations in Thailand

“…Tree plantations currently cover more than 60 million ha and expanding rapidly, especially in southeast Asia and south Africa (FAO 2010). They contribute not only to commercial woods production, but also to the significant carbon (C) sequestration or greening the land (Wang et al 2010). Microbial biomass is a key factor controlling nutrient dynamics in the soil; on an annual basis, most of nutrients for plants are provided through mineralization of soil organic nutrients or microbial turnover (Paul andClark 1997, Arunachalam andArunachalam 2000).…”