Investing in Natural Capital: Estimating the Value of Open Space Nature Preserves in Wake County, North Carolina

Abstract

ABSTRACT SCHMIDT, AMELIA ANNE. MASTERS IN NATURAL RESOURCE POLICY AND ADMINISTRATION. INVESTING IN NATURAL CAPITAL: ESTIMATING THE VALUE OF OPEN SPACE NATURE PRESERVES IN WAKE COUNTY, NORTH CAROLINA. We benefit from many of the services provided by nature's ecological functions that contribute to air and water quality, and the wildlife-associated recreational opportunities offered by species diversity. Working with valuation models and geospatial data, this study estimates the socio-economic value of conserving publicly managed open space through simulation models designed to estimate benefits based on the biophysical properties of landcover and the protection of biodiversity through species' habitat conservation. This assessment provides information intended to inform policy decisions by estimating both market and non-market values associated with the benefits provided to residents who directly or indirectly use these resources. The intent of this study is to heighten awareness of open space property values expressed in terms of their biological, ecological, geological and social worth. The InVEST program was used to model the benefits of biological carbon removal and nutrient retention. The benefits of carbon sequestration and storage were expressed as the avoided social cost of carbon. The benefits of nutrient retention were expressed as the replacement cost of biological filtration with artificial water treatment. The Wildlife Habitat Benefits Estimation Toolkit was used to quantify the benefits of biodiversity and wildlife-associated recreation based on a willingness to pay to observe wildlife or simply know that a species exists. The annual benefit of carbon sequestration averaged $612/ha. The lifetime benefit of carbon storage averaged $9,186/ha. The annual benefits of nutrient retention averaged $63/ha for nitrogen and $111/ha for phosphorus. Biodiversity protection through habitat conservation averaged $3,204/ha annually and its associated recreational opportunities averaged $2,774/ha. The 2.3 million tons of carbon stored is five orders of magnitude greater than the 30 tons of nutrients retained. The social cost of carbon used to quantify the benefit of carbon sequestration and storage was $60/ton. The cost of artificial water treatment used to quantify the benefit of nutrient retention averaged 18 cents/ton. Biodiversity and its associated recreational opportunities were quantified using fundamentally different methods from those applied to carbon and nutrient retention. A willingness to pay estimate includes both the non-market value of consumer surplus and the direct market value of costs. This assessment is a first step toward increasing the capacity of planners throughout Wake County to create a more effective way of protecting biological resources. As analytical capabilities and our understanding of ecosystem services increase, developing useful valuation methods can form the foundation of future policy- and decision-making. The purpose of valuing the natural world is to elicit a measure of human preference for or against environmental change; however, economic values are not the same as intrinsic values. Often, the intrinsic value of nature itself is ignored. In support of ecosystem service valuation, it can be argued that environmental economics does not seek to price intrinsic value but the human perception of intrinsic value. These actions complement traditional biodiversity protection by conserving land for people and not simply for nature’s sake.