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Geology topics

M.K. Laubhan

Publications and source records attributed to M.K. Laubhan.

5 recordsLinked to original sources
USGS2011

Balancing energy development and conservation: A method utilizing species distribution models

Alternative energy development is increasing, potentially leading to negative impacts on wildlife populations already stressed by other factors. Resource managers require a scientifically based methodology to balance energy development and species conservation, so we investigated modeling habitat suitability using Maximum Entropy to develop maps that could be used with other information to help site energy developments. We selected one species of concern, the Lesser Prairie-Chicken (LPCH; Tympanuchus pallidicinctus ) found on the southern Great Plains of North America, as our case study. LPCH populations have been declining and are potentially further impacted by energy development. We used LPCH lek locations in the state of Kansas along with several environmental and anthropogenic parameters to develop models that predict the probability of lek occurrence across the landscape. The models all performed well as indicated by the high test area under the curve (AUC) scores (all >0.9). The inclusion of anthropogenic parameters in models resulted in slightly better performance based on AUC values, indicating that anthropogenic features may impact LPCH lek habitat suitability. Given the positive model results, this methodology may provide additional guidance in designing future survey protocols, as well as siting of energy development in areas of marginal or unsuitable habitat for species of concern. This technique could help to standardize and quantify the impacts various developments have upon at-risk species.

Environmental Management↗
USGS2006

Seed germination of cirsium arvense and Lepidium latifolium: Implications for management of montane wetlands

Cirsium arvense and Lepidium latifolium are species that can aggressively invade wetland margins and potentially reduce biodiversity and alter ecosystem function. Although expansion of these species primarily occurs via rhizomatous growth, seeds are thought to be important in initial establishment. We conducted this study to investigate differences in seed germination of C. arvense and L. latifolium in montane wetlands of Colorado and Wyoming, USA. We used germination chambers to simulate environmental conditions (photoperiod, day/night temperature) during three periods of the growing season at each site and evaluated seed germination in relation to three soil moisture levels and two soil depths. A combination of shallow (<1 cm) seed burial and wet conditions resulted in the greatest germination probability of C. arvense (x = 63.0%), 95% CI = 41.2-80.5%), whereas deep (2-3 cm) seed burial and saturated moisture conditions resulted in almost no germination (x?? = 0.3%, 95% CI = 0.1-1.3%). The maximum germination probability of 44.0% (CI = 28.1-61.4%) for L. latifolium also occurred in the shallow burial and wet treatment; however, only effects of seed burial were significant (P < 0.05). The estimated mean germination probability of deeply buried seeds was <1.0% (CI = 0.3-1.4%) compared to 32% (CI = 19.7-47.9%) for shallowly buried seeds. Our results suggest that each species has the ability to germinate at similar rates throughout the growing season and across a large portion of the moisture gradient. This suggests that management actions, including water-level manipulations, at any time during the growing season may stimulate germination. Although burial of seed to depths of 2-3 cm reduced the germination potential of both species, the use of mechanical implements may be problematic in established stands because new plants of both species easily sprout from root buds. Further, disturbance resulting from such actions diminishes the density and vigor of other plants already present, which may ultimately decrease the competitive resistance of the disturbed environment to invasion by outside species. Detection of new invasions is a critical component of any integrated weed management program. Our results indicate that the incidence of C. arvense and L. latifolium germination is most likely in areas with seeds that are within 1 cm of the soil surface and soil moisture is 75-100% of field capacity for extended periods. ?? 2006, The Society of Wetland Scientists.

Wetlands↗
USGS2000

Managing wetlands for waterbirds: How managers can make a difference in improving habitat to support a North American Bird Conservation Plan

Wetlands are the most productive ecosystems in the world, yet they have suffered more loss and degradation than any other ecosystem. Not surprisingly, 50% (29 of 58) of all the bird species in the U. S. (excluding Hawaii and territories) that are listed either as federally threatened or endangered, or are on the U. S. Fish & Wildlife Service 1995 List of Migratory Nongame Birds of Management Concern, occupy wetland or aquatic habitats even though many remaining wetlands across the North American landscape already are managed primarily for waterbirds. Some of these wetlands are administered by federal and state entities (e.g., national wildlife refuges, national and state parks, state wetland management areas) or are maintained on private lands through federally supported restoration and enhancement programs (e.g., Conservation Reserve Program, Wetland Reserve Program, Waterfowl Production Areas, and Partners for Wildlife). Private organizations, such as the National Audubon Society, The Nature Conservancy, and private hunting clubs, also own wetland areas that are managed specifically to benefit wildlife. If management philosophies are altered to consider the entire complex of wetlands, many wetlands can provide benefits to a broad array of waterbirds, as opposed to just one or a few species. However, challenges for natural resource managers are in forming partnerships with owners-managers of wetlands where the objectives are not primarily wildlife oriented. These owners or managers need to be included in wetland training workshops in an attempt to educate them about wetland values and secondary wildlife benefits that may be derived in flooded agricultural lands, aquaculture ponds, altered coastal marshes (mosquito control), and salt evaporation ponds. In some cases, compensation for crop damages by wildlife may be a necessary part of any cooperative agreements. In the development of a North American Bird Conservation Plan we propose a four-step approach and recommend that emphasis be placed on working with Joint Ventures of the North American Waterfowl Management Plan to ensure that a diverse array of waterbird species will benefit. Efforts also should be devoted to developing similar partnerships in areas where important wetland resources exist but no Joint Ventures are planned.

Book chapter↗
USGS1999

Distribution and diurnal behavior of Steller's Eiders wintering on the Alaska Peninsula

We studied the distribution and activities of adult Steller's Eiders (Polysticta stelleri) during winter and spring on a deep-water embayment and a shallow lagoon along the Alaska Peninsula from September 1980 to May 1981. During the remigial molt, eiders were observed on Izembek Lagoon but not on Cold Bay. Following the flightless period, Izembek Lagoon continued to support 63-100% of eiders encountered during surveys. As ice cover on Izembek Lagoon increased, the number of birds decreased on Izembek Lagoon but increased on Cold Bay, suggesting that some eiders disperse to nearshore, deep-water habitats in close proximity to Izembek Lagoon during severe weather. Diurnal activity budgets indicated that the amount of time resting or engaged in aggression and alert activities was similar among locations, seasons, tidal stages, and sexes. In contrast, time spent foraging differed among seasons and locations but did not differ among tidal stages or sexes. Although time spent foraging was similar during winter and spring on Izembek Lagoon, eiders on Cold Bay foraged more during winter compared to spring. Synchronous diving was the dominant foraging strategy.

Condor↗