Microsatellite survey reveals possible link between triploidy and mortality of quaking aspen in Kaibab National Forest, Arizona

In the southwestern United States, populations of quaking aspen (Populus tremuloides Michx.) are experiencing widespread mortality. Although environmental factors contributing to mortality have been well characterized, less is known about how genotype and particularly ploidy level affect susceptibility. We used five microsatellite markers to infer the ploidy level of 212 aspen stems in Kaibab National Forest, Arizona. Many multilocus genotypes showed three alleles at one or more loci, suggestive of frequent triploidy among our samples. Sites populated with putative triploids had higher mortality. In addition, heterozygosity was positively associated with mortality and crown dieback. Our results suggest that triploidy is a predisposing factor for aspen mortality in Kaibab National Forest.

Artificial Project Time Horizons In The Absence Of Discounting: The Case Of Canyon Forest Village

In the summer of 1997, the Kaibab National Forest released the Draft Environmental Impact Statement for Tusayan Growth. This report analyzed various scenarios involving the transfer of National Forest land at the boundary of the Grand Canyon National Park to a private developer, in exchange for private inholdings scattered throughout the Kaibab National Forest in northern Arizona. The resulting private development was to be called Canyon Forest Village, and would include hotels, visitor facilities, private housing, community facilities and a transportation center for tourists accessing the Grand Canyon. The proposed build out of Canyon Forest Village (CFV) was to take place from 1999 to 2010. Consequently, the Forest Service analysis used that time frame as the basis for calculating the economic impacts CFV would be expected to have on local economies in the northern Arizona region. The Draft Environmental Impact Statement (EIS) concluded that overall growth in demand for lodging in northern Arizona would be robust over those years, and that CFV would have no net negative impacts. The results of the Draft EIS were sharply contested during the public comment phase, and, in the summer of 1998, a Supplement to the Draft Environmental Impact Statement for Tusayan Growth was issued. This document used a different modeling procedure and changed its primary focus to two, smaller, CFV proposals, involving only 900 and 1,270 hotel rooms. The Supplement did conclude that there would be some negative impacts to the communities surrounding Grand Canyon. The results of the Supplemental Draft EIS were also contested during the public comment phase following its release, although a year later, in the summer of 1999, the Forest Service issued a Final EIS and adopted the CFV proposal for 1,270 rooms. One peculiarity of the Forest Service reports, throughout this process, was the failure to identify an explicit discount rate of interest in order to identify costs and benefits in terms of their present value. While EIS documentation has been required for many years, the obvious focus is on purely environmental concerns and the analyses tend to be based on scientific findings. The inclusion of a socioeconomic analysis necessitates a careful accounting of benefits and costs. While this EIS is not the first to include an explicit accounting of economic benefits and costs, it may serve as a harbinger of more reporting of this type. Unless those with an appreciation of the discounting process, especially economists and accountants, are included in these analyses, present values may be employed only on an erratic basis, making the results of such reports difficult, if not impossible, to adequately interpret. This article applies basic and commonly accepted time value of money principles to an EIS report. Although an economic analysis was provided as part of the report, the time value of money was ignored. In order to present a viable economic impact, these basic financial tenants must be employed. The authors used basic time value of money principles with reasonable discount rates. The result is that impacts could be as much as six times greater than the values given by the Forest Service, representing upwards of one hundred and fifty million dollars.

Archaeological Survey Design, Units of Observation, and the Characterization of Regional Variability

It is generally presumed that intensive survey yields reliable representations of regional archaeological variability. We evaluate this assumption with an analysis of the results of two intensive surveys of the same terrain in the Upper Basin, a heavily forested upland ecosystem located south of Grand Canyon National Park in Kaibab National Forest, northern Arizona. By comparing differences between the results of site-based surveys with those of mapping-unit-based surveys, we demonstrate that units of observation have a profound effect on how archaeological landscapes and their variability are characterized and interpreted. In addition, results of four analyses of survey data show that the archaeological resource inventories created by the application of these two different units of observation cannot be reconciled. We suggest that because some units of observation may be more appropriate for certain problems and for different kinds of surface and near-surface archaeological records, additional studies of the effects of units of observation on characterizing the archaeological content of the same terrain should become a research priority in survey archaeology. Without such studies, the identification of archaeologically sensitive areas, particularly those that necessitate active management and vigilant protection on public lands, will be underdetermined, thereby placing those heritage properties at risk.

Cattle Grazing in a National Forest Greatly Reduces Nesting Success in a Ground-Nesting Sparrow

Grazing of domestic livestock on public lands in the western United States is a major source of habitat destruction. I quantified nest success of ground-nesting Dark-eyed Juncos (Junco hyemalis) breeding in ponderosa pine forests and pine savanna in the Kaibab National Forest of northern Arizona. Comparison of results for areas grazed by cattle to results for immediately adjacent areas protected from grazing revealed that cattle grazing was associated with a dramatic (75%) reduction in nest success. Cattle grazing reduced vegetation cover over nests by an average of 41%, exposing the nest to more extreme climatic conditions as well as possibly making them more conspicuous to predators. El Pastoreo por Ganado Reduce Fuertemente el Éxito de Nidificación de Junco hyemalis en un Parque Forestal Nacional Resumen. El pastoreo por parte de ganado doméstico en tierras públicas del oeste de los Estados Unidos es una de las principales fuentes de destrucción de hábitat. Cuantifiqué el éxito de nidificación de Junco hyemalis, una especie que nidifica en el suelo, en los bosques de pino Ponderosa y las sabanas de pinos en el Bosque Nacional Kaibab, norte de Arizona. La comparación entre los resultados de las áreas pastoreadas por ganado y de las áreas inmediatamente adyacentes que se encuentran protegidas del pastoreo mostró que el pastoreo por ganado se asoció con una reducción dramática (75%) del éxito de nidificación. En promedio el pastoreo por ganado redujo la cobertura vegetal sobre los nidos en un 41%, exponiendo a los nidos a condiciones climáticas más extremas y posiblemente haciéndolos más conspicuos ante los depredadores.