This documentation file was generated on 2019-11-19 by Thomas D. Stokely ------------------- # GENERAL INFORMATION ------------------- 1. Title of Dataset: Synergistic effects of wild ungulates and management intensification suppress native plants and promote exotics - Dataset 2. Creator Information Name: Thomas D. Stokely Institution: Oregon State University College, School or Department: College of Forestry, Department of Forest Ecosystems and Society Address: 321 Richardson Hall, Corvallis, Oregon 97331 Email: thomas.stokely@gmail.com ORCID: https://orcid.org/0000-0001-6044-5886 Role: Postdoc, Primary Author 3. Collaborator information Name: Matthew G. Betts College, School or Department: College of Forestry, Department of Forest Ecosystems and Society Address: 321 Richardson Hall, Corvallis, Oregon 97331 Email: matthew.betts@oregonstate.edu ORCID: https://orcid.org/0000-0002-7100-2551 Role: Professor, Secondary Author 3. Contact Information Name: Thomas D. Stokely Institution: Oregon State University College, School or Department: College of Forestry, Department of Forest Ecosystems and Society Address: 321 Richardson Hall, Corvallis, Oregon 97331 Email: thomas.stokely@gmail.com ORCID: https://orcid.org/0000-0001-6044-5886 ------------------- CONTEXTUAL INFORMATION ------------------- 1. Abstract for the dataset This dataset consists of native and exotic plant species metrics, including cover, richness, relative abundance and responses to the exclusion of wild ungulates and herbivory. The data were used for the manuscript: "Synergistic effects of wild ungulates and management intensification suppress native plants and promote exotics", published in the journal Forest Ecology and Management. We used mixed-effects models in the R Statistical Package to test the interactive effects of herbicide and herbivory on native and exotic species for six years following timber harvest. MANUSCRIPT ABSTRACT In managed forest landscapes, conflicts among wood production, ungulates, native biodiversity, and exotic species are common. As humanity allocates more land as intensively managed plantations, these conflicts may become more severe. For instance, native ungulates have been implicated in the loss of native plant diversity, declines in timber revenues and the spread of exotic species in many forest systems, yet the synergistic effects of management and ungulate herbivory are not well understood. We hypothesized that herbicide and herbivore-induced suppression of native forage species promotes the release of exotic species in young forest plantations. Further, we expected herbivory and the retention of native forage via less intensive management would have negative consequences for reforestation objectives. To test this hypothesis, we conducted an experiment that manipulated management intensity (via herbicides) and access of two deer species to vegetation (via exclosures) on 28 operational Douglas-fir plantations of the Pacific Northwest, USA. We recorded yearly plant species cover estimates and tested the effects of herbivory and herbicides on native and exotic plants during the first six years of plantation establishment. Heavier herbicide treatments reduced the cover and diversity of native plants, and increased the cover of exotics over time, particularly that of exotic herbaceous species. Regardless of herbicide intensity, herbivores had reduced the cover of native forage species. In a treatment that represents operational standards applied to over 2.5 million ha in the region, the suppression of native species by deer corresponded with an increase in exotic species cover by 23 percent, resulting in equitable abundance of native and exotic plants. As expected, Douglas-fir growth was suppressed when herbivores were present and vegetation was left untreated by herbicides, although the presence of deer promoted both crop-tree growth and the relative abundance of exotics in our most intensive treatment, presumably due to the added suppression of native competitors. Our findings suggest that wild ungulates amplify management-driven shifts toward exotic species in intensively managed forest plantations. Exotic plant forage status and adaptations to frequent disturbance seem to be key mechanisms for the synergistic effects we observed. Without herbicides, diverse assemblages of native species are buffered from herbivory and exotic species proliferation, with potential tradeoffs for timber production. Our results highlight the role of management intensity in modifying the interactions among exotic plants and native herbivores, contributing to a mechanistic understanding of the role of native biodiversity in regulating exotic species spread. Our data provide further support for growing evidence that synergistic effects of multiple drivers can facilitate exotic proliferation. 2. Context of the research project that this dataset was collected for. The objectives of the research was to quantify the interactive effects of silvicultural herbicides and herbivory by wild ungulates on native and exotic plant species. We hypothesized that the suppression of native species by silvicultural herbicides and herbivory would cause a release in exotic species, and that whether plants are considered forage or non-forage species would be a key mechanism for the release. We expected that the selection of native forage species by herbivores should promote both exotic non-forage species and crop-tree growth. Alternatively, we hypothesized that if exotics assemblages were primarily composed of forage species, then deer and elk would regulate their release. Further, we expected that the retention of native species via less intensive management would have negative consequences for crop-tree growth. To test these hypotheses, we implemented a large-scale experiment in the Oregon Coast Range, U.S.A., that manipulated both the intensity of forest plantation management and access to vegetation by deer and elk and measured plant species responses during the first six years of plantation development. 3. Date of data collection: 2011-6-15 to 2016-9-15 4. Geographic location of data collection: West_Bounding_Coordinate: -123.35 East_Bounding_Coordinate: -123.8333 North_Bounding_Coordinate: 45.75 South_Bounding_Coordinate: 44.7333 5. Funding sources that supported the collection of the data: Funding was provided by the United States Department of Agriculture, Agriculture and Food Research Initiative grant (AFRI-2009-04457, AFRI-2015-67019-23178), the National Council for Air and Stream Improvement, Inc., the Oregon Forest Industries Council, and the Oregon State University College of Forestry (Giustina Family Research grant, Noble fund, Fish and Wildlife Habitat in Managed Forests grant, Dean's fund and Institute for Working Forest Landscapes). -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: This work is on the Public Domain 2. Links to publications related to the dataset: Stokely, T. D., U. Kormann, M. G. Betts. 2019. Synergistic effects of wild ungulates and management intensification suppress native plants and promote exotics. Forest Ecology and Management. In press. 3. Recommended citation for the data: Stokely, T. D. (2019) Synergistic effects of wild ungulates and management intensification suppress native plants and promote exotics - Dataset (Version 1) [Dataset]. Oregon State University. https://doi.org/10.7267/2n49t7709 5. Dataset Digital Object Identifier (DOI) 10.7267/2n49t7709 -------------------------- VERSIONING AND PROVENANCE -------------------------- 1. Last modification date 2019-11-19 2. Was data derived from another source? Yes. 3. We used information from Neill and Peuttman (2013), Cook et al. (2016) and Ulappa et al. (2015) and the USDA plant database to assign species to native and exotic status as well as forage and non-forage status, based on the relative quality and acceptance of each species as forge by deer and elk in the Region. Neill, A. R., and K. J. Puettmann. 2013. Managing for adaptive capacity: thinning improves food availability for wildlife and insect pollinators under climate change conditions. Canadian Journal of Forest Research-Revue Canadienne De Recherche Forestiere 43:428-440. Cook, J. G., R. C. Cook, R. W. Davis, and L. L. Irwin. 2016. Nutritional ecology of elk during summer and autumn in the Pacific Northwest. Wildlife Monographs 195:1-81. Ulappa, A. C. 2015. Using foraging dynamics to answer landscape management questions: the nutritional ecology of black-tailed deer. Washington State University, Research Exchange. URL: http://hdl.handle.net/2376/6230 -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: The experiment was conducted with a repeated-measures, split-plot, randomized-block design with three factors, herbicide treatments, herbivore access and time (years). A wild-ungulate exclosure and open access plots were each nested within four experimental stands, each randomly assigned to one of four herbicide treatments (Untreated Control, Light, Moderate and Intensive herbicide treatments), each nested within an experimental block, with seven blocks in total. Within each exclosure and open plot, we visually measured the cover of each plant species with 12 1x1 m quadrats, systematically located in each plot for each years from 2011-2016. Within each exclosure and open plot, we also measured the diameter of each planted Douglas-fir seeding (Pseudotsuga menziesii) for each year from 2011-2015. 2. Methods for processing the data: We averaged the cover of each species among quadrats and then calculated the richness of native (NATIVE.RICH) and exotic species (EXOTIC.RICH) and summed cover of native species (NATIVE.COV), exotic species (EXOTIC.COV), native-forage species (NATIVE.FORAGE), native-nonforage species (NATIVE.NONFORAGE), exotic-forage species (EXOTIC.FORAGE) and exotic non-forage species (EXOTIC.NONFORAGE) We calculated the difference between the cover of natives in excluded and open plots (NATIVE.HBIV) and the difference between the cover of exotics (EXOTIC.HBIV) in excluded and open plots to test the herbivore-mediated release of exotics. We tallied the number of plant samples with and without evidence of ungulate herbivory among all native (NATIVE.BROWSE) and exotic plants (EXOTIC.BROWSE) among all years. We calculated Douglas-fir basal area as the sum of bole areas (pi*radius^2) among all trees (PLT.BA). 2. Environmental/experimental conditions: Non-crop vegetation measurements were conducted during the peak in vegetation production for each year (~June-August), corresponding to the dry summer season in the region. For crop trees, we took measurement in the fall, when crop trees were at the peak in annual growth, corresponding to the moist fall and winter in the region. Camera traps were deployed from May-October for each year. 6. Describe any quality-assurance procedures performed on the data: We conducted rigorous quality-assurance procedures, cross checking data among years, double checking data entry and correcting data entry mistakes using raw datasheets. 7. People involved with sample collection, processing, analysis and/or submission: Data collection was assisted by A. Kern, E. Ireland, S. Gilsdorf, E. McClelland, J. Hannon, M. Hovland, T. Laird, D. Uzez, A. Comstock, T. Schrautemeier, M. Silbernagel, and J. Gibson. --------------------- DATA & FILE OVERVIEW --------------------- 1. File List A. Filename: Stokely et al 2019_Forest Ecology and Management_Supplimentary Data.csv Short description: This dataset consists of native and exotic plant data and planted Douglas-fir data. B. Filename: Stokely et al. 2019_Forest Ecology and Management_Geographical Information.csv Short description: This dataset consists of geographical data for the study sites reported in the supplimentary dataset . 2. Relationship between files: Stokely et al. 2019_Forest Ecology and Management_Geographical Information.csv reports the geographical parameters (land position, aspect, elevation, location) related to the dataset in Stokely et al. 2019_Forest Ecology and Management_Supplimentary Data.csv. ----------------------------------------- TABULAR DATA-SPECIFIC INFORMATION FOR: Stokely et al 2019_Forest Ecology and Management_Supplimentary Data.csv ----------------------------------------- 1. Number of variables: 21 2. Number of cases/rows: 532 3. Missing data codes: NA = Data not available or applicable for a given cell. 4. Variable List: Name: Year Description: The year in which data were collected (2011-2016). ALL: Data pooled across the years 2012-2016. Name: Block Description: The experimental block, each with four-randomly assigned herbicide treatment stands. Blocks were used as random effects of mixed-effects models. Name: Stand Description: The experimental stand, four per block, each randomly assigned to one of four treatments. Stands were used as random effects of mixed-effects models. Name: Herbicide Description: Herbicide Treatment, Untreated-Control, Light Herbicide, Moderate Herbicide and Intensive herbicide. See Stokely et al. 2019 (Forest Ecology and Management) for herbicide prescriptions. Name: Herbivory Description: Plots open (Open) to and excluding (Excluded) deer and elk. Each exclosure 2.44 m tall and both plots were 15x15 m in area. Name: NATIVE.COV Description: Summed cover of all native plants for each plot Units: Percent (can exceed 100, due to overlapping plant canopies). Name: NATIVE.RICH Description: Number of native species for each plot Units: N Name: EXOTIC.RICH Description: Number of exotic species for each plot Units: N Name: EXOTIC.COV Description: Summed cover of all exotic plants for each plot Units: Percent (can exceed 100, due to overlapping plant canopies). Name: EXOTIC.REL Description: The relative abundance of exotic plants, defined as the proportion of sampled plant cover occupied by exotic plants. Units: proportion Name: NATIVE.FORAGE Description: Summed cover of all native forage plants for each plot Units: Percent (can exceed 100, due to overlapping plant canopies). Name: NATIVE.NONFORAGE Description: Summed cover of all native non-forage plants for each plot Units: Percent (can exceed 100, due to overlapping plant canopies). Name: EXOTIC.FORAGE Description: Summed cover of all exotic forage plants for each plot Units: Percent (can exceed 100, due to overlapping plant canopies). Name: EXOTIC.NONFORAGE Description: Summed cover of all exotic non-forage plants for each plot Units: Percent (can exceed 100, due to overlapping plant canopies). Name: NATIVE.HBIV Description: Difference in cover between open and excluded plots for all native species. Units: Percent Name: EXOTIC.HBIV Description: Difference in cover between open and excluded plots for all exotic species. Units: Percent Name: NATIVE.BROWSEY Description: Number of plant samples with evidence of ungulate herbivory for all native species, among years 2012-2016 Units: N Name: NATIVE.BROWSEN Description: Number of plant samples without evidence of ungulate herbivory for all native species, among years 2012-2016 Units: N Name: EXOTIC.BROWSEY Description: Number of plant samples with evidence of ungulate herbivory for all exotic species, among years 2012-2016 Units: N Name: EXOTIC.BROWSEN Description: Number of plant samples without evidence of ungulate herbivory for all exotic species, among years 2012-2016 Units: N Name: PLT.BA Description: Summed area of all planted Douglas-fir tree boles for each plot from 2011-2015 Units: m^3/ha ----------------------------------------- TABULAR DATA-SPECIFIC INFORMATION FOR: Stokely & Betts 2019_Forest Ecology and Management_Geographical Information.csv ----------------------------------------- 1. Number of variables: 10 2. Number of cases/rows: 28 3. Variable List Name: BLOCK Description: Experimental blocks which contain four experimental stands, each randomly assigned to an herbicide treatment The four stands per block were located a distance of 1-5 km from each other Name: STAND Description: Experimental stands that treatments were applied to, four replicated within each block Average stand size ~ 13 ha Name: HERBIVORY Description: Herbivory exclusion plot, 15x15 m plots, randomly located within each stand. Excluded = deer and elk excluded, Open = deer and elk allowed access to vegetation Name: HERBICIDE Description: Herbicide treatment, randomly assigned to each stand within each block Control - untreated; Light - 2011 herbaceous and 2012 broadleaf spray; Moderate - 2010 site preparation, 2011 herbaceous, 2012 coppice-sprouting maple sprays; Intensive 2010 site preparation, 2011-2013 herbaceous, 2011-2014 broadleaf spray Name: Aspect Description: Relative slope aspect of each plot Degrees Name: Slope Description: Relative steepness of slope Percent Name: Position (T) Description: Geographical position used for UTMs Name: UTM (E) Description: Easting UTM location Name: UTM (N) Description: Northing UTM location Name: ELEV Description: Elevation (m) Name: STAND AREA Description: Area of each stand, which treatments were applied (ha)