干旱区生态环境知识资源中心

In arid and semi-arid climates, the physical and chemical nature of the soil seedbed greatly effects success or failure of plant recruitment. We hypothesized that the presence or absence of microphytic soil crusts may influence the character of soil seedbeds. To test this hypothesis, we compared chemical and physical attributes of the soil seedbed (0-6 cm) between adjacent areas of well-expressed microphytic soil crusts and non-microphytic soil surfaces for 2 sites on granitic alluvial fans in northwestern Nevada. As compared with non-microphytic areas, microphytic soil seedbeds were finer-textured and contained more DTPA-extractable Mn, Cu, and Zn, Further research should examine in greater detail the role of microphytic soil surfaces in eolian dust entrapment, its relationship to nutrient deposition, and the interaction with seed recruitment.