Zoning has heterogeneous effects on housing growth, but in most cases is not strong enough to affect ecosystem functions

Zoning is a popular tool for managing housing growth - but does it perform well when you want to protect the ecosystem functions of lakes? Van Butsic recently shed some light on that question. He found that zoning only affects ecosystem functions of specific lakes, whereas for the majority of the lakes it turned out to be ineffective. Searching for reasons, Van concludes that the success of zoning for the protection of lakes is highly dependent on the baseline development level- in other words, how much housing is already there. His work shows that for effective protection of lake ecosystems, other land management strategies need to be implemented in the future.

Zoning is a popular strategy used by land managers to limit housing growth in the United States. However, considering the importance of conservation of ecosystem functions, it still was unclear whether zoning by itself is sufficient to manage housing growth AND to conserve ecosystem functions. Van Butsic attempted to answer this question for lake-filled Vilas County, WI where residential housing has increased and the consequent ecological effects have been well documented. His goal was to empirically quantify the ecological effects of minimum frontage zoning on lake shorelines.

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Bluegill
The backbone of Van's work is the combination of a statistical econometric model and a statistical model for ecosystem health. Using the econometric model, Van simulated many different possible zoning scenarios on lakeshore development. The simulations covered the time period between 1974 and 1998. He then estimated the effect of the parcel development under these different scenarios on the ecosystem function of the lakes. As indicators of the ecosystem function, Van used the amount of coarse woody debris and the growth rate of bluegills. He then put the results together into a spatially explicit framework to estimate the effect of policy changes on residential development and lake ecology, with the ultimate goal of providing information to land managers about the effect of zoning on the ecosystem functions of lakes.

Van evaluated his simulated landscape changes using the observed changes in the landscape during the same period, and found high coincidence between the original and the simulated landscape changes. This empirical evidence suggests the results of the ecosystem function model are reasonable. Van's results suggest that zoning likely changed development density, but the effect on coarse woody debris and bluegill was less clear at the scale of a single lake. The study indicates that one-size-fits-all zoning is, in most cases, not effective in regulating housing growth and protecting the ecosystem functions of lakes at the same time within a heterogeneous landscape.

Van concludes that within a heterogeneous landscape zoning for protecting the ecosystem function of a lake only works under certain conditions. He will now further investigate other land management optionswith the goal of finding a strategy that is effective in protecting the ecosystem function of a lake.

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Schematic of the simulation methodology
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