干旱区地理2024，Vol.47Issue(12)：2030-2040,11.DOI:10.12118/j.issn.1000-6060.2024.154
咸水灌溉对凋落物分解及土壤有机碳矿化的影响
Effects of saline water irrigation on litter decomposition and soil organic carbon mineralization
摘要
Abstract
Plant litter plays a pivotal role in the material and energy cycles of terrestrial ecosystems,serving as a primary source of plant-derived soil carbon,which is fundamental to the carbon cycle.The decomposition of lit-ter releases CO2 into the atmosphere,provides nutrients and energy essential for subterranean ecosystems,and sig-nificantly contributes to the maintenance of geochemical element cycling.In arid zone ecosystems,moisture serves as a crucial limiting factor,influencing both the abundance and activity of soil microorganisms and the geo-chemical processes within subsurface ecosystems.In the Taklimakan Desert Botanical Garden,plants are primari-ly irrigated with saline groundwater to support their growth and development,which in turn affects litter decom-position and the transformation of soil organic carbon.Although research on the effects of saline water irrigation on soil physicochemical properties in desert ecosystems has expanded,studies examining soil organic carbon min-eralization and litter decomposition under saline water conditions remain limited.To address this gap,two indoor incubation experiments were conducted to investigate the decomposition characteristics of Populus euphratica and Pyrus betulifolia litter and the rate of soil organic carbon mineralization under the influence of saline water with varying salt concentrations(0,7.5 g·L-1,15.0 g·L-1,22.5 g·L-1,and 30.0 g·L-1).The key findings are as fol-lows:(1)Saline water at different salt concentrations altered soil physicochemical properties.Soil conductivity in-creased with rising salt concentrations,while pH remained relatively stable.The decomposition rate of litter was influenced by saline water concentration,with the litter mass residual rate of both plant species showing a decreas-ing trend over time.The litter mass residual rate of P.betulifoliaincreased with higher saline water concentrations,whereas the decomposition of P.euphraticawas faster than that of P.betulifolia.(2)The highest soil organic carbon mineralization rate was observed in the freshwater group with P.betulifolia addition,reaching 201.3 mg·kg-1·d-1.This rate decreased with increasing saline water concentration.(3)The addition of litter enhanced soil organic car-bon content.After 180 days,the soil organic carbon content was significantly higher with 15.0 g·L-1 saline water addition compared to other concentrations.Saline water irrigation inhibited litter decomposition and soil organic carbon mineralization,although moderate saline water concentration(15.0 g·L-1)promoted soil organic carbon accumulation.In conclusion,saline water impacts litter decomposition and the accumulation and mineralization of soil organic carbon by altering soil physicochemical properties.These findings provide insights into the ecolog-ical value of planted protective forests in the Taklimakan Desert Botanical Garden and along desert highways,and they contribute to future research on carbon sequestration potential in arid zone ecosystems.关键词
凋落物分解/咸水灌溉/土壤有机碳/矿化速率Key words
litter decomposition/saline water irrigation/soil organic carbon/mineralization rate引用本文复制引用
韩欢,袁萍,李从娟,赵红梅..咸水灌溉对凋落物分解及土壤有机碳矿化的影响[J].干旱区地理,2024,47(12):2030-2040,11.基金项目
新疆维吾尔自治区杰出青年基金(2022D01E97) （2022D01E97）
国家自然科学基金(32360300)资助 （32360300）
