Unusual Suspects: “Allies in the Park, Are Closer Than They Appear”

One season, 1039 hours, as a Park Ranger at Mesa Verde National Park. Interps we are called, observing, telling stories, being stewards of the past, present and future of wildness. Wildness in the animal world is reserved to only 4% of the planets millions of animals, Wildness is why people come to the National Parks, they are the last stronghold of beauty that bears presence in each of our souls. As a Field Scientist it is all about observation over time, and if you are lucky even, at the right time in the right place, a story makes itself known. This year, 2021, finally after the unlucky stall of 2020, we were back at work in the park and I am the lucky one to tell this story of how nature is working together as allies to regrow the burned forests of this place. Who are the characters in nature that are regenerating this burned landscape?I call them the “Unusual Suspects” and use the adage that we all have seen on our review mirrors “Objects in Mirror Are Closer Than They Appear.” I have rewritten those words as “Allies in the Park Are Closer Than They Appear.” Those allies, in this case, the Yucca baccata (banana yucca), the most important plant of cultural use by the Ancient Pueblo People at Mesa Verde, the Pinyon-Juniper forest and particularly the Juniperus utahensis, Pack rats and horses. There is much more than is visible going on, but these are the key players to the questions I asked: Why are the burned Juniper trees still standing after twenty years, some 90 years ago burned, still standing, how? And where are the new saplings, it appears that the trees are not growing back. The last 20 years the forests have stood still like an eerie Tim Burton movie. This field report includes my daily observations on the mesas over six months, data collection on 175 trees and new discoveries found that indeed new trees are growing back, with the help of their allies, the unusual suspects working together in regenerating life after wildfires. I can say for certain that regeneration takes communication, and in this case it is between nature through chemical signals, electrical impulses and heartbeats, neural networks working under the surface, deep in the earth that are keeping the ecosystem intact, strong and diverse. I’ve offered insight from these types of communication in ecology that we are just learning to understand that are intriguing and calling for all humans to pay attention.

Extreme Aerosol Events at Mesa Verde, Colorado: Implications for Air Quality Management

A significant concern for public health and visibility is airborne particulate matter, especially during extreme events. Of most relevance for health, air quality, and climate is the role of fine aerosol particles, specifically particulate matter with aerodynamic diameters less than or equal to 2.5 micrometers (PM2.5). The purpose of this study was to examine PM2.5 extreme events between 1989 and 2018 at Mesa Verde, Colorado using Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring data. Extreme events were identified as those with PM2.5 on a given day exceeding the 90th percentile value for that given month. We examine the weekly, monthly, and interannual trends in the number of extreme events at Mesa Verde, in addition to identifying the sources of the extreme events with the aid of the Navy Aerosol Analysis and Prediction (NAAPS) aerosol model. Four sources were used in the classification scheme: Asian dust, non-Asian dust, smoke, and “other”. Our results show that extreme PM2.5 events in the spring are driven mostly by the dust categories, whereas summertime events are influenced largely by smoke. The colder winter months have more influence from “other” sources that are thought to be largely anthropogenic in nature. No weekly cycle was observed for the number of events due to each source; however, interannual analysis shows that the relative amount of dust and smoke events compared to “other” events have increased in the last decade, especially smoke since 2008. The results of this work indicate that, to minimize and mitigate the effects of extreme PM2.5 events in the southwestern Colorado area, it is important to focus mainly on smoke and dust forecasting in the spring and summer months. Wintertime extreme events may be easier to regulate as they derive more from anthropogenic pollutants accumulating in shallow boundary layers in stagnant conditions.

Mesa Verde National Park: Acoustic monitoring report

In 2015, the Natural Sounds and Night Skies Division (NSNSD) received a request to collect baseline acoustical data at Mesa Verde National Park (MEVE). Between July and August 2015, as well as February and March 2016, three acoustical monitoring systems were deployed throughout the park, however one site (MEVE002) stopped recording after a couple days during the summer due to wildlife interference. The goal of the study was to establish a baseline soundscape inventory of backcountry and frontcountry sites within the park. This inventory will be used to establish indicators and thresholds of soundscape quality that will support the park and NSNSD in developing a comprehensive approach to protecting the acoustic environment through soundscape management planning. Additionally, results of this study will help the park identify major sources of noise within the park, as well as provide a baseline understanding of the acoustical environment as a whole for use in potential future comparative studies. In this deployment, sound pressure level (SPL) was measured continuously every second by a calibrated sound level meter. Other equipment included an anemometer to collect wind speed and a digital audio recorder collecting continuous recordings to document sound sources. In this document, “sound pressure level” refers to broadband (12.5 Hz–20 kHz), A-weighted, 1-second time averaged sound level (LAeq, 1s), and hereafter referred to as “sound level.” Sound levels are measured on a logarithmic scale relative to the reference sound pressure for atmospheric sources, 20 μPa. The logarithmic scale is a useful way to express the wide range of sound pressures perceived by the human ear. Sound levels are reported in decibels (dB). A-weighting is applied to sound levels in order to account for the response of the human ear (Harris, 1998). To approximate human hearing sensitivity, A-weighting discounts sounds below 1 kHz and above 6 kHz. Trained technicians calculated time audible metrics after monitoring was complete. See Methods section for protocol details, equipment specifications, and metric calculations. Median existing (LA50) and natural ambient (LAnat) metrics are also reported for daytime (7:00–19:00) and nighttime (19:00–7:00). Prominent noise sources at the two backcountry sites (MEVE001 and MEVE002) included vehicles and aircraft, while building and vehicle predominated at the frontcountry site (MEVE003). Table 1 displays time audible values for each of these noise sources during the monitoring period, as well as ambient sound levels. In determining the current conditions of an acoustical environment, it is informative to examine how often sound levels exceed certain values. Table 2 reports the percent of time that measured levels at the three monitoring locations were above four key values.

The Curious Douglas-Fir (Pseudotsuga Menziesii) Trees in Schulman Grove, Mesa Verde National Park, Southwestern Colorado, USA

In 1954, archaeologists James Allen Lancaster and Don Watson and dendrochronologist Edmund Schulman asserted that a small grove of Douglas-fir (Pseudotsuga menziesii [Mirbel] Franco var. glauca [Beissener] Franco) trees in Navajo Canyon on the west side of Chapin Mesa in Mesa Verde National Park contained evidence of stone-axe-cut tree limbs. In 1965, archaeologists Robert Nichols and David Smith published an article entitled “Evidence of Prehistoric Cultivation of Douglas-Fir Trees at Mesa Verde,” in which they supported the Lancaster/Watson/Schulman assertion with tree-ring dates from suspected stone-axe-cut limbs. If correct, Nichols and Smith (1965) document the only trees in the entire U.S. Southwest that contain ancient stone-axe-cut stubs and evidence of precolumbian forest management. Rather than accept their interpretations at face value, we attempt to replicate their dates through the (re)analysis of archived and recently collected tree-ring samples, and through a controlled analysis and comparison of archived and published records. We could not confirm their results, and we have no option but to reject their claim that Schulman Grove contains evidence of precolumbian tree manipulation by Ancestral Puebloan inhabitants of Mesa Verde.

Arquitectura defensiva de la cultura Pueblo en los cañones de la región Mesa Verde, Colorado, EE.UU.

La cultura Pueblo se desarrolló el suroeste de Norteamérica sin interrupción durante casi tres mil años, experimentando un serie de cambios y transformaciones culturales y sociales. Dichos cambios se mani-fi estan principalmente en las formas de asentamiento y arquitectura diferenciadoras de otras culturas indígenas de Norteamérica. Desde el siglo VII d.C. aproximadamente las comunidades de la cultura Pueblo erigen edifi cios de varios pisos, de materiales como adobe, piedra arenisca y madera. A diferencia de las culturas de cazadores-recolectores la cultura Pueblo se caracteriza por su asentamiento permanente y su avanzada agricultura.El siglo XIII d.C. trae una transformación de las formas de asentamiento de los Pueblo en la región Mesa Verde. Los asentamientos empiezan a trasladarse de zonas planas y abiertas a los bordes y las laderas de los cañones, o incluso a nichos y refugios rocosos de difícil acceso en las empinadas laderas de los cañones. En las rocas crecen asentamientos y ciudades, a menudo rodeados de muros de piedra y difíciles de ac-ceder; al mismo tiempo empiezan a construirse torres de piedra y túneles subterráneos. Todo ello surgía probablemente de consideraciones defensivas, relacionadas con el deterioro de las condiciones ambienta-les y climáticas, así como con el aumento de confl ictos y peleas, tanto dentro de la cultura misma, como probablemente con atacantes de otras tribus.Uno de los complejos de asentamientos Pueblo del siglo XIII, ubicado en Sand Canyon, Rock Creek Ca-nyon y Graveyard Canyon en la región de Mesa Verde, en Colorado, lleva investigándose desde el año 2011, en el marco del Proyecto Arqueológico Sand Canyon-Castle Rock. Este proyecto arqueológico polaco centra su investigación en la reconstrucción del sistema de asentamientos y en el análisis de la arquitectu-ra defensiva de varias docenas de asentamientos pequeños y un gran asentamiento central (Castle Rock Pueblo). Recientemente las actividades del proyecto abarcan también la documentación y el análisis de los murales y los ejemplos del arte rupestre conservados en los sitios examinados.