Individual shrubs, large scale grass cover and seasonal rainfall explain invertebrate-derived macropore density in a semi-arid Namibian savanna
| Autor: | Jessica Heblack, Arnim Marquart, Elise Münch, Niels Blaum, Christoph Lobas, Katja Geissler |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
Soil health Hydrology 010504 meteorology & atmospheric sciences Ecology Macropore Perennial plant Tussock ved/biology ved/biology.organism_classification_rank.species 010603 evolutionary biology 01 natural sciences Arid Shrub Infiltration (hydrology) Environmental science Ecosystem Ecology Evolution Behavior and Systematics 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Journal of Arid Environments. 176:104101 |
| ISSN: | 0140-1963 |
| Popis: | Macropores created by invertebrates improve ecosystem functions such as soil properties and hydrological processes. In semi-arid savannas, where water is the main limiting resource and precipitation is scarce macropores might increase infiltration, and thereby improve water availability for plants. Macropores may therefore represent a buffering mechanism counteracting degradation in the form of shrub-encroachment. We investigated the interacting effects of vegetation structures at small scales and vegetation cover at landscape scales, and seasonality on invertebrate macropores. First, macropore density and size distribution was measured at open soil, in direct proximity to perennial grass tussocks and shrubs, at grass dominated, intermediate and shrub dominated sites. Secondly, we recorded macropores on randomly chosen plots along a shrub cover gradient at three points in time within the rainy season. Individual shrubs and the amount of large scale grass cover increased macropore densities. Interestingly, macropore numbers were highest at the beginning of the rainy season. We argue that macropore densities reflect the activity and influence of soil macrofauna on ecosystem functioning, which is greatest at highly heterogeneous vegetation. Rangeland management should aim for high grass cover with scattered shrubs for sustainable soil health, by applying appropriate stocking rates, selectively removing shrubs or reseeding perennial grasses. |
| Databáze: | OpenAIRE |
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