Geographical patterns in openland cover and hayfield mowing in the Upper Great Lakes region: implications for grassland bird conservation

Abstract Populations of many grassland bird species such as Grasshopper Sparrow (Ammodramus savannarum), Henslow's Sparrow (A. henslowii), and Bobolink (Dolichonyx oryzivorus) have experienced considerable declines over the last century. To foster multi-species grassland bird conservation in the Upper Great Lakes (UGL) states of Michigan, Minnesota, and Wisconsin, we quantified geographic patterns within three sub-regional zones (e.g., North, Central, and South) of the UGL. Patterns of interest included the distribution and abundance of openland cover type (including managed pasture-hayland), the distribution, phenology, habitat affinity, and longterm population trends of ten grassland bird species, and (in particular) the geographic patterns in hayfield mowing and the temporal changes in hayfield cover. Approximately 10, 38, and 53% of the UGL openland was proportioned in the North, Central, and South zones, respectively. The distribution of hayland also varied by zone: North, 17%; Central, 46%; and South, 37%. In the central portion of the UGL where the greatest area is devoted to hay production, alfalfa-more intensively managed than mixed-grass hay-predominates. Although we found significance differences (P \ 0.05) in hayfield mowing intensity between zones (with the majority of land under relatively low-intensity mowing found in the North Zone, particularly the Upper Peninsula of Michigan) no strong relationships were found between hayfield mowing patterns, other land cover-land use variables, and bird population trends at finer scales of study. Nonetheless, we suggest that the geographic patterns illustrated here provide useful information for grassland bird conservation planning across the UGL

Ecological forestry at National Wildlife Refuges: experiences from

ABSTRACT Although land management over much of the history of the U.S. Fish and Wildlife Service's National Wildlife Refuge System (NWRS) has emphasized single-species management, recent policy has encouraged land managers to focus on broader ecosystem restoration goals. One framework for forest ecosystem management that is becoming more popular in the NWRS and other federal and state resource agencies has been termed "ecological forestry"-an approach to forest ecosystem management where the focus is on incorporating an understanding of the outcomes of natural disturbances and stand development processes into designing silvicultural practices. This approach stresses understanding the effects of natural disturbances on biological legacies, structural and compositional heterogeneity, and the recovery periods between disturbance events (including how this recovery period influences stand complexity). Recently, resource managers and ecologists from Seney National Wildlife Refuge, The Ohio State University, and Central Michigan University have partnered to examine how these guiding principles can be integrated into NWRS forest ecosystem management. Specifically, we are partnering to develop management strategies to help: 1) restore the once extensive mixed-pine forest ecosystems of eastern Upper Michigan; 2) mitigate the effects of the beech-bark disease complex on American beech (Fagus grandifolia Ehrh.), a foundation species in northern hardwood forests of eastern North America; and 3) promote more natural forest patterns for wildlife species of young jack pine (Pinus banksiana Lamb.) forest ecosystems, including the federally endangered Kirtland's warbler (Dendroica kirtlandii). These efforts are ongoing and will continue to be monitored over time. However, initial collaborations suggest that the NWRS provides an excellent crucible to study the application of ecological forestry principles and develop novel ways to manage forest ecosystems

The Fire and Tree Mortality Database, for Empirical Modeling of Individual Tree Mortality After Fire

Wildland fires have a multitude of ecological effects in forests, woodlands, and savannas across the globe. A major focus of past research has been on tree mortality from fire, as trees provide a vast range of biological services. We assembled a database of individual-tree records from prescribed fires and wildfires in the United States. The Fire and Tree Mortality (FTM) database includes records from 164,293 individual trees with records of fire injury (crown scorch, bole char, etc.), tree diameter, and either mortality or top-kill up to ten years post-fire. Data span 142 species and 62 genera, from 409 fires occurring from 1981-2016. Additional variables such as insect attack are included when available. The FTM database can be used to evaluate individual fire-caused mortality models for pre-fire planning and post-fire decision support, to develop improved models, and to explore general patterns of individual fire-induced tree death. The database can also be used to identify knowledge gaps that could be addressed in future research

Aligning Endangered Species Management with Fire-Dependent Ecosystem Restoration: Manager Perspectives on Red-Cockaded Woodpecker and Longleaf Pine Management Actions

Background: Endangered species management has been criticized as emphasizing a single-species approach to conservation and, in some cases, diverting resources from broad-based, land management objectives important for overall biodiversity maintenance. Herein we examine perceptions on management for an endangered species whose habitat requirements largely depend on frequent fire, the red-cockaded woodpecker (Leuconotopicus borealis Vieillot). In doing so, we consider the alignment between species-specific population recovery actions and broader ecosystem restoration goals. Through semi-structured interviews with natural resource professionals (n = 32) in the Southeast Coastal Plain of the United States, we examined manager perspectives on the evolution of recovery efforts and the potential alignment of recovery efforts with other management goals and objectives on public lands. Results: Participants described an evolution of approaches to manage red-cockaded woodpeckers, from an initial emphasis on intensive management actions with a single-species focus to reduce extinction risk (e.g., artificial inserts and translocation of individual birds) to a broader focus on restoring forest conditions and the processes that maintain them (e.g., fire). Most participants considered red-cockaded woodpecker habitat management to be compatible with other resource management actions (e.g., prescribed fire, mechanical thinning). However, there were some notable exceptions as a smaller but substantive number of participants indicated that specific habitat management guidelines (basal area guidelines for foraging habitat) posed a barrier to implementing preferred ecosystem restoration actions (transitioning stands of fast-growing, short-lived pines to longleaf pine [Pinus palustris Mill.]). Overall, participants expected efforts to provide habitat for red-cockaded woodpeckers to continue regardless of its conservation status and that intensive, single-species management actions would likely decrease over time. Conclusions: Providing for the specific needs of specialist species that are in decline is often necessary to prevent their extinction in the near term. Our findings suggest that the ability to connect long-term management actions to recover endangered species to other agency priorities may promote the willingness of managers to prioritize and continue long-term management of their habitats

Detecting changes in climate forcing on the fire regime of a North American mixed-pine forest: A case study of Seney National Wildlife Refuge, Upper Michigan

The study of forests dominated by red pine (Pinus resinosa Ait.), one of the few fire-resistant tree species of eastern North America, provides an opportunity to reconstruct long-term fire histories and examine the temporal dynamics of climate forcing upon forest fire regimes. We used a 300-year long spatially explicit dendrochronological reconstruction of the fire regime for Seney National Wildlife Refuge (SNWR, 38,531 ha), eastern Upper Michigan to: (1) identify fire size thresholds with strong vs. weak climate controls, (2) evaluate effect of landform type (outwash channel vs. sand ridges) in modifying climate–fire associations, and (3) check for the presence of temporal changes in the climate control of large fire events over the time period 1700–1983. We used a summer drought sensitive red pine chronology (ITRDB code can037) as a proxy of past fire-related climate variability. Results indicated that fires \u3e60 ha in sand-ridge-dominated portions of SNWR and \u3e100 ha in outwash channels were likely climatically driven events. Climate–fire associations varied over time with significant climate–fire linkages observed for the periods 1700–1800 (pre-EuroAmerican), 1800–1900 (EuroAmerican settlement) and 1900–1983 (modern era). Although an increase in fire activity at the turn of 20th century is commonly associated with human sources of ignitions, our results suggest that such an increase was also likely a climatically driven episode

Snag Benchmarks and Treatment Options for Mixed-Pine Forest Restoration in Eastern Upper Michigan

Snags (dead-standing trees) are biological legacies that remain after disturbances in forests. We enhanced the ecological underpinnings of snag management within the context of mixed-pine forest restoration in the northern Lake States by quantifying characteristics of live trees and snags within eighty-five 500-m2 plots at Seney National Wildlife Refuge (NWR) in eastern Upper Michigan. Study plots represented reference conditions (i.e. no past harvesting, relatively unaltered fire regime) and altered (i.e. harvested, altered fire regime) conditions. We also compared three treatments for creating snags from live trees. Snags were found in 87% of the reference plots and 85% of the altered plots. The only snag variables that differed between plot types were mean snag basal area, which was greater in altered plots (Student’s t -test, p =0.04), and mean percent total basal area of snags (greater in reference plots, p =0.06). The composition of snags differed only in the 10- and 25-cm diameter classes (Multi-Response Permutation Procedure, p \u3c 0.10). The percentage of snags that developed into the most advanced decay class (DC) differed among treatments after 4 years (χ2 =16.49, p \u3c 0.01), with 26% of girdled trees, 3% of prescribed fire trees, and zero topped trees reaching DC5. Logistic regression illustrated that the influence of predictor variables on DC development varied by species and treatment. The findings from this study, past studies, and ongoing projects at Seney NWR are directly applicable to innovative management of snags in mixed-pine forests

Broad and local-scale patterns of exotic earthworm functional groups in forests of National Wildlife Refuges of the Upper Midwest, USA

The National Wildlife Refuge System is the world’s largest network of lands set aside specifically for wildlife conservation. For refuge planners and managers tasked with maintaining ecological integrity and wildlife habitat, many uncertainties exist. In forests in the Upper Midwest, for instance, exotic earthworms are impacting ecosystem structure and function, but their community composition and effects on refuges is unknown. We examined the association of earthworm functional group abundance and community composition within upland forests of refuges with broad scale patterns of anthropogenic land use and local scale differences in forest characteristics. Patterns of anthropogenic land cover, including proportion of the land, mean patch area, and largest patch index, were strongly correlated with the biomass of epi-endogeic earthworms. Earthworm community diversity, however, was inversely related to patterns of dominating anthropogenic land cover, and increased under high ratios of natural to anthropogenic lands in the surrounding ecoregion. Within forests, earthworm community composition could be partially explained by variables representing both dispersal opportunities and habitat suitability. In general, heavily-invaded forests had low conifer dominance, high silt content, high basal area, greater amounts of anthropogenic cover within 500 m, and were closer to roads and farther from agriculture. However, the relationship between local forest characteristics and biomass differed greatly among earthworm functional groups and between refuges dominated by natural lands and those dominated by anthropogenic lands. For refuges with high earthworm loads and well developed earthworm communities, managers may be confounded in restoring historic conditions and may need to look at multiple tools, including artificial regeneration, to mitigate for current earthworm effects. In refuges seemingly in earlier stages of earthworm invasion, future planning and management should be tempered by potential effects observed in those refuges in more anthropogenic landscapes