02572nas a2200289   4500008004100000245011400041210006900155260000800224300001200232490000800244520178000252653002302032653001402055653001402069653001502083653001402098653001702112653001402129653001202143653001402155653001202169653000902181653001502190100002302205700002002228856003402248       2003                        eng d00aUngulate community structure and ecological processes: body size, hoof area and trampling in African savannas0 aUngulate community structure and ecological processes body size   cMar  a560-5680 v1343 aA wide range of bioenergetic, production, life history and ecological traits scale with body size in vertebrates. However, the consequences of differences in community body-size structure for ecological processes have not been explored. We studied the scaling relationships between body mass, shoulder height, hoof area, stride length and daily ranging distance in African ungulates ranging in size from the 5 kg dik-dik to the 5,000 kg African elephant, and the implications of these relationships on the area trampled by single and multi-species herbivore communities of differing structure. Hoof area, shoulder height and stride length were strongly correlated with body mass (Pearson's r >0.98, 0.95 and 0.90, respectively). Hoof area scaled linearly to body mass with a slope of unity, implying that the pressures exerted on the ground per unit area by a small antelope and an elephant are identical. Shoulder height and stride length scaled to body mass with similar slopes of 0.32 and 0.26, respectively; larger herbivores have relatively shorter legs and take relatively shorter steps than small herbivores, and so trample a greater area of ground per unit distance travelled. We compared several real and hypothetical single- and multi-species ungulate communities using exponents of between 0.1 and 0.5 for the body mass to daily ranging distance relationship and found that the estimated area trampled was greater in communities dominated by larger animals. The impacts of large herbivores are not limited to trampling. Questions about the ecological implications of community body-size structure for such variables as foraging and food intake, dung quality and deposition rates, methane production, and daily travelling distances remain clear research priorities.10aAfrican herbivores10aallometry10abody mass10aecosystems10aelephants10ainfiltration10alivestock10amammals10apressures10ascaling10asoil10avegetation1 aCumming, D., H. M.1 aCumming, G., S.  u<Go to ISI>://00018158270001403334nas a2200385   4500008004100000245008200041210006900123260000800192300001100200490000600211520233300217653001102550653002302561653002202584653002102606653001002627653001602637653000902653653001402662653001802676653001002694653001302704653001002717653001202727653001102739653001902750653003302769653001302802653003002815653001902845100001802864700001702882700001502899856003402914       1995                        eng d00aLong-Term Glades in Acacia Bushland and Their Edge Effects in Laikipia, Kenya0 aLongTerm Glades in Acacia Bushland and Their Edge Effects in Lai  cFeb  a97-1080 v53 aThroughout the Laikipia ecosystem in Kenya, isolated glades occur within acacia bushland and woodland communities. These glades are at least several decades old. They are reported to be old settlement sites of traditional pastoralists no longer present, and their size, location, and orientation are consistent with the settlement sites of related pastoralists studied elsewhere. The purpose of this study was to document the effects of these glades at the local and landscape levels. Working in central Laikipia, we documented differences in vegetation, animal use, and soils at four of these glades, and at increasing distances from glade edges. Four ''glade specialists'' dominated the plant communities within glades, and were very rare outside of glades. Pennisetum stramineum, one of six glade edge species, formed a ring of dense tall grass around most glade edges. The transition to acacia bushland at the glade edges was not always abrupt (depending on the trait considered), resulting in edge effects that differed in depth and sharpness. Edge depth, defined as the distance required to attain two-thirds of background levels for a trait, ranged from 0 to 200 m. Understory plant species richness and diversity were lowest inside glades, and gradually increased with distance from glades. However, because glades supported species not found elsewhere, the presence of glades increased overall species diversity. The density of wild and domestic large mammal dung was up to 10 times greater inside the glades, and declined with distance from glade edges. Similarly, soil nitrogen, potassium, carbon, calcium, and sodium were greatest inside glades. Soil phosphorus, magnesium, and manganese were not elevated inside glades or within 100 m of glades, but instead were much more abundant in background samples. These glades may be maintained by high densities of large mammals, either through herbivory or through changes in soil chemistry. Glades may be attractive to mammals because of the high quality of food there, or as part of an anti-predator strategy. The result is a relatively permanent community mosaic that increases ecosystem heterogeneity and resource use by domestic and wild animals. The spatial nature of this heterogeneity differs among species, depending on their distributions relative to the glades.10aacacia10aamerican grassland10acattle enclosures10acommunity mosaic10adepth10adung counts10aedge10aelephants10agrazing lawns10akenya10alaikipia10alarge10amammals10anorth-10apatch dynamics10aplant-herbivore interactions10asimulate10asmall-scale heterogeneity10asoil chemistry1 aYoung, T., P.1 aPatridge, N.1 aMacrae, A.  u<Go to ISI>://A1995QK27600013