Browsing by Author "Frelich, Lee E."
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Item Climate-biome envelope model for the Western Great Lakes Region(2021-02-16) Toot, Ryan; Frelich, Lee E.; Butler, Ethan E.; Reich, Peter B.; tootx001@umn.edu; Toot, Ryan; Forest Ecology LabResearch Highlights: We modeled climate-biome envelopes at high resolution in the Western Great Lakes Region for recent and future time-periods. The projected biome shifts, in conjunction with heterogeneous distribution of protected land, may create both great challenges for conservation of particular ecosystems and novel conservation opportunities. Background and Objectives: Climate change this century will affect the distribution and relative abundance of ecological communities against a mostly static background of protected land. We developed a climate-biome envelope model using a priori climate-vegetation relationships for the Western Great Lakes Region (Minnesota, Wisconsin and Michigan USA and adjacent Ontario, Canada) to predict potential biomes and ecotones—boreal forest, mixed forest, temperate forest, prairie–forest border, and prairie—for a recent climate normal period (1979–2013) and future conditions (2061–2080). Materials and Methods: We analyzed six scenarios, two representative concentration pathways (RCP)—4.5 and 8.5, and three global climate models to represent cool, average, and warm scenarios to predict climate-biome envelopes for 2061–2080. To assess implications of the changes for conservation, we analyzed the amount of land with climate suited for each of the biomes and ecotones both region-wide and within protected areas, under current and future conditions. Results: Recent biome boundaries were accurately represented by the climate-biome envelope model. The modeled future conditions show at least a 96% loss in areas suitable for the boreal and mixed forest from the region, but likely gains in areas suitable for temperate forest, prairie–forest border, and prairie. The analysis also showed that protected areas in the region will most likely lose most or all of the area, 18,692 km2, currently climatically suitable for boreal forest. This would represent an enormous conservation loss. However, conversely, the area climatically suitable for prairie and prairie–forest border within protected areas would increase up to 12.5 times the currently suitable 1775 km2. Conclusions: These results suggest that retaining boreal forest in potential refugia where it currently exists and facilitating transition of some forests to prairie, oak savanna, and temperate forest should both be conservation priorities in the northern part of the region.Item Forest Wildlife Habitat Description and Data for Minnesota Species(University of Minnesota, 2012-06) Frelich, Lee E.; Ek, Alan R.; Zobel, John M.; Page, Kristen M.Forest wildlife habit relationships are important to a wide range of forest management decisions. This report describes the development and improvement of a forest wildlife habitat model format for use by natural resource professionals in silvicultural decision making and forest planning. Specifically, this paper describes rationale, data, and models assembled for describing habitat suitability indices (HSI) plus guidance for their application. Importantly, this work has also provided an update of habitat relationship data and model forms for many of the bird, mammal and amphibian species common to Minnesota. In total, data and models are provided for nearly 200 wildlife species. HSI are a coarse filter method for considering the impact of forest management on wildlife species habitats. They are best described as a hypothesis regarding species-habitat relationships. In this usage, the premise is that there is a functional relationship between habitat suitability and habitat features that are widely observed at the forest stand level, such as the forest covertype and stand age class or size class--information which is widely available from systematic forest inventory data. The modeling format is intended to allow rapid and straightforward analyses of potential changes in wildlife habitat for (1) long-term forest-wide planning efforts such as those by large landowners (forest-based industry, federal, state, and county managed lands), (2) rapid site-specific on-the-ground assessment of habitat conditions and considerations in timber sale or other project considerations, and (3) input to environmental review of large forestry-related project proposals. Sequel papers are under development to describe a PC-based model implementation package and trials to aid user interpretation of model outputs.Item Minnesota Timber Harvesting GEIS : an assessment of the first 10 years.(University of Minnesota, 2005-08) Kilgore, Michael A.; Ek, Alan R.; Buhr, Karen A.; Frelich, Lee E.; Hanowski, JoAnn M.; Hibbard, Calder M.; Finley, Andrew O.; Rathbun, Leah; Danz, Nicholas P.; Lind, James W.; Niemi, Gerald J.Item Patch formation and maintenance in an old-growth hemlock-hardwood forest(1993) Frelich, Lee E.; Calcote, Randy R.; Davis, Margaret B.; Pastor, JohnCause of patch formation was investigated on a 7.2 ha study area in Sylvania Wilderness Area, a primary forest remnant in Upper Michigan comprising a mosaic of hemlock, sugar maple, and mixed-forest patches. Spatial autocorrelation analysis of the stem map indicated that, although most species pairs have a neutral association between canopy trees and understory trees of other species, hemlock and sugar maple canopy trees both have strong positive self association and negative reciprocal association with each other. No species pairs have a positive reciprocal association on regeneration with each other. MOSAIC, a Markov simulation model in which transition probabilities depend on neighborhood species composition, shows that the negative reciprocal association between hemlock and sugar maple of the intensity observed in this study, could lead to spatial separation into monodominant patches over long time periods (3000 yr). The mixed-forest patches are along spatial continua of varying steepness between sugar maple and hemlock patches. Interactions sugar maple and hemlock overstory and understory trees, along with the pattern of invasion of hemlock, provide a reasonable explanation for the patch structure. Pedological, topographical, and disturbance history differences do not coincide with the location of patches within upland forests on the study area.Item Revegetation to slow buckthorn reinvasion: strengths and limits of evaluating management techniques retrospectively(Restoration Ecology, 2021-01) Wragg, Peter D.; Schuster, Michael J.; Roth, Alexander M.; Bockenstedt, Paul; Frelich, Lee E.; Reich, Peter B.Understanding the long‐term success of ecosystem restoration following invasive plant removal is challenging. Long‐term experiments are costly and slow to yield results, while management decisions must often be made immediately. Alternatively, retrospective studies can leverage contrasting historical management strategies to provide insight into long‐term vegetation responses. We used a retrospective approach to evaluate how management techniques and site characteristics affected re‐establishment of an invasive shrub, Rhamnus cathartica (common buckthorn), in midwestern North America. Following removal, buckthorn re‐establishes rapidly from resprouts and seeds, so follow‐up control is required but often lacking. We hypothesized that revegetating using native herbaceous seed after removing buckthorn increases herbaceous cover that competitively suppresses buckthorn regeneration, to a degree. We surveyed 46 management units at 24 sites. Revegetated units had higher herbaceous cover, lower buckthorn cover, and half the ratio of buckthorn:herbaceous cover compared with unseeded units. These effects, although considerable on average, were detected against a background of high variance. Seeding increased herbaceous cover and reduced buckthorn relative abundance more strongly on less acidic, more clayey soils and where follow‐up herbicide was not applied. Additional variability in revegetation impacts may have arisen from buckthorn resprouts having a head‐start on planted seeds. Only one site had both seeded and unseeded management units. This lack of blocking—a common challenge in retrospective studies—reduced statistical power. This investigation illustrates how retrospective studies can offer relatively inexpensive first assessments of long‐term effects of management techniques; for more rigorous inference, researchers can partner with managers to conduct long‐term experiments.Item Using plants to control buckthorn (Rhamnus cathartica): Improved biotic resistance of forests through revegetation(Ecological Engineering, 2022) Schuster, Michael J.; Wragg, Peter D.; Roth, Alexander M.; Bockenstedt, Paul; Frelich, Lee E.; Reich, Peter B.Woody invaders of temperate forest understories reduce native diversity worldwide. Common buckthorn Rhamnus cathartica, is among the most widespread of such invaders in North America. Invaded communities often have seedbanks largely comprised of the dominant invader - with few native species remaining - and therefore lack the capacity to build biotic resistance against re-invasion following invader removal. Consequently, invaders, including buckthorn, often quickly re-establish in the absence of continued management. We investigated the capacity of native plant revegetation to inhibit buckthorn re-establishment from seedbanks in the understories of three forests of Minnesota, USA. Specifically, we established experimental plots subjected to seeding of 35 native species, planting of Pennsylvania sedge (Carex pensylvanica) plugs, or bare-root plantings of either mixed shrubs (Sambucus canadensis, Sambucus racemosa, Corylus americana, and Cornus racemosa) or mixed trees (Abies balsamea and Acer saccharum). We then measured buckthorn germinant establishment, growth, and survival for the following four growing seasons. We observed consistent impacts of revegetation on ground-level light availability and associated buckthorn performance. Compared to unplanted understory controls beneath the mature tree canopy, shrub plantings were the most impactful. Shrubs reduced light availability to buckthorn seedlings by 67% relative to unplanted controls (to <2% total light by the third year) and led to 51% lower year-over-year survival of buckthorn by the end of the experiment. Revegetation also suppressed buckthorn seedling growth. After four years, shrub plantings resulted in buckthorn that were 53% shorter and had 38% fewer leaves than buckthorn grown in unplanted controls. Considering the combined impacts on survival and growth, planted shrubs, trees, and sedges reduced buckthorn invasion by 89%, 81%, and 66%, respectively; and seeding alone reduced invasion by 51%. Our findings indicate that revegetating forests, particularly with shrubs and trees, can greatly reduce invasion by buckthorn and potentially other species. Greater adoption of revegetation by land managers may therefore increase native biodiversity, reduce herbicide applications, and improve the overall health and value of forests.Item Wildlife database for Minnesota species(2012) Frelich, Lee E.; Ek, Alan R.; Page, Kristen M.