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Hansen, Leslie A.

Publications and source records attributed to Hansen, Leslie A..

8 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Avian community composition in response to high explosive testing operations at Los Alamos National Laboratory in Northern New Mexico

Breeding bird abundance, species richness, evenness, diversity, composition, productivity, and survivorship were determined near a high-explosive detonation site at Los Alamos National Laboratory, New Mexico, USA, during pre-operation (1997-1999) and operation (2000-2014) periods. The operation periods consisted of detonations (<23 kg in yield and <3 per breeding season) in open air (2000-2002), within foam containment (2003-2006) and within steel vessel containment (2007-2014) systems; the latter two were employed to reduce noise and dispersal of high-explosives residues. A total of 2952 bird captures, representing 80 species, was recorded during 18 years of mist net operations using the Monitoring Avian Productivity and Survivorship protocol. Individuals captured were identified to species, aged, sexed, and banded during May through August of each year. There were no significant differences (p > 0.05) in mean avian abundance and species evenness in any of the operation periods as compared with the pre-operation period. Species richness and diversity were significantly higher (p < 0.05) during the vessel containment period (2007-2014) than the pre-operation period. The time period of this study coincided with a wildfire (2000), a bark beetle infestation (2002), and two periods of drought (Nov 1999-Mar 2004 and Dec 2005-Dec 2014) that affected the study area. Furthermore, analysis of aerial photos determined that the average percent canopy cover of mature ponderosa pines (Pinus ponderosa) within 100 feet of mist net sites declined from 12% to 3% between 1991 and 2014 and the percent cover of shrubs slightly increased.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Integrated Forest Management Charter

The purpose of this charter is to establish, maintain, and implement programs for the protection, preservation, and enhancement of the land and water resources of Los Alamos National Laboratory in a changing climate.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2014

Feral Cattle in the White Rock Canyon Reserve at Los Alamos National Laboratory

At the request of the Los Alamos Field Office (the Field Office), Los Alamos National Security (LANS) biologists placed remote-triggered wildlife cameras in and around the mouth of Ancho Canyon in the White Rock Canyon Reserve (the Reserve) to monitor use by feral cattle. The cameras were placed in October 2012 and retrieved in January 2013. Two cameras were placed upstream in Ancho Canyon away from the Rio Grande along the perennial flows from Ancho Springs, two cameras were placed at the north side of the mouth to Ancho Canyon along the Rio Grande, and two cameras were placed at the south side of the mouth to Ancho Canyon along the Rio Grande. The cameras recorded three different individual feral cows using this area as well as a variety of local native wildlife. This report details our results and issues associated with feral cattle in the Reserve. Feral cattle pose significant risks to human safety, impact cultural and biological resources, and affect the environmental integrity of the Reserve. Regional stakeholders have communicated to the Field Office that they support feral cattle removal.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2013

The La Mesa Fire: Studies and Observations from 1975 through 2012

In 1996, Swetnam and Baisan stated the following: “The 1977 La Mesa burn was a wake-up call to perhaps the most pressing forest health problem in Southwestern forests—historically anomalous, catastrophic wildfire in the ponderosa pine—created by many decades of fire exclusion.” However, the wake-up call was only momentary and was forgotten until the Dome Fire (1996), Oso Complex Fire (1998), and Cerro Grande Fire (2000) burned lands within the community of Los Alamos, Los Alamos National Laboratory (LANL), Bandelier National Monument (BNM), and Santa Fe National Forest (SFNF). After the Dome Fire, several initiatives were under way to understand the wildland-urban interface and the conditions that have brought the forests of the Pajarito Plateau dangerously close to multiple, large, and intense wildfires. After the Dome Fire, the Interagency Wildfire Management Team was formed, bringing together adjoining agencies to deal with the ever-increasing threat of conflagration that could result in loss of property and human life. This study is about the history before and after the La Mesa Fire—at the time, the first large wildfire on the Pajarito Plateau in over 80 years. It represents 37 years of research and observations that began when management of fire on the Pajarito Plateau was first being explored by BNM. It documents changes in vegetation composition since June 1977 and shows the progression of change in understanding fire’s essential place in the ecosystems of the Pajarito Plateau. The study began in 1975 and 1976, when Loren Potter and I examined previously burned areas to determine a fire frequency for the east Jemez Mountains. We had examined areas of 10 acres or more that had burned at various times, e.g., 1939, 1945, 1950, 1955, 1960, and 1976. A year and a half into the study, the La Mesa Fire ignited on Mesa del Rito, ultimately burning about 15,000 acres of BNM, SFNF, and LANL, including our established plots. After the fire, we set up 20- by 50-meter permanent plots along four ornithological transects established by ornithologist Roland Wauer. Wauer’s transects were mostly in ponderosa pine, with one in mixed conifer and one in the piñon-juniper woodland. Plots within the ponderosa pine were visited in 1977, 1978, 1985, 1992, 1998, 1999, 2010, 2011 and 2012. We mapped the standing trees, photographed each plot, and collected data on the understory components. Transects in the mixed conifer were visited in 1977, 1992, 1999, 2010 and 2012. Plots in the piñon-juniper were visited in 1977, 1999, and 2010 for taking photographs and data years after the fire. Additionally, plots were established in LANL Technical Area 49 as a control to post-fire seeding. We visited these plots in 1977, 1992, and 1998. Ironically, this study ends with another large fire burning over the plots we have followed all these years. In June 2011, the Las Conchas Fire became the largest fire in New Mexico’s history to that time and burned most of the area of the La Mesa Fire and the plots studied over the years. In this report, we summarize information about the vegetation changes within the boundaries of the La Mesa Fire. Thirty-seven years of observations and studies have provided long-term data related to regeneration of trees, water relations of grasses and pines, the influence of seeding with non-native grasses, pyrodendrochronology, and plant succession as related to fire.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2012

Measures of soil, sediment, and groundwater background used by Los Alamos National Laboratory, 2012

This document summarizes approaches used by Los Alamos National Laboratory (LANL) to estimate background concentrations of constituents in soils, sediment, and groundwater. For the sake of presentation and interpretation, LANL frequently reports a “background value” that statistically represents an upper bound for a data set of background concentrations. However, actual background concentrations vary by soil and bedrock type, disturbance regimes, precipitation levels, vegetative cover, and a wide variety of other factors. The LANL reported background values are estimates for comparison, not absolute limits of possible background concentrations. In evaluating whether a sample result represents a background concentration, LANL staff evaluate the results statistically (if the sample size is large enough) or graphically against the complete distribution of the relevant background data set. For analytes with no established background data set, LANL site results are sometimes compared to upgradient or geographically distant results on a study-specific basis.

Environmental Protection↗
DOE OSTI2012

Life in the Fast Lane: Road Crossing Behavior of Mule Deer in a Wildland-Urban Interface

In 2009, approximately 260,000 animal-vehicle collisions were reported in the United States, resulting in 12,000 human injuries and 173 human fatalities. Research has focused on identifying factors associated with high densities of animal-vehicle collisions, including variables such as traffic speed and volume, road design, topographic features, vegetative cover, and local deer or elk (Cervus elaphus) abundance. The purposes of this study were to document how often and where mule deer (Odocoileus hemionus) crossed roads in a western United States wildland-urban interface area, and to relate deer road-crossing behavior to deer-vehicle collision locations. Seven adult mule deer (four males [M] and three females [F]) were captured and collared with GPS-enabled collars during December 2001 and January 2002. Five of the seven deployed collars were recovered. None of the roads in the study area appeared to act as a substantial barrier to deer passage. Deer home ranges straddled highways and primary, secondary, and tertiary arterial roads. Deer crossed all types of roads. The average number of times deer crossed road during 24 hours of monitoring ranged from 2.1 to 7.0. Deer in the Los Alamos townsite avoided crossing roads during day and before sunset. Deer-vehicle accidents occurred at 350 percent of the level expected after sunset. All other time periods had fewer accidents than expected. The distribution of accidents across time periods was not similar to the distribution of road crossings across time periods for any deer. Within Los Alamos County there was a clear trend for deer-vehicle collisions to occur on roads with speed limits > 35 mph. Deer in the townsite frequently crossed roads with lower speed limits; therefore, the reason for the paucity of accidents along these roads was evidently the ability of drivers to detect deer (or the ability of deer to detect vehicles) and respond before an accident occurred. There was a significant but not strong correlation between the density of accidents and the density of road crossings. This was probably related to the high number of deer crossings of tertiary arterial roads, where accidents were not likely to occur.

ABUNDANCE↗
DOE OSTI2012

2011 Los Alamos National Laboratory Riparian Inventory Results

A total length of 36.7 kilometers of riparian habitat were inventoried within LANL boundaries between 2007 and 2011. The following canyons and lengths of riparian habitat were surveyed and inventoried between 2007 and 2011. Water Canyon (9,669 m), Los Alamos Canyon (7,131 m), Pajarito Canyon (6,009 m), Mortandad Canyon (3,110 m), Two-Mile Canyon (2,680 m), Sandia Canyon (2,181 m), Three-Mile Canyon (1,883 m), Canyon de Valle (1,835 m), Ancho Canyon (1,143 m), Canada del Buey (700 m), Sandia Canyon (221 m), DP Canyon (159 m) and Chaquehui Canyon (50 m). Effluent Canyon, Fence Canyon and Potrillo Canyon were surveyed but no areas of riparian habitat were found. Stretches of inventoried riparian habitat were classified for prioritization of treatment, if any was recommended. High priority sites included stretches of Mortandad Canyon, LA Canyon, Pajarito Canyon, Two-Mile Canyon, Sandia Canyon and Water Canyon. Recommended treatment for high priority sites includes placement of objects into the stream channel to encourage sediment deposition, elimination of channel incision, and to expand and slow water flow across the floodplain. Additional stretches were classified as lower priority, and, for other sites it was recommended that feral cattle and exotic plants be removed to aid in riparian habitat recovery. In June 2011 the Las Conchas Wildfire burned over 150,000 acres of land in the Jemez Mountains and surrounding areas. The watersheds above LA Canyon, Water Canyon and Pajarito Canyon were burned in the Las Conchas Wildfire and flooding and habitat alteration were observed in these canyon bottoms (Wright 2011). Post fire status of lower priority areas may change to higher priority for some of the sites surveyed prior to the Las Conchas Wildfire, due to changes in vegetation cover in the adjacent upland watershed.

Basic Biological Sciences(59)↗