CAJ | 학술논문

为了探讨农地撂荒对土壤水分生态的影响，该文以湘中紫色丘陵区自然撂荒旱地为研究对象，以相邻样地比较法研究了不同演替阶段土壤物理特性、蓄水性能及其影响。结果表明：湘中紫色丘陵区旱地撂荒植被自然恢复，各演替阶段表层土壤（0～20 cm）容重显著变化（P<0.05），大小依次顺序为：旱地>草本群落>乔灌群落>灌丛群落，说明植被恢复导致表层土壤容重变小；灌丛和乔灌群落具有使土壤由粗粒径向细粒径转变的效能，此外，植被恢复能提高表层土壤孔隙度和蓄水性能。相关分析表明，旱地撂荒植被自然恢复土壤蓄水性能主要决定于土壤容重、孔隙度、粗砂粒（<1～0.25 mm）和粉粘粒（<0.05 mm）含量等指标；土壤粗砂粒含量高，容重大，非毛管孔隙度减小，蓄水量低；粉粘粒含量增加，土壤容重小，非毛管孔隙度增大，蓄水量高。该研究可为紫色丘陵区植被恢复及生态环境建设提供参考。
위료탐토농지략황대토양수분생태적영향，해문이상중자색구릉구자연략황한지위연구대상，이상린양지비교법연구료불동연체계단토양물리특성、축수성능급기영향。결과표명：상중자색구릉구한지략황식피자연회복，각연체계단표층토양（0～20 cm）용중현저변화（P<0.05），대소의차순서위：한지>초본군락>교관군락>관총군락，설명식피회복도치표층토양용중변소；관총화교관군락구유사토양유조립경향세립경전변적효능，차외，식피회복능제고표층토양공극도화축수성능。상관분석표명，한지략황식피자연회복토양축수성능주요결정우토양용중、공극도、조사립（<1～0.25 mm）화분점립（<0.05 mm）함량등지표；토양조사립함량고，용중대，비모관공극도감소，축수량저；분점립함량증가，토양용중소，비모관공극도증대，축수량고。해연구가위자색구릉구식피회복급생태배경건설제공삼고。
The restoration of vegetation in the abandoned land requires support of water resources, but as drought events occur frequently in Southern China, especially significant in purple hilly region of central Hunan the restoration is often difficult. As a result, the vegetation is rare in purple hilly region and the eco-environment is very fragile, and soil degradation and erosion are very severely. Since 1990s, more and more dry-land in the hilly region was abandoned by the farmers because of the enlarging gap between the prices of farm products and manufactured products. After dry-land was abandoned, the pioneer plants inhabit first and vegetation succession begin, which affect soil characteristics, microbiology and microclimate. Conversely, the soils in the region also affect the type, distribution and dynamic change of vegetation through providing water and mineral nutrients. Earlier studies reveal that vegetation restoration improves soil structure, increase proportion of soil porosity, and soil water storage capacity for vegetation succession. Vegetation restoration is one of the primary measures to improve eco-environment of the purple hilly region. Our objective was to determine the impact of natural vegetation restoration in abandoned dry-land and the impact of succession stages on soil physical properties and soil water characteristics . In this paper, four natural lands with various succession stages on abandoned dry land from the purple hilly region were selected to study soil water storage capacity and related soil physical properties by using “adjacent plot comparing method”. The results showed that: no obvious changes occurred in subsoil (20-40 cm) bulk density among different succession stages (P>0.05). However, there was notable changes in surface soil layer (0-20 cm), the order of the average values was as follows: dryland > herbosa > arbor-shrub community>shrub community, and the value of soil bulk density was 1.38 g/cm3、1.3 g/cm3、1.24 g/cm3 and 1.19 g/cm3, respectively, indicating that vegetation restoration incurred lower bulk density of surface soil. The results also showed that the quality distribution of soil particle varied obviously (P<0.05). The content of gravel (1-2 mm) and coarse sand (0.25-1 mm) in herbosa was higher comparing with dry land. The content of gravel and coarse sand decreased and that of silty clay (<0.05 mm) and fine sand (0.05-0.25 mm) increased in stage of arbor-shrub and shrub community. In the same soil layer for different succession stages, there was higher proportion (P<0.05) of finer soil particle content in arbor-shrub and shrub community, however, soil particle content in vertical structure of profile varied obviously in succession middle stage and it was uniform in arbor-shrub stage. In addition, the results showed that the soil capillary porosity of surface soil in herbosa stage was significantly lower (P<0.05) than the other types of vegetation, indicating vegetation succession on abandoned dry land can increase soil capillary porosity. Non-capillary porosity varied indistinctively in different succession stages. All soil total porosity of surface soil was higher than subsoil at different succession stages and there was significant level (P<0.05) in herbosa stage, showing that vegetation succession affected soil total porosity. Moreover, the results showed that soil water-storage capacity had the same changing pattern with soil porosity in different succession stages. Soil capillary and total water-storage capacity of topsoil with various succession stages increased (P<0.05), which showed that vegetation restoration might raise soil water storage capacity. Last, correlation analysis of various soil physical properties indicated that soil water storage capacity mainly determined by soil bulk density, porosity, coarse sand (0.25-1 mm) and silt and clay (<0.05 mm) content. We concluded that vegetation succession stages altered soil surface physical properties greater than the subsurface soil. The decrease in bulk density and increase in porosity helped to improve soil water holding capacity and hence improved the environment for vegetation establishment.