2013-05-25T11:13:53Zhttp://library.wur.nl/oai

oai:library.wur.nl:wurpubs/395993 2011-12-20

urn:nbn:nl:ui:32-395993 2011-12-20 urn:nbn:nl:ui:32-395993/mods Allometric scaling of resource acquisition by ruminants in dynamic and heterogeneous environments Kramer K. aut Prins H.H.T. aut 080429734 074173839 text info:eu-repo/semantics/article 2010 en We present a mechanistic formulation of the intake response of ruminants to vegetation biomass based solely on physiological and morphological parameters that scale allometrically with the animal's body mass. The model is applied to describe herbivore–vegetation interactions in dynamic and heterogeneous landscapes with low quality but abundant “tall grass” and high quality but sparsely available “short grass”, under two conditions: “uncoupled” (such that the effect of food intake on vegetation biomass can be neglected), or “coupled” (such that the vegetation biomass is determined by herbivore feeding). The results show that under uncoupled conditions, the minimum acceptance (proportion of vegetation consumed by the herbivore) at which the herbivore can leave its current patch without reducing its intake rate is when it has depleted the current patch by the energetic cost required to travel to another patch. The maximum acceptance at which the herbivore should leave its patch is when it has depleted the current patch by the cumulative energetic cost of traveling, handling, cropping, and digesting. Under coupled conditions, the optimal acceptance equals half the relative growth rate of the vegetation. Analytical solutions are obtained for equilibrium values for utilization of the vegetation, and for the densities of vegetation and ruminants, expressed in physiological and morphological herbivore parameters. Centrum Ecosystemen - Vegetation and Landscape Ecology Leerstoelgroep Resource Ecology Ecological Modelling 221 2555 2564 URN:ISSN:0304-3800 urn:nbn:nl:ui:32-395993/obj 2010-09-27 qhttp://purl.org/eprint/accessRights/RestrictedAccess