Mogollon Plateau Research Articles

Lesser Long-Nosed Bat (Leptonycteris yerbabuenae) Range Expansion into Northern Grant County, New Mexico

The lesser long-nosed bat (Leptonycteris yerbabuenae) previously was known only from extreme southwestern New Mexico in southern Hidalgo County. Herein, we documented L. yerbabuenae from northern Grant County along the Gila River on the southern edge of the Mogollon Plateau, which represents a 110-km range expansion to the north. We captured mostly volant young-of-the-year (68.5%) and adult females (25.9%) as well as a few adult males (5.6%) in September 2019. With assistance from local residents, we have evidence that nectar-feeding bats have been using hummingbird feeders in the area at least since 2014 and are a relatively new arrival to the area. In 2019, the latest observation of bats emptying hummingbird feeders at our study site was on 25 October, the latest reported date for the presence of this species in the state. Fur coloration on the back and head of volant young was dull gray compared to the richly orange- and brown-colored adults. Forearm lengths were shorter and body weights lighter in young compared to adults. It is unclear whether this species bears and/or raises its young in the Gila area or whether the documented individuals represent those dispersing from maternity roosts after the young become volant, a common late-season behavior for this species in the northern reaches of its distribution. Our documentation of this nectar-feeding bat adds to the high diversity of bat species associated with the Mogollon Plateau in southwestern New Mexico.

Meta-replication reveals nonstationarity in multi-scale habitat selection of Mexican Spotted Owl

ABSTRACT Anthropogenic environmental changes are leading to habitat loss and degradation, driving many species to extinction. In this context, habitat models become increasingly important for effective species management and conservation. However, most habitat studies lack replicated study areas and do not properly address the role of nonstationarity and spatial scales in determining factors that limit species occurrence under different environmental settings. Here we provide an optimized multi-scale framework for analyzing habitat selection of the threatened Mexican Spotted Owl (Strix occidentalis lucida) between 2 meta-replicated study areas: the Sacramento Mountains, New Mexico, and the Mogollon Plateau, Arizona. The optimized scales of habitat variables strongly differed between the 2 study areas. Percent cover of mixed-conifer was more strongly associated with the relative likelihood of Mexican Spotted Owl occurrence in the Sacramento Mountains than in the Mogollon Plateau. Topographic covariates str...

Historical Stand-Replacing Fire in Upper Montane Forests of the Madrean Sky Islands and Mogollon Plateau, Southwestern USA

The recent occurrence of large fires with a substantial stand-replacing component in the southwestern United States (e.g., Cerro Grande, 2000; Rodeo-Chedeski, 2002; Aspen, 2003; Horseshoe 2, Las Conchas, and Wallow, 2011) has raised questions about the historical role of stand-replacing fire in the region. We reconstructed fire dates and stand-replacing fire patch sizes using four lines of tree-ring evidence at four upper montane forest sites (>2600 m) in the Madrean Sky Islands and Mogollon Plateau of Arizona and New Mexico, USA. The four lines of tree-ring evidence include: (1) quaking aspen (Populus tremuloides) and spruce-fir age structure, (2) conifer death dates, (3) traumatic resin ducts and ring-width changes, and (4) conifer fire scars. Pre-1905 fire regimes in the upper montane forest sites were variable, with drier, south-facing portions of some sites recording frequent, low-severity fire (mean fire interval of all fires ranging from 5 yr to 11 yr among sites), others burning with stand-replacing severity, and others with no evidence of fire for >300 yr. Reconstructed fires at three of the four sites (Pinaleno Mountains, San Francisco Peaks, and Gila Wilderness) had stand-replacing fire patches >200 ha, with maximum patch sizes ranging from 286 ha in mixed conifer-aspen forests to 521 ha in spruce-fir forests. These data suggest that recent stand-replacing fire patches as large as 200 ha to 500 ha burning in upper elevation (>2600 m) mixed conifer-aspen and spruce-fir forests may be within the historical range of variability.

Bias and error in using survey records for ponderosa pine landscape restoration

AbstractAim Public land survey records are commonly used to reconstruct historical forest structure over large landscapes. Reconstruction studies have been criticized for using absolute measures of forest attributes, such as density and basal area, because of potential selection bias by surveyors and unknown measurement error. Current methods to identify bias are based upon statistical techniques whose assumptions may be violated for survey data. Our goals were to identify and directly estimate common sources of bias and error, and to test the accuracy of statistical methods to identify them.Location Forests in the western USA: Mogollon Plateau, Arizona; Blue Mountains, Oregon; Front Range, Colorado.Methods We quantified both selection bias and measurement error for survey data in three ponderosa pine landscapes by directly comparing measurements of bearing trees in survey notes with remeasurements of bearing trees at survey corners (384 corners and 812 trees evaluated).Results Selection bias was low in all areas and there was little variability among surveyors. Surveyors selected the closest tree to the corner 95% to 98% of the time, and hence bias may have limited impacts on reconstruction studies. Bourdo’s methods were able to successfully detect presence or absence of bias most of the time, but do not measure the rate of bias. Recording and omission errors were common but highly variable among surveyors. Measurements for bearing trees made by surveyors were generally accurate. Most bearings were less than 5° in error and most distances were within 5% of our remeasurements. Many, but not all, surveyors in the western USA probably estimated diameter of bearing trees at stump height (0.3 m). These estimates deviated from reconstructed diameters by a mean absolute error of 7.0 to 10.6 cm.Main conclusions Direct comparison of survey data at relocated corners is the only method that can determine if bias and error are meaningful. Data from relocated trees show that biased selection of trees is not likely to be an important source of error. Many surveyor errors would have no impact on reconstruction studies, but omission errors have the potential to have a large impact on results. We suggest how to reduce potential errors through data screening.

Seismicity and Tectonics of the Blue Ridge Area of the Mogollon Plateau, Arizona

Abstract The seismicity of the Blue Ridge area of the Mogollon Plateau exists within a framework of Tertiary volcanics and normal faulting. The seismicity includes earthquake sequences in 1989 and 2005 with principal events as large as Richter local magnitude ( M L ) 4.6 (National Earthquake Information Center [NEIC]). Analysis of this seismicity indicates that it is characterized by normal faulting on northwest-trending planes. The normal faults form part of the Cataract Creek fault system that has historically generated earthquakes as large as surface wave magnitude ( M S ) 6.2 (Brumbaugh, 1991; Bausch and Brumbaugh, 1997). Regionally these northwest-trending fracture systems/faults of the southern Colorado plateau appear to pose the greatest seismic hazard to the Grand Canyon National Park with almost five million visitors per year and the rapidly growing Flagstaff area.

Distribution and Habitat of the Arizona Gray Squirrel (Sciurus arizonensis) in New Mexico

Abstract Little is known about the Arizona gray squirrel (Sciurus arizonensis), which is endemic to mid-elevation riparian habitats in Arizona, New Mexico, and Sonora. In New Mexico, previous compilations of specimen records were restricted to the San Francisco River drainage in western Catron County. We compiled information on museum specimens, literature records, and observations by credible persons to document the distribution and habitats of S. arizonensis in New Mexico. Sciurus arizonensis is broadly distributed throughout the southern Mogollon Plateau region of Catron, Grant, and Sierra counties, including the San Francisco, Gila, Mimbres, and Rio Grande river drainages. All records were closely associated with riparian areas and most were from broadleaf riparian habitats. Sciurus arizonensis was observed to interact with other tree squirrels, including the Abert's squirrel (Sciurus aberti) and red squirrel (Tamiasciurus hudsonicus). We conclude that there has been neither a recent range expansion n...

New Taxa in Oenothera (Onagraceae)

A new species, three new sections, and one new subsection of Oenothera are described and a new combination in 0. flava is made here so that the names will be available. Oenothera coryi (sect. Megapterium), which ranges from north-central Texas to the southern part of the panhandle, is described. The combination 0. flava subsp. taraxacoides (sect. Lavauxia) is made for large-flowered, modally outcrossing populations of 0. flava from three disjunct areas: 1) Mogollon Plateau, Arizona to Catron Co., New Mexico; 2) Sacramento Mountains and Sierra Blanca in southeastern New Mexico; and 3) Sierra Madre Occidental from Chihuahua to Durango, Mexico. As part of a genus-wide reevaluation of the infrageneric classification, three new sections, sect. Ravenia, sect. Eremia, and sect. Contortae, are proposed for species formerly included in subg. Pachylophus, which is no longer recognized, and subsect. Australis is described for the two white-flowered South American species of sect. Lavauxia.

Mid‐Tertiary ash flow tuff cauldrons, southwestern New Mexico

This summary characterizes 28 known or suspected mid‐Tertiary ash flow tuff (ignimbrite) cauldrons, up to 40 km in diameter, in southwestern New Mexico. A combination of postcauldron block faulting and erosion has resulted in widely ranging levels of three‐dimensional exposures, down to plutonic roots. The evolution of the largest resurgent cauldrons followed the course determined by other workers for the Valles caldera (New Mexico) and Lake City cauldron (Colorado), with local variations. Five principal stages can be recognized: (1) precursor, (2) caldera collapse, (3) early post‐collapse volcanism, (4) major ringfracture volcanism, and (5) hydrothermal activity. Development can be terminated at any stage; stages can also be repeated. Resurgent doming can occur during stage 3 or later; doming can also be enhanced by reactivation of cauldron structures by postvolcanic basin and range faulting. Even where the surface of caldera‐fill tuff is domed, the base may have quite a different configuration. Recognition of resurgent doming may be difficult in deeply eroded cauldrons. A proposed modification in the definition of “resurgence” places emphasis on one or more magma pulses after a caldera‐forming eruption; doming is one of several effects that may or may not occur when magma invades a previously subsided cauldron. In some cauldrons, postcollapse lavas can be divided into (1) “cauldron lavas,” i.e., relatively mafic crystal‐rich disequilibrium assemblages derived from shallow defluidized residues of caldera‐forming ash flow tuff eruptions, and (2) “framework lavas,” i.e., relatively siliceous crystal‐poor near‐equilibrium assemblages derived from an evolving siliceous pluton at deeper levels, below the cauldron complex. Special features of New Mexico cauldrons include zoned outflow sheets; zoning may be normal (most siliceous at the bottom) or reversed. Posteruption potassium metasomatism may mask some chemical trends. Several styles of eruption can be recognized among mid‐Tertiary cauldrons of southwestern New Mexico. The largest ones tend to occur in clusters, interpreted as surface expressions of buried composite plutons (e.g., Mogollon Plateau). In an early stage of development, or on the fringe of a cluster, cauldrons tend to be asymmetrical trapdoor structures, formed by repeated small eruptions separated by quiescent periods. During the height of activity, cauldrons formed by eviscerating eruptions, commonly followed by resurgence. The youngest known cauldron is shallow and resulted from asymmetrical subsidence and collapse of caldera walls.

Subsurface extensions of the Santa Rita–Hanover axis: A major early Tertiary structure, New Mexico

Structural data and field relationships in the southern part of the Mogollon Plateau volcanic province of southwestern New Mexico show that significant shallow intrusive activity occurred during early Tertiary time along a north-northeast–trending belt 1.5 to 3.0 km wide and 35 to 45 km long. Magmas were injected into Paleozoic-Mesozoic sedimentary strata, causing arching and other deformation of the country rocks. The resulting structure, called the Santa Rita-Hanover axis, initially had considerable topographic relief. It acted as a barrier to mid-Tertiary volcanic flows, causing the development of two volcanic subprovinces. The Santa Rita and Hanover-Fierro intrusions define the southern part of the axis and are associated with large deposits of copper, zinc, and iron, which give the structure major economic importance. Other ore deposits may also be associated with the axis.

Squirrel Springs Volcano-Tectonic Depression: A Buried Cauldron in Southwestern New Mexico

The Squirrel Springs depression is a 25-km-diameter structural basin in the northwest part of the Mogollon Plateau volcanic province, which is interpreted as the surface expression of a buried cauldron. Evidence for the buried cauldron includes (1) a shallow, terraced structural basin 25 km in diameter in which postcauldron volcanic rocks are ponded, (2) a circular fault pattern around the basin that is discordant with regional structural trends, (3) a porphyritic quartz latite dome complex centered within the basin, and (4) flow direction measurements showing flow of the Tularosa Canyon ash-flow tuff outward from the structure. The Squirrel Springs depression developed by (1) cauldron collapse accompanied by eruption of the Tularosa Canyon ash-flow tuff 30.7 m.y. ago, (2) burial of the cauldron by younger volcanic rocks, (3) reactivation of ring fractures forming a structural basin, and eruption of the John Kerr Peak Quartz Latite domes, and (4) arching of the northwest rim of the Mogollon Plateau, obscuring the western part of the Squirrel Springs depression.

Hooded Skunk on the Mogollon Plateau, New Mexico

Hooded Skunk on the Mogollon Plateau, New Mexico

Distribution and Directional Fabric of Ash-Flow Sheets in the Northwestern Mogollon Plateau, New Mexico

Individual ash-flow sheets distributed over wide areas in the Mogollon-Datil volcanic province can be delineated and related by flow direction techniques to specific source cauldrons. Two major mid-Tertiary ash flows in the Mogollon Plateau have measurable microscopic directional fabric indicative of primary flow direction imprinted in the ash-flow sheets during late-stage laminar flow. Regional stratigraphic relationships and flow patterns of the ash-flow sheets indicate a late Tertiary origin of the Mogollon Plateau depression. They also show that Basin-Range faulting in southwestern New Mexico was not initiated until after emplacement of the younger ash flow (23 m.y. B.P.). Directional fabric is an inherent property of many calc-alkalic ash-flow sheets and measurement of preferred orientation provides a powerful tool in unravelling the geologic history of complex volcanic terrane.

Fe content in pyroxenes from a calc-alkalic volcanic suite, New Mexico, U.S.A.

Electron microprobe analyses of clinopyroxene, both phenocrysts and groundmass, in the calc-alkalic suite (basalt-basaltic andesite-andesite-latite) of the Mogollon Plateau, New Mexico, show little variation in Fe content. The clinopyroxene averages approximately Wo 40En 42Fs 18 in composition and does not vary more than about 7 percent Fs content throughout a suite of rocks that range from 50 to 65 percent in SiO 2 content. Orthopyroxene, on the other hand, is restricted to basaltic andesites and andesites and shows slightly greater variation in Fe content than the clinopyroxenes. It is suggested that the factors limiting concentration of Fe in calc-alkalic magmas, such as high oxygen pressures, are reflected in the clinopyroxenes crystallizing in these magmas by their limited range in Fe content.

Environmental Studies of Fort Apache Member, Supai Formation, East-Central Arizona

The Fort Apache Member of the Supai Formation is a marine unit of variable lithologic composition, and is limited areally to east-central Arizona. The member was measured, described, and sampled at 17 surface exposures along the Mogollon Rim from the Fort Apache--White River area northwest to Oak Creek Canyon. Examination of samples and well logs from 22 oil tests indicates that the member is extensive in the subsurface of the southern Mogollon Plateau. The Fort Apache Member is thickest in the extreme east-central part of Arizona and thins northwestward. The type section at Kelly Butte is incomplete and relatively inaccessible; therefore the Corduroy Creek and Middle Cedar Creek sections were established as reference localities. Distinct limestone, dolomite, and evaporite-dolomite lithofacies are present within the Fort Apache Member. The facies is confined mainly to the Fort Apache Indian Reservation and adjacent areas, and consists of dark, dense, very finely crystalline, fossiliferous with a biomicrosparite-intramicrosparrudite texture. The facies contains a mollusk-echinoderm-foraminifer fauna. Terrigenous admixtures generally are less than 5 per cent; clay minerals are illite and minor montmorillonite. The dolomite facies is present only in the central and western Mogollon Rim region and areas adjacent on the north. The strata consist of light-colored, dense, silty, and very finely crystalline dolomite bearing a fauna composed predominantly of mollusks, foraminifers, and ostracods. The abrupt change from the to the dolomite facies is accompanied by a marked thinning of the Fort Apache Member and an increase in the amount of quartz silt. Illite and montmorillonite are the principal clay minerals, and kaolinite is abundant locally. The evaporite-dolomite facies is present only in the Holbrook basin and consists mainly of dolomite with interstratified and intergrown anhydrite and halite. Foraminifers and ostracods are the principal biogenic constituents. Clay minerals consist of an illite-montmorillonite-chlorite assemblage. Because the rocks of the Fort Apache Member are predominantly dolomite, it is recommended that use of the lithologic qualifying term limestone be discontinued and that the unit be referred to as the Fort Apache Member of the Supai Formation. Petrographic studies indicate that the Fort Apache sedimentary rocks were deposited originally as an aragonitic or calcitic, allochem-bearing or microcrystalline, allochemical mud. Most of the textures are characteristic of carbonate accumulation in a shallow-marine environment free of persistent currents or wave motion. Intraclastic textures are indicative of intermittent, vigorous agitation of the sea bottom. An early diagenetic (syngenetic) origin is suggested for the dolomite.

RHYOLITE ASH‐FLOW PLATEAUS, RING‐DIKE COMPLEXES, CALDERAS, LOPOLITHS, AND MOON CRATERS*

Data supporting idea that terrestrial volcano- tectonic depressions resembling Moon craters exist, noting Mogollon plateau in New Mexico

Revision of the Desert Cottontail, Sylvilagus audubonii, in the Southwest

Individual, secondary sexual and geographic variations are analyzed in Sylvilagus audubonii in the Southwest. Ways of distinguishing this species from both S. floridanus and S. nuttallii in this region are presented. A method of selecting homogeneity in age of specimens is suggested. Individual variation appears to be average and secondary sexual variation probably unimportant in most characters. Cranial and external characters are most useful in studying geographic variation while color, except in one subspecies, is of little significance. The geographic location of character shifts in 12 characters is shown graphically. Those shifts showing a high degree of concordancy form the primary basis for subspecific boundaries. Four subspecies of S. audubonii ( warreni, arizonae, minor and goldmani ) are recognized, and the name cedrophilus is placed in synonymy. Strong local variation occurring in certain subspecies is described. The Mogollon Plateau is shown to have been a most important geographic feature affecting the differentiation within this species in Arizona.