No abstract

We developed components of a decision structure that could be used in an adaptive management framework for responding to invasion of hemlock woolly adelgid Adeleges tsugae on the Cumberland Plateau of northern Tennessee. Hemlock woolly adelgid, an invasive forest pest, was first detected in this area in 2007. We used a structured decision-making process to identify and refine the management problem, objectives, and alternative management actions, and to assess consequences and tradeoffs among selected management alternatives. We identified four fundamental objectives: 1) conserve the aquatic and terrestrial riparian conservation targets, 2) protect and preserve hemlock, 3) develop and maintain adequate budget, and 4) address public concerns. We designed two prototype responses using an iterative process. By rapidly prototyping a first solution, insights were gained and shortcomings were identified, and some of these shortcomings were incorporated and corrected in the second prototype. We found that objectives were best met when management focused on early treatment of lightly to moderately infested but relatively healthy hemlock stands with biological control agent predator beetles and insect-killing fungi. Also, depending on the cost constraint, early treatment should be coupled with silvicultural management of moderately to severely infested and declining hemlock stands to accelerate conversion to nonhemlock mature forest cover. The two most valuable contributions of the structured decision-making process were 1) clarification and expansion of our objectives, and 2) application of tools to assess tradeoffs and predict consequences of alternative actions. Predicting consequences allowed us to evaluate the influence of uncertainty on the decision. For example, we found that the expected number of mature forest stands over 30 y would be increased by 4% by resolving the uncertainty regarding predator beetle effectiveness. The adaptive management framework requires further development including identifying and evaluating uncertainty, formalizing other competing predictive models, designing a monitoring program to update the predictive models, developing a process for re-evaluating the predictive models and incorporating new management technologies, and generating support for planning and implementation.

Native grasslands throughout the Great Plains, USA, have undergone varying levels of fragmentation. The prairie ecosystems of Nebraska, USA, provide habitat for culturally and economically important galliforms, including greater prairie‐chicken (GRPC; Tympanuchus cupido pinnatus) and plains sharp‐tailed grouse (STGR; Tympanuchus phasianellus jamesi). The Sandhills region in north‐central Nebraska remains largely intact as grasslands, but cropland development at the margins has provided potential for alternative winter forage sites. Our objectives were to describe intraspecific seasonal shifts and interspecific differences in landscape use of these 2 species of prairie grouse in the Sandhills. We captured and radiomarked 87 birds (68 STGR, 19 GRPC) during 2015–2016 and used aerial telemetry to collect location data on birds. We used presence‐only location data and ecological and anthropogenic variables (e.g., land‐cover types, topography, vegetation productivity, and roads) in a maximum entropy (using MaxEnt software) approach to construct and compare seasonal species distribution models. During the breeding season, GRPC distribution probabilities were greater in areas more distant from center‐pivot irrigation locations, proximate to wet meadows, and at moderate distances from crop fields, whereas during the nonbreeding season, distributions were positively influenced by conifer and mixed‐grass (generally areas on peripheries of wetlands or meadows) land‐cover types. For STGR during both seasons, distribution probabilities were greatest in areas more distant from wet meadows, whereas during the nonbreeding season the probabilities were also greater in areas more distant from sandy ecological sites. Using an ecological‐niche‐similarity approach to examine interspecific use of the landscape, we found evidence that landscape use on our study area differed between species during the breeding season, but not during the nonbreeding season. Our results provide support for coordinated, landscape‐level management of galliforms, which can now be extended to seasonal priorities during management decisions on publicly and privately managed lands. © 2019 The Wildlife Society.