Li Y.,Beijing Forestry University |
Yu X.,Beijing Forestry University |
Li X.,Shanxi Academy of Forestry
Journal of Food, Agriculture and Environment | Year: 2013
As one of the most environmentally vulnerable regions in China, the Loess Plateau faces new challenges. The new sources of soil erosion and water loss, artificial slopes, have been created numerously in large engineering projects. Plant establishment is critical to environmental protection on these slopes, but the mechanisms regulating establishment can be obscured by the influences of slope features. This study aimed to characterize the relative effects of the slope features on vegetation distribution and to find the slope threshold for vegetation restoration. A detailed investigation combining floristic composition, soil characteristics and climatic data were carried out at 200 slopes, which mainly located in semi-humid areas of the Shanxi Province, China. We used constrained ordination to identify variation in species distribution along geographical and environmental gradients. Besides, in order to define the slope threshold for vegetation distribution, the curve fitting method was employed to establish an empirical model. Canonical correspondence analysis (CCA) revealed that slope aspect was the primary factor for the vegetation distribution, followed by the slope angle, and the first CCA axis was effectively a topographical gradient. Regressions indicated the relationship between the plant cover and slope angle was not linear, but a quadratic curve; the slope threshold for vegetation distribution was approximately 75°. The plant cover decreased rapidly when the slope angle is larger than 45°. This study suggests that plant establishment is an effective method when the slopes are gentler than 45°, and the engineering measures (i.e. Rock-bolt and Shotcrete) might be a better choice for the slopes steeper than 75°. These results provide a reliable theoretical basis for vegetation restoration and developing effective management practices on those artificial slopes.
Li X.-P.,Shanxi Academy of Forestry |
He Y.-P.,Jincheng Bureau of Parks and Woods of Shanxi Province |
Wu X.-J.,Shanxi Academy of Forestry |
Ren Q.-F.,Shanxi Academy of Forestry
Forest Research | Year: 2011
By taking two-year-old Platycladus orientalis and Pinus tabulaeformis mulched by plastic film, stone, etc. as the research objects, the water stress experiments were conducted in calcareous rock area in middle Taihang Mountain. The soil water content was measured three times a day by using time domain reflectometry (TDR), and the wilting time was recorded. The results are as follows: the mulching treatments could decrease soil water consumption, increase soil water-holding time of effective water, prolong the survival time of sapling under water stressed condition; the least soil water content for sapling survive were 6.70% and 7.80% for Platycladus orientalis and Pinus tabulaeformis, respectively, and forest planting could not be carried out when soil water content was lower.
Zhang X.-B.,Shanxi Academy of Forestry |
Li Y.,Beijing Forestry University |
Yuan H.-W.,Beijing Forestry University |
Li W.,Beijing Forestry University |
And 3 more authors.
Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University | Year: 2014
Shanxi Province is both the central distribution area of Pinus tabuliformis and the major seed sources for surrounding provinces. In this paper, genetic variations of growth traits in 21-year-old progeny tests of 23 natural stands mainly from Shanxi provenance of P. tabuliformis were investigated. The results showed that variations in growth traits among progeny tests of 23 natural stands were highly significant. Natural distribution of P. tabuliformis in Shanxi Province exhibited a feature of geographic regionalization and mountainous regionalization. Similar performance in growth traits of stand progenies within the same mountain region, but highly different among mountain regions were observed. In order of descending of progeny growth of 23 stands in different geographic regions, it went as middle region, south region and north region. While in different mountain regions, it went as Guandi Mountain region, Taiyue Mountain region, Zhongtiao Mountain region, Lüliang Mountain region, Taihang Mountain region and Guancen Mountain region, which were different from the stand growth determination in situ. Growth of progenies in 6 selected elite stands was much higher than stand progeny in testing region. Conserving elite natural stands, developing seed stands for improvement would be facilitated for afforestation of P. tabuliformis in testing regions.