黑龙滩水库消落带植被恢复模式对土壤水稳性团聚体组成及其稳定性的影响

Effects of Vegetation Restoration Patterns on Soil Water-stable Aggregates Composition and Their Stability in the Water Level Fluctuation Zone of the Heilongtan Reservoir

[目的]为阐明水库消落带不同植被恢复模式对土壤水稳性团聚体组成及其稳定性的影响。[方法]以川中丘陵区黑龙滩水库消落带人工恢复与自然恢复植被下的土壤为研究对象,利用湿筛法测定分析土壤水稳性团聚体组成特征及其稳定性指标。[结果]消落带土壤>0.25 mm水稳性大团聚体含量与未淹水对照相比降低4.21%,其中,自然恢复植被下土壤水稳性大团聚体含量较对照下降12.27%,人工恢复植被下大团聚体含量较对照增加3.84%;不同植被恢复模式下土壤水稳性团聚体组成差异显著(p<0.05),人工恢复植被下土壤大团聚体含量(69.48%)显著高于自然恢复模式(43.20%);消落带土壤水稳性团聚体稳定性随水位高程增加而升高,团聚体稳定性指标>0.25 mm水稳性团聚体含量(R_(0.25))、平均重量直径(MWD)、几何平均直径(GMD)人工恢复模式下均大于自然恢复模式,团聚体分形维数(D)、土壤可蚀性因子(K)与团聚体破坏率(PAD)人工恢复模式小于自然恢复模式,表明人工恢复模式下土壤水稳性团聚体稳定性、土壤抗蚀性高于自然恢复模式。[结论]黑龙滩水库消落带在淹水后土壤团聚体稳定性下降,但人工恢复模式能有效改善土壤团粒结构,研究结果可为黑龙滩水库消落带土壤结构稳定性评价及植被恢复提供科学依据。

[Objective]This study aimed at elucidating the effects of different vegetation restoration modes on soil water-stable aggregates and stability in the water level fluctuation zone(WLFZ).[Methods]The characteristics of soil water-stable aggregates and their stability indexes were determined and analyzed by the wet sieve method on the soil under artificially and naturally restored vegetation in the WLFZ in the hilly region of central Sichuan Basin.[Results]The content of>0.25 mm water-stable macroaggregates in WLFZ soils was 4.21%lower compared to unflooded area.The soil water stability macroaggregates content decreased by 12.27%under naturally restored vegetation and increased by 3.84%under artificially restored vegetation compared to unflooded area;With the rise of water elevations,the soil water stability macroaggregates content showed an increasing trend,the microaggregates content showed an overall decreasing trend,and the soil aggregate stability gradually increased with the rise of water elevations;The soil water-stable aggregates composition differed significantly(p<0.05)among the different restoration modes,and the soil water-stable aggregates particle size increased overall under the artificially restored vegetation,in which the content of soil water-stable macroaggregates under the artificially restored vegetation(69.48%)was significantly higher than that of the natural restoration mode(43.20%);With increasing flooding time,there was a decrease in soil in soil water-stable aggregates stability in the WLFZ,the values of R _(0.25),MWD,and GMD in the artificial recovery mode were greater than those in the natural recovery mode.and the values of D,K,and PAD were smaller than those in the natural recovery mode.Soil water-stable aggregates stability and soil erosion resistance were higher in the artificial restoration model than in the natural restoration model.[Conclusion]The soil aggregate stability of WLFZ decreased after inundation,but the artificial restoration mode could effectively improve the soil aggregate structure,and the results of the study can provide a scientific basis for the evaluation of soil structure stability and vegetation restoration of the WLFZ.