Interaction Cascades in Anthropogenic Glades

Trophic Interaction Cascades;Indirect Effects;Bomas;Glades;Gecko;Laikipia;Kenya;Natural Resources and Environment

Donihue, Colin M.Perfecto, Ivette ;

University of Michigan

关键词: Trophic Interaction Cascades;    Indirect Effects;    Bomas;    Glades;    Gecko;    Laikipia;    Kenya;    Natural Resources and Environment;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/83507/Donihue_SNRE_Thesis.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Pastoralism was traditionally, and is currently, one of the most pervasive andwidespread livelihoods throughout East African savannas. After abandonment, livestockcorrals in East African savannas develop into nutrient-rich, treeless ;;glades” that persist fordecades. Other research has shown that glades have significantly higher concentrations ofsoil nutrients including nitrogen, potassium and carbon, which support several specialistgrass species, and turning these patches long-term primary productivity hotspots. Usingdetailed observations, extensive sampling, and experimental methods, we demonstrate thatthese effects on primary productivity cascade up two trophic levels to increase abundance ofinsects and the gecko Lygodactylus keniensis. Extending previous research, we find thatAcacia drepanolobium trees close to glade edges are larger and grow faster than those fartherfrom the glade. Furthermore, we demonstrate experimentally that grasshoppers growsignificantly faster inside glades than far away from glade edges and that arboreal insectabundance, biomass and diversity show the same significant trend. Finally, we find thatgeckos are significantly more abundant in trees close to the glade edge than far away. Ourresults show that traditional pastoral methods have significant impacts on multiple trophiclevels at multiple scales and add important habitat heterogeneity to an otherwise homogenouslandscape.