caa a22 4500 38638102X CHVBK 20180307112041.0 cr unu---uuuuu 161130e198902 xx s 000 0 eng 10.1017/S0266467400003254 doi S0266467400003254 pii (NATIONALLICENCE)cambridge-10.1017/S0266467400003254 Georgiadis Nicholas J. Biological Research Laboratories, 130 College Place, Syracuse, NY 13244 USA Microhabitat variation in an African savanna: effects of woody cover and herbivores in Kenya [Elektronische Daten] [Nicholas J. Georgiadis] Effects of extreme livestock pressure on the abundance and distribution of a drought-deciduous shrub Sericocomopsis pallida, and effects of the shrub canopy on microclimate, soil fertility and grass production, were studied in savanna grasslands of southern Kenya. Canopy volume declined with increasing herbivore pressure, but shrub density was not systematically affected, suggesting strong resilience against destruction by herbivores. However, shrubs became more aggregated with increasing herbivory, suggesting that clumps of individuals are more resilient to destruction than are isolated individuals. Grass production was three times greater under the canopy of S. pallida than in the open. Comparisons of physical-chemical properties among soils derived from four microsites revealed far higher nutrient levels in sub-canopy soil than in soil derived from open ground between canopies, and radically different properties compared to soil heavily enriched with livestock dung and urine. Higher nutrient levels beneath the canopy most likely resulted from Utter decomposition. A pot experiment, designed to simulate shading and soil conditions in the field, showed that grass growth promotion was largely due to a substantial increase in soil fertility beneath the canopy of S. pallida, comparable to grass productivity in soil enriched with livestock excreta. However, this increase in sub-canopy grass production did not significantly increase regional grass layer production. Copyright © Cambridge University Press 1989 Africa nationallicence grass production nationallicence herbivory nationallicence Kenya nationallicence savanna nationallicence shade nationallicence soil nationallicence trees nationallicence Journal of Tropical Ecology Cambridge University Press 5/1(1989-02), 93-108 0266-4674 5:1<93 1989 5 TRO https://doi.org/10.1017/S0266467400003254 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0266467400003254 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Georgiadis Nicholas J. Biological Research Laboratories, 130 College Place, Syracuse, NY 13244 USA NATIONALLICENCE 773 0- Journal of Tropical Ecology Cambridge University Press 5/1(1989-02), 93-108 0266-4674 5:1<93 1989 5 TRO CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge