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2481347 
Journal Article 
Top-down and bottom-up control of large herbivore populations: a review of natural and human-induced influences 
Gandiwa, E 
2013 
1 
Tropical Conservation Science
ISSN: 1940-0829 
SAGE PUBLICATIONS INC 
THOUSAND OAKS 
6 
4 
493-505 
English 
WOS:000332704600005 
The question whether animal populations are top-down and/or bottom-up controlled has motivated a thriving body of research over the past five decades. In this review I address two questions: 1) how do top-down and bottom-up controls influence large herbivore populations? 2) How do human activities and control systems influence the top-down and bottom-up processes that affect large herbivore population dynamics? Previous studies suggest that the relative influence of top-down vs. bottom-up control varies among ecosystems at the global level, with abrupt shifts in control possible in arid and semi-arid regions during years with large differences in rainfall. Humans as super-predators exert top-down control on large wild herbivore abundances through hunting. However, through fires and livestock grazing, humans also exert bottom-up controls on large wild herbivore abundances through altering resource availability, which influences secondary productivity. This review suggests a need for further research, especially on the human-induced top-down and bottom-up control of animal populations in different terrestrial ecosystems. 
Ecosystem; predation; primary production; savanna; trophic level