Forest & Land

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    Minnesota National Forest Breeding Bird Monitoring Program Annual Report 1995–2023
    (University of Minnesota Duluth, 2023-12) Grinde, Alexis R; Siebers, Reid; Kolbe, Stephen; Bednar, Joshua D
    The Avian Ecology Lab at the Natural Resources Research Institute completed the 29th year of Minnesota's National Forest Breeding Bird Monitoring Program in 2023. These data have provided insights into the impacts of forest management on breeding bird populations and informed the development of management policies and conservation initiatives. This report summarizes forest bird monitoring data gathered from 1995 through 2023. Here we summarize the current status of species trends and overall trends for migration, habitat, and nesting guilds. We focus our discussion on species of conservation importance in the state to provide ecological context and to discuss management implications of the observed patterns for these species in the region.
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    Chippewa National Forest Hunter Walking Trail Project 2023 Report
    (University of Minnesota Duluth, 2023-12) Grinde, Alexis R; Kolbe, Stephen; Bednar, Joshua D
    The primary objective of the Chippewa National Forest Hunter Walking Trail Project is to assess the effects of experimental harvesting on Ruffed Grouse and breeding bird species. The results from the pre-harvest study (2020–2021) established baseline data for future reference. Here, we report the results from pre- and post-harvest (depending on the study area) line transect and ARU (Autonomous Recording Unit) surveys conducted during the 2023 breeding bird season. These two survey methods are complementary to one another and provide a comprehensive assessment of Ruffed Grouse and breeding bird communities. Specific objectives include: 1. Assess Ruffed Grouse abundance and characterize breeding bird communities before and after harvest treatments that were implemented in 2021–2023; and 2. Summarize preliminary results as a part of the National Forest Bird Monitoring Project annual report and provide data to Chippewa National Forest.
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    Interstate Island Habitat Restoration: Phase III – Long-Term Monitoring and Maintenance Plan Common Tern Monitoring & Migratory Shorebird Assessment 2023 Final Report
    (University of Minnesota Duluth, 2023-12-01) Bracey, Annie; Kolbe, Stephen; Strand, Fred; Grinde, Alexis R
    The goal of the Interstate Island avian habitat restoration project was to restore and enhance critical breeding habitat for the Common Tern (Sterna hirundo) and Piping Plover (Charadrius melodus) in the St. Louis River Estuary (SLRE). The primary objective of the habitat restoration was to maintain and increase the population of Common Terns breeding at the Interstate Island colony. To assess the effectiveness of the restoration, post-restoration field surveys were conducted to document the breeding status of Common Terns relative to pre-restoration averages. To document breeding population size and productivity, we followed the long-term monitoring protocol developed by the Wisconsin Department of Natural Resources (DNR), to ensure comparability between pre- and post- restoration monitoring. There were no monitoring objectives related to Piping Plover since this species has not been documented on Interstate Island. A secondary objective of the project was to document shorebird use of the island during migration to determine if this species group was utilizing the restored habitat. To meet this objective, researchers developed a shorebird monitoring protocol, conducted in- person surveys, and utilized remote camera traps to observe and quantify shorebird species diversity, abundance, and spatial and temporal use of Interstate Island. Based on post-restoration surveys, population targets are not currently being met for Common Tern, with the number of nesting pairs currently at some of the lowest recorded since the island was colonized. However, post-restoration productivity is above the range deemed necessary to sustain a viable population and above pre-restoration averages. The overall quality of the nesting habitat for Common Terns was greatly improved. If habitat quality is the primary factor limiting the size of the breeding population, we anticipate the restoration actions will result in an increase in breeding numbers but there may be a lag in response time. We also documented 22 shorebird species and 38 other avian species using the island during our surveys. Our results indicate that shorebirds as well as many other species of birds will readily use the newly restored habitat at Interstate Island, habitat which is much needed in this important bird region. Continued monitoring and management will be necessary to determine long-term effects of restoration for both Common Terns and migratory shorebirds.
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    Chippewa National Forest Hunter Walking Trail Project 2022 – Pre-harvest Results
    (University of Minnesota Duluth, 2022-12) Grinde, Alexis R; Kolbe, Stephen; Bednar, Joshua D
    The primary objective of the Chippewa National Forest Hunter Walking Trail Project is to assess the effects of experimental harvesting on Ruffed Grouse and breeding bird species. The results from the pre-harvest study (2020-2021) established baseline data for future reference. Here, we report the results from pre- and post-harvest (depending on the study area) line transect and ARU (Autonomous Recording Unit) surveys conducted during the 2022 breeding bird season. These two survey methods are complementary to one another and provide a comprehensive assessment of Ruffed Grouse and breeding bird communities. Specific objectives include: 1. Assess Ruffed Grouse abundance and characterize breeding bird communities before and after harvest treatments that were or will be implemented in 2021-2022; and 2. Summarize preliminary results as a part of the National Forest Bird Monitoring Project annual report and provide data to Chippewa National Forest.
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    Minnesota National Forest Breeding Bird Monitoring Program Annual Report 1995–2022
    (University of Minnesota Duluth, 2022-12) Grinde, Alexis R; Siebers, Reid; Kolbe, Stephen; Bednar, Joshua D
    The Avian Ecology Lab at the Natural Resources Research Institute completed the 28th year of Minnesota's National Forest Breeding Bird Monitoring Program in 2022. These data have provided insight into the impacts of forest management on breeding bird populations and informed the development of management policies and conservation initiatives. This report summarizes forest bird monitoring data gathered from 1995 through 2022. Here we summarize the current status of species trends and overall trends for migration, habitat, and nesting guilds. We focus our discussion on species of conservation importance in the state to provide an ecological context and discuss management implications of the observed patterns in the region for these species.
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    Assessing forest land conversion risk to maintain water quality in North Central Minnesota
    (University of Minnesota Duluth, 2018-07) Host, George E; Kovalenko, Katya; Meysembourg, Paul
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    Plant Communities of Hartley Park
    (University of Minnesota Duluth, 2019-09-18) Reschke, Carol; Nixon, Kristi; Pomroy, Deb; Barnes, Ray; Host, George E
    This project builds on and updates an ecological survey of Hartley Park in Duluth, Minnesota that was conducted in 2003 by consulting ecologist Ethan Perry to evaluate the potential to nominate the park to the Duluth Natural Areas Program (DNAP). In 2003 DNAP was a new program to provide legal protection to city-owned or private lands of ecological or geological significance. DNAP guidelines explain that land in Duluth can be eligible for this protection by meeting criteria in at least one of five categories. The 2003 ecological survey gathered information necessary to determine if parts of Hartley Park qualify for the Native Plant Communities category of DNAP criteria. Although Hartley Park was not designated under DNAP after the 2003 survey, the City of Duluth and Hartley Park managers recently wanted to update the maps and submit a DNAP nomination package in fall of 2019. The City of Duluth contracted with ecologists and geographic information system (GIS) staff at the University of Minnesota Duluth, Natural Resources Research Institute (NRRI) to update the maps. This technical report describes the methods and results of surveys conducted in summer 2019 to update the Plant Community maps of Hartley Park. The project area for this map includes Hartley Park (660 acres) and 38 acres of adjacent open land that the park wants to evaluate for acquisition. The total area mapped in 2019 was 698 acres, with a wide variety of types of vegetation. To evaluate the quality of these vegetation types, the entire park was divided into patches or polygons of different plant community types, most of which were visited by ecologists, some more intensively than others. Access to some polygons was difficult due to steep topography and many trees blown down in a July 2016 wind storm. For these more remote or difficult-access polygons, air photo imagery was interpreted, and additional low-altitude air photos were acquired by NRRI staff using unmanned aerial vehicles (UAVs). For native plant communities, the polygons were classified using the system developed by the MN DNR Biological Survey Program, described in the 2003 publication Field Guide to the Native Plant Communities of Minnesota, The Laurentian Mixed Forest Province. Since the names of the DNR communities are often long and not always descriptive of local vegetation, we have provided alternative cover names specific to Hartley (Table 1). Vegetation types not considered native plant communities (including conifer plantations, parking lots, ball fields, and areas dominated by non-native species) were divided into general land cover categories; these land cover types as a group are called “Cultural and other communities” similar to NOAA classifications of “Cultural” cover types so modified by human activities that they are not considered “natural” or native plant communities. The cultural cover types had a total of 168 acres. This report focuses primarily on the 530 acres of native plant communities in the project area.
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    Mobile Water Treatment Demonstration System for Sulfate Reduction
    (University of Minnesota Duluth, 2022-08) Cai, Meijun; Rao, Shashi; Post, Sara P; Hanson, Adrian; Chun, Chan Lan; Johnson, Lucinda B; Hudak, George J; Weberg, Rolf
    The State of Minnesota adopted a sulfate standard of 10 mg/L for wild rice waters in 1973. Although under review, current technology for achieving this standard is a challenge for small industries and municipalities. Membrane-based technologies such as nanofiltration and reverse osmosis are capable of treating water to reach the Minnesota wild rice water sulfate standard; however, they typically require high capital and operation costs. Therefore, there is a need to develop cost-effective sulfate treatment alternatives. The Natural Resources Research Institute (NRRI) has developed a treatment system based on barite chemical precipitation reactions to reduce sulfate levels in water from 60-200 mg/L to below 10 mg/L. This system was demonstrated at bench-scale batch and continuous tests. The data collected from these lab tests were used to scale up the process to a trailer-based modular demonstration treatment system. This study highlights the outcomes of field pilot tests conducted by NRRI using this treatment system. The objectives of the field pilot trials were to: (1) Evaluate the efficacy of the chemical precipitation process when scaled up from 200 ml/min to 2 GPM; (2) Study the effect of co-existing chelating organics of the raw wastewater on barite precipitation reactions; (3) Optimize the chemical reagent dosage levels; (4) Investigate the potential of reusing process sludge to promote precipitation reactions; (5) Identify strategies to minimize scale formation on process equipment; and (6) Estimate the chemical reagent costs. The pilot tests were conducted using effluent from two municipal wastewater treatment plants (WWTP)—the Virginia WWTP and the Grand Rapids WWTP in northeastern Minnesota—from June 2021 until October 2021.
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    Interstate Island Habitat Restoration: Phase III – Long-Term Monitoring and Maintenance Plan Common Tern Monitoring & Migratory Shorebird Assessment Final Report
    (University of Minnesota Duluth, 2022-09-01) Bracey, Annie; Kolbe, Stephen; Nelson, Stephen; Strand, Fred; Grinde, Alexis R
    The goal of the Interstate Island avian habitat restoration project was to restore and enhance critical breeding habitat for the Common Tern (Sterna hirundo) and Piping Plover (Charadrius melodus) in the St. Louis River Estuary. The primary objective of the habitat restoration was to maintain and increase the population of Common Terns breeding at the Interstate Island colony. To assess the effectiveness of the restoration, post-restoration field surveys were conducted to document the breeding status of Common Terns relative to pre-restoration averages. To document breeding population size and productivity, we followed the long-term monitoring protocol developed by the Wisconsin Department of Natural Resources (DNR), to ensure comparability between pre- and post-restoration monitoring. A secondary objective of the project was to document shorebird use of the island during migration to determine if this species group was utilizing the restored habitat. To meet this objective, researchers developed a shorebird monitoring protocol, conducted in-person surveys, and utilized remote camera traps to observe and quantify shorebird species diversity, abundance, and spatial and temporal use of Interstate Island. Based on post-restoration surveys, population targets are not currently being met for Common Tern, with the number of nesting pairs being at their lowest since the island was colonized. However, productivity was within the average range compared to pre-restoration numbers and the quality of the nesting habitat was greatly improved. If habitat quality is the primary factor limiting the size of the breeding population, we anticipate the restoration actions will likely result in an increase in breeding numbers but there may be a lag in response time. We also documented 18 shorebird species and 35 other avian species using the island during our surveys. Our results indicate that shorebirds as well as many other species of birds will readily use the newly restored habitat at Interstate Island, which is much needed in this important bird region. Continued monitoring and management will be necessary to determine long-term effects of restoration.
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    Fisher Den Box Building Plans
    (University of Minnesota Duluth, 2022-08) Joyce, Michael; Moen, Ronald
    The design for this fisher den box is based on a design that has been used for fishers in British Columbia (Davis 2016). We made minor design modifications as described in this manual, for example we used screws instead of nails in all construction. Almost 100 of these boxes were deployed in northern Minnesota, with several boxes used by fishers (M. Joyce, 2022, Final Report, Environment and Natural Resources Trust Fund project M.L. 2019, First Special Session, Chp. 4, Art. 2, Sec. 2, Subd. 03i).
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    Minnesota Land Trust Final Report - Let the Birds Guide You
    (University of Minnesota Duluth, 2019-12) Grinde, Alexis R; Walton, Nicholas G; Bracey, Annie; Liljenquist, Alexis L
    Identifying environmental and habitat characteristics associated with specific bird communities can help guide conservation and habitat management efforts. The goal of this project was to quantify and characterize bird communities in the St. Louis River Estuary (SLRE) based on bird-habitat associations. Bird communities are commonly described with respect to their associated cover types (i.e., habitat). However, birds often respond to combinations of local cover types and larger-scale landscape features (e.g., forested wetlands in proximity to emergent wetlands), which are not adequately described by a single attribute such as dominant plant species or aquatic habitat type. Therefore, to understand bird species’ ecological needs and habitat preferences, we evaluated community assemblages without initially linking the locations sampled for birds with standard habitat categories. Bird assemblages were first identified using hierarchical cluster analysis, which revealed relationships among locations sampled within the SLRE based solely on bird species composition. This approach identified assemblages of species that tend to co-occur irrespective of traditionally defined habitat types. We used percent perfect indication (PPI) models to identify which species or groups of species were most strongly associated with specific landscape features. We also assessed habitat availability at the landscape-scale (i.e., within a 400m buffer from the shoreline) to identify specific features that are under-represented in the SLRE but likely important to a species or group of species. We also quantified species relative abundance, richness, and diversity throughout the SLRE to identify locations of high use and diversity. Once those locations were identified, we summarized local-scale habitat data define vegetation characteristics at locations with the highest and lowest species richness. Together, these analyses will provide a holistic assessment of the environmental and habitat requirements of migratory and breeding birds at multiple spatial scales. We quantitatively assessed which landscape and habitat characteristics are most likely to be beneficial for birds that use the SLRE and, ultimately, to assist in informing habitat management objectives for current and future projects in the area.
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    Minnesota National Forest Breeding Bird Monitoring Program Annual Report 1995–2020
    (University of Minnesota Duluth, 2020-12) Grinde, Alexis R; Bednar, Joshua D; Kolbe, Stephen; Seibers, Reid
    The Avian Ecology Lab at the Natural Resources Research Institute completed the 26th year of Minnesota's National Forest Breeding Bird Monitoring Program in 2020. These data have provided insight into the impacts of forest management on breeding bird populations and informed the development of management policies and conservation initiatives. This report summarizes forest bird monitoring data gathered from 1995 through 2020. Here we summarize the current status of species trends and overall trends for migration, habitat, and nesting guilds. We focus our discussion on species of conservation importance in the state to provide an ecological context and discuss management implications of the observed patterns in the region for these species.
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    Implementing Conservation Plans for Avian Species of Concern: Submitted to Audubon Minnesota
    (University of Minnesota Duluth, 2020-12) Grinde, Alexis R; Bracey, Annie; Liljenquist, Alexis L
    Audubon Minnesota is interested in establishing benchmark survey locations throughout Minnesota to guide restoration and enhance activities within designated Important Bird Areas (IBAs) for three species of conservation concern: common tern, black tern, and yellow rail. Data collected during the 2009–2013 Minnesota Breeding Bird Atlas (MNBBA) project (Pfannmuller et al. 2017) were used to identify potential and confirmed breeding locations for black tern and common tern in the state. These data were then aligned with IBA boundaries and previously established survey locations from Audubon’s statewide marshbird monitoring program. Using this information, survey locations were identified within selected IBAs to document presence and abundance of tern species during the 2020 breeding season. Collectively, survey results can be used as a first step by Audubon Minnesota to formalize high-priority benchmark survey locations for long-term monitoring of these species in IBAs throughout the state.
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    Chippewa National Forest Hunter Walking Trail Project 2020 – Pre-harvest Results
    (University of Minnesota Duluth, 2020-12) Grinde, Alexis R; Bednar, Joshua D; Kolbe, Stephen; Seibers, Reid
    Minnesota’s managed forests provide critical habitat for hundreds of resident and migrant bird species. Forest management provides an important opportunity to conserve and cultivate critical habitat for species of management and conservation concern. Recent declines in upland game populations in the state have generated a renewed interest in using forest management to create habitats that not only support breeding adults but also those that maximize juvenile survival and increase recruitment into the populations. Conservation concerns regarding Ruffed Grouse (Bonasa umbellus) and American Woodcock (Scolopax minor) have been extensively documented:  North American populations of American Woodcock have declined by over 30% in the last 50 years. In Minnesota, American Woodcock are a Species in Greatest Conservation Need. Approximately 10% of the global population breeds in Minnesota.  Ruffed Grouse populations in Minnesota are significantly declining. Recent declines in harvest numbers of Ruffed Grouse and potential issues with recruiting birds into the population have caused concern range-wide, including in Minnesota. American Woodcock and Ruffed Grouse require a matrix of forest size classes throughout the breeding season. Historically, periodic natural disturbances would create habitat for these species—wildfires or flooding from beaver dams produced a patchwork of shrubby openings amid a largely forested landscape. Currently, the major mechanism of disturbance is harvest; this provides an important opportunity for habitat management for these species. There is increasing interest from forest managers to promote heterogeneous forest matrices that can optimize wildlife occupancy and diversity over time. Chippewa National Forest is planning a long-term habitat improvement project by implementing small-scale, frequent harvests (<5 acres, 5-year intervals) adjacent to hunter walking trails. Currently, there are more than 600 miles of hunter walking trails in Minnesota, and maintaining and enhancing these areas as productive hunting grounds is a priority. The goal of this project is to create and maintain a long-term matrix of habitat in the region that is suitable for Ruffed Grouse while supporting additional game species such as American Woodcock and breeding forest birds. The primary objective of the Chippewa National Forest Hunter Walking Trail Project is to assess the effects of experimental harvesting on Ruffed Grouse and breeding bird species. The results from the pre-harvest study will establish baseline data for future reference. Here, we report the results from pre-harvest line transect and ARU (Autonomous Recording Unit) surveys conducted during the 2020 breeding bird season. These two survey methods are complementary to one another and provide a comprehensive assessment of Ruffed Grouse and breeding bird communities. Specific objectives include: 1. Assess Ruffed Grouse abundance and characterize breeding bird communities before harvest treatments planned for winter 2021-2022; and 2. Summarize preliminary results as a part of the National Forest Bird Monitoring Project annual report and provide data to Chippewa National Forest.
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    Avian Response to Group Selection Harvest in Northern Hardwoods, Aitkin County, Minnesota
    (University of Minnesota Duluth, 2021-10) Bednar, Joshua D; Grinde, Alexis R
    The breeding bird communities of the western Great Lakes region have among the richest diversity of breeding bird species in North America (Neimi et al. 2016). The importance of this diversity and past concerns about potential declines of some species has led to a strong interest in studying forest bird populations in relation to forest management in the region (Hanowski and Niemi 1995, Niemi et al. 2016). Northern hardwood forests provide habitat for a variety of breeding bird species, including many long-distance migrants. Before European settlement, northern hardwoods (e.g., sugar maple and black ash) comprised approximately 20% of Minnesota’s forest (5.3 million acres). Over the past century, almost 4 million acres of northern hardwood stands in Minnesota have converted to other forest types, primarily shade-intolerant species such as aspen, and today northern hardwoods account for approximately 12% of forestlands in the state. There has been a recent interest in limiting future loss of northern hardwoods in Minnesota by managing this forest type on an uneven-aged basis. The Aitkin County Forestry Department has recently started implementing an uneven-aged approach using a group or patch selection for managing northern hardwood forests across the landscape. The goal of this management approach is to retain mature northern hardwood species throughout each rotation while providing wood resources for local industry and promoting regeneration and growth of high-value hardwood trees. Because northern hardwood forests provide habitat for a variety of breeding bird species, it is important to document potential shifts in breeding bird communities associated with forest management practices. To do this, we implemented a BACI (Before, After, Control, Impact; Conquest 2000) monitoring framework to assess the effect of uneven-aged management on breeding bird communities in Minnesota’s northern hardwood forests. This assessment is important because although the response of breeding birds to successional forest stages—from clear-cut to mature stand ages—are relatively well known for northern Minnesota forests, breeding bird response to uneven-aged management, specifically group selection, in northern hardwoods has not been thoroughly studied in Minnesota. We hypothesized that mature forest breeding species abundance will decrease after harvest and that abundance of early-successional species would increase to correspond with the newly created habitat on the treatment plot. This report summarizes breeding bird surveys completed pre-harvest in two mature forest stands in Aitkin County, Minnesota, 2013–2015 and the two years of post-harvest surveys that occurred in 2020– 2021. Our overall objectives were to: 1) conduct breeding bird surveys in northern hardwood study plots, 2) document bird community composition and species abundances, and 3) determine whether there are differences between breeding bird communities in the control (not harvested) versus the treatment (harvested) areas.
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    Minnesota National Forest Breeding Bird Monitoring Program Annual Report 1995–2021
    (University of Minnesota Duluth, 2021-12) Grinde, Alexis R; Siebers, Reid; Bednar, Joshua D
    The Avian Ecology Lab at the Natural Resources Research Institute completed the 27th year of Minnesota's National Forest Breeding Bird Monitoring Program in 2021. These data have provided insight into the impacts of forest management on breeding bird populations and informed the development of management policies and conservation initiatives. This report summarizes forest bird monitoring data gathered from 1995 through 2021. Here we summarize the current status of species trends and overall trends for migration, habitat, and nesting guilds. We focus our discussion on species of conservation importance in the state to provide an ecological context and discuss management implications of the observed patterns in the region for these species.
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    Minnesota Department of Natural Resources 2021 Minnesota Colonial Waterbird Surveys
    (University of Minnesota Duluth, 2021-12) Bracey, Annie; Kolbe, Stephen; Grinde, Alexis R; Cuthbert, Francesca J
    The Minnesota colonial waterbird surveys began in 2004 in an effort to document the distribution and abundance of colonial nesting waterbirds in the state. The Minnesota Department of Natural Resources (MN DNR) partnered with researchers at the University of Minnesota to initiate monitoring efforts at colony sites of target waterbird species across the state (Table 1; Cuthbert and Hamilton 2016). The monitoring initially focused on documenting the number and distribution of two focal species, American White Pelican (Pelecanus erythrorhynchos) and Double-crested Cormorant (Phalacrocorax auritus), due to public concerns about the potential impacts of perceived population increases on recreation activities (e.g., fishing; Wires and Cuthbert 2006). The goal of monitoring was to evaluate efficacy of Double-crested Cormorant control efforts and document the status of American White Pelicans, which are a state-listed Species of Special Concern and Species in Greatest Conservation Need (SGCN; MN DNR 2016). Since the initial MN DNR waterbird surveys, conducted in 2004 and 2005, the intent was to conduct statewide surveys every five years. Surveys were conducted as planned in 2010 and 2015, but due to Covid-19 related work and travel restrictions, it was only possible to conduct a partial survey in 2020. Therefore, the primary objective of the 2021 survey was to complete the fourth census and provide a summary of the combined 2020–2021 survey results to MN DNR. The 2020 surveys were conducted by researchers at the University of Minnesota - Twin Cities campus and the 2021 surveys were conducted by researchers in the Avian Ecology Lab at the Natural Resources Research Institute (NRRI), Duluth, MN. The broad aim of this report is to provide a description of how sites were selected in 2020/21, which species were included as targets, and to provide recommendations for future monitoring efforts in the state. We include site-specific estimates of abundance for primary and secondary (when possible) target species for the combined 2020–2021 surveys. We also provide abundance and distribution estimates for primary target species for the current (2020–2021) and past census efforts at priority monitoring locations and focus on how future monitoring objectives and survey methodologies can best be tailored to maximize efficiency while providing necessary detail to effectively document population status of waterbirds breeding in Minnesota. Several additional waterbird species listed as SGCN in Minnesota include: Common Tern (Sterna hirundo), Black Tern (Chlidonias niger), Forster’s Tern (Sterna forsteri), Piping Plover (Charadrius melodus), Franklin’s Gull (Leucophaeus pipixcan), and Black-crowned Night-Heron (Nycticorax nycticorax). These species also require long-term monitoring to assess population status and associated habitat conditions, which are poorly monitored by other non-targeted surveys (MN DNR 2016; Cuthbert and Hamilton 2016). There are ongoing concerns for two additional colonial nesting species: Great Blue Heron (Ardea herodias) and Great Egret (Ardea alba). Although they are not state-listed species, the number of Great Blue Heron nesting colonies appears to have declined by ~30% since 1985, and the number of Great Egret nesting colonies remains low throughout the state. Overall, little is known about colony persistence or changes in the distribution and abundance of these species throughout the state (Pfannmuller et al. 2017). For these reasons, in 2021 we implemented additional surveys at secondary sites in an attempt to obtain information about the status of these species in the state.
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    Chippewa National Forest Hunter Walking Trail Project 2021 – Pre-harvest Results
    (University of Minnesota Duluth, 2021-12) Grinde, Alexis R; Kolbe, Stephen; Bednar, Joshua D
    Minnesota’s managed forests provide critical habitat for hundreds of resident and migrant bird species. Forest management provides an important opportunity to conserve and cultivate critical habitat for species of management and conservation concern. Recent declines in upland game populations in the state have generated a renewed interest in using forest management to create habitats that not only support breeding adults but also those that maximize juvenile survival and increase recruitment into the populations. Conservation concerns regarding Ruffed Grouse (Bonasa umbellus) and American Woodcock (Scolopax minor) have been extensively documented: ● North American populations of American Woodcock have declined by over 30% in the last 50 years. In Minnesota, American Woodcock are a Species in Greatest Conservation Need. Approximately 10% of the global population breeds in Minnesota. ● Ruffed Grouse populations in Minnesota are significantly declining. Recent declines in harvest numbers of Ruffed Grouse and potential issues with recruiting birds into the population have caused concern range-wide, including in Minnesota. American Woodcock and Ruffed Grouse require a matrix of forest size classes throughout the breeding season. Historically, periodic natural disturbances would create habitat for these species—wildfires or flooding from beaver dams produced a patchwork of shrubby openings amid a largely forested landscape. Currently, the major mechanism of disturbance is harvest; this provides an important opportunity for habitat management for these species. There is increasing interest from forest managers to promote heterogeneous forest matrices that can optimize wildlife occupancy and diversity over time. Chippewa National Forest is planning a long-term habitat improvement project by implementing small-scale, frequent harvests (<5 acres, 5-year intervals) adjacent to hunter walking trails. Currently, there are more than 600 miles of hunter walking trails in Minnesota, and maintaining and enhancing these areas as productive hunting grounds is a priority. The goal of this project is to create and maintain a long-term matrix of habitat in the region that is suitable for Ruffed Grouse while supporting additional game species such as American Woodcock and breeding forest birds. The primary objective of the Chippewa National Forest Hunter Walking Trail Project is to assess the effects of experimental harvesting on Ruffed Grouse and breeding bird species. The results from the preharvest study will establish baseline data for future reference. Here, we report the results from preharvest line transect and ARU (Autonomous Recording Unit) surveys conducted during the 2021 breeding bird season. These two survey methods are complementary to one another and provide a comprehensive assessment of Ruffed Grouse and breeding bird communities. Specific objectives include: 1. Assess Ruffed Grouse abundance and characterize breeding bird communities before harvest treatments planned for 2021-2022; and 2. Summarize preliminary results as a part of the National Forest Bird Monitoring Project annual report and provide data to Chippewa National Forest.
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    Inter-Tree Competition Effects in Hybrid Poplar Genotype Testing
    (University of Minnesota Duluth, 2022-02) Nelson, Neil D; Buchman, Daniel; Cai, Meijun; McMahon, Bernard G; Berguson, William E
    The effects of inter-tree competition on growth in family field trials (FFT), clone trials (CT) and yield blocks (YB) were studied in NRRI experimental field plots in Minnesota, USA. FFT and CT competition is inter-clonal , YB competition is intra-clonal. Two approaches were explored: (1) regression analysis of growth of individual trees versus growth of immediate neighboring trees in FFT and CT; (2) bole volume growth as measured by DBH2 in CT versus YB for the same clones on each site to determine whether inter- clonal competition in CT overestimates tree growth in YB. In CT on five sites planted the same year with the same population of clones (“simultaneous CT”), significant negative slopes, indicating the onset of inter-tree competition, occurred in the fifth and sixth years for the two fastest-growing CT. The top 50th growth percentile clone group in the fastest-growing of the simultaneous CT had a significant negative regression line slope; the lower 50th group did not. The three slower growing CT did not exhibit competition (significant negative slopes) from three through six years. A separate clone trial measured through 9 years showed little evidence of inter-tree competition. The regression slopes in FFT were almost all positive, indicating no inter-tree competition effects from three through ten years of stand age. All significant regression R2 values were low–a maximum of 24 % for CT, 22 % for FFT. Clonal genetic potential for growth likely predominates prior to significant inter-clonal competition, suggesting that randomization of single-tree replications of each clone within each block is effective in evaluating clone genetic growth potential within the initial six years selection window that we have used in our program. There was no significant difference between CT and YB for tree bole volume growth (yield) in a population of clones. There was wide variation in the YB/CT yield ratios between individual clones on a site. Some individual clones exhibited wide variation in YB/CT ratios between different sites, indicating a clone x site interaction for this trait. The commercial clone NM6, used as a check clone in most of our studies, had the widest variation of any clone in YB/CT ratios between sites, ranging from 53 % to 104 %. Of the 22 YB/CT yield ratios for specific clones on 14 sites, only four were above 100 %, indicating a clear trend for CT overestimating yields in YB. The average of the 22 YB/CT ratios was 86 %, again indicating overestimation of YB yield in the CT. The YB/CT ratio for NM6 averaged 79 %, while five elite (fast growing, disease resistant) clones averaged a YB/CT yield ratio of 89 % over the 14 sites. CT/YB yield ratios are too variable to use CT growth as an estimate of growth for specific clones under near commercial conditions (YB).
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    Mapping Avian Movement in Minnesota
    (University of Minnesota Duluth, 2021-09) Grinde, Alexis R; Bracey, Annie; Kolbe, Stephen
    The western Great Lakes region is home to one of the most diverse breeding bird communities in North America and is a key migration pathway for a wide array of species, including neotropical migrants and birds that breed in boreal ecosystems. To better understand and document how birds move in this region, we focused on two applications of automated radio telemetry technology: 1) large- and small-scale (local) movements of birds during the non-breeding season (i.e., migration and winter), and 2) local movements of breeding Common Terns and dispersal behavior of both adult and juvenile birds. Our goal was to assess the utility of using Motus automated telemetry technology at various spatial scales and on a variety of species to study different ecological questions. First, to study timing and behavior of fall migration along the shores of Lake Superior, we focused on two species: Blue Jay (Cyanocitta cristata) and Northern Saw-whet Owl (Aegolius acadicus). Second, we focused on Rusty Blackbirds in the St. Louis River Estuary to document the temporal and geographic use during their fall migratory stopover. Rusty Blackbirds are among the most rapidly declining bird species in North America, but the reasons driving these declines are unknown; a lack of suitable habitat during the migratory and non-breeding seasons is likely a contributing factor. Thousands of Rusty Blackbirds use the north shore of Lake Superior and the SLRE as a migration corridor each spring and fall, yet habitat use and duration of stopover is poorly understood. For this reason, we used automated radio tracking technology to document stopover duration of individual birds in relation to minimum daily temperature and to assess potential differences between sex and age. Third, we focused on documenting winter movement patterns of Black-capped Chickadees (Poecile atricapillus) in an urban-forested landscape: Hartley Park, Duluth MN, USA, to assess how detection rates related to minimum daily temperature and food availability at feeding stations. Black-capped Chickadees are an abundant resident species in our study area and have broad public appeal but are relatively understudied in the winter, particularly in urban settings. Finally, we assessed the utility of automated radio telemetry to study breeding behavior of Common Terns (Sterna hirundo). Common Tern are identified as one of the most vulnerable species at both a federal and state level in the region and as a high priority species for conservation in the state. Interstate Island, located in the SLRE, is one of only two breeding colonies of Common Terns in Lake Superior. Movement of juvenile birds is also a critical piece of the life-history of Common Terns that is not well understood due to previously existing limitations of tracking this age class. The ability to track individuals using the Motus network, which does not require re-encountering the individual to retrieve data, is a huge advancement in tracking of juvenile birds. Documenting breeding behavior and dispersal of adult and juvenile terns will help inform population dynamics, which is particularly important for at-risk and declining populations.