岩溶山区和石漠化区表土孢粉组合的差异性--以重庆市南川区为例

通过对重庆市南川区岩溶山区和石漠化区14个不同植被类型的表土调查和采样,以研究该区表土孢粉组合特征的差异性。结果显示:(1)岩溶山区的表土孢粉组合中以乔木花粉为优势,含量为34.38%-63.39%,其次是草本和蕨类植物的孢粉,含量为32.04%-58.18%,灌木花粉含量最小,为6.08%-29.77%,沼生草本也有少量,仅为0.14%,这与当地的现代植被基本相同;(2) 石漠化地区的表土孢粉组合以草本和蕨类植物孢粉占优势,含量为46.40%-76.47%,其次是乔木花粉(主要为马尾松),含量为17.73%-46.84%,灌木花粉含量最小,为5.79%-12.50%,说明其植被退化严重;(3)石漠化区的表土孢粉组合中有很多喜钙性、旱生性、石生性植物,对生态恢复和重建有很好的指示意义,为该区恢复和重建自然生态环境提供参考性依据。

Differences in the surface palynomorph assemblages on a karst mountain and rocky desertification areas: a case in Nanchuan District,Chongqing

Karst rocky desertification is a fragile environment because of extreme human activities which have led to destruction of vegetation, soil erosion and decline of land productivity. To curb desertification, there have been many treatments proposed, with fruitful results. Most of these studies have focussed on hydrology, ecology and soils. There has been little use of palynology. In the present study, the authors investigated Nanping Town, of Nanchuan District of Chongqing City, a representative karst area in the Mt. Jinfo with two kinds of good ecological protection and erious desertification area by sampling 14 different types of surface vegetation in order to study the palynomorph assemblages's differences and features. The results show:(1) In the palynomorph assemblage of karst mountain, the trees dominate with the content to 34.38%-63.39%, herbs and ferns takes the 2nd place with the content about 32.04%-58.18%,and the shrub pollen about 6.08%-29.77%,Marsh herbs also to have few, is only 0.14%, which is the local basically the same as the modern vegetation; (2) In the palynomorph assemblage of rocky desertification areas, herbs and ferns dominate with the content to 46.40%-76.47%,the trees (mainly Pinus massoniana) takes the 2nd place with the content about 17.73%-46.84%,and the shrub pollen the least,about 5.79%-12.50%,that indicating a serious degradation of local vegetation; (3) Pollen of many calcicole, drought-tolerant, stone endogenous species is present in the karst rocky desertification, suggesting good potential for ecological restoration.