The Value of Wetlands
We are exploring the economic value of retained wetlands in agricultural cropland. Wetlands provide a range of functions and associated ecosystem services that are beneficial to agriculture, including flood protection, water quality treatment, soil retention, and nutrient cycling. Despite a rising scientific awareness of wetland benefits and resultant government policies to prevent or minimize impacts, wetland ecosystems continue to be lost in the Prairie Pothole Region of Canada, with an estimated 40 to 70% loss of wetlands in the White area of Alberta over the past century. A major driver of wetland loss is conversion by agricultural producers to increase the amount of land available for more intensive farming. While the livestock sector has begun to prioritize sustainability standards and wetland conservation on pasture and hay land, the crop sector has been slower to adopt these practices, primarily because the financial benefits of wetland conservation for individual crop producers are less tangible. As such, a recurring message communicated from wetland policy makers, crop sector industry organizations, and environmental conservation organizations in Prairie Canada has been the need to quantitatively assess the impact of wetland conservation on the productivity of cultivated crops and the economic costs or benefits related to this conservation practice.
While the ecosystem service benefits of wetlands are well documented, the impact of wetland retention on crop productivity and profitability remains poorly understood. Wetlands influence surrounding lands by increasing soil moisture and nutrient retention, as well as by moderating temperature and humidity. These positive “halo” effects likely result in an increase in crop productivity and yield along the margin of an intact wetland; however, how far this effect extends and whether this effect has a measurable impact on crop productivity, are questions that have been largely unexplored quantitatively. Further, a common perception of many in the agricultural industry is that crop productivity and yields are higher if a wetland is drained and put into cultivation; however, crop productivity on lands adjacent to and within the basin of a drained wetland has to our knowledge never been directly compared to productivity adjacent to an intact wetland.
Working collaboratively with producers in the Camrose Creek watershed of central Alberta, the main objective of this study is to quantify how wetland management practices influence agricultural crop productivity. We will examine the question of whether the practice of retaining a wetland can increase the productivity of agricultural crops adjacent to an intact wetland, and if so, quantify the magnitude of that increase. Specifically, we will compare differences in productivity within and adjacent to wetland basins that have been drained and/or cultivated and planted to crops, to crop productivity along the periphery of wetlands that have been retained and are considered intact hydrologically. This information will then be used to estimate the profitability and economic value associated with wetland retention versus wetland drainage.