Research Interests
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System equilibrium theory; Regime shift; Early warning signal; Ecohydrology; Dryland restoration; Biocrust
Alternative stable states, regime shift, and early warning signals
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During a specific range of drivers, an ecosystem may co-exist in two or more alternative stable states that display contrasting characterics. When driver is approaching a critical point or the ecosystem is disturbed dramatically, one ecosystem may abruptly from one stable state to another state, a process called regime shift (or phase transition). In the period, some statistics may serve as early warning signals to indicate the approaching of the critical point.
I mainly investigate this issue in dryland ecosystems, using a combination of field experimental, long-term observational, and modelling approaches. Generally, we confine target ecosystems to the types where life history of dominant species is short such as grasslands. Recently, I become more and more interested in dryland forest alternative stable states, specifically in Loess Plateau where forests may potentially widely spread. There are several fundings supporting my works on this topic.
Ecohydrological effects of biological soil crust
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Biological soil crust (biocrust) is one very important component of drylands, and plays a significant role in affecting ecosystem function and services, such as stabilizing land surface, regulating water and nutrient cycles. Particularly, I am interested in the ecohydrological effects of biocrust. I mainly focus on 1) how biocrust influences the soil hydrological processes (land surface runoff, rainfall infiltration and evaporation), and thereby impact on vascular plant dynamics and restoration; 2) how global climate change acts on both vascular plants and biocrust; 3) the role of different biocrust types on ecohydrological processes. In general, process-based models are employeed. I developed a new ecohydrological model to explicitly involve biocrust as a system state variable rather than just a influencing environmental factor. In future, I plan to take the direct interaction between vascular plants and biocrust into account to explore the distribution pattern of both vascular plants and biocrust in global scale.
