三峡库区紫色土植被恢复过程的土壤团粒组成及分形特征
作者:
作者单位:

重庆市林业科学研究院 重庆市三峡库区森林生态保护与恢复市级重点实验室,重庆市林业科学研究院 重庆市三峡库区森林生态保护与恢复市级重点实验室,重庆市林业科学研究院 重庆市三峡库区森林生态保护与恢复市级重点实验室

作者简介:

通讯作者:

中图分类号:

基金项目:

国家林业公益性行业科研专项(201004039);重庆市科委基本科研业务费专项(BS1002)联合资助


Composition and fractal features of purple soil aggregates during the vegetation restoration processes in the Three Gorges Reservoir Region
Author:
Affiliation:

Forestry Academy of Chongqing; Chongqing Key Laboratory of Forest Ecology, Protection and Restoration in Three Gorges Reservoir Region,,

Fund Project:

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 文章评论
    摘要:

    采用空间代替时间方法,研究了三峡库区紫色土植被恢复过程的土壤团粒结构特征。结果表明:与撂荒地相比,柏木新造林、幼龄林和中龄林表层土壤的5-2 mm干筛团聚体分别增加6.03%、10.32%和10.97%,而<0.25 mm干筛团聚体明显减少;各层土壤的≥0.25 mm水稳性团聚体均随植被恢复进程而明显增加,但其分形维数明显减小;紫色土水稳性团聚体的平均质量直径和几何平均直径均与≥5 mm团聚体呈极显著(P<0.01)正相关,与<0.25 mm团聚体呈极显著负相关,相反地,分形维数与<0.25 mm团聚体呈极显著正相关。研究表明三峡库区植被恢复能有效改善紫色土土壤团粒结构,且随植被恢复年限增加而增强,但是,对郁闭度过大的柏木中龄人工林,应适当抚育间伐。

    Abstract:

    The quantity and quality of soil aggregates are important parameters of soil physical properties and plays an important role for sustaining soil porosity, improving soil infiltration, preventing soil erosion and so on. The Three Gorges Reservoir Region is regarded as an important region to secure the ecological safety of the mid-upper reaches of Yangtze River of China. Thus, big attention has been always paid to prevent the soil and water losses in this region, and many projects of vegetation restoration were carried out. Purple soil is the important soil resource easy to be eroded in this region. This study tries to understand and assess the changes of purple soil structure in different phases of vegetation restoration. Cupressus funebris is one of the most important tree species used for forestation and widely distributes in the low mountain and hill areas of this region. Using the method of taking space instead of time, the structure characteristics of purple soil aggregate during the vegetation restoration processes were investigated. Results showed that the dry-sieved soil aggregates in all soil layers at different restoration phases were mainly composed of particles with size ≥2 mm. Their ratio to the total was above 80%, but the proportion of particles with size of 0.5-0.25 mm was the least. Compared with abandoned land, the quantity of dry-sieved soil aggregates (5-2 mm) in surface soil layer for new forest land, sapling forest and mid-mature forest of Cupressus funebris was increased by 6.03%, 10.32% and 10.97% respectively, but the dry-sieved soil aggregates of <0.25 mm was decreased obviously. The water stable soil aggregates at different restoration phases were mainly composed of particles with sizes <0.25 mm and 3-1 mm. The quantity of water stable soil aggregates of ≥0.25 mm obviously increased with the vegetation restoration processes in all soil layers, but decreased with increasing soil depth. Their fractal dimension (D) decreased significantly with the vegetation restoration processes. Mean weight diameter (MWD) and geometric mean diameter (GMD) of dry-sieved aggregates were positively related with the bigger size particles (≥3 mm) and negatively related with the smaller size particles (<3 mm), but they all had a significant relation with ≥10 mm and 2-1 mm. The D was influenced significantly by the amount of particles with size <1 mm, especially the particles <0.5 mm (P<0.01). The MWD and the GMD of water stable aggregates presented a significantly positive relation (P<0.01) with the amount of particles with size ≥5 mm and negative relation (P<0.01) with particles <0.25 mm, inversely, the D presented a significantly positive relation (P<0.01) with particles <0.25 mm. Whether the dry-sieved or the water stable soil aggregates, their relation between D and soil particle sizes reflected that the increase of small aggregates would improve soil fractal dimension, but weaken the structure stability of aggregates; and the increase of big aggregates could decrease the soil fractal dimension, but strengthen the structure stability of aggregates. Thus, the purple soil aggregates structure can be effectively improved after vegetation restoration in this region studied, and the improvement increases with the vegetation restoration time. However, the mid-mature artificial forest of Cupressus funebris with higher canopy density shall be thinned properly.

    参考文献
    相似文献
    引证文献
引用本文

王轶浩,耿养会,黄仲华.三峡库区紫色土植被恢复过程的土壤团粒组成及分形特征.生态学报,2013,33(18):5493~5499

复制
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数: