ASSESSING RIPARIAN CONDITION AND PRIORITIZING LOCATIONS FOR STREAMSIDE REFORESTATION PROJECTS: NORTHERN MANABÍ PROVINCE, ECUADOR

Abstract

Riparian corridors perform ecological functions to a degree that vastly exceeds their spatial area on the landscape. These unique ecotones decrease sedimentation, provide unique wildlife habitat, help attenuate flood waters, and improve stream water quality by regulating and absorbing nutrient and pollutant flows across system boundaries. However, human actions at the landscape scale are a primary threat to the integrity of river ecosystems. This project focuses on maximizing ecological benefits through effective riparian restoration planning within one of the world’s most threatened biodiversity hotspots: the coastal semi-deciduous, tropical dry forests of northwestern Ecuador. In order to meet the restoration objectives in a cost-effective manner, satellite remote sensing and geospatial modeling were employed to (a) understand relationships between land use/land cover (LULC) and drinking water quality across four watersheds of varying sizes and levels of forest-to-pasture conversion; (b) accurately identify potential restoration sites along important riparian corridors; and (c) prioritize and recommend restoration sites using a rank system that focuses on restoration feasibility and the potential to improve water quality, hydrologic functioning, and wildlife habitat. Within the four coastal watersheds in the study area, the severity of deforestation ranges from 24% to 50% mainly due to conversion to pasture for livestock production. This type of land use change further increases by as much as 10% for areas closest to higher order streams showing an increased threat to riparian zones. The substantial loss of riparian forest cover led to the identification of 1,668 potential restoration sites, with an average size of 0.2 ha. Of these potential sites, 3.8% ranked as “high” priority, 47.6% ranked as “moderate” priority and 48.6% ranked as “low” priority. Those sites that are ranked the highest priority for reforestation efforts are larger in size, maximize core-area/edge ratios for prospective wildlife habitat improvements, and have the best potential to enhance riparian buffer functioning once restored.