喀斯特区石漠化治理对土壤水分-物理性状的影响--以黔中杠寨小流域为例

【目的】为了更科学系统地评价喀斯特区石漠化综合治理的土壤效应,揭示小流域石漠化综合治理土壤水分-物理性状的演变趋势,为喀斯特地区生态恢复以及石漠化综合治理提供理论基础和技术支持。【方法】以黔中喀斯特区杠寨小流域为例,于2009年、2012年和2018年分别对不同石漠化程度下各工程治理措施、植被类型以及不同土层深度土壤的水分-物理性状进行了长期、持续的动态监测。【结果】不同石漠化程度,土壤水分-物理性状以非石漠化的最佳,潜在石漠化的次之,中度和重度石漠化的居中,轻度石漠化的最差,且非石漠化与轻度石漠化间差异显著;随着石漠化治理年限的增加,流域内土壤容重的变化不明显,但土壤总孔隙度、持水量和渗滤率则均呈增加趋势,土壤质量总体得到了一定提升;土壤水分-物理性状随土层深度的加深基本上呈降低趋势;不同工程治理措施,荒山造林和封山育林土壤水分-物理性状的改善程度较大,而退耕还林的则恢复较慢;不同植被恢复模式,针叶林、针阔混交林和灌木林的土壤水分-物理性状其改善程度均要高于阔叶林和经果林。对区域土壤水分-物理性状的解释程度依次为土层深度(39.10%)>坡度(26.32%)>监测年限(18.05%)>石漠化程度(11.65%)>工程措施(3.20%)>植被类型(1.69%)。【结论】喀斯特区石漠化综合治理要防治结合,因地制宜,综合考虑各影响因素,采取适宜的工程治理措施,最终达到恢复生态的目的。

Effects on soil moisture-physical characteristics during rocky desertification comprehensive control in karst region: A case study of Gangzhai small watershed of central Guizhou province

【Objective】In order to scientific evaluate the soil effect of rocky desertification comprehensive control in karst region, and reveal the evolution trend of soil moisture-physical characteristics in small watershed, and provide theoretical basis and technical support for ecological restoration and comprehensive control of rocky desertification.【Method】Selected the Gangzhai small watershed of central Guizhou province as a sample area, conducted long-termand dynamicalmonitoring of soil moisture-physical characteristics of different vegetational types, different engineering measures under different degrees of rocky desertification in 2009, 2012 and 2018 respectively.【Result】For different degrees of rocky desertification,the soil moisture-physical characteristics were best under non-rocky desertification, followed by potential rocky desertification, medium and severe rocky desertification,and mild rocky desertification was worst, and between non-stony desertification and mild rocky desertification were significant. With the increase of monitor time,the change of soil bulk density was not obvious, while soil porosity, water holding capacity and permeability coefficient all showed an increase trend, and the soil quality was improved to a certain extent;The soil moisture-physical characteristics basically decreased with the deeper of the soil depth;With different engineering measures, the improvement of soil moisture-physical characteristics of barren mountain afforestation and closing the land for reforestation were greater, while returning farmland to forest wasslower;With different vegetation restoration models, the improvement degree of soil moisture-physical characteristics of coniferous forest, coniferous and broadleaved mixed forest and shrubbery were superior to broadleaved forest and economic fruit forest.The results of redundancy analysis showed that the interpretation degree of regional soil moisture-physical characteristics was successively as follows: soil depth(39.10%) > gradient(26.32%) > monitoring time(18.05%) > rocky desertification degree(11.65%) > engineering measures(3.20%) >vegetation types(1.69%).【Conclusion】The comprehensive control of rocky desertification in karst region should combine prevention and control, adjust measures to local condition, consider all the influencing factors, and take appropriate engineering treatment measures to achieve the goal of ecological restoration.