Friday, June 1, 2012

Answers to Questions

Below, Dr. Adamus answers some questions.  What do you think of them?  I find his answers about the Zhang paper particularly interesting. When pressed about statistics at various meetings, Dr. Adamus has declined to answer and has suggested that a statistician should be consulted. But Dr. Adamus' admitted lack of statistical prowess doesn't prevent him from choosing between Mayer and Zhang, which are both statistical studies.

How can someone provide expert advice on a topic encompassing their self-professed ignorance?

He also gives a statistical answer to the question about the accuracy of the wetlands map. According to Dr. Adamus, the maps have a false positive rate of 3.8% but an unknown false negative rate, implying that it could be quite high. The maps "likely omit" many wetlands, he claims. How many? Only those all-knowing "resident wetland experts" know for sure.

1.     Why does upland habitat need to be protected?

The WAC does not limit protection only to wetlands, streams, lakes, and marine habitats.  In WAC 365-190-030(6a), FWHCA’s are defined as:
“areas that serve a critical role in sustaining needed habitats and species for the functional integrity of the ecosystem, and which, if altered, may reduce the likelihood that the species will persist over the long term. These areas may include, but are not limited to, rare or vulnerable ecological systems, communities, and habitat or habitat elements including seasonal ranges, breeding habitat, winter range, and movement corridors; and areas with high relative population density or species richness.”

One scientific reason for protecting upland habitat is that several wetland-dependent species of amphibians and birds require both upland habitats and wetland habitats to complete their life cycle.  Under the Growth Management Act, Counties are required to protect wetland functions.  One wetland function that is specifically mentioned in official guidance is the provision of habitat -- meaning habitat for all species, not just ones listed as threatened or endangered.

2.     Is the forest buffer only necessary to protect conifers? Why do wetland conifers need to be protected, when there are so many conifers in upland (non-wetland) area?

No.  Forested buffers are needed to protect stands consisting of any type of wetland tree from excessive blowdown.  Trees in wetlands need protection even though there are many times more trees in uplands, for the simple reason that wetland trees are more likely to provide essential habitat to animal species that need to live in or very near wetlands.  An example is wood duck, a species which prefers to nest in (or as close as possible) to wetlands.   Counties are required to protect the habitat functions of wetlands, and wetland trees are a major contributor to a wetland’s habitat functions.

3.     How accurate is the “Possible Wetlands” map?

As explained in the Wetlands BAS chapter:
“Of 105 [“possible wetland”] sites visited, there were four where no evidence (vegetative, soils, or hydrology) of wetland conditions was found anywhere on the accessible parcel, indicating either a map error or less likely a recent alteration.  In other words, the County’s new map of “Possible Wetlands” was determined to have a 3.8% commission error.

The rest of the story is that the maps likely omit many wetlands that could not be detected using only aerial photos and LiDAR.  This is particularly true of forested wetlands.  Resident wetland experts have confirmed this.  However, the omission error rate cannot be measured without large expenditures of field time.

4.     Why should the Mayer paper be used to size buffers rather than the Zhang paper?

The Zhang et al. used less than one-fifth of the full spectrum of 45 buffer studies which they might have, either because they weren't aware of some ("didn't do their homework") or because they purposely avoided using some.  Whereas Mayer et al. have ferreted out nearly every nitrate buffer study published up to that point, and objectively included all of them in their analysis.  If anything, the Mayer et al. curve is conservative because it includes a few studies of nitrate removal by wetlands; wetlands usually remove nitrate more effectively than upland buffers, although sometimes with detrimental effects to the wetland.  Also, at both the "lower and upper ends of the curve" for nitrate, Mayer et al. have more data points than Zhang et al. and thus more credibility to the curve.  Most important, the Mayer et al. publication is not only far more inclusive of published studies, it also is more transparent and compliant with standard procedures of academic research and meta-analysis.

Although in theory one could pick through the studies used in the Zhang or Mayer analysis and analyze only the studies that had land uses most similar to those in San Juan County, there are two major problems with doing that:
(1) One cannot assume similarity of land use (e.g., was it a study in an urban or agricultural setting?) is the most important driver of how wide a buffer should be.  Factors such as buffer slope, soils, size of the development, and climate are often much more important, so one would have to determine all of those factors for every study before one could select “just the studies most relevant to San Juan County situations.”
(2) Doing so would require an enormous expenditure of time and money, and would prove fruitless in some cases because many researchers do not report all those background conditions when they write up their results.

5.     With regard to wetlands that don’t have a surface water outlet – if the soils had high conductivity, with good subsurface flow out of the wetland, could they be placed in the Low Water Quality/ Sensitivity category?

In theory, probably yes.  However, determining if the soils had high connectivity and good subsurface flow out of the wetland (a) would require judgment by a qualified professional who visits the wetland at an appropriate time of year, thus requiring landowners to pay for a consultant, and (b) lacks any basis for deciding what constitutes “high” connectivity and “good” subsurface flow.

6.     Jon Cain (legal counsel) would like the definitions of lakeside wetland and large pond wetland refined to be clearer.

            I will need additional guidance as to what is unclear.

“Lakeside wetland” means a wetland that is within or contiguous to and within 100 feet of a ponded water body larger than 20 acres, and whose water levels fluctuate in near synchrony with those of the water body.  This does not include wetlands that develop on non-wetland sites, as may occur when water is impounded with a structure.

“Large pond wetland” means a wetland that is within or contiguous to and within 100 feet of a body of surface water that is between 5 and 20 acres in size and is present for all or most of a normal year; or a wetland which contains patches of standing water that cover between 5 and 20 acres during all or most of a normal year.

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