El Malpais Research Articles

Comparison of Fungal and Bacterial Microbiomes of Bats and Their Cave Roosting Environments at El Malpais National Monument, New Mexico, USA

The arrival in North America of white-nose syndrome (WNS), a devastating fungal disease in bats, has emphasized the necessity of a comprehensive understanding of the bats’ external skin microbiota. Here, we investigated the composition of the natural bat microbiota pre-WNS and how they are acquired. The fur surfaces of 12 roosting bats, adjacent cave walls, and cave chamber air were sampled in two New Mexican lava caves. Bacterial and fungal diversity were assessed using Illumina MiSeq sequencing. Although many taxa were shared among the sample types, there were significant differences in alpha and beta diversity within and among communities. Bacterial phyla Actinobacteriota (39.1%) and Proteobacteria (27.9%) comprised two-thirds of the sequences. Fungal communities were dominated by Ascomycota (78.9%), followed by Basidiomycota (14.7%), and Mucoromycota (4.3%). Results for bacterial communities suggested that cave walls and cave air influence the bat microbiome and that the bat microbiome can have a reciprocal influence on the microbiome of cave walls. Fungal microbiomes of cave walls, air, and bats appear to have very low impact on each other. Our results begin to elucidate how cave environments may provide natural microbial defenses for bats, one facet in predicting the effect of WNS on western bats.

A Diverse Flea (Siphonaptera) Assemblage from the Small Mammals of Central New Mexico

The geographical ranges of many mammals and their associated parasites are dynamic. Comprehensive documentation of these communities over time provides a foundation for interpreting how changing environmental conditions, driven by accelerating climate change, other anthropogenic disturbances, and natural events, may influence host-parasite interactions. Fleas (Order Siphonaptera) are obligate, hematophagous parasites of birds and mammals with medical interest because of their role in transmitting pathogens. From 2016 to 2019, we sampled the small mammal and associated flea communities in El Malpais National Conservation Area (El Malpais) in Cibola County, New Mexico. Among 898 mammalian specimens, 925 fleas representing 29 species were collected from 18 host species. Pleochaetis exilis was the most abundant flea species, composing 27% of the total fleas collected, whereas Aetheca wagneri was the most prevalent flea species, parasitizing 8% of the community sampled. Across a total of 284 hosts recorded with fleas, A. wagneri, Malaraeus eremicus, and Peromyscopsylla hesperomys adelpha parasitized the most host species (n = 6 each). Onychomys leucogaster (Wied-Neuwied, 1841), the northern grasshopper mouse, a rodent highly implicated in plague dynamics, was host for the highest number of flea species (n = 15), followed by Peromyscus truei (Shufeldt, 1885) (n = 10). Our aims are to (a) describe the flea-mammal assemblage of a central New Mexico site, creating a baseline for diversity against which changing patterns of association can be assessed over time; (b) identify previously unrecognized host associations; and (c) examine infestation parameters, including the relationships of flea prevalence and mean abundance to host sex, host abundance, and seasonality. As such, our study exemplifies the Documentation and Assessment phases of the DAMA protocol (Document, Assess, Monitor, Act), a central component of exploring distribution and diversity of complex pathogen-host communities across space and time that are essential to a proactive understanding of emerging disease.

U.S. National Park visitor perceptions and behavioral intentions towards actions to prevent white-nose syndrome.

In the United States, the discovery and spread of white-nose syndrome (WNS) has drastically changed how bats and caves are managed. The U.S. National Park Service has been instrumental in the national response to WNS, as it manages extensive cave resources and has a close relationship with the public. However, managers lack information on visitor support for disease prevention measures designed to slow the spread of WNS and minimize human disturbance of vulnerable bat populations. This study utilized the Theory of Planned Behavior to determine how visitor attitudes, subjective norms, and perceived behavioral controls influenced their behavior regarding WNS preventive actions, including participation in educational programming on bats, wearing clothes or shoes in caves that have not been contaminated with the fungus that causes WNS, walking over decontamination mats, and complying with cave closures. During summer of 2019, data were collected using an on-site survey of 1365 visitors to eight U.S. national park units: Oregon Caves, Lava Beds, Carlsbad Caverns, El Malpais, Wind Cave, Jewel Cave, Mammoth Cave, and Cumberland Gap. Visitors were willing to participate in all preventative actions addressed in the survey (77.7%-96.7%). Visitors expressed that engaging in these actions was very desirable (36.0%-65.6%), and their decision to engage in these actions was most strongly influenced by park staff (39.2%-68.8%) or signage (35.5%-61.9%). Attitudes and subjective norms were positive predictors of behavioral intentions for all measures. Perceived behavioral control was not a direct predictor for behavioral intent, but its interaction with attitudes and subjective norms had a moderating influence on intention to comply with multiple WNS preventive actions. With the continued spread of WNS and emergence of other threats to bats, understanding visitor behavioral intent and underlying factors will facilitate successful implementation of preventive actions that are publicly supported and promote conservation of bat populations in U.S. national parks.

Bryophytes of El Malpais National Monument

The bryophytes of El Malpais National Monument in west-central New Mexico were collected and inventoried. The study area is dominated by lava flows and tubes some of which form ice caves and fascinating moss gardens. These gardens contain disjunct bryophyte populations enabled by ice and cool year-round temperatures at cave entrances. A total of 110 bryophyte species were found including 95 moss species in 23 families, and 15 liverwort species in 10 families. Six of these bryophyte species are new state records for New Mexico. No hornworts were found. We review past work on bryophytes in this unique habitat, and present a short biography of Alton A. Lindsey. This is a fragile habitat and global warming may put it at risk.

Chronology of young basalt flows from lava tube gypsum U-series ages

Basaltic lavas provide a window into their mantle sources and the associated geodynamic processes associated with them. Obtaining absolute chronology on young basalt flows is often challenging. Some gypsum crusts in pyro-duct (lava tube) caves crystallize during the last “cooling” stages of tube formation probably at relatively low temperatures (i.e., <100 °C). Here we propose uranium-series dating of these ‘speleogenetic’ gypsum crusts as a way to establish the ages of young basalt flows. We demonstrate the technique using cave crusts from four young basalt flows in El Malpais National Monument, New Mexico, three of which are moderately well-dated by alternative methods ( 14 C, 36 Cl, and 3 He ages). They all exhibit well-formed lava tube systems that contain gypsum crust speleothems interpreted to be remnant of the volcanic sulfur or sulfate processes when the tube systems were active during their terminal stages. δ 18 O SO4 , δ 34 S, 87 Sr/ 86 Sr, and δ 234 U values for the gypsum crusts have near-basaltic signatures, and the crusts contain uranium concentrations suitable for uranium-series dating in three of these four basalt flows. Analyses of gypsum from caves of two well-dated basalt flows yielded uranium-series ages that agree with the ages determined by other techniques showing that absolute ages of young basalt flows can be achieved by this method. The fourth flow, the Hoya de Cibola basalt, previously undated by other absolute means has a U–Th gypsum crust isochron age of 16.9 ± 0.9 ka. The uranium-series age and isotopic analyses of these gypsum crusts should be useful in geologic applications involving young basalt flows.

Are microclimate conditions in El Malpais National Monument caves in New Mexico, USA suitable for Pseudogymnoascus growth?

Are microclimate conditions in El Malpais National Monument caves in New Mexico, USA suitable for Pseudogymnoascus growth?

A new millipede, Austrotyla awishoshola n. sp., (Diplopoda, Chordeumatida, Conotylidae) from New Mexico, USA, and the importance of cave moss gardens as refugial habitats.

Austrotyla awishoshola n. sp. is described from the moss gardens of one lava tube cave in El Malpais National Monument, Cibola Co., New Mexico. Most chordeumatidans require mesic conditions, and these environments are limited to moss gardens in several cave entrances and beneath cave skylights in El Malpais. Presently, this species is known from the moss gardens of a single of cave in the monument. We suggest A. awishoshola may be a climatic relict, having become restricted to the cave environment following the end of the Pleistocene. We discuss the importance of cave moss gardens as refugial and relictual habitats. Recommendations are provided to aid in the conservation and management of A. awishoshola and these habitats.

Surface uplift above the Jemez mantle anomaly in the past 4 Ma based on40Ar/39Ar dated paleoprofiles of the Rio San Jose, New Mexico, USA

We combine 15 new 40 Ar/ 39 Ar ages with existing age constraints of basalts to investigate the incision and denudation history of the ∼150-km-long Rio San Jose (RSJ) of west-central New Mexico (USA) over the past 4 Ma. Temporal and spatial scales of differential incision may help evaluate the relative importance of neotectonic, geomorphic and climatic forcings. The RSJ is a southeast-flowing river that orthogonally crosses the northeast-trending Jemez volcanic lineament, which is underlain by a zone of low-velocity mantle. Preserved basalt flows along the length of the river at different elevations that directly overlie river gravels are used to construct paleoprofiles of the RSJ and give insight into the differential incision history, which can test the hypothesis that epeirogenic uplift associated with the Jemez lineament influenced differential incision of the RSJ. Observations include (1) a northeast-trending graben along the central reach of the RSJ (El Malpais valley graben) which is parallel to the Jemez lineament, (2) the present-day east tilt of the originally west-flowing 3.7 Ma Mesa Lucero flow along the eastern edge of the Jemez lineament, and (3) modern profile convexities that are colocated with ca. 3 Ma paleoprofile convexities and are centered above the Jemez lineament. The arched ca. 3 Ma paleoprofile defined by the pre–Mount Taylor strath has greater convexity than younger profiles, suggesting neotectonic bowing of ∼135 m (∼50 m/Ma) in this reach over the past ∼3 Ma relative to areas off axis of the Jemez lineament, in spite of graben subsidence and aggradational fill in this reach exceeding 100 m. Differential incision of the 184 ka Suwanee flow at the edge of the Colorado Plateau may be attributable to base-level fall in downstream reaches of the RSJ and/or headwater uplift, and more erosive climate in the past several hundred thousand years. However, these observations, when considered together, cannot be explained entirely by geomorphic or climatic forcings. Rather, they are best interpreted as resulting from surface uplift centered over the northeast-trending Jemez lineament, and our model suggests that both the faulting and broad bending may relate to mantle driven epeirogeny that caused differential river incision. Several interacting neotectonic and magmatic mechanisms may have contributed to postulated uplift. Magmatically driven geodynamic uplift forcings may include construction of the Mount Taylor stratovolcano just north of the RSJ that changed surface elevation by several kilometers at the volcanic peak itself. However, semisteady denudation and similar incision rates in other rivers in the region indicate that a regional erosional landscape was the primary driver of differential river incision over the past 5–8 Ma. Our focus on the pre–Mount Tayler RSJ paleoprofile reinforces this conclusion. Other mantle-related uplift mechanisms that may have generated mantle buoyancy include thermal buoyancy or magmatic inflation due to dike and sill networks related to the building of the Mount Taylor stratovolcano and eruption of Zuni-Bandera volcanic fields. Both could have contributed to uplift, but their relative importance is unknown. Broad epeirogenic uplift is also possible due to small-scale upper mantle convection beneath a thin elastic plate and resulting dynamic topography.

Strontium isotopes and nutrient sourcing in a semi-arid woodland

Sr isotopes are widely used as a tracer of Sr and Ca in surficial systems. Basalt flows ranging in age from 3ka (kiloyears ago) to>200ka from El Malpais National Monument (EMNM), New Mexico provide an ideal setting to examine strontium, and hence calcium cycling by plants in a semi-arid woodland. To gauge plant dependence on atmospheric dust versus local weathering products for strontium and calcium, we measured 87Sr/86Sr ratios in local bedrock and soils, and compared them to leaf/wood cellulose of four different conifers, a deciduous tree, three shrubs, an annual C4 grass, and a lichen. Sampling sites varied by parent material (limestone, sandstone, granite, and basalt) and age (Quaternary to Precambrian), providing a wide range in end-member 87Sr/86Sr ratios, whereas the target plant species varied in physiognomy, life history, and rooting depth. On non-basalt parent material, the contribution from dust changed with the supply of weatherable Sr-bearing minerals in local bedrock. Soils developed on Paleozoic limestone showed significant bedrock contributions. On basalts, the Sr budget of soils at EMNM is dominated by atmospheric dust on young, 3ka flows, incorporates a mixture of basalt-dust in 9ka flows, and is basalt-dominated in 120ka flows. This is unlike the pattern observed in tropical soils developed on basalt in Hawaii, where basalt weathering dominates the Sr inventory of the youngest soils and aerosols dominate in older, deeply weathered soils. This contrast is mainly due to different water/rock (W/R) ratios: bedrock subjected to high W/R over short periods is quickly (<10ka) depleted in Sr (and Ca), except for the ongoing replenishment from aerosols. In arid settings where W/R are lower, soil Sr is still abundantly available first from dust, and increasingly from bedrock even after 120 ka. For plants, 87Sr/86Sr variations within and across sites at EMNP showed that evergreen trees varied most in 87Sr/86Sr ratios, shrubs were least dependent on eolian input of Sr, and both foliage density and rooting depths influence soil Sr pools.

Historical Dendroarchaeology in the EI Malpais Area: Lessons from the Savage Homestead

The El Malpais National Conservation Area (EMNCA) of west central New Mexico contains dozens of early-20th-century archaeological sites. One site, the Savage homestead (LA 74544), contains evidence of a relatively intensive settlement history in the form of more than 20 structures, roads, fields, and artifacts. The Savage homestead settlement history is investigated through dendrochronological, documentary, archaeological, and oral history data. The assembled data testify to the tenacity and strength of a widow with six children subsisting in the isolation of the high desert of New Mexico and threading her way through the federal paperwork maze to earn a homestead patent—a task accomplished, but an occupation that was short-lived. The social, economic, and environmental contexts of the occupation and abandonment suggest implications for understanding the regional occupation of the area both historically and prehistorically.

Evaluating highly resolved paleoclimate records in the frequency domain for multidecadal-scale climate variability

[1] Do the chronological methods used in the construction of paleoclimate records influence the results of the frequency analysis applied to them? We explore this phenomenon using the Dongge Cave speleothem record (U-series chronology with variable time steps, Δt) and the El Malpais tree-ring index (cross-dating of ring-width series). Interpolation of the Dongge Cave record to a constant Δt resulted in the suppression of periodicities (<20 years) altering the red noise model used for significance testing. Frequency analysis of temporal subsets of the El Malpais tree-ring index revealed that concentrations of variance varied with the number of ring-width series. Frequency analyses of these records identified significant periodicities, some common to both (∼25 and ∼69 years). Cross-wavelet analysis, which examines periodicities in the time domain, revealed that coherency between these records occurs intermittently. We found the chronology methods can influence the ability of frequency analysis to detect periodicities and tests for coherency.

Cool- and Warm-Season Precipitation Reconstructions over Western New Mexico

Abstract Precipitation over the southwestern United States exhibits distinctive seasonality, and contrasting ocean–atmospheric dynamics are involved in the interannual variability of cool- and warm-season totals. Tree-ring chronologies based on annual-ring widths of conifers in the southwestern United States are well correlated with accumulated precipitation and have previously been used to reconstruct cool-season and annual precipitation totals. However, annual-ring-width chronologies cannot typically be used to derive a specific record of summer monsoon-season precipitation. Some southwestern conifers exhibit a clear anatomical transition from the earlywood and latewood components of the annual ring, and these exactly dated subannual ring components can be measured separately and used as unique proxies of cool- and warm-season precipitation and their associated large-scale ocean–atmospheric dynamics. Two 2139-yr-long reconstructions of cool- (November–May) and early-warm season (July) precipitation have been developed from ancient conifers and relict wood at El Malpais National Monument, New Mexico. Both reconstructions have been verified on independent precipitation data and reproduce the spatial correlation patterns detected in the large-scale SST and 500-mb height fields using instrumental precipitation data from New Mexico. Above-average precipitation in the cool-season reconstruction is related to El Niño conditions and to the positive phase of the Pacific decadal oscillation. Above-average precipitation in July is related to the onset of the North American monsoon over New Mexico and with anomalies in the 500-mb height field favoring moisture advection into the Southwest from the North Pacific, the Gulf of California, and the Gulf of Mexico. Cool- and warm-season precipitation totals are not correlated on an interannual basis in the 74-yr instrumental or 2139-yr reconstructed records, but wet winter–spring extremes tend to be followed by dry conditions in July and very dry winters tend to be followed by wet Julys in the reconstructions. This antiphasing of extremes could arise from the hypothesized cool- to early-warm-season change in the sign of large-scale ocean–atmospheric forcing of southwestern precipitation, from the negative land surface feedback hypothesis in which winter–spring precipitation and snow cover reduce surface warming and delay the onset of the monsoon, or perhaps from an interaction of both large-scale and regional forcing. Episodes of simultaneous interseasonal drought (“perfect” interseasonal drought) persisted for a decade or more during the 1950s drought of the instrumental era and during the eighth- and sixteenth-century droughts, which appear to have been two of the most profound droughts over the Southwest in the past 1400 yr. Simultaneous interseasonal drought is doubly detrimental to dry-land crop yields and is estimated to have occurred during the mid-seventeenth-century famines of colonial New Mexico but was less frequent during the late-thirteenth-century Great Drought among the Anasazi, which was most severe during the cool season.

Localized Weathering: Implications for Theoretical and Applied Studies

In situ quantification of localized weathering processes on basalt flows in New Mexico and Hawaii demonstrates that small-area factors can be more important than other more readily observable factors. Further, it demonstrates that the factorial concept of the Pope Boundary-Layer weathering model is partially solvable, that organic weathering can accentuate glass weathering (with implications for climate models and storage of nuclear waste), and that silica coatings are not a simple solution for the preservation of stone monuments. Enhancement of glass weathering by lichens on the McCartys flow, El Malpais National Monument, New Mexico, remains restricted to a half-millimeter directly underneath the lichen-covered surface. In contrast, although the inorganic rock coating of silica glaze reduces weathering directly underneath the coating by up to nine times rates found in uncoated locales, silica glaze can almost double variability in weathering along its margins.

In situ determination of long-term basaltic glass dissolution in the unsaturated zone

Maximum in situ weathering rates of basaltic glass measured at the El Malpais National Monument in New Mexico are on the order of 2–5×10 −19 mol/cm 2 s. Rates were calculated from backscattered electron (BSE) imaging of weathered porosity and are equivalent to 1.7–5% of the surface per 1000 years. Weathering is independent of glass composition but appears to increase with flow elevation at El Malpais. Measured rates represent weathering over 3000 years and are substantially lower than glass dissolution rates measured in the laboratory over much shorter time spans. Basaltic glass is a close chemical analogue to glass hosts proposed for encapsulation of high-level nuclear wastes. Radionuclide release rates predicted from the basis of in situ field rates are substantially less than those predicted from short-term laboratory experiments.

Calcium carbonate effects on soil textural class in semiarid wildland soils

Soils from the upper Rio Puerco watershed and El Malpais wilderness study area in New Mexico were analyzed for particle‐size distribution and classified into 1 of 12 textural classes before and after calcium carbonate (CaCO3) removal. The samples selected for analysis had a CaCO3 content of ≥ 5% by volume that represented 32% of the total study samples. All of the samples having CaCO3 changed particle‐size distribution, and 60% of those samples changed textural class following the pretreatment for CaCO3 removal. The greatest changes in particle size were from sand‐ to clay‐size fractions. Therefore, we recommend that all wildland soil samples from the semiarid Southwest be pretreated for CaCO3 removal prior to particle‐size analysis and subsequent textural classification.

Public Historians and Southwestern History

History of Fort Davis, Texas by ROBERT WOOSTER. Southwest Cultural Resources Center, Professional Papers No. 34. Santa Fe, N. Mex.: Southwest Cultural Resources Center, Division of History, National Park Service, 1990; vi + 416 pp., notes, maps, photographs, illustrations, bibliography; paperbound. In the Land of Frozen Fires: A History of Occupation in El Malpais Country by NEIL C. MANGUM. Southwest Cultural Resources Center, Professional Papers No. 32. Santa Fe, N. Mex.: Southwest Cultural Resources Center, Division of History, National Park Service, 1990; viii + 106 pp., notes, maps, figure, photographs, selected bibliography; paperbound. Cooke's Peak-Pasaron Por Aqui: A Focus on United States History in Southwestern New Mexico by DONALD HOWARD COUCHMAN. Cultural Resources Series No. 7. Las Cruces, N. Mex.: Las Cruces District, Mimbres Resource Area, Bureau of Land Management, 1990; maps, notes, photographs, bibliography, appendices; paperbound. A Forgotten Kingdom: The Spanish Frontier in Colorado and New Mexico, 1540-1821 by FREDERIC J. ATHEARN. Cultural Resources Series No. 29. Denver: Colorado State Office of the Bureau of Land Management, 1989; x + 104 pp., map, notes, illustrations, bibliographic essay, bibliography; paperbound.