A spatial bioeconomic model of the harvest of wild plants and animals

The intensity of harvest of wild plants and animals often varies with the distance from human settlements, processing facilities, markets, and transportation routes such as roads and rivers, resulting in marked spatial gradients in the abundance of such resources. Spatial modeling of the harvest of wild species has therefore emerged as an important research approach. The literature on such modeling is, however, fragmented between different resource types, and empirical validation of the models is often weak or absent. This paper presents a model that is intended to have validity for a wide variety of wild plant and animal resources. It combines a logistic model of resource growth with an economic model assuming that costs associated with harvest consist of three components, namely transport, search, and handling, and a one-dimensional spatial structure where resource harvesters are based at a “central place” surrounded by infinite extensions of habitat for the harvested resource. Model outcomes show that the spatial distribution of harvest heavily depends on the carrying capacity and the catchability coefficient, i.e. the ease of finding and harvesting a resource unit. An empirical study of wildlife hunting and palm leaf harvest in indigenous villages in Ecuadorian Amazonia confirmed the validity of model outcomes.