22 research outputs found

    Improving the Cost-Effectiveness of Ecosystem Management: An Application to Waterfowl Production

    No full text
    Species conservation is an important global policy issue. The design of cost-effective species conservation programs requires resource managers to choose from a suite of conservation activities and sites. This article determines cost-effective conservation strategies for waterfowl using a bioeconomic modeling framework, which is developed using a biological simulation model for waterfowl and regression analysis. The model accounts for (a) a broad range of land-use and direct wildlife conservation activities, (b) the effect of landscape heterogeneity, and (c) interactions between conservation activities. Results indicate that accounting for the three factors listed above can improve the cost-effectiveness of waterfowl conservation on agricultural land. Copyright 2007, Oxford University Press.

    Natural Cavities Used by Wood Ducks in North Central Minnesota USA

    No full text

    Macro‐ and Micromorphology of Subsurface Carbon in Riparian Zone Soils

    No full text
    Soil organic matter (SOM) contains fractions that range from very active to passive, relative to microbial-driven ecosystem processes and functions. A classification system is needed that can test the hypothesis that SOM can be separated by morphology into functionally meaningful fractions. The objectives of this study were to use macro- and micromorphological techniques to classify the various C forms present in saturated (or seasonally saturated) subsurface horizons of hydric riparian soils, and to increase our understanding of their genesis. Nine soils formed in outwash or alluvium, located in Rhode Island riparian wetlands, were described and sampled up to depths of over 3 m. The majority of these soils had seasonally high water table levels at or above the soil surface. Thirty-four thin sections were constructed from undisturbed samples collected from subsurface horizons for micromorphological investigation. Six C forms (roots, fragmental organic matter [FOM], lenses, infillings, masses, and horizon C) and five root-decomposition classes were identified. All C forms were more abundant in the subsurface of alluvial soils than in the subsurface of outwash soils. Masses and roots were the most abundant C form identified. Most masses have likely formed from dispersion of C associated with decomposed roots. Alluvial deposition has resulted in considerable C in subsurface riparian zone soils in the form of buried A and O horizons, lenses, and FOM. Illuvial-horizon C was found primarily in sandy horizons having outwash parent materials. Carbon dating suggested that many of these C forms persist for thousands of years in the riparian subsurface. The variety of C forms that exist in riparian zone subsoils suggests that understanding C morphology, and how these forms are related, may prove useful for developing functionally different morphologic classes of soil C. © Soil Science Society of America
    corecore