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Chapter 9 - Ecological Research at the Idaho National Environmental Research Park
 

Contents:

• Chapter Highlights
• Ecological Research at the Idaho National Environmental Research Park
  • The Effect of Landscape Change on the Life History of Western Rattlesnakes (Crotalus oreganus)
  • Fine-scale Movement Patterns of Coyotes (Canis latrans) on the INEEL in Idaho
  • Behavior, Dispersal, and Survival of Captive-raised Idaho Pygmy Rabbits (Brachylagus idahoensis) Released onto the INEEL in Idaho
  • Phylogenetic Analysis of the Abronia ammophila Green (Nyctaginaceae) Species Complex
  • Factors that Influence the Road Mortality of Snakes on the Eastern Snake River Plain
  • Ecological Impacts of Irrigating Native Vegetation with Treated Sewage Wastewater
  • The Protective Cap/Biobarrier Experiment
  • Natural and Assisted Recovery of Sagebrush (Artemisia tridentata) in Idaho’s Big Desert: Effects of Seeding Treatments and Livestock Grazing on Successional Trajectories of Sagebrush Communities
  • Developing Advanced Scientific Methods for Landscape Level Management of Federal Facilities
• References

Chapter Highlights

The Idaho National Engineering and Environmental Laboratory (INEEL) was designated as a National Environmental Research Park (NERP) in 1975. The NERP program was established in the 1970s in response to recommendations from citizens, scientists, and members of Congress to set aside land for ecosystem preservation and study. In many cases, these protected lands became the last remaining refuges of what were once extensive natural ecosystems. The NERPs provide rich environments for training researchers and introducing the public to ecological sciences. They have been used to educate grade school and high school students and the general public about ecosystem interactions at U.S. Department of Energy (DOE) sites; train graduate and undergraduate students in research related to site-specific, regional, national, and global issues; and promote collaboration and coordination among local, regional, and national public organizations, schools, universities, and federal and state agencies.

Ecological research at the INEEL began in 1950 with the establishment of the long-term vegetation transect. This is perhaps DOE's oldest ecological data set and one of the oldest vegetation data sets in the West. Ecological research on the NERPs is leading to planning better land use, identifying sensitive areas on DOE sites so that restoration and other activities are compatible with ecosystem protection and management, and increasing contributions to ecological science in general.

The following ecological research activities took place at the Idaho NERP during 2004:

• The Effect of Landscape Change on the Life History of Western Rattlesnakes (Crotalus oreganus);
• Fine-scale Movement Patterns of Coyotes (Canis latrans) on the INEEL in Idaho;
• Behavior, Dispersal, and Survival of Captive-raised Idaho Pygmy Rabbits (Brachylagus idahoensis) Released onto the INEEL in Idaho;
• Phylogenetic Analysis of the Abronia ammophila Green (Nyctaginaceae) Species Complex;
• Factors that Influence the Road Mortality of Snakes on the Eastern Snake River Plain;
• Ecological Impacts of Irrigating Native Vegetation with Treated Sewage Wastewater;
• The Protective Cap/Biobarrier Experiment;
• Natural and Assisted Recovery of Sagebrush (Artemisia tridentata) in Idaho’s Big Desert: Effects of Seeding Treatments and Livestock Grazing on Successional Trajectories of Sagebrush Communities; and
• Developing Advanced Scientific Methods for Landscape Level Management of Federal Facilities.

Results
The project is still in the data collection phase, although a few preliminary results have been provided below for those interested.

1. Home ranges for coyotes on the INEEL site appear to be relatively large compared to previous studies. While this trend is true for most territories monitored, one pair of elderly coyotes (approximately 10 years old) appear to be an exception with their comparatively small home range (see Figure 9-3).
2. Using serial locations to examine coyote movement patterns allows one to visualize how coyotes actually travel within their home ranges. Figure 9-6 shows the 5-minute GPS data (approximately 12,000 locations) and travel paths superimposed on the home range for a single coyote. A computer algorithm was used to divide locations into either "stationary" or "moving." This allows us to group locations into unique continuous "movement paths" and "resting spots" for further analyses (See Figure 9-7).

Plans for Continuation

• Two additional captures are scheduled for 2005 (Spring and Fall/Winter) with plans to deploy between 16 and 24 GPS collars during each period. This should generate roughly 500,000 coyote locations.

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9.3  Behavior, Dispersal, and Survival of Captive-Raised Idaho Pygmy Rabbits (Brachylagus idahoensis) Released onto the INEEL in Idaho

Investigators and Affiliations
Rodney D. Sayler, Assoc. Professor, Department of Natural Resource Sciences, Washington State University, Pullman, WA
Robert Westra, Graduate Student, Department of Natural Resource Sciences, Washington State University, Pullman, WA
Lisa A. Shipley, Assoc. Professor, Department of Natural Resource Sciences, Washington State University, Pullman, WA

Funding Sources
Washington Department of Fish and Wildlife

Background
The pygmy rabbit (Brachylagus idahoensis) is the smallest rabbit in North America, a sagebrush foraging specialist, and one of only two North American rabbits to dig its own burrow. The long-isolated and genetically unique population of Columbia Basin pygmy rabbits located in eastern Washington State has declined precipitously to dangerously low levels and the U.S. Fish and Wildlife Service recently listed the Washington pygmy rabbits as an endangered population segment under the Endangered Species Act. Because little is known about successful captive-rearing and methods for restoring pygmy rabbits back into vacant natural habitats, reintroduction techniques in southeastern Idaho are being tested to develop protocols for the eventual restoration of endangered pygmy rabbits in Washington State. Idaho pygmy rabbits are propagated in captivity at Washington State University (WSU) and elsewhere and released into the wild in southeastern Idaho. The Idaho Fish and Game Department supervises these releases to determine whether selected captive rearing and release methods influence the behavior, dispersal, and survival of pygmy rabbits reintroduced into suitable sagebrush habitat.

Objectives

• Develop techniques to enhance the survival of captive-bred Idaho pygmy rabbits released into natural habitats for the purpose of establishing new local populations of pygmy rabbits.
• Test the effects of captive-rearing and release methods on the resulting behavior, dispersal, and survival of reintroduced pygmy rabbits.
• Develop recommended protocols for restoring pygmy rabbits in areas of vacant, suitable sagebrush habitat, and model the numbers of captive-bred animals and survival rates needed to establish new local breeding populations.

Accomplishments through 2004
A total of 42 pygmy rabbits were released from 2002-2004 at the INEEL to study behavior and survival of reintroduced animals. Rabbits originating from a source population in Idaho were raised in captivity at WSU, fitted with radio collars weighing < 2 percent of body weight, and released into temporary, weld-wire containment pens on the INEEL. The temporary pens surrounded the two openings of 3.0 to 4.5 m (10 to 15 ft) long plastic drainage tube burrows dug into the soil about 0.75 to 1.0 m (2.5 to 3.5 ft) deep in the center. The plastic-tubing burrows were used to partially replicate a natural pygmy rabbit burrow system and provide both thermal buffering and some protection against digging predators. Another goal of the artificial burrow system was to reduce premature dispersal of rabbits away from the release site selected in good sagebrush habitat. Released rabbits were monitored almost daily to record behavior, dispersal and habitat use.

Results
All released rabbits readily adapted to the small, temporary holding cages surrounding their burrow openings and continued normal feeding on provided foods (i.e., sagebrush tips, spinach, lettuce, pellet food). All containment pens were removed from the burrows by the fourth day, allowing free movement and dispersal of the animals.

Rabbits moved an average of 54.1 m (177.5 ft) from their initial release burrow during their first week after soft release. Most rabbits remained fairly localized on the release site. Mean movement distances did not vary significantly among the first, second, or third week after soft release. Most captive-bred, dispersing animals selected an appropriate habitat consisting of relatively tall, dense big sagebrush with relatively good grass and forb availability. Released animals appeared to adapt to natural local forage quickly and appeared to use a high proportion of grass and forbs until colder weather in fall and winter, which prompted greater use of sagebrush.

Predation was the main source of mortality for released pygmy rabbits. Of the 42 released animals, approximately 26 percent were censured from the study (primarily because radio signals were lost and because of one collar malfunction), 42 percent were lost to predators, 19 percent were lost to unknown mortality factors, and 12 percent were alive at the end of the project.

Eighteen of the 27 documented mortalities were caused by predators. Four mortalities were caused by raptors; northern harriers (Circus cyaneus) were directly observed in two predation events. Twelve animals were killed by long-tailed weasels (Mustela frenata) and two were confirmed coyote (Canis latrans) kills.

Survival - Total survivorship for the release population was 0.138 (Standard Error ± 0.085). This survivorship translates to an annual survival rate of 32 percent. Age and sex did not significantly influence survival, although the ability to detect such differences was limited. Males and females had similar survivorship; however, females experienced a higher mean survival time (175.7 days) than males (83.6 days). Annual survival rate was 18 percent for males and 30 percent for females.

Survival varied significantly among seasons (i.e., release groups). The annual survival rate was 0 percent for July, 24 percent for August, 32 percent for September, and 18 percent for February. However, the February release group had 50 percent of the rabbits released from the soft-release cages survive until the breeding season.

Survival quantiles for the released rabbits show a 76 percent survivorship for the first six days post soft-release, declining to 28 percent by day 95. Survivorship did not drop below 25 percent until day 260.

Reproduction of Reintroduced Pygmy Rabbits - At least two of the surviving released females appear to have given birth on the INEEL release site. One of the females was observed in 2003 and one in 2004. Consequently, it appears that surviving females will produce litters in the first spring after their release.

Plans for Continuation
This study on the INEEL has been a major research component of the recovery program for the endangered Columbia Basin pygmy rabbit in Washington, but will also provide valuable information in the event that local reintroductions are ever needed for populations of Idaho pygmy rabbits. The study was terminated on the INEEL and two graduate theses were completed at WSU in summer 2004, to finish the research project. Technical research publications currently are being prepared from the theses for publishing in scientific journals. Interested parties may contact the investigators for more information.

9.4  Phylogenetic Analysis of the Abronia ammophila Green (Nyctaginaceae) Species Complex

Investigators and Affiliations
N. Elizabeth Saunders, Graduate Student, Southern Illinois University Carbondale, Carbondale, IL
Sedonia D. Sipes, Assistant Professor, Southern Illinois University Carbondale, Carbondale, IL

Funding Sources
Southern Illinois University
Wyoming Native Plant Society

Background
Abronia ammophila Greene and Abronia mellifera Dougl. ex Hook have a disputed taxonomic status. Abronia ammophila is thought endemic to Yellowstone National Park, and Abronia mellifera is thought to enjoy a more widespread distribution in Utah, Wyoming, Idaho, Washington and Oregon. Although the most recent morphological studies separate them into two species, some local botanists disagree with the determination. In fact, some taxonomists lump both species in with the even more widespread congener, Abronia fragrans Nutt. ex Hook, which is thought to range from Texas through Utah.

The existing taxonomy is based on morphological characters. Unfortunately, Abronia species in general tend to show incredible plasticity in morphological characters of interest for taxonomic determination. Indeed, among these two species the most informative characters overlap such that definitive determination to species is nearly impossible. This study was designed to collect molecular characters to build a phylogeny for the Abronia ammophila species complex with the hope that a molecular-based approach would succeed where a morphological approach has resulted in ambiguous and often subjective species determinations for individual plants.

Objectives
The overall objective of this research is to resolve the taxonomy of the Abronia ammophila species complex. Specifically, the research objectives are:

• Collect leaf material and voucher specimens from Abronia ammophila Greene, Abronia mellifera Dougl. Ex Hook, and Abronia fragrans Nutt. Ex Hook for molecular analysis;
• Investigate the use of molecular characters to build a phylogenetic tree of the species complex.

Accomplishments through 2004
Leaf material was collected from representative samples of Abronia ammophila from Yellowstone National Park, from A. mellifera at Big Piney, WY, and INEEL, ID, and from A. fragrans from Texas and Utah. Leaf material was brought back to the lab at Southern Illinois University for analysis. Deoxyribonucleic acid (DNA) was extracted from all samples. Several regions of the nuclear and chloroplast genomes have been amplified and sequenced in order to find regions evolving at a sufficient rate as to differentiate closely related species. To date, the internal transcribed spacer regions of the ribosomal gene family (ITS I and 2) have been sequenced. These genes exhibit little variation among the Abronia species. However, we are going to evaluate several additional DNA regions that have shown potential in recent studies for resolving species-level relationships.

9.5  Factors that Influence the Road Mortality of Snakes on the Eastern Snake River Plain

Investigators and Affiliations
Denim M. Jochimsen, MS student, Herpetology Laboratory, Department of Biological Sciences, Idaho State University, Pocatello, ID.
Charles R. Peterson, Professor, Herpetology Laboratory, Department of Biological Sciences, Idaho State University, Pocatello, ID.

Funding Sources
ISU Biological Sciences Department
ISU Graduate Student Research Committee
BBW Bechtel and the INEEL - ISU Education Outreach Program
ISU Biology Youth Research Program
National Science Foundation (NSF) GK-12 project

Background
Transportation lies at the center of our society, linking destinations, and is ever expanding. A vast network of roads stretches across our landscape affecting ecosystem processes in myriad ways. Roads transform existing vegetation into a compacted earthen surface with altered thermal and moisture characteristics, and generate an array of ecological effects that disrupt ecosystem processes and wildlife movement.

Researchers have conducted surveys along roads in attempts to quantify the most conspicuous effect that roads impose on wildlife, mortality inflicted by vehicles. In reviewing the literature, it became apparent that rigorous studies concerning road mortality of snakes are scarce. Furthermore, studies tend to be focused in the southeast and southwestern US, with only three studies conducted in northern latitudes.

However, northern temperate snakes possess several characteristics that increase their susceptibility to road mortality. They migrate seasonally to locate specific resources (Gregory et al. 1987; King and Duvall 1990) such as refuge, mates, prey and egg-laying habitat (for oviparous species). These resources tend to be located in distinct habitats that are patchily distributed across the landscape. Many large-bodied snake species make a loop-like migration from a communal hibernaculum (overwintering den site) to summer foraging habitats (King and Duvall 1990). Seasonal movements are defined by three distinct phases: 1) egress, or rapid movement away from the hibernacula, 2) stationary, or periods of short-distance movements associated with foraging, gestation, or ecdysis, and 3) ingress, or long-distance movements toward the hibernacula as described by Cobb (1994). The overlap of these movement corridors with the road network may result in high mortality. Publications tend to report numbers of fatalities according to species, but rarely explore the relationship of mortality with season, sex, or age of individuals.

Road mortality of snakes is a conservation issue that needs to be addressed. Future research must question if this mortality has the potential to severely reduce snake populations to a level where reproductive output cannot replace road-killed individuals (Rosen and Lowe 1994; Rudolph et al. 1999). The adverse effects of roads can be minimized, but the correct placement of mitigation efforts is critical. Ultimately, this research seeks to identify landscape and road variables that are highly correlated with snake mortality. These correlations could then be used to identify areas that may represent high risks for snake road mortality. Studies suggest that mitigation success is dependent on correct placement of efforts (Jackson 1999) by identifying high-risk sites.

Objectives
This study was designed to address five objectives: (1) quantify the road mortality of snakes on the eastern Snake River Plain; (2) identify any variation of mortality with respect to species, season, sex, age, traffic volume; (3) examine the spatial pattern of mortality across the survey route; (4) evaluate the importance of various landscape factors influencing this pattern; (5) develop a logistic regression model to predict road sections with intense mortality.

Accomplishments

• Successful completion of the 2003 and 2004 field seasons including 333 total road observations of snakes along the survey route in over 10,000 kilometers driven.
• Performed spatial and statistical analyses of the data, as well as identification of important landscape and habitat features that influence where snakes cross roads.
• Presented general findings of this research at the Intermountain Herpetological Rendezvous in Logan, Utah (2004), Society for Northwest Vertebrate Biology meeting in Corvallis, Oregon (February, 2005), and at the International conference on Ecology and Transportation in San Diego, California (September 2005).
• Successfully defended a master's thesis based on this work.
• Generated a poster publication to be used for subsequent presentation.

Results
Road mortality of snakes was quantified by road cruising (driving slowly in a vehicle and recording all snakes observed on a road surface) a 170-kilometer route from May through October of 2003. The survey route is located within the northeastern portion of the Snake River Plain and covers portions of US Highways 20, 26, 20/26, 22/33, Franklin Boulevard, and Lincoln Boulevard. Sampling consisted of 55 total trips along this route, and resulted in 9,350 total kilometers traveled over the 2003 field season (Table 9-4).

A total of 253 snakes were observed on roads along the survey route and across the entire survey period; 93 percent of these animals were found dead on the road surface (kill rate of 0.023 individuals/km surveyed). Spatial visualization and analyses indicate that these observations are clustered along the survey route (Figure 9-8). We documented the road mortality of 4 species belonging to families Colubridae and Viperidae. However, the majority of observations belonged to 2 species, Pituophis catenifer (gophersnake) and Crotalus oreganus lutosus (Great Basin rattlesnake). We observed gophersnakes most often on roads, comprising 74 percent of all road records, and rattlesnakes were observed more frequently than the remaining two species, comprising 18 percent of all road records (Figure 9-9). Furthermore, we observed more adult males dead on roads for both these species than any other sex or age class. Juvenile observations comprised only 28 percent of total gophersnakes, and 17 percent of total rattlesnake road mortality.

Monitoring data indicate that rattlesnakes are the most abundant species based on hand and drift fence captures at dens. In fact, rattlesnakes made up 85 percent of captured snakes (n=2,459), with gophersnakes representing most of the remaining percentage of snakes (n=372) over a ten-year sampling period. This raises an interesting question, are gophersnakes more susceptible to road mortality on the Eastern Snake River Plain? This species is a habitat generalist and is perhaps more vagile than rattlesnakes, indicating that individuals would encounter roads more often, exposing them to the risk of road mortality.

The road mortality of snakes was documented in all months surveyed and seasonal patterns were evident. The mean number of snakes observed per route while road cruising was highest during the fall season, with a secondary peak in spring. These differences were significant (analysis of variance [ANOVA], F = 3.638, P = 0.033). The total number of sampling days without snake observations (11 total) was highest in late July and early August. There were also significant differences across season based on sex and age in gophersnakes (Figure 9-10).

Specifically, more males were killed in spring, whereas more subadults were dead in fall (results based on Kruskal-Wallis test). The higher numbers of certain age and sex classes with respect to seasons indicates that individuals may be more susceptible to road mortality during specific movements. Methods designed to ameliorate the road mortality of snakes should therefore coincide with these activity periods to be effective.

In addition to the systematic surveys, a 10 km segment of the route along State Highway 22/33 (running north/south) located on the western most edge of the study area was road-cruised in 2004. These surveys were designed to assess the probability of a snake successfully crossing the road. In attempts to address this, the shortened segment was driven between June and October in 2004, during periods of peak snake activity. Twelve of these routes were surveyed, covering 746 km and 80 snakes were observed (rate 0.107 snakes/km surveyed). Of these 80 snakes, 59 were observed killed. Similar to the 2003 surveys, 74 percent of observations were gophersnakes and 23 percent were rattlesnakes. This high mortality rate occurred in low traffic, and it appears that a traffic volume of less than ten vehicles per hour was sufficient to cause 100 percent mortality on some nights.

To assess the effect of road and landscape variables on snake mortality, several relevant variables were measured at each observation location from 2003, as well as an equal number of randomly chosen non-crossing points along the route. The variables measured were road slope, percent vegetation and major cover type within 10 meters of the road, distance to nearest vegetation, distance to nearest shrub, presence of burrows, presence of basalt, mean distance to dens (including those identified in this research), solar radiation, and major cover type at 50, 100, and 500 meters from the road (based on a geographic information system [GIS] coverage). A multiple logistic regression analysis was used to determine those variables significantly associated with road crossing locations. Finally, only gophersnake locations were used in this analysis as this was the only species with enough sample locations. Four variables were consistently included in each significant model. These were the grass major cover type (positively associated with snake crossing), percent vegetation cover within 10 meters (positively associated), presence of basalt (positively associated), and mean distance to den (positively associated). These results were surprising because it was expected that snake presence would be correlated with shrubs and would be negatively associated with den distance (i.e. the closer a den was to the road, the more mortality would be expected). A possible explanation for the positive association of grass cover type with snakes on roads is that this habitat is less suitable. If this is unsuitable habitat, individual snakes may move more to find more suitable habitat, and this increased movement would increase the likelihood of encountering a road. Second, if increased proximity of dens to a road actually reduces the probability of a snake encounter, then this likely indicates a population effect of road mortality. Specifically, this means that dens near roads either have reduced numbers of individuals or that snakes from those dens are not moving towards roads. Either way, this could influence population connectivity and ultimately, population persistence.

9.6  Ecological Impacts of Irrigating Native Vegetation with Treated Sewage Wastewater

Investigators
Roger D. Blew, Amy D. Forman, Sue J. Vilord, and Jackie R. Hafla - Environmental Surveillance, Education and Research Program, S.M. Stoller Corporation, Idaho Falls, ID

Funding Sources
U.S. Department of Energy Idaho Operations Office

Background
In 1995, the INEEL began disposing of treated wastewater at the Central Facilities Area (CFA) by applying it to the surface of soils and native vegetation using a center pivot irrigation system. Research conducted on this disposal method at the INEEL provides an opportunity to determine the benefits and/or hazards of disposal of wastewater on native vegetation in arid and semi-arid regions. Results will be applicable to a wide range of municipal, industrial and agricultural wastewater disposal needs. Because permits to dispose of agricultural and industrial wastewater may have restriction on application to prevent deep percolation, this research may refine some of the models used to predict the maximum rate of wastewater application possible without percolation below the rooting zone.

The wastewater land application facility at CFA covers approximately 29.5 ha (73 acres). The permit for operating this system limits the application rate to 63.5 cm (25 in.) water per year, which must be applied such that no more than 7.6 cm (3 in.) of water leach through the root zone toward groundwater. The 63.5 cm (25 in.) maximum application rate is more than two and one-half times the average annual precipitation and depending on the timing of application, plants may not be able to deplete this in one growing season to prevent leaching. Most of the precipitation in this cool desert biome occurs in the winter and spring, and soil moisture recharge occurs in the spring with snowmelt and rainfall. Therefore, wastewater application must be timed to avoid spring recharge to minimize deep percolation of wastewater. The wastewater also contains organic carbon, nitrogen, other nutrients, and trace metals that may have impacts on the proper functioning of native soil-plant systems.

Different plant species respond differently to addition of water and nutrient elements, especially if those additions come at times of the year that are normally dry. These differences in response can result in some species being favored and others discouraged. Changes in plant community structure can be expected. For example, in arid and semi-arid regions grasses are known to dominate where precipitation occurs mostly in the summer and shrubs tend to dominate in areas where moisture occurs as snow. Summer irrigation may lead to decreases in shrub dominance and increases in grasses.

Changes in plant community structure also mean changing habitats for other organisms such as small mammals, birds, insects, and big game animals. Because the area is relatively small, it is unlikely that decreased habitat quality would have significant impacts on wildlife populations on the INEEL. Increases in habitat quality, however, could have substantial impacts on wildlife use pattern in and near this small area.

Objectives
The primary objective of the research study was to determine the ecological benefits or hazards of applying wastewater on native vegetation in semiarid regions. Specific objectives were to determine the potential for impacts on rangeland quality, resident wildlife populations, and soil water balance.

Accomplishments through 2004
Plant cover surveys were completed in 39 study plots within the three distinct plant community types (sagebrush steppe, crested wheatgrass, and a transition type) on the application area and in control areas adjacent to the wastewater application area. Soil moisture data was collected once every two weeks at 19 sites in the wastewater application area and 20 control sites throughout the growing season (beginning mid-March and ending mid-October), and a breeding bird survey was conducted according to United States Geological Survey (USGS) guidelines on and around the study site to determine any differences between irrigated and non-irrigated areas in bird usage. Additionally a complete ecological impacts report detailing results from the 2002 growing season was completed in early 2004.

Results
Spring wetting fronts in 2004 ranged from 0.4 m to 1.0 m and did not differ substantially between irrigated and control plots. Subsequent to infiltration, soil moisture decreased steadily throughout the wetted profile through the summer as a result of evapotranspiration. Soils began to approach the lower limit of extraction by early July in 2004. The soil moisture profiles do not indicate an increase in soil moisture at 20 cm or deeper due to wastewater application. If irrigation were to affect soil moisture, it would be expected to see either small wetting fronts in the profile throughout the summer (in the case of pulses in application), or it would be expected that soil moisture in at least some portion of the top of the soil profile to remain elevated (in the case of relatively steady application of water). Neither of these patterns is apparent in the irrigated soil profiles. In fact, those profiles dried down throughout the summer in a manner very similar to that of the control soil profiles. Thus, most of the additional water received by a soil profile through wastewater application was evaporated or transpired before it percolated to a depth of 20 cm within the soil profile. The soil moisture dynamics described here were similar across all plant communities on the application area. Therefore, the probability of water percolating through the rooting zone and continuing to move downward was essentially the same for the wastewater application area and control locations during the 2004 growing season.

9.7 The Protective Cap/Biobarrier Experiment

Investigators and Affiliations
Amy D. Forman, Environmental Surveillance, Education, and Research Program, S. M. Stoller Corporation, Idaho Falls, ID

Funding Sources
U.S. Department of Energy Idaho Operations Office

Background
Shallow land burial is the most common method for disposing of industrial, municipal, and low-level radioactive waste, but in recent decades it has become apparent that conventional landfill practices are often inadequate to prevent movement of hazardous materials into ground water or biota (Suter et al. 1993, Daniel and Gross 1995, Bowerman and Redente 1998). Most waste repository problems result from hydrologic processes. When wastes are not adequately isolated, water received as precipitation can move through the landfill cover and into the wastes (Nyhan et al. 1990, Nativ 1991). Presence of water may cause plant roots to grow into the waste zone and transport toxic materials to aboveground foliage (Arthur 1982, Hakonson et al. 1992, Bowerman and Redente 1998). Likewise, percolation of water through the waste zone may transport contaminants into ground water (Fisher 1986, Bengtsson et al. 1994).

In semiarid regions, where potential evapotranspiration greatly exceeds precipitation, it is theoretically possible to preclude water from reaching interred wastes by (i) providing a sufficient cap of soil to store precipitation that falls while plants are dormant and (ii) establishing sufficient plant cover to deplete soil moisture during the growing season, thereby emptying the water storage reservoir of the soil.

The Protective Cap/Biobarrier Experiment (PCBE) was established in 1993 at the Experimental Field Station, INEEL to test the efficacy of four protective landfill cap designs. The ultimate goal of the PCBE is to design a low maintenance, cost effective cap that uses local and readily available materials and natural ecosystem processes to isolate interred wastes from water received as precipitation. Four evapotranspiration (ET) cap designs, planted in two vegetation types, under three precipitation regimes have been monitored for soil moisture dynamics, changes in vegetative cover, and plant rooting depth in this replicated field experiment.

Objectives
From the time it was constructed, the PCBE has had four primary objectives

• To compare the performance of caps having biobarriers (capillary breaks) with that of that of soil-only caps and that of caps based on U.S. Environmental Protection Agency recommendations for Resource Conservation and Recovery Act caps;
• To examine the effects of biobarriers as capillary breaks placed at different depths within the soil profile on water percolation, water storage capacity, plant rooting depths, and water extraction patterns;
• To evaluate the performance of caps receiving higher precipitation than expected under either the present climate or that anticipated in the foreseeable future; and
• To compare the performance of a community of native species on ET caps to that of caps vegetated with a monoculture of crested wheatgrass.

Specific tasks for the PCBE in 2004 included maintenance of the study plots, continuation of the irrigation treatments, and collection of soil moisture and plant cover data. The data will be analyzed according to the four major objectives listed above and analyses will focus on long-term cap performance. The PCBE has one of the most complete, long-term data sets for ET caps, which makes it a model system for studying ET cap longevity. Long-term performance issues that will be addressed with the PCBE include changes in plant community composition, species invasion, and changes in soil moisture dynamics as the caps continue to age and the biological communities associated with the caps continue to develop.

Accomplishments through 2004
Two supplemental irrigation treatments were completed on the PCBE in 2004. Fifty millimeters of water was applied to the summer irrigated plots once every other week from the end of June through the beginning of August for a total of 200 mm. Two hundred millimeters of water was applied to the fall/spring irrigated plots during a two week period at the end of September. Soil moisture measurements were collected once every two weeks from mid-March through mid-October. Vegetation cover data were collected throughout the month of July and into August.
Soil moisture and vegetation data collected in 2004 were archived. Soil moisture data were compiled and summarized, and soil moisture profiles were completed for each cap, irrigation and vegetation treatment.

Several presentations pertaining to alternative landfill cover designs and the PCBE were given in 2004. An invited talk detailing the ecological approach to revegetation design utilized on the PCBE was presented at the Design, Building, and Regulating Evapotranspiration (ET) Landfill Covers Conference sponsored by the U.S. Environmental Protection Agency, Remediation Technology Development Forum Program. A similar presentation was given as an invited talk at the 2004 Sediment Control/Wetlands Workshop conducted by the Idaho Department of Environmental Quality. Finally, a poster discussing the use of native vegetation for water extraction on landfill covers was presented at the Ecological Society of America 89th Annual Meeting.

Results and Discussion
Initial data analyses from the 2004 soil moisture data indicated that the spring infiltration event was deeper and more variable than it was in 2003 on the ambient and summer irrigated plots. The wetting front ranged from 40 cm to 160 cm in depth on those plots. Spring infiltration extended below the biobarrier on many of the shallow biobarrier caps, and extended into the biobarrier, but not below the biobarrier on many of the deep biobarrier caps. On the fall irrigated plots, the soil profile became saturated subsequent to the October 2003 irrigation and remained at field capacity until the following spring. Thus, any water entering the soil profile during spring infiltration in 2004 likely percolated through the cap and into the soil below.

Over the ten year study period, the widespread cap failure that occurred in response to the fall irrigation treatment of 2003 marks the first event of this type under the experimental treatment conditions. Similar cap failures occurred on all cap designs and vegetation types with fall irrigation again in 2004. Soil moisture data will be closely compared with vegetation cover data to determine possible causes of the cap failure. Continued irrigation and soil moisture measurements will be critical over the next few years to gauge whether cap failure under fall irrigation will continue to be a regular event, or whether the cap failures in 2003 and 2004 were a random and reversible occurrence.

Plans for Continuation
Soil moisture and plant community composition and cover were still experiencing important changes in 2004, as evidenced by the cap failures in response to the fall irrigation treatment. The PCBE should continue to be monitored at least until cap failure occurs on the fall/spring irrigated caps consistently or until the caps recover and the ecological and soil moisture parameters stabilize and long-term fluctuations can be characterized.

Additional recommended research for the PCBE includes studies pertaining to long-term maintenance issues such as response to fire, invasive plant species, erosion, and the role of soil microbiota in cap function. Research on specific uptake parameters and soil moisture distributions associated with native vegetation species will also be useful in optimizing water use by native vegetation, allowing cap revegetation plans and species recommendations to be designed specifically to address various capping issues.

9.8 Natural and Assisted Recovery of a Sagebrush (Artemisia tridentata) in Idaho’s Big Desert: Effects of Seeding Treatments and Livestock Grazing on Successional Trajectories of Sagebrush Communities

Investigators and Affiliations
Mike Pellant, Idaho State Office of the Bureau of Land Management, Boise, ID
Roger D. Blew, Amy D. Forman and Jackie Hafla, Environmental Surveillance, Education and Research Program, S. M. Stoller Corporation, Idaho Falls, ID
Robert Jones, U.S. Department of Energy Idaho Operations Office, Idaho Falls, ID
Greg White, Idaho National Engineering and Environmental Laboratory, Bechtel BWXT Idaho, LLC, Idaho Falls, ID
Alan Sands, The Nature Conservancy, Boise, ID

Funding Sources
Bureau of Land Management
U.S. Department of Energy Idaho Operations Office
The Nature Conservancy

Background
Averaged over the last 10 years, approximately 95,000 ha (235,000 acres) of lands managed by the Bureau of Land Management (BLM) in Idaho have burned annually. The BLM and other managers of Idaho rangelands, including the INEEL, must decide whether the burned areas need stabilization and rehabilitation treatments to prevent soil erosion and inhibit the invasion of exotic species such as cheatgrass (Bromus tectorum). Most of these rangelands have historically been dominated by big sagebrush (Artemisia tridentata), which does not resprout after fire.  Sagebrush provides critical food and habitat for sage grouse, a species proposed for listing under the Endangered Species Act. With the accelerating loss of native sagebrush communities and habitat for sage grouse and other sagebrush-obligate species, sagebrush reseeding following fire has become an important consideration, as has the issue of livestock grazing impacts on recovering native vegetation and seeded areas. In the last three years, approximately 70 percent of the sage grouse habitat in eastern Idaho's Big Desert has been burned by wildfire. Fire suppression and rehabilitation costs are rising, and the threats to human life and property are increasing in eastern Idaho.

This study has been divided into three components to address management concerns relative to: (1) native plant recovery in good ecological condition rangeland, (2) success of aerial seeding sagebrush, and (3) whether livestock grazing affects recovery on sagebrush steppe rangelands. These three components will provide new scientific information that addresses current management concerns relative to wildfire impacts and rehabilitation treatments on the eastern Snake River Plain. These studies are designed to establish long-term, replicated monitoring sites that can be reread in the future to provide additional information to managers about post-fire recovery and rehabilitation success. These studies will also provide insight into restoring sagebrush and understory herbaceous species for sage grouse and other sagebrush obligate wildlife species and domestic livestock in the Great Basin.

Objectives
The overall objectives of this research project are to examine some of the key factors that influence trajectories of community diversity and structure following wildfire in sagebrush-steppe ecosystems. Specifically, the factors that influence the recovery of these systems following fire and the replacement of native plant communities with vegetation dominated by cheatgrass (B. tectorum) will be examined. The three basic research objectives were to:

• Describe post-wildfire trajectories in community composition and structure in areas in good ecological condition;
• Compare sagebrush recruitment on areas that have been aerially seeded to areas relying on natural recruitment processes; and
• Determine whether trajectories of community composition and structure differ between areas returned to grazing after fire and areas where grazing is excluded.

Accomplishments through 2004
The trend in seedling density measured in 2003 on the 1994 burn pointed to the role of wind in seed dispersal and therefore it was determined to collect better data on that distribution pattern. To collect that data, six, 1000 m transects were used extending downwind from the upwind edge of the fire. Fifteen meter radius plots were surveyed at 50 m intervals along those transects. The center of the first plot on each transect was set 20 m from the fire edge. These surveys were conducted in burns from 1994, 1995, 1996, 1999 and 2000. This data will be used to look for changes in that distribution pattern with age since fire, possibly allowing us to determine a rate of spread into the burn.

Because those fires cover a period spanning from relative wet conditions through the current drought, this data can be used to further test the idea that sagebrush establishment is controlled by climatic conditions and not seed dispersal alone.

To address the first and third objectives, paired research plots were established in a portion of the area burned by the 2000 Tin Cup Fire. Grazing exclosure fences were constructed around one plot from each pair. The exclosed plot will be used to address questions related to recovery of vegetation in ungrazed sagebrush steppe rangeland. The unfenced plot will be used to examine the role of livestock grazing on that recovery. In all of these plots, plant cover, species richness and diversity were measured. Permanent photoplots and photopoints were established and photographed.

To address the first objective further, plots for addressing plant density and species richness in some of the older burned areas on the INEEL were established.

Grazing treatments were initiated in 2003 so utilization measurements were initiated at that time. Utilization was measured with the Ocular Estimate Method. Key species (one grass and one forb) were selected for each plot. Selection criteria included consideration of the most abundant species that had actually been grazed and for which there were sufficient numbers of individuals in the plot to obtain a reasonable sample.

Results
Heterogeneity chi-square tests were used to determine whether seedling counts were evenly, or uniformly, distributed among the twenty positions along each transect line. Overall, seedling counts were not uniformly distributed among the twenty plot positions along each transect for 27 of the 29 transects. Seedling counts were not comparable at the same position along each transect line within each burn, or stated differently, seedling count patterns were different along each transect within a burn. Thus, the highest seedling counts in any single transect did not necessarily occur at positions near the burn edge. In fact, the positions with the highest seedling counts were quite variable from one transect to the next.

A Poisson distribution was calculated for the frequency of occurrence of seedling counts among the 120 plots for each burn. The calculated Poisson distribution was then statistically compared to the actual frequency of occurrence of seedling counts among the plots using a Chi-Square Goodness of Fit Test to determine whether or not sagebrush seedlings occur randomly within the burned area. If the actual frequency of seedling occurrence among plots departed significantly from a random distribution, a variance to mean ratio was calculated to determine whether the seedling spatial pattern was clumped or uniform. However, there was already certainty the distribution would not be uniform because the possibility had been ruled out by the heterogeneity analysis. The variance to mean ratio for the sagebrush seedlings/plot on the all burns indicated either clumped or highly clumped distributions.

Species Richness, Density and Frequency - A total of 79 plant species were encountered in the ten pairs of plots (20 plots). Three species found in 2003 were not found in 2004. All three were perennials and two were native species. Twelve species not found in 2003 were found in 2004. Seven of those twelve were present in 2002, but not in 2003. Five were species not previously found in these plots. All of the species added in 2004 were native and ten of those were annuals.

Coefficient of Community is the percentage of total species that the two communities have in common. It was calculated here as to compare the two plots of each pair for similarity in terms of the species present. Coefficient of Community varied from 0.72 to 0.90. The Coefficient of Community went up in all but one plot pair (Plot 10).

Species/area curves were plotted based on the species counted in the nested plots. The y-intercept and slope increased in nearly all of the species/area curves. This is likely due to the increases in species richness and frequency.

Utilization - Utilization of grasses on each plot ranged from 0.0 to 1.4 percent with an average utilization of 0.26 percent. Forb utilization ranged from 0.0 to 6.7 percent with an average utilization of 1.9 percent. These numbers are obviously very low and indicate that the needed grazing treatment was not achieved on these plots in the spring of 2004.

Plant Cover - Mean total cover was 11.7, 13.6 and 20.1 percent in 2002, 2003 and 2004 respectively. Native perennial grass basal cover increased from 1.5 percent in 2002 to 2.3 percent in 2003 and remained unchanged through 2004. Percent aerial cover of native perennial forbs remained relatively stable with a high of 4.1 in 2003 and a low of 3.6 in 2004. Cover by introduced species (primarily annual forbs) was 0.6, 0.3 and 1.9 percent in 2002, 2003 and 2004 respectively. Aerial cover by native annual and biennial forbs was 0.6, 0.0 and 3.2 percent in 2002, 2003 and 2004 respectively. The increase in cover by annual and biennial species in 2004 may have been the result of higher precipitation in May and June of 2004 compared to 2002 and 2003.
Shannon-Weiner Diversity Indices for each plot ranged from 1.20 to 2.75. The diversity index went up on most of the plots between 2003 and 2004. The Morisita's Similarity Indices for comparing plots within a pair ranged from 62.62 to 98.52. The similarity index went up on four pairs of plots (2, 4, 7 and 9) and went down on six plot pairs (1, 3, 5, 6, 8 and 10).

Older Burned Area Plots - Of the 32 plots planned for this study, surveys were completed on 18 during 2003 and the remainder was surveyed in 2004. A total of 101 species were encountered on the 32 plots. There were more species of annual forbs in 2004 than 2003 and they were present in higher densities in 2004. There is a trend for big sagebrush density and frequency to be higher in the older burns than the more recent ones. Green rabbitbrush density and frequency varied greatly from plot to plot and from fire to fire with no apparent relationship to fire age.  Cheatgrass frequency averaged about 0.5, but the density rarely exceeded 10 plants m-2. There was no relationship between cheatgrass density or frequency with fire age. Halgeton density and frequency were higher on the areas burned in 1994 and 1996.

Project Conclusions

Natural Sagebrush Seedling Recovery - Sagebrush seedling spatial distribution was clumped in all five of the burns sampled. The 1994 and 2000 burns most closely approximate the exponential decay model that has been proposed for seedling distribution from the edge of a burn scar; those burns also have the highest variance to mean ratios, indicating the more strongly clumped distributions (likely driven by plots with higher seedling counts close to the burn edge). However, all of the burns sampled exhibited clumped seedling distributions, indicating that seedlings establish in clusters in burns that do not show a strong edge effect. Additionally, groups of seedlings may become established several hundred meters from the burn edge, as seen in all burns sampled except the 2000 burn. The clustered pattern may be influenced by seed from remnant islands. The clustered pattern may also reflect soils, topography, and microclimate.

The mechanism is likely a combination of remnant islands and an appropriate microhabitat, though the relative importance of each factor is unclear at this point. Most importantly, sagebrush seed does appear to become dispersed and seedlings established the interior of the burn scars that were sampled in substantial numbers and within a relatively short time frame. However, the presence of sagebrush seedlings in the interior of burn scars does not necessarily indicate a short recovery period; it simply indicates that initial seed dispersal and establishment may not be as limited as previously thought. These results also demonstrate that there must be seed dispersal from the fire edge well into the burn area (something greater than 1000 m). That annual seed rain may be important for providing seed each year far into the burn to take advantage of a climate-driven establishment event.

Natural Recovery Trajectory - Consistent increases in cover by native species have been observed during each year of the study. This happened concurrent with a severe drought. Total annual precipitation since the fire in 2000 ranged from 110 to 155 mm while the long term mean annual precipitation at the INEEL is 220 mm. It was also interesting to see the return of native annuals in 2004 acting as ephemerals responding to summer conditions that were wetter than normal. During 2004, the plots received a substantial portion of the total annual precipitation during late spring. This is in contrast to 2003 when there was no precipitation between early May and late August. At this time, it appears that none of the plots are at risk of a recovery trajectory to anything other than communities dominated by native perennial species.

When that trajectory is extended by considering the data collected in the older burn plots a similar pattern is seen. It was interesting to find no sagebrush on the survey plots in an area that burned more than 55 years ago. This along with previous data collected at the INEEL indicate that natural recovery times for Wyoming big sagebrush may be much longer than previously estimated. Similarly the lack of an apparent relationship between time since burn and green rabbitbrush frequency and density suggests that the assumption that rabbitbrush acts as a successional species may need to be reconsidered.

Recovery Trajectory With Livestock Grazing - Unfortunately, meaningful grazing treatments were not achieved during 2004. Cattle were released onto the allotment around July 1, 2004, and removed in early August. When it was found that some of the plots would be grazed, albeit later than expected, it was attempted to capture as much information as possible about that event. It was hoped to be able to extend the study for at least one more year in an effort to determine if livestock grazing has an effect. To that end, utilization was re-measured on the ten pairs of plots on August 10, 11 and 12, 2004. In addition, six new grazed plots were established in an area that had received moderate to heavy utilization. Utilization was measured on those plots as well. A plan is in place to continue surveying the ten paired plots and the newly established plots should funding come available.

9.9 Developing Advanced Scientific Methods for Landscape Level Management of Federal Facilities

Investigators and Affiliations
Jerry L. Harbour, Robert P. Breckenridge, Randy D. Lee, Idaho National Engineering and Environmental Laboratory

Funding Sources
Idaho National Engineering and Environmental Laboratory

Background
Many Federal lands are subject to creeping environmental problems that often go unnoticed on a site-specific basis but, when reviewed from a landscape level, can have dramatic impacts on natural resource management (i.e., threatened and endangered species, invasive weeds, and fire).

This Laboratory Directed Research and Development (LDRD) project is researching the use of advanced concepts in landscape ecology and remote sensing to develop a unified theory for management of federal lands. Development of a unified theory that takes advantage of advanced technologies for identification and mapping of landscape features will enhance resource management to meet appropriate regulations, facilitate future facility sighting, and enhance the scientific basis for evaluating options for future management of these lands.

Objectives
Technical objectives for fiscal year 2004:

• Develop a theoretical model for land cover and land use on and around the INEEL.
• Evaluate ecological health indicators needed to support end state planning and risk assessment.
• Develop advanced methods to monitor conditions of sagebrush steppe vegetation using unmanned aerial technology for improving monitoring approached.
• Define the long-term research niche for the INEEL in understanding sagebrush steppe ecosystems.

Accomplishments through 2004
Development of theoretical model. In fiscal year 2004, the project team completed a report titled "Conducting Landscape Level Analysis: A Focus on Remote Sensing and GIS" that identifies the data and remote sensing imagery that can be incorporated into a theoretical modeling approach for the INEEL. The theoretical model being developed evaluates the framework for addressing end state planning and could help DOE achieve two aspects of its mission in managing lands in Idaho. These two aspects are 1) to understand the future use for sagebrush ecosystems, and 2) to take actions to ensure that future DOE offices Nuclear Energy and Environmental Management and clean-up missions are achieved as efficiently as possible.

Evaluation of ecological health indicators. An extensive amount of ecological data has been collected over the many years that work has been conducted on the INEEL. Some data sets, such as the long-term vegetation plots, have records that go back over 50 years. The available data have been cataloged and, where appropriate, incorporated into a GIS format. These data will be used to support identification of the most appropriate indicators for evaluation of ecological health. The research team has been invited by the Sustainable Rangeland Executive Committee to join their group in identifying criteria and indicators for sustainable rangeland management. Current activities have focused on identifying critical linkages between ecological parameters, and how these will support long-term risk management for rangeland systems. A list of 64 criteria and indicators has been identified. This list is under evaluation to identify those parameters most appropriate for the INEEL.

Evaluate vegetation using Unmanned Aerial Vehicles (UAV's). Analysis of vegetation by traditional ground methods is very labor intensive. Evaluations are being conducted to determine if there are alternative aerial approaches`` for collecting data about the amount of vegetative cover present on the INEEL that are comparable to ground based methods, Two different UAV platforms (fixed wing and rotary) are being evaluated with both fixed and video cameras to determine if they are capable of assessing creeping environmental problems (Figure 9-11 and Figure 9-12). This includes identification of species to the life form (shrub, grass, forb and bare ground) to determine if it is possible to evaluate large tracks of land at one time, resulting in cost savings and improved safety from reduced fieldwork.

Long-term research niche for INEEL. A series of meetings and conference calls have been held with senior representatives from the U.S. Department of Interior, USGS, Fish and Wildlife Service, and Nature Conservancy to evaluate long-term uses for INEEL as a sagebrush steppe research facility. The National Academy of Science also has recently endorsed the creation of an ambitious network of ecological research stations that the NSF has been advocating for the past six years. INEEL, along with university collaborators, will pursue involvement of the INEEL in the National Ecological Observatory Network (NEON). During fiscal year 2005 the research team will meet with NSF and other collaborators to help identify INEEL's potential role in supporting the NEON concept.
A number of accomplishments were made this year. This LDRD resulted in a presentation on conceptual models for monitoring rangelands made to the Sustainable Rangeland Roundtable meeting in Spokane, Washington. Contacts also were made with the U.S. Department of the Interior (Dr. Jim Tate, science advisor) during discussions about applying state-and transition-modeling approaches for landscape management of federal lands. A conceptual model of a landscape management approach was also presented to Jon Sandavol, chief of staff, Idaho Division of Environmental Quality. The project team discussed the scientific basis for land management of federal lands with Dr. Steve Bunting (University of Idaho) and Dr. Mike Scott, a senior scientist for USGS. An abstract titled "Development of Ecological Indicators for Sustainable Management of Semiarid Ecosystems" was presented on October 2003 at the Sustainable Rangeland Roundtable in Boise, Idaho.

Results
Field data will be collected during the spring/summer of 2005. Results will be compiled and presented at appropriate professional meetings and published in the scientific literature.

Plans for Continuation
INEEL UAV program will continue to grow with continued interest in using the technology to support developing National Security and Nuclear missions. The UAV technology is in its developmental stages, system improvements are being evaluated and tested to determine if this approach will provide a viable alternative to conventional monitoring methods. UAVs and other remote sensing technologies will continue to be pursued, because they provide an opportunity to extend our ability to collect data on ecological resources across the vast landscape of INEEL that otherwise may not be accessible.