From Ancient Hydraulic Engineering to Megaherbivore-Mediated Pedogenesis: A Comparative Analysis of Desert Agricultural Techniques Across Civilizations and Contemporary Large Herbivore Ecosystem Restoration

This dissertation presents a comprehensive examination of desert agricultural techniques employed across human civilizations from the Bronze Age to the present, followed by a rigorous analysis of contemporary ecosystem restoration through large herbivore reintroduction. Part I systematically documents hydraulic engineering systems developed independently across six continental regions: the Persian qanat systems (c. 1000 BCE), Nabatean runoff agriculture in the Negev (300 BCE–700 CE), Hohokam canal networks in Arizona (50–1450 CE), Andean terrace agriculture (2000 BCE–1533 CE), Egyptian basin irrigation (3000 BCE), and Sahelian zaï pit systems. Part II examines recent empirical evidence (2020–2026) demonstrating accelerated pedogenesis and hydrological recovery in degraded agricultural lands following megaherbivore reintroduction, comparing restoration rates, mechanisms, and ecological trajectories. This work synthesizes archaeological, hydrological, pedological, and contemporary ecological data to establish both historical precedent for human desert modification and novel pathways for restoration through animal-mediated ecosystem engineering.