Conservation and Ecology of Natural Resources and Habitats

Contributed Paper
ROOM: Room 220 – Ruidoso

1:10PM Evaluating the Suitability of Designated Critical Habitat for Imperiled Flatwoods Salamanders
Susan C. Walls; William J. Barichivich; Kevin M. Enge; Thomas A. Gorman; John G. Palis
We evaluated the suitability of designated critical habitat (CH) for two federally-listed pond-breeding amphibians: the reticulated (Ambystoma bishopi, endangered) and frosted (A. cingulatum, threatened) flatwoods salamanders. Using Geographic Information System (GIS) analytic tools, we compared the total area of designated habitat for each species, the size of each species’ critical habitat units (CHUs), and the percentage of each CHU comprised of habitat belonging to three different land-use categories. To evaluate the potential for designated CHUs to support metapopulation dynamics, we measured the minimum distance between known occupied wetlands and adjacent ones within each unit. Last, because land management practices could be a consequence of public vs. private ownership, we accessed public land database layers to determine the percentage of CH located on public lands. Ambystoma cingulatum has significantly larger CHUs and five times more designated CH, with significantly less agriculture/disturbed and plantation habitat types within each CHU, compared to A. bishopi. For both species, an average of 40% to 50% of the habitat within each CHU is disturbed. Public ownership of CHUs also differs markedly between A. cingulatum (73.7%) and A. bishopi (18.8%). For CHUs in which there were multiple wetlands, the densities of those wetlands were three orders of magnitude less, on average, than that of naturally-occurring wetland densities reported for other amphibian studies. Last, we demonstrated that a re-analysis of terrestrial buffer zones around breeding ponds could result in a maximum increase of more than 40% in the amount of terrestrial habitat protected for adult and juvenile salamanders. Our results indicate that the role of CH in the conservation of flatwoods salamanders could be enhanced by addressing these and other issues. We provide options for consideration if flatwoods salamander CH is re-examined for its adequacy in promoting the persistence and recovery of these species.
1:30PM Islands of Tallgrass Prairie: the Case of the Regal Fritillary
Andrew Caven; Kelsey C. King; Josh Wiese; Emma Brinley Buckley
One trophic level, the insect community, which comprises a critical food source for many vertebrates, has increasingly been found to be unable to cross habitat barriers. One species unable to cross even finely-scaled habitat changes is the regal fritillary (Speyeria idalia: Lepidoptera). This butterfly, endemic to tallgrass prairies, has declined by as much as 95 percent in the last three decades and is currently a candidate for the Endangered Species Act. We evaluated habitat components in this species’ western range limit, central Nebraska. We used presence/absence modelling on data collected from biological monitoring transects to identify key habitat traits associated with the regal fritillary. Our findings elucidate the habitat trends indicating that regal fritillaries become stranded on islands of suitable relict prairies with little to no dispersal capability. Therefore, populations of this butterfly may be genetically isolated, leading to further declines. Conservation planning is urgently needed to save this species; corridors and restorations adjacent to patches where the butterfly is known to exist would prevent the need to manually disperse this species (preventing genetic uniformity), and benefit the biological community associated with this species. The dispersal-avoidance behavior exhibited in this species is likely found in other insects as well. Dispersal-avoidance behaviors may help explain the inherent differences between relict and restored habitats. This study provides further evidence on the need for conservation corridors and restorations directly adjacent to relict habitat.
1:50PM Predicting Gopher Tortoise Habitat Connectivity in Georgia Using Forest Structure, Land Cover, and Soils
Jeffrey Hepinstall-Cymerman; Tom Prebyl; Bryan Nuse; Clint Moore
Gopher tortoises require suitable soils and conifer or mixed stands with open canopies where light penetrates to a ground layer of forbs and grasses maintained by prescribed fire or mechanical treatment. Our objectives were to determine the extent and connectivity of habitat for gopher tortoises in Georgia. We used multi-season Landsat-derived vegetation indices and field surveys to develop maps of forest overstory and understory structure as of 2015. We modeled gopher tortoise habitat distribution throughout its range in Georgia using SSURGO soil attributes, 2011 National Land Cover Data, Landsat-derived forest structure characteristics, and ecoregion layers. We evaluated three scales of habitat selection and constructed logistic regression models covering combinations of the predictor variables and their two-way and three-way interactions and quadratic forms of some variables and ranked model performance with AIC. Our top model contained variables from two spatial scales which we compared to the top model constrained to variables from a single scale and included soil suitability, forest structure, land cover, and ecoregion. From our model parameter estimates, we developed predictive maps of habitat. We used the inverse of habitat suitability to estimate resistance to movement and quantified least cost paths and landscape connectivity with Linkage Mapper and Circuitscape. We compared connectivity of known populations against connectivity of large patches of predicted habitat to identify key areas to survey for gopher tortoises and key linkages between known and potential populations. The combination of multi-season moderate resolution imagery with field data on vegetation and wildlife populations combined with statistical and geospatial modeling provided data products of direct relevance to natural resource managers in Georgia. Similar methods are now being used to map moose habitat in the Adirondacks of New York.
2:10PM Soil Chemistry and Its Effect on Central Pennsylvania’s Forest Wildlife Habitat
Danielle R. Begley-Miller; Duane R. Diefenbach; Marc E. McDill; Christopher S. Rosenberry; Emily Just
Pennsylvania public lands represent millions of hectares of largely contiguous forest which are home to hundreds of wildlife species. Soil acidification is known to change forest soil conditions, reducing Ca and Mg available to plants, while increasing toxic metals (Al, Mn, and Fe). As a result, the quality of forage in areas with pH < 5.0 declines. How soil chemistry influences understory plant species occurrence, however, is not well understood. To investigate this relationship, we used single-species occupancy models to compare 2015 baseline forest inventory data to site-specific soil chemistry (pH, extractable nutrients, and toxic metals) for several species. We studied 24 sites on the Rothrock and Bald Eagle state forests in central Pennsylvania. Probability of detection (p) for all species (mountain laurel (Kalmia latifolia), huckleberry (Gaylussacia spp.), Indian cucumber-root (Medeloa virginiana), red maple (Acer rubrum), red oak (Quercus rubra), and black birch (Betula lenta)) was constant and high (ρ-hat > 0.66). Lower pH (2.5-3.5) was a predictor of increased occupancy (ψ) for mountain laurel and huckleberry. High levels of Mn (> 0.2 cmol(+)/kg) reduced occupancy of mountain laurel and Indian cucumber-root, while high levels of Al (> 5.0 cmol(+)/kg) reduced occupancy for black birch. Occupancy of red maple was constant between study areas (ψ = 0.30) but for red oak differed by state forest (Rothrock ψ = 0.28; Bald Eagle ψ = 0.01). In addition to known changes in forage quality, species occupancy changes with pH and toxic metal concentration. In particular, nutrient-rich forage species, such as Indian cucumber-root are absent from soils high in Mn. Furthermore, plant responses to soil chemistry are species specific and complicate inferences about plant species distribution in relation to other environmental factors.
2:30PM Diet Overlap of Wild Bees and Ungulates in a Forested Riparian System
Mary M. Rowland; Sandra J. DeBano; Samantha M. Roof; Lauren A. Smith
The benefits of native pollinators and the ecosystem services they provide are increasingly recognized, even as many pollinator populations decline. Pollinator conservation, however, must be balanced with other land uses such as timber and crop production, livestock grazing, and managing wildlife habitat. One area of potential conflict is grazing by wildlife of flowering plants that are important food sources (i.e., pollen and nectar) for bees, an area of scant research to date. To better understand potential impacts of herbivory by large mammals on floral resources used by native bees, we reviewed literature on flowering plant occurrence in ungulate diets (mule deer [Odocoileus hemionus], elk [Cervus elaphus], and cattle [Bos taurus]) and compared this information with floral preferences of bees. We also investigated spatial and temporal variation in the wild bee community, ungulates, and flowering plants along a 12-km reach of Meadow Creek within the Starkey Experimental Forest and Range in northeast Oregon, site of a long-term research project evaluating effects of riparian restoration on salmonids and myriad other responses. Sampling sites were partitioned between two grazing treatments: total exclusion from large ungulates, and grazing by deer and elk. Our literature review revealed relatively high potential overlap between bee and ungulate diets for plants found along Meadow Creek (e.g., 60-64% overlap at genus level), especially for elk. Flowering stems (n = 25,050) were generally more abundant in ungrazed vs. grazed sites; however, patterns were highly variable in time and space and across species. For some species frequently visited by bees and also preferred by elk (e.g., Potentilla gracilis), we found significantly lower flower abundance in grazed sites. These differences increased over time (3 yrs) as years of protection from grazing increased. Our study can inform pollinator conservation and ungulate management when multiple objectives must be considered.
2:50PM Refreshment Break
3:20PM Impact of Logging Residue Retention on Small Mammals in the Southern Appalachian Region
April D. Boggs; Christopher E. Moorman; Dennis W. Hazel; Cathryn H. Greenberg
There is growing interest in the use of wood for bioenergy. However, removing low value woody material for renewable energy could reduce downed wood important as food and cover for ground-dwelling wildlife that use young forest. We examined the relationship between levels of downed woody debris and occurrence of mice (Peromyscus spp.) following timber harvests in western North Carolina. We sampled mice in 10 sites that were clearcut or shelterwood harvested in 2013-2015; 5 of the sites were hardwood stands prior to harvest and the other 5 were dominated by white pine (Pinus strobus). We captured mice from May to August 2016 using 60 Sherman traps per site spaced every 15 m and checked for 5 consecutive days. Traps were categorized as either ≤5 m from coarse woody debris (near debris) or >5 m from coarse woody debris (far from debris). Approximately 65% of the traps were located near debris and 35% were far from debris. Variables for analysis also included vegetation structure at each trap and site-level woody debris volumes, measured using prism sweep sampling. Total captures were greater in white pine stands (185) than in hardwood stands (85 captures), possibly because of greater volumes of downed woody material present after harvest in white pine stands. Preliminary analysis indicated that a greater percentage (76%) of captures occurred near coarse woody debris than far from debris. Piles of logging debris retained following harvest may provide critical resources for mice and other early succession wildlife.
3:40PM Active Adaptive Management in Action: Recovery Options for Woodland Caribou
Robert Serrouya; Bruce N. McLellan; Harry van Oort; Garth Mowat; Stan Boutin
One of North America’s greatest conservation challenges is the recovery of woodland caribou. They are naturally rare yet broadly distributed and the old forests they prefer are sought by industry. Their decline is caused by apparent competition, where expanding moose and deer populations lead to more predators that incidentally consume caribou. Using an adaptive management experiment, we tested the hypothesis that reducing moose to historic levels would reduce apparent competition and therefor recover caribou populations. Nested within this broad hypothesis were three specific hypotheses: 1) sport hunting could be used to substantially reduce moose numbers to an ecological target; 2) wolves in this ecosystem were primarily limited by moose abundance; and 3) caribou were limited by wolf predation. These hypotheses were evaluated with a before-after control-impact (BACI) design that included response metrics such as population trends and vital rates of caribou, moose, and wolves. Three caribou subpopulations were subject to the moose reduction treatment and two were in a reference area where moose were not reduced. When the moose harvest was increased, the moose population declined substantially in the treatment area (by 70%) but not the reference area, suggesting that the policy had the desired effect and was not caused by a broader climatic process. Wolf numbers subsequently declined in the treatment area, with wolf dispersal rates 2.5 × greater, meaning that dispersal was the likely mechanism behind the wolf numerical response, though reduced recruitment and starvation was also documented in the treatment area. Caribou adult survival increased from 0.78 to 0.88 in the treatment area, but declined in the reference. Caribou recruitment was unaffected by the treatment. The largest caribou subpopulation stabilized in the treatment area, but declined in the reference area. The observed population stability is comparable to other studies that used intensive wolf control, but is insufficient to achieve recovery, suggesting that multiple limiting factors and corresponding management tools must be addressed simultaneously to achieve population growth.
4:00PM The Ecology of the Monarch Butterfly Relative to Density, Host Plant Occurrence and Habitat Use in the Flint Hills
Caroline Skidmore
Monarch butterflies (Danaus plexippus) were once abundant across North America, but populations have declined by 81% in the last decade. Population declines and consideration for listing under the Endangered Species Act makes research on the ecology, population trends, and habitat requirements of the Monarch especially relevant. Modeling occurrence of milkweeds (Asclepias spp.) will assist in management of Monarchs throughout their range. Knowledge of the habitat use patterns of Monarchs is necessary to improve conservation efforts in the central Great Plains (CGP). Although much of the Monarch’s range within the CGP consists of cropland, understanding Monarch habitat requirements in native prairies should also be a focus. We measured Monarch density in tall-grass prairie managed using haying, grazing, and prescribed fire at Fort Riley Military Reservation (FRMR) and Konza Prairie Biological Station (KPBS) in the Flint Hills of Kansas. Our objectives were to (1) derive temporal population density estimates of Monarchs during May-August, (2) compare average population density responses among management strategies, and (3) create models to predict the influence of vegetation composition on the density of adult Monarch butterflies and predict the occurrence of milkweed within FRMR and KPBS. We conducted repeated transect surveys of Monarch butterflies among 37 and 25 transects in FRMR and KPBS during 2015 and 2016, respectively. Concurrently, we recorded locations of ~100 milkweed clusters. The greatest density of Monarchs was found in transects with high fire return interval or hayed. Monarch densities greatly increased within the Flint Hills in August due to their migration south. Milkweed distribution was most influenced by the land cover type variable, grassland being selected. Other influential variables included complex soil, high sunlight, gentle slopes, moderate fire return interval, and moderate elevation. Our results suggest that Monarch conservation could benefit by management of their habitat through high fire return intervals and haying.
4:20PM A National Approach to Map and Quantify Terrestrial Vertebrate Biodiversity
William G. Kepner; Kenneth G. Boykin; Anne C. Neale; Kevin J. Gergely
Biodiversity is crucial for the functioning of ecosystems and the products and services from which we transform natural assets of the Earth for human survival, security, and well-being. The ability to assess, report, map, and forecast the life support functions of ecosystems is absolutely critical to our capacity to make informed decisions to maintain the sustainable nature of our environment now and into the future. Because of the variability among living organisms and levels of organization (e.g. genetic, species, ecosystem), biodiversity has always been difficult to measure precisely, especially within a systematic manner and over multiple scales. In answer to this challenge, we have developed an approach that uses deductive habitat models for all the terrestrial vertebrates of the conterminous United States and clusters them into biodiversity metrics that relate to ecosystem service-relevant categories that reflect elements of A) Biodiversity Conservation; B) Food, Fiber, and Materials; and C) Recreation, Culture, and Aesthetics. Several metrics, such as harvestable species (big game, small game, furbearers, and waterfowl) richness, have been developed down to the 30m scale of resolution. Collectively, these provide a consistent scalable process from which to make geographic comparisons, provide thematic assessments, and to monitor status and trends in biodiversity. Currently, we include 1699 terrestrial vertebrate species (684 bird spp., 434 mammal spp., 322 reptile spp., and 259 amphibian spp.). As example, we provide selected results for the conterminous U.S. along with sub-national areas of interest to demonstrate the multi-scale utility of the approach. In these examples, geographic patterns differed among metrics and across the study areas. Additionally, we have created a dynamic element to the system to allow the exploration and addition of other metrics as they become identified and tested.
4:40PM Breeding Bird Response to Post Oak Savanna Restoration in Eastern Texas 8 Years Post-Management
Courtney K. Williams; Christopher Comer; Jeffrey Gunnels
Oak savannas were once an abundant vegetation type in the Midwestern United States that have now declined to <1% of their original distribution. Historically, natural disturbances such as periodic fire maintained oak savannas, but these have been reduced or eliminated resulting in woody encroachment and subsequent habitat loss and degradation. In 2007, a baseline, pre-restoration study (Phase I) was completed to determine breeding bird abundances, nest success, and nest site selection. The results of Phase I showed a lack of savanna vegetation structure on degraded sites and few savanna or grassland obligate bird species. The goal of this study is to determine how breeding birds of oak savanna vegetation types in eastern Texas respond to restoration effects 8 years after initial management. Currently the post-restoration study (Phase II) is underway to document breeding bird responses to post oak savanna restoration using line-transects and nest searching during 2016 and 2017 breeding seasons. Phase II first year data shows a significant increase in species richness (Phase I = 44; Phase II = 55) and abundance of target grassland and savanna birds. A shift in bird communities has been observed from a more woodland dominated community to grassland/savanna community. For instance, the number of detections for tufted titmouse (Baeolophus bicolor), a species typically found in forest with dense canopies, decrease by 150 detections. During Phase II, we also confirmed breeding for 2 species of savanna birds that were not present during the Phase I study: dickcissel (Spiza americana) and lark sparrow (Chondestes grammacus). The presence of savanna species can be linked to the herbaceous vegetation that was restored to more closely resemble historic oak savanna structure and can quantify the success of restoration efforts.


Contributed Paper
Location: Albuquerque Convention Center Date: September 24, 2017 Time: 1:10 pm - 5:00 pm