PARENT SESSION
Poster Session # 7: Restoration, Resource Management, and Conservation.
Monday, August 4 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.
Aloe secundiflora shrubs facilitate a native perennial grass in degraded Kenyan rangelands: Implications for restoration.
King, Elizabeth *,1, 1 Section of Evolution and Ecology, Davis, CA, U.S.A.
ABSTRACT- Over 75% of Kenya is arid and semi-arid land. Human and livestock pressure has led to severe vegetation degradation and soil erosion across vast areas of Kenya's drylands. I hypothesize the presence of Aloe secundiflora shrubs positively affects the success of perennial grasses and other vegetation in degraded rangelands. If so, propagating and planting aloes may be an effective tool in restoration efforts. An observational vegetation study in the Kerio Valley, Kenya, indicated that vegetation cover, litter cover, soil retention, and soil seed bank were all greater in the immediate vicinity of naturally occurring A. secundiflora shrubs. The positive effect of aloes was likely due to physical protection, shade, and perennial ground cover offered by the aloes. To test whether mature transplanted A. secundiflora shrubs can provide similar ecological benefits, I performed a manipulative experiment in northern Laikipia District, Kenya, in which seeds of the native perennial grass Cenchrus ciliaris were planted next to three different facilitator treatments: around transplanted aloe shrubs, around small piles of thorny Acacia tortilis branches, and in bare areas with no facilitator. The success of grasses at each life history stage was compared among the three facilitator treatments. Aloe presence significantly enhanced C. ciliaris seedling emergence rate, seedling survival, and adult plant survival, while thorn protection enhanced some of these fitness aspects to a lesser degree than aloes. Findings indicate that propagating and planting aloes may indeed be a useful restoration tactic, especially when combined with perennial grass seed planting. If utilized, this restoration tactic can offer rural communities additional benefits, because valuable sap can be legally and sustainably harvested from propagated aloes as the basis of a rural economic enterprise.
Key words: restoration, facilitation, rangelands, Aloe secundiflora