生态修复模式对淮南矿区重构土壤CO2通量日变化的影响

目的]探讨淮南矿区不同生态修复模式(植被类型和覆土厚度)对土壤CO_2通量的影响,以期为该区域以及相似矿区的生态修复提供理论依据及参数。方法]采用静态箱—碱液吸收法对淮南市采煤沉陷生态修复区土壤CO_2通量进行动态测定,分析土壤CO_2通量日变化特征,以及土壤呼吸速率对地表温度、地下5cm土壤温度和土壤含水量的敏感性。结果]不同生态修复模式下土壤CO_2通量日变化格局均表现为单峰曲线,最高峰出现在14∶00,最低值出现在6∶00,其均值大小依次为:B区(灌木林)C区(灌木林)D区(乔木林)A区(草地),且B,C与A区差异显著(p0.05),其他区之间差异不显著(p0.05)。不同覆土厚度下土壤表层CO_2通量平均值的大小依次为:40—80cm0—20cm20—40cm80—100cm。其最大值和变幅的大小顺序也遵循平均值大小顺序。4种修复模式下土壤CO_2通量与地下5cm土壤温度、地表温度均呈指数方程关系,R2值分别在0.34~0.70,0.48~0.83之间,与土壤含水量呈二次方函数关系,R2值在0.08~0.44之间。结论]不同植被类型条件下,土壤CO_2通量大小表现为:灌木林乔木林草地;不同覆土厚度条件下,除了覆土40—80cm的样地外,土壤CO_2通量随覆土厚度的增加而减少。植被类型对土壤CO_2通量的影响较覆土厚度显著。

Effects of Ecological Restoration Patterns on Diurnal Variation of CO2 Flux fromRehabilitated Soil of Coal Mining Areas in Huainan City

Objective] To explore the effects of ecological restoration patterns in coal ming areas of Huainan City,including rehabilitation thickness of soil and reestablished vegetation type on soil CO2 flux,and to provide theoretical basis for ecological restoration patterns similar coal mining region.Methods] Method of close static chamber-alkali absorption was used to measure the diurnal variation of reconstructing soil CO2 flux.Meanwhile,temperatures of soil surface and 5 cm depth and soil water content were measured and their influences on soil CO2 flux were analyzed in different ecological remediation patterns for coal mining district in Huainan City,Anhui Province.Results] Diurnal variation of soil CO2 flux exhibited an obvious unimodal pattern during the whole observation period,with peak value at 14:00 and minimum flux at 6:00 for all of the ecological restoration models.The flux ranked at different revegetation districts as:B(brushwood)＞C (brushwood)＞D(arboreal forest)＞A(grassland).Soil CO2 flux of B and C districts were significantly higher than that of A(p＜0.05);no significant differences among others were observed(p＞0.05).Soil CO2 flux with different rehabilitation thickness ranked as:40-80 cm＞0-20 cm＞20-40 cm＞80-100 cm,and their maximum and amplitude also followed this order.Significant relationships were found between soil temperature in 0 and 5 cm depth and soil CO2 flux,which could be described by exponential equation.R2 ranged from 0.34 to 0.70 and from 0.48 to 0.83,respectively.Relationship between soil CO2 flux and soil water content can be described by quadratic equation,with 0.08～0.44 R2 value.Conclusion] Soil CO2 flux differed under different vegetation types,the highest occurred in brushwood5.22 μmol/(m2 · s)],followed by arboreal forest4.56 μmol/(m2 · s)],the lowest was grassland3.89 μmol/(m2 · s)].Except for 40-80 cm thick ness,soil CO2 flux decreased with the increase of soil rehabilitation thickness.The influence of vegetation on soil CO2 flux was more significant than the one of soil rehabilitation thickness.