EP039-0010
Targeting Riparian Reforestation to Enhance Ecosystem Services: The Case of Costa Rica
Friday, 11 December 2020
Poster
Kelley Langhans1,2, Rebecca Chaplin-Kramer3, Rafael Monge4, Rafael J. P. Schmitt5, Jeffrey R Smith6, Stacie Wolny7 and Gretchen Daily1,3, (1)Stanford University, Department of Biology, Stanford, CA, United States, (2)Stanford University, Center for Conservation Biology, Stanford, CA, United States, (3)Natural Capital Project, Stanford University, Woods Institute for the Environment, Stanford, CA, United States, (4)Ministry of Environment and Energy, San Jose, Costa Rica, (5)Stanford University, The Natural Capital Project / Woods Institute for the Environment, Stanford, CA, United States, (6)Stanford University, Stanford, CA, United States, (7)Stanford University, The Natural Capital Project, Stanford, CA, United States
Abstract:
As habitats degrade worldwide, there is an increasing need to protect and restore natural areas to safeguard benefits they provide for humans and biodiversity. Riparian corridors are key places to focus such efforts: they generate many essential ecosystem services, and often provide disproportionately high levels of services relative to their spatial extent. Many countries have laws protecting riparian buffers, but they often are not well-enforced. Using Costa Rica as a case study, we explore the consequences of implementing an existing riparian protection law, Forest Law 7575, which specifies an amount of natural habitat to be preserved around rivers. We model changes in nutrient retention, sediment retention, and carbon sequestration in both a baseline scenario, using current land use, and a simulated reforestation scenario, where riparian forests are increased as per law. We do this using InVEST, an open source software that creates spatially explicit maps of ecosystem services based on different land use scenarios.
Our results show that a relatively small increase in forest cover of under 2% from riparian reforestation in Costa Rica could lead to large increases in ecosystem services. With reforestation, the nationwide carbon stock is projected to increase by almost 8 million tons, a 1.6% increase above current levels. Sediment, nitrogen, and phosphorous export to streams are all projected to decline, with decreases of 1 million tons/year (5% of current levels), 1.9 million kg/year (10.8% of current levels), and 230,000 kg/year (12.9% of current levels), respectively. Our models show that riparian buffers have the largest potential impact on ecosystem services in areas that are steep, erosion-prone, have high nutrient fertilization. Fine-scale spatial modeling can pinpoint priorities for policy interventions, and in this case shows that broader implementation of Forest Law 7575 in Costa Rica would have disproportionate benefits.
