岩质公路边坡生态恢复土壤特性与植物多样性

Soil-property and plant diversity of highway rocky slopes

以深圳市盐田港高速公路岩质边坡上历经10a的植被恢复边坡为研究对象,在厚层基材喷附、客土喷附、自然复绿3种边坡生态恢复方式下,重点分析和研究了土壤理化性质与酶活性、植物多样性、土壤特性与植物多样性之间的相关性。结果表明:3种生态恢复方式下,1)土壤含水量、养分与酶活性均呈现出厚层基材喷附边坡>客土喷附边坡>自然复绿边坡的分布差异;2)3种生态恢复方式的植物群落指数均偏低,群落演替仍处于灌草植物群落阶段;3)土壤特性同植物多样性之间存在明显的相关关系,即土壤速效氮与均匀度指数存极显著的正相关,与木本层多样性指数存显著的正相关;土壤全磷与均匀度指数存显著的负相关;土壤有效磷与丰富度指数、多样性指数及均匀度指数都存极显著的负相关;土壤全钾与丰富度指数存极显著的负相关,与草本层多样性指数存显著的负相关;土壤速效钾与均匀度指数存极显著的负相关;土壤蔗糖酶活性与草本均匀度指数存显著的负相关。该调查研究有助于对岩质边坡这类特殊生境下植被恢复基础生态资料的积累,其结果可为边坡生态恢复工程技术方法的开发、设计、施工,调控植被演替速度和预期植被恢复绩效等提供依据。

Soil is one of the main environmental factors which affects plant community composition and diversity in space and time.Especially during the restoration of rocky slopes,the properties of artificial soil play key roles in determining the generation and development of vegetation.Meanwhile,it is an important factor to assess the performance of slope eco-engineering.In order to evaluate the soil properties and recover vegetation features,field survey was carried out in Yantian Port of Shenzhen City in China,in which highway slopes have been ecologically restored using varied methods since 2002.This area locates in the sub-tropical maritime monsoon climate zone,Where annual rainfall is 948.8 mm and mean annual temperature is 22.4℃.The highway rocky slopes investigated are granite cut slopes and with slope ratio about 1 ∶0.75.Three approaches were applied in the slope vegetation recovery,i.e.,thick layer base material spraying method,external-soil spray seeding method and natural restoration,among which the artificial soils were about 10cm thick.Over ten years recovering,the plant communities of all rocky slopes investigated here are composed of woody,shrub and herb layers. In the present studies,the physic-chemical and enzymatic activity of soil as well as plant diversity were investigated on different restoration patterns.Furthermore,the relationship between soil property and plant diversity was also analyzed.The results were shown as follows：（1）The enzymatic activities,contents of water and nutrient in the soil from thick layer base material sprayed slopes were the highest,while those from natural restoration slopes the lowest among three restoration patterns.（2）There were 6 plant species of 5 genus of 5 families in the natural restoration slope,7 species of 7 genus of 6 families in the external-soil spray seeding slope,11 species of 11 genus of 7 families in the thick layer base material spraying slope,and 14 species of 13 genus of 12 families in the natural slope.The plant diversity indices evaluated by species richness（R）,the Shannon-Wiener index（H） and Pielou evenness（E） were lower than those of natural slopes,although R and H of thick layer base material sprayed slopes were much higher than those of other two kinds of slopes.This result suggested that those plant communities recovered were still in the early succession stages—herb/shrub stage.（3）According to the correlation analysis,plant diversity was significantly correlated with the soil properties,i.e.,soil available N had significantly positive correlation with E and with H of woody layer;soil available P was highly significantly negative correlated with all plant diversity measures,while soil total P significantly negative to E;soil total K was significantly negative correlated with R and with H of herb layer,while soil available K highly significantly negative to E.（4）The soil enzymatic activities of urease and sucrase decreased with the order of thick layer base material sprayed,external-soil spray seeded,natural and natural restoration slopes.And activity of soil sucrase showed significant negative correlation with the evenness of herbs. Based on above mentioned results,it indicated that the thick layer base material spraying approach is more suitable for the restoration of rocky slope.