SCIENCE

According to http://ucanr.org/blogs/anrnews/index.cfm?tagname=public%20policy, “Rilla…wrote the report with Lisa Bush…to bring some scientific information into the conversation.”  But the UC Report contains scientific errors, selective presentation of science, misleading science and unsubstantiated scientific conclusions.   

For example, Page 2, paragraph 5: UC Davis erroneously claims that “most native grazers [are] extinct” and claims without any substantiation that “livestock grazing is the only ecosystem process that...keep(s) shrubs from invading grasslands.”   But PRNS pointed out that “most native grazers are present ” and that no data supports the claimed shrub invasion, which may be “a reversion to historic conditions.”    

Page 4, paragraph 3:  The UC Report admits, “livestock grazing has certainly been a factor in the loss of native plant species on some of California’s grasslands,” however, it erroneously attributes this impact wholly to the “past.”  In fact, today, the great majority of Marin’s commercial grazing continues to be driven by economic, not biological, needs, and thus continues to have significant negative impacts on biodiversity.  Tomales Bay is “impaired” due to excess coliform and sediment in part because commercial grazing destroyed and continues to suppress native riparian vegetation.

Page 4 paragraphs 5:  UC Davis quotes Hayes and Holl (2003) as stating that grazing can benefit annual forbs.  However, this is misleading and a selective presentation because PRNS’s Response points out that the very same study also states, “cover and species richness of native perennial forbs were higher in ungrazed areas.”    This distinction is particularly important, and thus the UC Davis errors particularly misleading, given that,” the coastal prairie of PRNS is a perennial system. 

Page 4, paragraph 6: the UC Davis Report claims, “In all cases [commercial] grazing has proven compatible with the preservation of special status species found at PRNS.”   However. PRNS points out that the quoted UC sentence is erroneous and contradicted by the prior UC sentence that notes, “Research and anecdotal information have shown that grazing is strongly linked to maintaining habitat for some special-status species at PRNS, while they have been inconclusive for others.”  There is no dispute that commercial grazing, when managed with the goal of increasing biodiversity, as opposed to increasing profits, can help control invasive species.  However, the benefits to some special status species that are claimed to come only from commercial grazing are unsubstantiated because they could also (and preferentially) be provided by native grazers such as tule elk.  By favoring cattle over elk with the unstated johne's disease red-herring, the UC Report fuels a range war whose prize is the PRNS grass and whose victims are elk confined to the “Refuge” solely to benefit commercial grazing.

UCCE claims as its grazing baseline the now-extinct ice-age Pleistocene epoch browsers/grazers such as mammoth, camel, bison and giant sloth.  UCCE again twists the baseline to the ice-age Pleistocene to justify its predetermined political agenda.  A baseline of mammoth, camel, miniature horses, saber-toothed tigers and giant sloths is ecologically irrational and unjustified.  The NPS ecological baseline is and should be the conditions that evolved naturally in the Holocene epoch that included the melting of the ice caps, the significant rise in sea levels, and the extinction of mammoth, camel, miniature horses, saber-toothed tigers and giant sloths that UCC absurdly claims as a current baseline.   Those Holocene conditions were well recorded by the early Spanish explorers who found this area rich in large grazer/browser herds of deer and elk.    These native brewers/gazers remain available to do the work that UCCE falsely claims only commercial livestock can perform, except for the fact that agricultural advocates themselves have self-servingly argued against release of the elk from their “refuge” due to invented concerns over Johne’s disease.

Page 6, paragraph 3.  The UC Davis Report repeats the statistical fallacy that correlation proves causation.   This fallacy occurs in the Report’s discussion of the Myrtle’s silverspot butterfly and the California red-legged frog.   For example, It is incorrect to state that simply because there are large numbers of red-legged frogs in the pastoral zone, then grazing benefits frogs.  In contrast, the PRNS Response notes that red-legged frogs benefit from ponded water and marsh areas.  Since the pastoral zone is generally flatter than other areas in the park, it naturally has more frog areas.