Informatics Publishing Limited

Xiangjin Shen ¹, Binhui Liu ², Daowei Zhou ¹

Affiliations
1 Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, CN
2 College of Forestry, Northeast Forestry University, Harbin 150040, CN

Abstract

Grassland degradation due to human activities is a critical problem in Songnen plain of northeast China, but the possible regional climate changes, especially air and soil temperature changes because of grassland degradation, are still not clearly known. From May to September of 2014, we simulated a Leymus chinensis degradation experiment in Songnen plain to study the effects of grassland degradation on air temperature, soil temperature and the difference between soil and air temperatures. The results demonstrated that grassland degradation will increase both the growing season surface air and soil temperature by 0.49-1.49°C and 0.6-2.27°C respectively. The difference between soil and air temperatures also increases with the reduction of L. chinensis vegetation cover, implying that the increase in soil temperature will be much faster than air temperature with the degradation of the grassland in Songnen plain.

Keywords

Climate Change, Grassland Degradation, Leymus chinensis, Surface Air Temperature, Soil Temperature.

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Shengchao Guan ¹, Pujia Yu ¹, Daowei Zhou ¹

Affiliations
1 Northeast Institute of Geography and Agro-Ecology, Chinese Academy of Science, Changchun-130102, CN

Abstract

Grassland salinization and sodification has become a global concerning issue in recent years. Many bare sodic patches have appeared after grassland degeneration caused by soil salinization in Songnen plain, which inhibits growth and development of forage grass. In order to searching for an effective method to restore vegetation on sodic patches, a 3-year study was carried out to test whether laying cornstalks could promote vegetation restoration on bare sodic patches. The study contained 3 cornstalk amount, namely, 1 (T1), 2 (T2) and 3 (T3), and 4 directions, namely, east-west (EW), south-north (SN), northeast-southwest (NESW), southeast-northwest (SENW), respectively. Compared with spot without cornstalk laying (CK), soil organic carbon (SOC) was not significantly altered by cornstalk (p>0.05). EC in 2013 and pH in 2014 showed significantly (p<0.05) decrease compared with CK for all the 3 treatments, but no significant differences (p>0.05) were observed among T1, T2 and T3. Application of cornstalks promoted vegetation restoration than CK in the 3 years, but amount and direction of cornstalk didn't have significant effect on the indices (above ground biomass, community height, community coverage and specie number) except for community coverage in 2013 (p>0.05) when CK was excluded. Average above ground biomass, community height and specie number presented highly variability among years. Laying cornstalk is effective in revegetation on bare sodic patches, regardless of laying amount and direction.

Keywords

Laying Cornstalk, Bare Sodic Patches, Amounts, Directions.

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