The effect of forest composition on outdoor recreation.

Climate change will shift the composition of northern Minnesota forests from boreal to temperate by the end of the century. This shift in forest composition will likely affect outdoor recreation, a valuable ecosystem service and a key economic driver for the region. In this context, the objective of our paper is to empirically examine the relationship between forest composition and recreation. We analyze the effect of changes in forest composition for seven forest types on seven types of recreation using a lognormal pooled panel regression model for Minnesota's Laurentian Mixed Forest Province. Earlier research showed forest composition affected recreation at the level of broad groups of broadleaved or coniferous species. We find a statistically significant empirical association between forest composition and recreation at the forest type level (forest types within those broad groups). This relationship varies across forest types and recreation categories. For example, big game hunting is positively related to elm-ash-cottonwood and white-red-jack pine and negatively associated with aspen-birch. We find individual forest types within broad groups of broadleaved or coniferous forests, have different relationships with recreation, so that these broad groups are not sufficient in capturing the effect of forest composition on recreation. Our results are of interest in the context of current shifts in forest composition caused by climate change, which could also affect recreation. Our findings suggest adding a forest composition lens to existing policies could facilitate strategies for more effective recreation management and climate change adaptation.

Centralized softening as a solution to chloride pollution: An empirical analysis based on Minnesota cities.

Chloride is a key component of salt, used in many activities such as alkali production, water treatment, and de-icing. Chloride entering surface and groundwater is a concern due to its toxicity to aquatic life and potential to degrade drinking water sources. Minnesota being a hard-water state, has a high demand for water softening. Recent research has found that home-based water softeners contribute significantly to chloride loading at municipal wastewater treatment plants (WWTPs). Because of this, many WWTPs would now require water quality based effluent limits (WQBELs) to comply with the state's chloride water quality standards (WQS), unless they install chloride treatment technologies, which are limited and cost-prohibitive to most communities. A potential solution to this problem, is shifting from home-based water softening to a system where water is softened at drinking water plants, before reaching homes, i.e. centralized softening, analyzed in this paper based on its ability to address both chloride pollution and water softening needs, at reasonable cost. We estimate lifetime costs of three alternative solutions: centralized softening, home-based softening, and a Business as Usual (BAU) or baseline alternative, using annualized 20-year loan payments and Net Present Value (NPV), applied to 84 Minnesota cities with matching data on drinking water plants and WWTPs. We find that centralized softening using either Reverse Osmosis (RO) or lime-softening technologies is the more cost-effective solution, compared to the alternative of home-based softening with end-of-pipe chloride treatment, with a cost ratio in the range 1:3-1:4. Between the two centralized softening options, we find RO-softening to be the lower cost option, only slightly more costly (1.1 cost ratio) than the BAU option. Considering additional environmental and public health benefits, and cost savings associated with removal of home-based softeners, our results provide helpful information to multiple stakeholders interested in an effective solution to chloride pollution.