Browsing by Author "Reinhardt, Jason"
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Item Status of Invasive Plants and Management Techniques in Minnesota: Results from a 2018 Survey(University of Minnesota, 2019-04) Reinhardt, Jason; Russell, Matthew B.; Lazarus, William; Chandler, Monika; Senay, SenaitInvasive weeds are an ongoing concern in Minnesota. Despite broad interest in addressing invasive plant-related problems in the state, there are relatively few datasets regarding species-specific concerns, costs, and management efforts. In this study, we address this knowledge gap using a questionnaire-survey approach. We asked landowners, stakeholders, and land managers a series of questions regarding thirteen invasive weeds in Minnesota, including both buckthorn species (Rhamnus cathartica, Frangula alnus) and wild parsnip (Pastinaca sativa). Respondents (249 total) shared their concerns, cost information, and information regarding recent and planned management efforts for these weeds. Frequently-cited concerns varied considerably by species and type of respondent, but broadly included the potential impacts of weeds on conservation and ecology, weed-related impacts on forest regeneration, and weed-related impacts on recreation. Reported costs and management approaches varied depending on respondent type (private landowner or public lands professional), with public land professionals generally more willing and able to implement more expensive management approaches (i.e., mechanical removal, controlled burn) than private landowners. The broad results and data from this survey may be of interest to a number of researchers and natural resource professionals, as it provides some foundational context for further analyses.Item Using Observational, Experimental, and Focal Species Approaches to Inform the Adaptive Management of Oak Savanna Ecosystems in Western Michigan, USA(2015-08) Reinhardt, JasonMidwestern oak savannas are among the rarest ecosystems in North America. While these systems were historically fairly common across the Midwestern United States and Canada, a combination of land use change and fire suppression has led to significant habitat loss-- it is estimated that less than one percent of the pre-European settlement oak savanna remains on the landscape. As a result, many species associated with oak savanna systems have become threatened or endangered, such as the Karner Blue butterfly (Lycaeides melissa samuelis), frosted elfin (Callophrys irus), and Persius duskywing (Erynnis persius). In addition, the removal of fire from the landscape has resulted in the mesophication of many oak-dominated systems and a loss of early-successional oak habitat across the Eastern United States. In the context of global environmental change, it is becoming increasingly important to understand the structure and function of rare ecosystems, especially in the context of changing disturbance regimes. In addition, climate change is likely to alter the geographic ranges and distribution of suitable habitat for a number of taxa. Because resources are often limited in conservation and restoration efforts, effectively identifying the most viable sites for management is critically important, in both the short- and long-term. In this context, the work presented here explores the plant community composition of Michigan oak savannas, their response to different management approaches, and the use of the Karner Blue butterfly and other rare species as focal points for site selection at the management-scale, and regionally in the context of climate change. As a whole, the results of this work address several knowledge gaps regarding oak savannas, and Michigan oak savannas in particular. Results suggest that sites within the same oak savanna community type can have quantifiably distinct plant communities as a result of differences in disturbance regime. The demonstrated importance of disturbance frequency and type is further illustrated in a restoration experiment, where results suggest that shear cutting trees may be the most effective mechanical harvesting approach for meeting local management goals. In addition to site-level characteristics, this work indicates that both landscape-level environmental factors as well as climatic factors are important in defining habitat suitability for the Karner Blue, an important and endangered oak savanna indicator species. Finally, this research suggests that climate change is likely to have variable but significant (in terms of conservation) effects on the distribution and accessibility of suitable habitat for three rare oak savanna butterflies.