Modelling the Economics of Grassland Degradation in Banni, India, using System Dynamics

Abstract

This is a study of the interactions between the ecology and economy of the Banni grassland, located in the district of Kutch, Gujarat, India. The study focuses on modelling the economic impact of grassland degradation in the Banni from 1992–2015 and simulates future scenarios up to 2030 using system dynamics. The specific sectors being modelled are the area spread of the invasive species Prosopis juliflora, palatable grass, the populations of livestock as well as the livestock and charcoal incomes of Banni. An economic valuation is done by discounting the future earnings of the pastoral (milk, livestock sale, dung manure) and charcoal economy under two scenarios 1) Base case (Business as Usual), i.e. keeping current policies constant and 2) P. juliflora removal policy (PRP) i.e. where a decision is implemented to remove P. juliflora from Banni. Under the BAU scenario, modelling results indicate that the Banni grassland is headed for severe fodder scarcity due to the shrinking area under grassland. Under the PRP scenario, Banni is able to revive its grasslands and increase the present value of future earnings (up till 2030) by 62 per cent. A delay of five years in the decision to remove P. juliflora results in a 28 per cent reduction in earnings indicating the policy’s time sensitivity. The model serves as a test bed for generating what-if scenarios of the Banni grassland.

Invasive Prosopis juliflora: Role in Maintaining the Ecosystem Resilience of the Banni Grassland in Arid Gujarat, India

“…Such traveling across territories causes conflict among the native tribes and migrants. Degradation of grassland productivity has increased the market demand for fodder for the pastoral communities (Maldharis) which imposes an economic loss for the locals (Mathur and Sharma, 2018).…”

“…After that, P. juliflora's dense cover continued to grow at an average pace of 2,670 ha/year during the second decade (Jadhav et al, 1992) before progressively slowing down economically over the years. The introduction of P. juliflora has slowly naturalized and has become an integral part of the Banni ecosystem and started supporting provisional services (fodder, gum, wood for fuel, and charcoal production) with Charcoal making as a secondary income source for local peoples, for which P. juliflora wood is harvested (Mathur and Sharma 2018).…”

Removal or utilization? Testing alternative approaches to the management of an invasive woody legume in an arid Indian grassland

“…Compared to lopping, mechanically removing Prosopis is costly (around 85$/ha; Mathur & Sharma 2018). Nonetheless, feasibility of mechanical removal may depend on the profits from the sale of mechanically removed biomass sustaining follow-up monitoring and other interventions that are required to restore grassland composition.…”

“…With forage availability greatly reduced due to increasing woodlands, the Maldharis now also utilize Prosopis for making charcoal. This situation thus represents complex trade‐offs (and in some cases, synergies) between pastoralism‐based versus charcoal‐based livelihoods (Mathur & Sharma 2018). With increasing Prosopis invasion, it is important to know if, and how, Banni's grasslands can be managed and restored.…”