Theoretical Modelling of Livestock-Driven Land Degradation and Its Feedback Effects on Pastoral System Resilience in Semi-Arid Nigeria

This study develops theoretical models of livestock-driven land degradation dynamics and their feedback effects on pastoral system resilience in semi-arid Nigeria, contributing an original ecological-economic framework for understanding the conditions under which degradation becomes self-reinforcing and identifying intervention thresholds. Semi-arid pastoral systems in Nigeria's North West and North East face progressive land degradation from a combination of climate change, population pressure, and overgrazing, creating poverty traps where reduced livestock productivity further intensifies grazing pressure in a degradation spiral. Understanding the dynamics of this feedback system is essential for identifying effective intervention points. This study develops a coupled livestock-vegetation-soil dynamics model using system dynamics methodology, parameterised using 15-year longitudinal vegetation productivity data from NDVI time series analysis of Sokoto, Katsina, and Borno pastoral zones, long-term livestock population data from NBS and LGA agricultural surveys, and original soil degradation measurements from transect surveys in representative pastoral areas. Bifurcation analysis identifies tipping points beyond which degradation becomes irreversible without major external intervention. Resilience analysis quantifies the system's capacity to absorb shocks without crossing critical thresholds. Economic model integration assesses the cost-effectiveness of alternative interventions at different system states. Findings reveal that the pastoral system in 38 percent of surveyed areas has crossed critical resilience thresholds and requires active restoration investment rather than management improvement alone. The model identifies herd size reduction combined with rangeland restoration as the only cost-effective recovery pathway for the most degraded zones. The study contributes an original pastoral system resilience model for semi-arid Nigeria and recommends integrated restoration-livelihood transition programmes.

Keywords: land degradation, pastoral resilience, semi-arid Nigeria, system dynamics, rangeland restoration.