Coronado National Forest Research Articles

Multiscale ecological niche modeling exhibits varying climate change impacts on habitat suitability of Madrean Pine-Oak trees

Anthropogenic climate change and increasing greenhouse gas emissions are expected to globally impact the biological function, community structure, and spatial distribution of biodiversity. Many existing studies explore the effect of climate change on biodiversity, generally at a single spatial scale. This study explores the potential effects of climate change on the habitat suitability of seven tree species at two distinct spatial scales: the Coronado National Forest (CNF), a local management area, and the Sierra Madre Occidental (SMO), an ecoregional extent. Habitat suitability was determined by extrapolating Ecological Niche Models (ENMs) based on citizen-science tree occurrence records into future climatic conditions using projected 30-year normals for two anthropogenic emissions scenarios through the end of the century. These ENMs, examined at a spatial resolution of 1 km2, are constructed using a mean average ensemble of three commonly used machine learning algorithms. The results show that habitat suitability is expected to decrease for all seven tree species at varying degrees. Results also show that climate-forcing scenario choice appears to be far less important for understanding changes in species habitat suitability than the spatial scale of modeling extent. Additionally, we observed non-linear changes in tree species habitat suitability within the SMO and CNF dependent on forest community type, latitude, and elevational gradient. The paper concludes with a discussion of the necessary steps to verify the estimated alters of these tree species under climate change. Most importantly, provides a framework for characterizing habitat suitability across spatial scales.

First Report of Biscogniauxia mediterranea on Quercus emoryi in Southern Arizona.

In 2019, a decline of Quercus emoryi (Emory oak) was observed on the Coronado National Forest located in southeastern Arizona. Symptoms associated with oak mortality included crown die-back and large cankers revealing charcoal-like stromal growth. Trunks and root collars showed girdling and many affected trees also displayed evidence of gold-spotted oak borer activity. Initial surveys in stands identified clusters of severe infections. Samples with black perithecia and stromal tissue were collected from symptomatic hosts. Morphological characterization of the fungus was completed on fresh perithecial tissue. Stromata were pulvinate and black showing embedded perithecial bumps, with ostioles visible from the surface of the stroma. Asci were short stipitate and cylindrical with visible oil drops, 6.6 to 9.4 (mean: 8.8) × 139.8 to 179.9 μm (mean: 166.4). Ascospores were smooth ovoid, brown to dark brown, with narrowed and round ends, 6.9 to 9.1 (mean: 7.7) × 13.8 to 25.9 μm (mean: 16.5). Colonies grown on ½ strength potato dextrose agar (½ PDA) (Korhonen 1980) at 25°C for 14 days were whitish-grey when viewed from the top and darkened embedded spheres were visible from the bottom. Single-spored cultures were isolated by dissecting the hymenium and placing in distilled water. The suspension was streaked onto ½ PDA plates and incubated for 12 hours, and pure cultures were grown on ½ PDA. DNA was isolated from a mycelial scrape and extracted using a 10% Chelex solution (Safaee 2017). The internal transcribed spacer region was amplified with the ITS1/ITS4 primers (White et al. 1990) and PCR products were sequenced at Eurofins Scientific (Lewisville, KY). Isolates (BSS1, BSS2, BSS3, BSS4) were compared to other Biscogniauxia mediterranea sequences in the NCBI database (MG098274, EF026134) and had 100% sequence identity. Pathogenicity assays were conducted using 8-year-old Emory oaks in a greenhouse. The oaks were drought stressed and watered at 50% pot capacity for two months prior to inoculation. Each tree received approximately 2400 ml of water every two weeks for the remainder of the experiment. Eight trees were wounded three times with a 5mm corer. A 5mm plug of mycelium of isolate BSS2 was used to inoculate wounds. Four trees were used as controls and inoculated with ½ PDA plugs. Wounded and inoculated areas were assessed after three months. All eight trees exhibited dark necrotic tissue in the vascular cambium and lesions ranged from 11.4 - 25.8 mm in length and were 3.9 - 13.3 mm wide. The controls exhibited no fungal sign, lesions, or necrotic tissues. The pathogen B. mediterranea was recovered from 13 of the 24 total inoculations and its identity was confirmed with ITS sequencing. Mortality and die-back caused by Biscogniauxia spp. are commonly associated with drought-stressed trees, with increasingly hot and dry conditions routinely noted as inciting factors (Desprez Loustau et al.). Emory oaks are among the dominant tree species in much of the Madrean oak woodlands of the southwestern US and Mexico and provide vital ecological and cultural services. As southwestern states continue to experience hotter and drier, conditions, it is likely Emory oak will become increasingly susceptible to die-back and mortality due to this Biscogniauxia species (Southern et al.).

Statistical analysis reveals the onset of synchrony in sparse swarms of Photinus knulli fireflies.

Flash synchrony within firefly swarms is an elegant but elusive manifestation of collective animal behaviour. It has been observed, and sometimes demonstrated, in a few populations across the world, but exactly which species are capable of large-scale synchronization remains unclear, especially for low-density swarms. The underlying question which we address here is: how does one qualify a collective flashing display as synchronous, given that the only information available is the time and location of flashes? We propose different statistical approaches and apply them to high-resolution stereoscopic video recordings of the collective flashing of Photinus knulli fireflies, hence establishing the occurrence of synchrony in this species. These results substantiate detailed visual observations published in the early 1980s and made at the same experimental site: Peña Blanca Canyon, Coronado National Forest, AZ, USA. We also remark that P. knulli’s collective flashing patterns mirror those observed in Photinus carolinus fireflies in the Eastern USA, consisting of synchronous flashes in periodic bursts with rapid accretion and quick decay.

Impact of Inclement Weather on Overwinter Mortality of Montezuma Quail in Southeast Arizona

Inclement weather such as droughts or hard freezes are known to negatively impact quail species and population viability models exist which have evaluated northern bobwhite (Colinus virginianus) response to summer and winter catastrophes. Previous research suggests inclement weather may be an important factor that contributes to mortality of Montezuma quail (Cyrtonyx montezumae), but few data have been collected to evaluate actual rates of overwinter mortality. We evaluated the overwinter mortality of Montezuma quail in southeast Arizona following an episode of severe winter weather consisting of 27.54 cm of precipitation, which occurred from January to March 2010. Overwinter mortality for radio-marked birds (n 1⁄4 23) was 95.6%. Total abundance using flush counts at a control site estimated an 88% reduction in the population following the episode of above-average precipitation. Post-hunting season flush counts across multiple study sites throughout the Coronado National Forest also support this trend. The 3-year (2007–2009) average (6 SD) (41.67 6 4.73) of birds flushed was ~ 80% higher than number of birds (n 1⁄4 8) flushed in the 2010 post-hunting season.

Enhancing Recreation Sustainability through Social Capital Development

Recreation areas represent a socio-ecological system in which the primary purpose is to sustain the ecologic functions of the environment while also providing satisfying recreation experiences. Sustainability in a recreation area requires that the components that support this system are maintained or increased over time. These components can be thought of as ‘capital'. The focus of this study, social capital, examines the human element of this system by recognizing the potential value added by the visitor in terms of overall sustainability. The goal of this research was to measure the potential to build social capital amongst the visitors in the Sabino Canyon Recreation Area (SCRA) of the Coronado National Forest, United States, as a means of contributing to the overall sustainability of the recreation area. Recreation visitors were surveyed to determine their values surrounding the SCRA. The survey results defined visitor values by their willingness to devote time and finances, respect for the environment and resources, and actual statements of value. Based on responses to the survey questions, each respondent's relationship with the SCRA was characterized as contributing to the system's sustainability, having no effect, or reducing its sustainability. Fundamental features of social groups that allow individuals to work together for a common purpose are present at SCRA. By uniting visitors around their shared values, managers may be able to catalyze the collective efforts of social groups to foster a mutual commitment to the sustainability of the SCRA.

Cultural Survival in Action: Ola Cassadore Davis and the Struggle for dzi nchaa si'an (Mount Graham)

NAIS 1:2 FALL 2014 Cultural Survival in Action 151 JOEL T. HELFRICH Cultural Survival in Action: Ola Cassadore Davis and the Struggle for dził nchaa si’an (Mount Graham) I’m just a little bitty lady. I’ve never grabbed anyone before. But he [Senator Dennis DeConcini, D-Ariz.] is working for us in Arizona. He doesn’t scare me because I know I’m doing the right thing—standing up for my people. —OLA CASSADORE DAVIS MOUNT GRAHAM, an ecologically unique mountain range in Arizona, is one of the mostwritten-aboutand contendedoverIndigenous sacredsitesglobally.1 It is an oasis in the middle of a desert, an exceptional “sky island” ecosystem that possesses the most life zones or biotic communities of any solitary mountain in North America, and the home of at least 18 endemic species, especially the imperiled Mount Graham red squirrel. Mount Graham, or dził nchaa si’an (“big seated mountain”) in the Apache language, is the only place where Western Apache (Nneé) people collect certain plant and animal resources for use in ceremonials, learn how to live, and go to understand their cosmology— all of which are central to their culture and sovereignty.2 The landscape that has encompassed the “traditional Western Apache” homeland is diamond-­ shaped and includes Mount Graham, San Francisco Peaks, the White Mountains , especially Mount Baldy, and the Mazatzal Mountains.3 A sacred place since “time immemorial” to the Western Apache people, Mount Graham has been a site of struggle since the 1870s when it was removed from reservation lands by U.S. presidential order, but especially since the 1980s as a consortium of international research institutions led by the University of Arizona (UA) has sought astrophysical development opportunities. The struggle for this mountain has been long and contested. In the early 1980s, UA and its research partners selected Mount Graham as the location for a new generation of telescopes. Soon afterwards, environmental groups not only began to protest and litigate but also to point out the Apache connections to the mountain. In early 1987, Paul Pierce, a Tucson businessman and Director of the Coalition for the Preservation of Mount Graham, wrote to the Coronado National Forest. He pointed out the sacredness of the mountain and its present-day use by Apaches of the mountain: “We have since identified a group of San Carlos Apache people who are still using the high peaks Joel T. Helfrich NAIS 1:2 FALL 2014 152 of [Mount Graham] for religious reasons. Evidently this religious use of the mountain is contemporary and has been happening over the last few hundred years,” a comment that is supported by ethnohistorical records from approximately 1910 to 1940. Pierce stated that Mount Graham is sacred to members of the San Carlos Apache tribe and was still being used for religious rites. “The proposed development is viewed as potentially damaging to the Apache religion and the ceremonies that take place,” argued Pierce. He urged that the Forest Service address the potentially harmful impacts of UA’s astrophysical development. However, UA decided habitually to ignore and fight against ecological facts, Apache spiritual and tribal concerns, and its own data regarding the usefulness of its site selection and the limited astrophysical value of the mountain.4 In the face of legitimate concerns and strong opposition from both environmentalists and Apache people, UA lobbied the U.S. Congress in 1988 in order “to establish an international astronomical observatory on Mount Graham.”5 UA became the initial academic institution to achieve several dubious firsts regarding U.S. environmental, cultural, religious, and human rights law in its pursuit of astronomical excellence. Before it obtained an exemption from federal environmental and cultural laws, UA was the first university to lobby against the creation of a national wilderness (Mount Graham Wilderness Area) in 1984 and the first university to fight against the listing of an endangered species in 1986.6 UA obtained the additional recognition of being the first university to lobby and secure not one, but two, precedent-­ setting congressional exemptions (1988 and 1996) to subvert American Indian cultural and religious protection law, as well as U.S. environmental law; to promote a project whose biological approval was...

Bringing indices of species vulnerability to climate change into geographic space: an assessment across the Coronado national forest

Indices that rate the vulnerability of species to climate change in a given area are increasingly used to inform conservation and climate change adaptation strategies. These species vulnerability indices (SVI) are not commonly associated with landscape features that may affect local-scale vulnerability. To do so would increase their utility by allowing managers to examine how the distributions of vulnerable species coincide with environmental features such as topography and land use, and to detect landscape-scale patterns of vulnerability across species. In this study we evaluated 15 animal species that had been scored with the USDA-Forest Service Rocky Mountain Research Station's sys- tem for assessing vulnerability of species to climate change. We applied the vulnerability scores to each species' respective habitat models in order to visualize the spatial patterns of cross-species vulnerability across the biologically diverse Coronado national forest, and to identify the considerations of spatially referencing such indices. Across the study extent, cross-species vulnerability was higher in higher-elevation woodlands and lower in desert scrub. The results of spatially referencing SVI scores may vary according to the species examined, the area of interest, the selection of habitat models, and the method by which cross-species vulnerability indices are created. We show that it is simple and constructive to bring species vulnerability indices into geographic space: landscape-scale patterns of vulnerability can be detected, and relevant ecological and socioeconomic contexts can be taken into account, allowing for more robust conservation and management strategies.

A Plan for Landscape Fire Restoration in the Southwestern Borderlands

Fires were prevalent in the Southwestern Borderlands of Arizona and New Mexico prior to the arrival of European-American settlers in the 1880s. The almost total exclusion of fires for more than 100 years has been linked to declines in biological diversity and a loss of productivity associated with the encroachment of woody vegetation into the grasslands and open woodlands. Private and public land managers agreed that reintroducing fire could improve or reverse these landscape changes. The Coronado National Forest developed the Peloncillo Programmatic Fire Plan after intense consultations with federal, state, and county agencies and the ranching community to reintroduce landscape level prescribed and managed fire into the Peloncillo Mountains (Allen 1999). The final plan helped streamline the management decision and approval processes that previously were delayed by long, complicated, and often contentious discussions. The Plan and the consultation process that led to consensus among diverse partners can serve as a model for the development of programmatic fire plans in other areas.

Forest Service Grazing Permittee Perceptions of the Endangered Species Act in Southeastern Arizona

This study reports the results of a survey of Coronado National Forest grazing permittees about their attitudes regarding the Endangered Species Act (ESA) and the management of threatened and endangered (T&E) species on grazing allotments in southeastern Arizona. A majority of respondents perceived negative impacts from ESA implementation. However, the degree of impact remained independent of the number of listed species on allotments and of the potential for restrictions on those allotments. Perceptions of negative impact and attitudes toward T&E species policies were more related to attitudes toward federal regulation. Permittees broadly supported the idea of species conservation and expressed willingness to work with federal agencies but did not perceive the federal agencies as having the same responsiveness to their concerns. A more proactive agency strategy with science-based, focused recovery objectives coupled with economic incentives could improve support for species recovery efforts.

Post‐wildfire changes in suspended sediment rating curves: Sabino Canyon, Arizona

AbstractWildfire has been shown to increase erosion by several orders of magnitude, but knowledge regarding short‐term variations in post‐fire sediment transport processes has been lacking. We present a detailed analysis of the immediate post‐fire sediment dynamics in a semi‐arid basin in the southwestern USA based on suspended sediment rating curves. During June and July 2003, the Aspen Fire in the Coronado National Forest of southern Arizona burned an area of 343 km2. Surface water samples were collected in an affected watershed using an event‐based sampling strategy. Sediment rating parameters were determined for individual storm events during the first 18 months after the fire. The highest sediment concentrations were observed immediately after the fire. Through the two subsequent monsoon seasons there was a progressive change in rating parameters related to the preferential removal of fine to coarse sediment. During the corresponding winter seasons, there was a lower supply of sediment from the hillslopes, resulting in a time‐invariant set of sediment rating parameters. A sediment mass‐balance model corroborated the physical interpretations. The temporal variability in the sediment rating parameters demonstrates the importance of storm‐based sampling in areas with intense monsoon activity to characterize post‐fire sediment transport accurately. In particular, recovery of rating parameters depends on the number of high‐intensity rainstorms. These findings can be used to constrain rapid assessment fire‐response models for planning mitigation activities. Copyright © 2006 John Wiley & Sons, Ltd.

First Report of Chihuahua Pine Dwarf Mistletoe (Arceuthobium gillii) on Apache Pine (Pinus engelmannii).

Arceuthobium gillii Hawksw. & Wiens (Viscaceae) is primarily distributed in the Sierra Madre Occidental of Mexico from central Durango and northern Sinaloa into Chihuahua and Sonora (3). In Mexico, it commonly parasitizes Pinus leiophylla Schiede & Deppe var. leiophylla and var. chihuahuana (Engelm.) G. R. Shaw, P. lumholtzii Robinson & Fern., and P. herrerai Martinez and rarely infects P. arizonica Engelm. and P. cooperi Blanco (3). This dwarf mistletoe also occurs in the Chiricahua, Huachuca, Santa Rita, Rincon, and Santa Catalina Mountains of southern Arizona and the Animas Mountains of southwestern New Mexico (1,3). In the United States, A. gillii has only been reported to parasitize P. leiophylla var. chihuahuana (1,2,3). The host range of A. gillii has consistently not included P. engelmannii Carr. (2,3). However, we have located a small population of P. engelmannii naturally infected by A. gillii in the South Fork of Cave Creek, Chiricahua Mountains, Arizona. The infected P. engelmannii occurred approximately 2.6 km west of the South Fork Cave Creek Picnic Area, Coronado National Forest, along Forest Trail 243 (31°50'53″N, 109°12'14″W, elevation 1,670 m). Only four P. engelmannii were infected: one tree had four infections as indicated by small, dense witches' brooms and branches with large, spindle-shaped swellings, and three trees had one infection each based on the presence of brooms. One branch was collected from the tree with four infections because observations of the branch with binoculars indicated it had dwarf mistletoe shoots. Only four male shoots of A. gillii were on the branch and they were consistent morphologically with other male plants of this dwarf mistletoe collected from nearby P. leiophylla var. chihuahuana. The infected P. engelmannii were all growing in close association with P. leiophylla var. chihuahuana severely infected with A. gillii. The only other dwarf mistletoe reported to infect P. engelmannii in the Chiricahua Mountains is A. vaginatum (Willd.) Presl subsp. cryptopodum (Engelm.) Hawksw. & Wiens. This dwarf mistletoe was not present or anywhere near the Cave Creek population of P. engelmannii. In addition, plants of A. gillii can be easily distinguished morphologically from those of A. vaginatum subsp. cryptopodum by their color (2,3). Plants of A. gillii are consistently green to greenish brown, while plants of A. vaginatum subsp. cryptopodum are consistently orange to reddish brown. A specimen of A. gillii on P. engelmannii has been deposited at the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession No. 75392). To our knowledge, this is the first report of A. gillii on P. engelmannii. This host-dwarf mistletoe combination is evidently very rare because other investigators have reported that P. engelmannii was probably immune to A. gillii (2,3).

AHP as a means for improving public participation: a pre–post experiment with university students

Abstract Students enrolled in a course in natural resources management and economics at the University of Arizona tested the application of the multi-criteria decision method, the Analytic Hierarchy Process (AHP), to a national forest planning situation. The students first used an intuitive method and then the AHP method to express their preferences for eight possible wilderness sites that were characterized and thus differentiated by 19 criteria. The sites were located in the Coronado National Forest in southeastern Arizona, USA. Spearman's rank correlation coefficient was calculated to test for correlation between the rankings generated by the intuitive decision method and the AHP method. The Spearman's tests indicated for 16 of the 20 students a lack of correlation between individual rankings by the two methods thus suggesting that the AHP can influence preference rankings. Questionnaire responses by the students indicated that the AHP requires closer scrutiny and a more comprehensive consideration of all criteria than does an intuitive preference ranking approach. This study demonstrates that the AHP offers potential for actual application as a public participation tool.

Transforming Forests with Good Intentions

Transforming Forests with Good Intentions

Interactions between Predators and Mt. Graham Red Squirrels (Tamiasciurus hudsonicus grahamensis)

Predation in populations of small mammals is a rarely observed event (Pearson, 1985); however, the role of predators in population regulation often is considered to be important. Documentation and assessment of mortality factors are especially critical when considering the population dynamics of threatened or endangered species. Herein, we document interactions of the endangered Mt. Graham red squirrel with potential predators. The Mt. Graham red squirrel (Tamiasciurus hudsonicus grahamensis) is an isolated subspecies found only on the highest peaks of the Pinalefio Mountains, Graham Co., Arizona (Hoffmeister, 1986). The squirrel is slightly smaller in body size and has a slightly narrower skull (United States Fish and Wildlife Service, 1993) than other red squirrels found in North America. Genetic evidence also supports the distinctiveness of this geographically isolated subspecies (Sullivan and Yates, 1994). The squirrel was reported to be extinct in the 1960s (Minckley, 1968) but was rediscovered in 1972 (Spicer et al., 1985) and listed as endangered in 1987. In fall 2000, the total population of the Mount Graham red squirrel was estimated at approximately 470 individuals (T. Snow, Arizona Department of Game and Fish, pers. comm.). Mount Graham red squirrels inhabit sprucefir and mixed conifer forests (United States Fish and Wildlife Service, 1993). Red squirrels larderhoard seed cones into piles known as middens, typically near the center of their territory (Steele, 1998). Preferred midden locations include areas of thick foliage, dense canopies, and high stem densities (Smith and Mannan, 1994). Depending on season and availability, the squirrels feed mainly on conifer seeds, fungi, bone, and conifer twigs (Coronado National Forest, 1988). Nest sites typically are located in large decaying snags (Froehlich and Smith, 1990). Our monitored area, approximately 250 ha, incorporates both mixed conifer forest dominated by Douglas-fir (Pseudotsuga menziesii), ponderosa pine (Pinus ponderosa), corkbark fir (Abies lasiocarpa var. arizonica) and southwestern white pine (Pinus strobiformis) and sprucefir forest composed principally of Englemann spruce (Picea engelmannii) and corkbark fir. During the course of other investigations (Young, 1994), observations of potential predators were recorded nearly monthly from 1989 until 1996 and quarterly thereafter. A minimum of 41,000 h of field observation, including 3,269 h of focal animal observations, was expended. Eighty-three observations of predators were made during monitoring periods (Table 1). Eight species of potential predators (6 avian, 2 mammalian) were observed. Five predation attempts, 1 successful and 4 unsuccessful, were recorded. Evidence of 6 possible predation attempts was documented and 5 potential predator species were observed in or near middens but did not attempt predation. On 19 October 1989, 2 juvenile red squirrels (presumed siblings) chased each other as a Mexican spotted owl (Strix occidentalis lucida) unsuccessfully attacked at 1354 h MST. After 1 min the squirrel chase resumed and the owl looked on from a perch 15 m away. Eight min later the owl made a second, and this time successful, attempt. Carrying the squirrel by the neck, the owl flew 30 m east, perched in a tree for a few minutes and then left the area. Im-

Nest-Site Characteristics and Nesting Success of the Greater Pewee in Arizona

Nest-Site Characteristics and Nesting Success of the Greater Pewee in Arizona

Three Road-Crushing Demonstration Projects

At the Sixth International Conference on Low-Volume Roads Yves Provencher, Forest Engineering Research Institute of Canada, presented a paper on the F.A.H.R. rock crusher mounted to a front-end loader. At the same time the Coronado National Forest in Arizona was renting a F.A.H.R. rock crusher for an in-place road-crushing project. In 1997 San Dimas Technology and Development Center, in partnership with the Coronado National Forest, sponsored two demonstration projects to further test the crusher at unique locations to gain additional information from actual field trials. These projects were located on the Rio Grande National Forest in Colorado and the Plumas National Forest in California. The three projects are described here, with results and conclusions gained from the demonstration projects. The concentration is on the characteristics of the processed material. Samples taken from windrows during the crushing operation were tested to determine hardness and gradations before and after crushing. Cost varied from $8 to $26 per m3 including roadbed preparation, crushing, and blading. Rocks and boulders to 405-mm maximum size were crushed. The processed material has a maximum size of 50 to 75 mm. The product produced by the crusher offers a viable alternative for aggregate on a road surface, particularly as a road surface cushion material, where the quality and expense of standard crushed aggregate, such as base course material, are not needed on low-volume roads.

Habitat Use and Its Effect on Body Size Distribution in a Population of the Tree Lizard, Urosaurus ornatus

The abiotic environment can play an important role in generating variation within and among populations of ectotherms (see Dunham et al., 1989). Among the more important of abiotic factors influencing ectotherm life histories and growth rate is temperature (Sinervo and Adolph, 1989,1994; Sinervo, 1990), which is often mediated by its potential effect on the duration of activity periods (Grant and Dunham, 1990). Individuals and/or populations living in different habitats or slopes (e.g., east vs. west-facing; north vs. south-facing) can potentially have different potential activity periods which, in turn, may influence an individual's ability to grow, as well as the body size distributions among habitats and slopes within a single population. In a population of Sceloporus virgatus along a creekbed in the Chiricahua Mountains of southeastern Arizona, G. Smith (1995) found that the mean body sizes of individuals differed between habitats (an open slide habitat vs. a closed woods habitat) and between slopes (north-facing vs. south facing). In addition, there were differences in growth rate, survivorship, and proportion of females reproducing in their first year (G. Smith, 1995). In this paper, I report observations on habitat use and body size in a population of Urosaurus ornatus occurring in the same creekbed as the S. virgatus studied by G. Smith (1995, 1996), where they have previously been shown to be potential competitors (D. Smith, 1981). Because of the differences in body size distributions and life history and demographic traits previously observed in S. virgatus, I expected to find parallel differences in U. ornatus. A population of Urosaurus ornatus was studied from 8 April to 22 July 1993 (concurrent with the studies on S. virgatus). The study site was located in the Coronado National Forest, 2.5 km SW of the Southwestern Research Station in the Chiricahua Mountains of southeastern Arizona. The site consisted of a 1.2 km

Forest Service and Livestock Permittee Behavior in Relation to Wilderness Designation

Even though the Wilderness Act of 1964 provided for continuation of livestock grazing after wilderness designation, there has been continued debate about the Forest Service's implementation of this provision and the impact on livestock grazing permittees. The effect of wilderness designation, during the first 20 years after designation, on Forest Service and permittee behavior on Coronado and Tonto National Forests in Arizona was evaluated by (1) comparing changes in permitted AUMs, changes in permit ownership, and proportion of nonuse of permitted AUMs between paired wilderness and nonwilderness grazing allotments, and (2) assessing the importance of the proportion of an allotment in wilderness on these same behavioral parameters. In general, permitted AUMs increased on wilderness allotments but remained the same for nonwilderness allotments. However, there was no difference on Coronado National Forest when forests were analyzed separately. Compared to nonwilderness allotments, wilderness allotments had greater permittee turnover on Coronado National Forest, but there were no differences between wilderness and nonwilderness allotments when forests were combined. The higher the proportion of an allotment in wilderness, the faster the turnover of permit owners, but wilderness proportion did not affect nonuse or changes in permitted AUMs.

One Rancher's Experience: In The Grassland Range of Southern Arizona

The ranch we are writing about lies near the Mexican border in southern Arizona in some of the best grass country in the West. The topography is rather gentle, the range being crossed by a number of low ridges and intermittent water courses. Most of the soils are of granitic origin and hence very open although some of the ridge tops are charact.erized by more droughty tighter soils. The avergao _ annual precipitation is 18 i&es, of which about 14 inches comes during the frostfree period. The ranch base property was built up by consolidating a number of homesteads. Like many other southwestern homesteaders, those in this area found that the 160 acres allotted by the Homestead Act was too small to make a family living. Those who stayed longest managed to survive by working part-time at nearby mines, but gradually, as the mines closed down, the homesteaders were nearly all forced to leave. The ranch now comprises 1,310 acres of patented land acquired from eight different owners, and 6,700 acres of forest allotment on the Coronado National Forest.