High rainfall frequency promotes the dominance of biocrust under low annual rainfall
High rainfall frequency promotes the dominance of biocrust under low annual rainfall
复制标题
高降雨频率促进了低年降雨量下生物结皮的主导地位。
DOI：
10.1007/s11104-018-3880-6
复制
发表时间：
2019-02-01
期刊：
影响因子：
4.9
通讯作者：
Zhao, Changming
中科院分区：
文献类型：
--
作者：
Jia, Rongliang;Chen, Ning;Zhao, Changming
目标全球气候变化可能极大地改变旱地的结构和稳定性，迫切需要恢复其功能和服务。生物土壤结皮是土壤与大气之间的界面，在生态水文过程中起着至关重要的作用，因而影响着旱地生态系统的恢复动态。以往的研究一般都是将生物壳作为一种外生因子来研究其对生态水文过程的影响。然而，目前还不清楚生物结壳作为许多生态系统的组成部分（即，MethodsThis study developed a new ecohydrologic model with biocrust cover as a system state variable，and explored the response of dryland ecosystem to altered rainfall regimens.ResultsBiocrust cover responded with inverted U-shaped curve relationship to increasing annual rainfall and linearly to increasing rainfall frequencies.维管植物（草、灌）覆盖度随年降雨量的增加而增加，随降雨频率的增加而减少。因此，生物锈菌通常占优势，超过维管植物（即，高生物壳覆盖和低维管植物覆盖）。此外，增加降雨频率将扩大由生物结壳主导的环境（降雨）条件的范围，从0-100 mm（降雨频率为0.025 day-1）到0-500 mm（降雨频率为1 day-1）。结论本研究开发了一个模型框架，用于预测全球气候变化下生物结壳覆盖的旱地动态。我们建议，恢复工作可以针对生物结壳为主的状态在沙漠中，特别是在（未来）干燥的气候。
AimsGlobal climate change may greatly alter the structure and stability of drylands, creating an urgent need to recover their functions and services. Biological soil crust (biocrust), an interface between the soil and atmosphere, plays a crucial role in ecohydrological processes, and thus in influencing the restoration dynamics of dryland ecosystems. Previous studies have generally investigated the influences of biocrust on ecohydrological processes as an exogenous factor. However, it remains unclear how biocrusts, as an integral part of many ecosystems (i.e., as a system state variable), will change under global climate change.MethodsThis study developed a new ecohydrological model with biocrust cover as a system state variable, and explored the response of dryland ecosystems to altered rainfall regimes.ResultsBiocrust cover responded with an inverted U-shaped curve relationship to increasing annual rainfall and linearly to increasing rainfall frequency. Vascular plant (grass and shrub) cover showed an increasing trend with increasing annual rainfall and a decreasing trend to increasing rainfall frequency. Therefore, biocrust usually dominated over vascular plants (i.e., high biocrust cover and low vascular plant cover) under low annual rainfall. Furthermore, an increasing rainfall frequency would amplify the range of environmental (rainfall) conditions dominated by biocrust from an annual rainfall 0–100 mm under a rainfall frequency of 0.025 day−1to 0–500 mm under a rainfall frequency of 1 day−1.ConclusionsThis study developed a model framework to predict dryland dynamics for surfaces covered by biocrust under global climate change. We suggest that restoration efforts could target at biocrust-dominated state in deserts, especially in a (future) drier climate.