Historical Ecologies of Pastoralist Overgrazing in Kenya: Long-Term Perspectives on Cause and Effect

Abstract

The spectre of 'overgrazing' looms large in historical and political narratives of ecological degradation in savannah ecosystems. While pastoral exploitation is a conspicuous driver of landscape variability and modification, assumptions that such change is inevitable or necessarily negative deserve to be continuously evaluated and challenged. With reference to three case studies from Kenyathe Laikipia Plateau, the Lake Baringo basin, and the Amboseli ecosystemwe argue that the impacts of pastoralism are contingent on the diachronic interactions of locally specific environmental, political, and cultural conditions. The impacts of the compression of rangelands and restrictions on herd mobility driven by misguided conservation and economic policies are emphasised over outdated notions of pastoralist inefficiency. We review the application of 'overgrazing' in interpretations of the archaeological record and assess its relevance for how we interpret past socio-environmental dynamics. Any discussion of overgrazing, or any form of human-environment interaction, must acknowledge spatio-temporal context and account for historical variability in landscape ontogenies.

A 3000-year record of vegetation changes and fire at a high-elevation wetland on Kilimanjaro, Tanzania

“…Anthropogenic activities, notably grazing, hunting, metallurgy, settlement, agriculture, and burning (e.g., for honey hunting, agricultural field preparation, grazing resource management, animal viewing spaces in parks), significantly modify vegetation patterns (Wood, 1965b; Archibald et al, 2012; Vehrs and Heller, 2017; Boles et al, 2019). The potential of increased natural or anthropogenic-driven burning (or both) influencing the increased apparent biodiversity in the pollen taxa assemblage during Maua2 is particularly interesting among investigations of relationships between fire and biodiversity (Parr and Andersen, 2006).…”

Savannah Phenological Dynamics Reveal Spatio-Temporal Landscape Heterogeneity in Karamoja Sub-region, Uganda

“…In parts of the Horn of Africa that are semi-arid, it has already been shown that even within a dryspell, vegetation and especially trees and shrubs, remains green and abundant (Vrieling et al, 2013). According to Ellis and Swift (1988) pastoralists have relied on these varying forms of vegetation response and at varying spatial and temporal scales to graze their livestock across landscapes and have thus formed a strong basis for the resilience of pastoral livelihoods and rangeland ecosystems (Boles et al, 2019).…”

“…They are critical for traditionally guided plant inflorescencephenological dynamics (Dunning et al, 2016). They also form the basis for the ecological resilience of both pastoral livelihoods and rangeland ecosystems (Boles et al, 2019).…”

“…Accelerated environmental changes in pastoral landscapes in East Africa have been registered in the last two decades (Little, 1996;Boles et al, 2019). These changes include increased extreme weather events especially drought and flash floods (Ayal et al, 2018;Kimaro et al, 2018), land use land cover change and habitat fragmentation (Kimiti et al, 2018).…”

The Eneolithic/Bronze Age Transition at Tegole di Bovino (Apulia): Geoarchaeological Evidence of Climate Change and Land-Use Shift

“…Almost for the same reason, colluvial infilling of canals may have been triggered-at least in part-by human activities. Rapid anthropogenic deforestation and/or overgrazing of soils in the context of progressive reduction of water availability [94] may have enhanced the effect of surface processes leading to the dismantling and removal of the pristine Holocene soil cover. Elsewhere, prehistoric and historical records point to the coupled effect of climatic changes-triggered surface processes and human agency as a major cause of soil loss [14,15,29,[95][96][97][98][99][100].…”