Relationships between cattle and biodiversity in multiuse landscape revealed by Kenya long-term exclosure experiment

Authors: YOUNG, TRUMAN - University Of California; Porensky, Lauren; RIGINOS, CORINNA - University Of Wyoming; VEBLEN, KARI - University Of Utah; ODADI, WILFRED - Egerton University; KIMUYU, DUNCAN - Karatina University; CHARLES, GRACE - University Of California; YOUNG, HILARY - University Of California

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/25/2018
Publication Date: 1/25/2019
Citation: Young, T.P., Porensky, L.M., Riginos, C., Veblen, K.E., Odadi, W.O., Kimuyu, D.M., Charles, G.K., Young, H.S. 2019. Relationships between cattle and biodiversity in multiuse landscape revealed by Kenya long-term exclosure experiment. Rangeland Ecology and Management. 71:281-291. https://doi.org/10.1016/j.rama.2018.01.005.
DOI: https://doi.org/10.1016/j.rama.2018.01.005

Interpretive Summary: This paper seeks to disentangle the complex relationships between livestock and biodiversity in savanna ecosystems, where uneasy coexistence between livestock and wildlife is the norm worldwide. Since 1995, we have been manipulating the presence of cattle, medium-sized herbivores, and mega-herbivores (elephants and giraffes) in a series of eighteen 10-acre plots at the Kenya Long-term Exclosure Experiment (KLEE). In 2013, we crossed these treatments with small-scale controlled burns. These replicated experimental treatments simulate different land management practices. Here, we synthesize 15 years of data to address three central questions about the potentially unique role of cattle in savanna ecology: 1) To what extent do cattle and wild herbivores compete with or facilitate each other? 2) Do the effects of cattle on vegetation mimic those of wildlife, or do cattle have unique effects? 3) Do cattle and commercial cattle management have unique effects on other savanna organisms? We found that: 1) Cattle compete as strongly with browsers as grazers, and wildlife compete with cattle, although these negative effects are mitigated by cryptic herbivores (rodents), rainfall, fire, and elephants. 2) Cattle effects on herbaceous vegetation (composition, productivity) are similar to those of the rich mixture of ungulates they replace, differing mainly due to the greater densities of cattle. 3) In contrast, cattle, wild meso-herbivores, and mega-herbivores have strongly guild-specific effects on woody vegetation. 4) Both cattle and wild ungulates regulate cascades to other consumers, notably termites, rodents, and disease vectors and pathogens. Overall, cattle management, at moderate stocking densities, can be compatible with the maintenance of considerable native biodiversity, although returning to these livestock densities in African rangelands is a major challenge.

Technical Abstract: On rangelands worldwide, cattle interact with many forms of biodiversity, most obviously with vegetation and other large herbivores. Since 1995, we have been manipulating the presence of cattle, medium-sized herbivores, and mega-herbivores (elephants and giraffes) in a series of eighteen 4ha (10-acre) plots at the Kenya Long-term Exclosure Experiment (KLEE). We recently (2013) crossed these treatments with small-scale controlled burns. These replicated experimental treatments simulate different land management practices. We seek to disentangle the complex relationships between livestock and biodiversity in a biome where worldwide, uneasy coexistence is the norm. Here, we synthesize 15 years of data to address three central questions about the potentially unique role of cattle in savanna ecology: 1) To what extent do cattle and wild herbivores compete with or facilitate each other? 2) Do the effects of cattle on vegetation mimic those of wildlife, or do cattle have unique effects? 3) Do cattle and commercial cattle management have unique effects on other savanna organisms? We found that: 1) Cattle compete as strongly with browsers as grazers, and wildlife compete with cattle, although these negative effects are mitigated by cryptic herbivores (rodents), rainfall, fire, and elephants. 2) Cattle effects on herbaceous vegetation (composition, productivity) are similar to those of the rich mixture of ungulates they replace, differing mainly due to the greater densities of cattle. 3) In contrast, cattle, wild meso-herbivores, and mega-herbivores have strongly guild-specific effects on woody vegetation. 4) Both cattle and wild ungulates regulate cascades to other consumers, notably termites, rodents, and disease vectors and pathogens. Overall, cattle management, at moderate stocking densities, can be compatible with the maintenance of considerable native biodiversity, although returning to these livestock densities in African rangelands is a major challenge.