TY  - JOUR
A1  - Marquart, Arnim
A1  - Eldridge, David J.
A1  - Geissler, Katja
A1  - Lobas, Christoph
A1  - Blaum, Niels
T1  - Interconnected effects of shrubs, invertebrate-derived macropores and soil texture on water infiltration in a semi-arid savanna rangeland
JF  - Land degradation & development
N2  - Many semi arid savannas are prone to degradation, caused for example, by overgrazing or extreme climatic events, which often lead to shrub encroachment. Overgrazing by livestock affects vegetation and infiltration processes by directly altering plant composition (selective grazing) or by impacting soil physical properties (trampling). Water infiltration is controlled by several parameters, such as macropores (created by soil-burrowing animals or plant roots) and soil texture, but their effects have mostly been studied in isolation. Here we report on a study, in which we conducted infiltration experiments to analyze the interconnected effects of invertebrate-created macropores, shrubs and soil texture (sandy soil and loamy sand) on infiltration in two Namibian rangelands. Using structural equation modeling, we found a direct positive effect of shrub size on infiltration and indirectly via invertebrate macropores on both soil types. On loamy sands this effect was even stronger, but additionally, invertebrate-created macropores became relevant as a direct driver of infiltration. Our results provide new insights into the effects of vegetation and invertebrates on infiltration under different soil textures. Pastoralists should use management strategies that maintain a heterogeneous plant community that supports soil fauna to sustain healthy soil water dynamics, particularly on soils with higher loam content. Understanding the fundamental functioning of soil water dynamics in drylands is critical because these ecosystems are water-limited and support the livelihoods of many cultures worldwide.
KW  - hydrology
KW  - infiltration
KW  - invertebrate macropores
KW  - shrub-encroachment
KW  - soil function
KW  - soil texture
Y1  - 2020
U6  - https://doi.org/10.1002/ldr.3598
SN  - 1085-3278
SN  - 1099-145X
VL  - 31
IS  - 16
SP  - 2307
EP  - 2318
PB  - Wiley
CY  - Chichester, Sussex
ER  -