Energy Extraction and Use in a Nomadic Pastoral Ecosystem

TLDR

Energy use in this arid tropical ecosystem is low and maintenance‑oriented, with high energy flow to maintenance to support biotic responses and stabilize the system during drought. The study analyzes annual energy flows in a nomadic pastoralist ecosystem to understand a drought‑resilient subsistence lifestyle that has persisted for centuries. The Ngisonyoka largely follow a plant‑to‑animal‑to‑human energy pathway but also harvest diverse solar energy, and their utilization aligns with ecological patterns that promote stability under stress.

Abstract

An analysis of annual energy flows in an arid tropical ecosystem inhabited by nomadic pastoralists provides insight into a subsistence life-style that has persisted in droughted environments for hundreds to thousands of years. Although a large fraction of the total energy consumed by the Ngisonyoka of Kenya followed a single pathway from plant to animal to human, they also harvested solar energy from a relatively diverse assemblage of energy flow channels. Energy utilization and conversion efficiencies were generally low, as the system is maintenance-rather than production-oriented. Energy flow to maintenance must be relatively high to support biotic responses that enable tolerance of abiotic variability and to stabilize energy flow under the stress of severe droughts. Energy utilization by the Ngisonyoka is therefore consistent with ecological patterns that promote rather than diminish ecological stability under stress.