Papers by Roger C. Anderson
Clinical obesity, Jan 30, 2015
Despite several clinical practice guidelines, there remains a considerable gap in prevention and ... more Despite several clinical practice guidelines, there remains a considerable gap in prevention and management of obesity in primary care. To address the need for changing provider behaviour, a randomized controlled trial with convergent mixed method evaluation, the 5As Team (5AsT) study, was conducted. As part of the 5AsT intervention, the 5AsT tool kit was developed. This paper describes the development process and evaluation of these tools. Tools were co-developed by the multidisciplinary research team and the 5AsT, which included registered nurses/nurse practitioners (n = 15), mental health workers (n = 7) and registered dieticians (n = 7), who were previously randomized to the 5AsT intervention group at a primary care network in Edmonton, Alberta, Canada. The 5AsT tool development occurred through a practice/implementation-oriented, need-based, iterative process during learning collaborative sessions of the 5AsT intervention. Feedback during tool development was received through f...
Data is used to generate Fig. S1, which includes densities of rosettes and mature plants from 200... more Data is used to generate Fig. S1, which includes densities of rosettes and mature plants from 2004-2014 /*Data are rosettes, plotid (plot identification), counts, and quadrats. There are two woods each with two blocks. Quadno are quadrat numbers, numbers 1-11 indicate sample years from 2004-2014. Codes are SAS for PROC GLIMMIX.*/
PeerJ, Mar 15, 2018
Introduction. Alliaria petiolata, an herbaceous plant, has invaded woodlands in North America. It... more Introduction. Alliaria petiolata, an herbaceous plant, has invaded woodlands in North America. Its ecology has been thoroughly studied, but an overlooked aspect of its biology is seed dispersal distances and mechanisms. We measured seed dispersal distances in the field and tested if epizoochory is a potential mechanism for longdistance seed dispersal. Methods. Dispersal distances were measured by placing seed traps in a sector design around three seed point sources, which consisted of 15 second-year plants transplanted within a 0.25 m radius circle. Traps were placed at intervals ranging from 0.25-3.25 m from the point source. Traps remained in the field until a majority of seeds were dispersed. Eight probability density functions were fitted to seed trap counts via maximum likelihood. Epizoochory was tested as a potential seed dispersal mechanism for A. petiolata through a combination of field and laboratory experiments. To test if small mammals transport A. petiolata seeds in their fur, experimental blocks were placed around dense A. petiolata patches. Each block contained a mammal inclusion treatment (MIT) and control. The MIT consisted of a wood-frame (31 × 61× 31 cm) covered in wire mesh, except for the two 31 × 31 cm ends, placed over a germination tray filled with potting soil. A pan filled with bait was placed in the center of the tray. The control frame (11 × 31 × 61 cm) was placed over a germination tray and completely covered in wire mesh to exclude animal activity. Treatments were in the field for peak seed dispersal. In March, trays were moved to a greenhouse and A. petiolata seedlings were counted and then compared between treatments. To determine if A. petiolata seeds attach to raccoon (Procyon lotor) and white-tailed deer (Odocoileus virginianus) fur, wet and dry seeds were dropped onto wet and dry fur. Furs were rotated 180 degrees and the seeds that remained attached were counted. To measure seed retention, seeds were dropped on furs and rotated as before, then the furs were agitated for one hour. The seeds retained in the fur were counted. Results. For the seed dispersal experiment, the 2Dt function provided the best fit and was the most biologically meaningful. It predicted that seed density rapidly declined with distance from the point source. Mean dispersal distance was 0.52 m and 95% of seeds dispersed within 1.14 m. The epizoochory field experiment showed increased mammal activity and A. petiolata seedlings in germination trays of the MIT compared to control. Laboratory studies showed 3-26% of seeds were attached and retained by raccoon and deer fur. Retention significantly increased if either seed or fur were wet (57-98%). How to cite this article Loebach and Anderson (2018), Measuring short distance dispersal of Alliaria petiolata and determining potential long distance dispersal mechanisms. PeerJ 6:e4477; DOI 10.7717/peerj.4477 Discussion. Without animal seed vectors, most seeds fall within a short distance of the seed source; however, long distance dispersal may be accomplished by epizoochory. Our data are consistent with A. petiolata's widespread distribution and development of dense clusters of the species in invaded areas.
Journal of Chemical Ecology, 1978
Abstraet-A method to rapidly screen species suspected of producing allelochemics, using results f... more Abstraet-A method to rapidly screen species suspected of producing allelochemics, using results from simple bioassay tests, is presented. By measuring the osmotic potential of H. mollis extracts and using mannitol solutions of comparable osmotic potential, the influence of osmotic potential in the bioassay was eliminated. Nested analysis of variance was used to examine the separate influences of (1) extract concentration, (2) source of plants used in extract preparation (edge or center of clones) (3) osmotic potential of the extract, and (4) the differential development of radicles and shoots of species used in the bioassay tests. Bioassay tests for allelopathy showed that extracts made of whole H. mollis plants significantly inhibited both radicle and shoot development of radish and wheat, but only the radicle of little bluestem. There was a significant increase in the inhibition of radish shoots and wheat radicles at high concentration of the extract, but the radicle of little bluestem was inhibited more at the lower concentration. Extracts prepared from plants collected from the clone center inhibited radish radicle development significantly more than extracts made of plants growing at the clone edge.
Effect of Removal of Garlic Mustard (Alliaria petiolata, Brassicaeae) on Arbuscular Mycorrhizal Fungi Inoculum Potential in Forest Soils
The Open Ecology Journal, 2010
Restoration Ecology, Sep 1, 2000
We studied vegetation change of a remnant barrens in southern Illinois over twenty-five years. Th... more We studied vegetation change of a remnant barrens in southern Illinois over twenty-five years. The study area was periodically burned between 1969 and 1993, but fire was excluded for a 16-year period (1974-1989). During the study, the barrens supported a mixture of species whose preferred habitats ranged from prairie and open woodlands to closed forest communities. The herbaceous vegetation may be on a trajectory characterized by increasing dominance of woodland species and declining prairie species. Fire management temporarily reversed this trend, but it continued once fire was excluded. Reintroduction of prescribed burning in 1990-1993 altered the vegetation trajectory but not back toward a species composition comparable to that present on the site before cessation of fire management after 1973. Following interruption of prescribed burning, tree basal area more than doubled, and density showed a 67% increase between premanagement conditions in 1968 and 1988. Salix humilis (prairie willow) density had significant negative correlations with tree density and basal area. However, there was no consistency in response of shrub species on the site to the varied site conditions over time. Fire management on the site may not recover the historic barrens that occurred on the site. Nevertheless, consistent fire management will drive vegetation changes toward increasing abundance of prairie and open woodland species that would otherwise be lost without burning.
Ecological restoration, North America, Sep 1, 2011
Garlic mustard, a biennial Eurasian species, has extensively invaded eastern North American decid... more Garlic mustard, a biennial Eurasian species, has extensively invaded eastern North American deciduous forests. We studied effects of 3 years (2005-2007) of annual removal of second-year garlic mustard plants on first-year plants and native spring herbaceous species in upland and lowland woods. Treatments compared removal of second-year plants in mid-March (early treatment) or mid-May (late treatment) to a control. We recorded first-and second-year plants and native herbaceous species percent cover on April 19 and 20. First-year plant cover was higher on control than treatment plots; however, in the upland woods only control and late treatment plots differed significantly. First-year plant cover was less in removal than control plots, indicating reduced seed input; however, we found no difference in cover of second-year plants between late treatment and control plots. Results suggest second-year plants strongly compete with younger conspecifics, and their removal decreases first-year plant mortality. Removal of second-year garlic mustard did not significantly affect total cover of native herbaceous species. Second-year plants complete vegetative growth before late May and might impact early developing native species more than later growing species. We tested effect of removal of garlic mustard on native species in 2 phenological categories: spring-and summer-dominant species. We found no treatment effects on summer-dominant species. However, early treatment plots had significantly more cover of spring-dominant plants than late treatment and control in the upland woods. Indicator Species Analysis indicated a majority of spring (75%) and summer (50%) dominant species maximized performance in the early treatment.
We examined the effect of white~tailed deer (Odocoiieus virginianus Zimmermann) browsing on commu... more We examined the effect of white~tailed deer (Odocoiieus virginianus Zimmermann) browsing on community quality of tallgrass prairie forbs at a site in northeastern Illinois over a period of ten yea rs (1992-2001). Deer densities in the study area varied from 32-50 km-2 (83-130 deer mi-2) between 1992 and 1997 and declined to 7-9 km-2 (18-23 mi-2) following initiation of hun ting. In a plot protected from deer browsing, abundances of browse~sensitive species increased and unpreferred and browse~tolerant species decreased. Community quality of forbs measured with a new index, Weighted Mean Fidelity, decreased on the unprotected plot until deer density was reduced. Several commonly used indices of floristic quality, mean C and floristic quality index, were unable to detect changes in community quality because the compliment of species on our site did not change over time. H owever, changes occurred in the relative abundances of species with different coefficients of conservatism, which was detected by Weighted Mean Fidelity. In contrast, on the protected plot community quality initially declined, followed by an increase, suggesting a lag time fo r recovery from browsing. Previous stud ies on our study site demonstrated that diversity of prairie forbs was maximized at an intermediate level of deer browsing, supporting the intermediate disturbance hypothesis, which posits that diversity is maximized at intermediate levels of disturbance. However, we found that community quality of forbs declined as duration of intense deer browsing (disturbance) increased, and was highest after eight years of protection from browsing, suggesting a potential trade-off between maximizing diversity and maintaining quality of forb communities that land managers should consider.
Ecosphere, May 1, 2021
Alliaria petiolata, a strict biennial in North America, can have an annual alternating high abund... more Alliaria petiolata, a strict biennial in North America, can have an annual alternating high abundance of rosettes and flowering plants. We monitored changes in abundance of rosettes and flowering plants in permanent plots (2004-2014). Three times during our study, the alternating yearly cycle was not
North American Conference on Savannas and Barrens
Ecological Restoration, 1995
communities." T he First North American Conference on Savannas and Barrens, with the theme &... more communities." T he First North American Conference on Savannas and Barrens, with the theme "Living in the Edge," convened on the campus of Illinois State University, Normal, Illinois, on October 15-16, 1994. The conference planners believed that the most important goal to be accomplished was fusion of the two tracks along which many savanna "enthusiasts" have been working. One track was being followed by those who were interested in finding and restoring remnant savannas, but whose previous experience did not include formal research or publication in major scientific journals. The other track was pursued by persons whose primary focus, sometimes less visible, was research that happened to include studies of savanna organisms or community processes. The 24-person Conference Steering Committee believed that the most valuable information about savannas would emerge when these two groups of people engaged in a dialogue with each other, and to this end, the conference had a broad base of sponsors including the Society for Ecological Restoration, The Nature Conservancy, the Environmental Protection Agency (Great Lakes Program Office), the Illinois Department of Conservation, and Illinois State University. In addition, there were 14 co-sponsors including several public and private institutions of higher education, and local and statewide conservation organizations. The conference built upon the groundwork laid by the Midwest Oak Savanna Conference held at Northeastern Illinois University in February, 1993 (R&MN 12(1):60-64), which generated increased interest in savannas and raised many provocative questions regarding savannas and their origins. At the North American Conference, the 440 persons in attendance included personnel from local, state and federal agencies, volunteer stewards, and members of the general public. Consequently, sessions and activities were planned to appeal to persons sharing a common interest in the management, restoration and preservation of native savanna and barrens ecosystems. Invited and contributed papers in six concurrent sessions, poster presentations and exhibits were presented the first day. Field trips the second day, organized by William McClain of the Illinois Department of Conservation, provided attendees the opportunity to visit local savanna and barrens remnants and restoration sites. The plenary speaker, Paul G. Risser, a past president of the Ecological Society of America and Institutes of Biological Sciences, and currently president of Miami University (Ohio), considered the role of savannas in a world-wide context. While in the United States the social importance of savannas has not been clearly articulated, Risser delineated the importance of savanna habitats to the rural residents of Kenya in an agrarian society. In this social setting, the savanna is the core of the economic structure. Savannas provide grazing areas for cattle during the day; the animals are penned in holding areas within the villages at night. Cattle provide villagers with animal protein, and their manure is collected from the holding pens and used as fertilizer on agricultural fields. The production of meat and the transfer of essential nutrients from the savanna to the village sustains the economy of the village. Risser, a leader in the scientific community, emphasized that even though we have accumulated a considerable amount of information on the ecology of savanna and barrens we do not always use this knowledge in an effective manner.
Mycorrhizal Dependence of Andropogon gerardii and Schizachyrium scoparium in Two Prairie Soils
American Midland Naturalist, Oct 1, 1994
-Previous research in tallgrass prairie in Kansas indicated that warm-season, C4, grasses are obl... more -Previous research in tallgrass prairie in Kansas indicated that warm-season, C4, grasses are obligate mycotrophs and do not grow normally in the absence of mycorrhizal symbiosis. However, the degree to which such grasses depend on mycorrhizae in other prairie soils has not been examined. Growth and mycorrhizal colonization of roots of Andropogon gerardii and Schizachyrium scoparium were compared in soil collected from Konza Prairie Research Natural Area (KPRNA), Riley County, Kansas and from Sand Ridge State Forest (SRSF), Mason County, Illinois. Plants of both species were grown in the two soils and were inoculated with Glomus etunicatum spores originally collected from KPRNA or colonized root pieces from S. scoparium plants collected from SRSF. Glomus etunicatum inoculum resulted in significantly greater root colonization and biomass of both plant species in steamed KPRNA soil than did root piece inoculum. There was no benefit from inoculation in nonsterile soil which contained indigenous mycorrhizal fungi. In SRSF soil, there was no response to inoculation with mycorrhizal fungi from either source. The lack of mycorrhizal response in SRSF soil is attributed to the greater plant-available P level of this soil. For S. scoparium grown in SRSF soil, plants grown in steamed soil produced more biomass than plants grown in steamed soil amended with nonsterile soil sievings (containing soil organisms other than mycorrhizal fungi), or in nonsterile soil. These differences could be due to competition for inorganic nutrients between soil microbes and the plant or antagonistic relationships between the plant or the mycorrhizal association and the soil microbes. Thus, the mycorrhizal dependence of these plant species is related to both soil and inoculum type or species.
Biological Invasions, Feb 7, 2014
Invasive plants can have strong impacts on native communities, which have prompted intense effort... more Invasive plants can have strong impacts on native communities, which have prompted intense efforts at invasive removal. However, relatively little is known about how native communities will reassemble after a dominant invader has been removed from the system. Legacy effects of invasive plants on soil microbial communities may alter native plant community reassembly long after the invader is gone. Here we found that arbuscular mycorrhizal fungal (AMF) communities have shown some recovery in experimental plots following 6 years of removal of the invasive Alliaria petiolata (garlic mustard, a species known to degrade AMF communities) in terms of taxonomic richness and community composition. However, despite this recovery, the density of A. petiolata at the beginning of the experiment (in 2004) still correlated with lower AMF richness and altered community composition after 6 years of annual weeding, suggesting long-term legacies of dense A. petiolata infestations. Because native plant and mycorrhizal fungal communities may show interdependence, reassembly of one community may be limited by the reassembly of the other. Restoration may be more effective if practices address both communities simultaneously.
Data is used to generate Fig. S1, which includes densities of rosettes and mature plants from 200... more Data is used to generate Fig. S1, which includes densities of rosettes and mature plants from 2004-2014 /*Data are rosettes, plotid (plot identification), counts, and quadrats. There are two woods each with two blocks. Quadno are quadrat numbers, numbers 1-11 indicate sample years from 2004-2014. Codes are SAS for PROC GLIMMIX.*/
The American Midland Naturalist, 2020
Abstract. Bearing-tree data were used to calculate an index, pyrophilic percentage, depicting the... more Abstract. Bearing-tree data were used to calculate an index, pyrophilic percentage, depicting the importance of fire before Euro-American settlement on three landscapes, two within the Prairie Peninsula and one outside the region. Based on functional traits, bearing trees were classified as either pyrophilic or pyrophobic, applied to Public Land Survey points, and the pyrophilic percentage was calculated for each point. Kriging was applied to this point database to create a continuous surface of pyrophilic percentages. Regression analysis was used to relate this surface to environmental factors. Regression models created separately for each study area explained 38 to 53% of the variation in pyrophilic percentage. A positive association between pyrophilic percentage and distance to water and summer potential evapotranspiration was consistent across all study sites. The consistently high values and spatial patterns of pyrophilic percentage revealed fire-dominated landscapes interspers...
The Journal of the Torrey Botanical Society, 2006
BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access t... more BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses.
The Journal of the Torrey Botanical Society, 2011
Phenological niche separation from native species increases reproductive success of an invasive s... more Phenological niche separation from native species increases reproductive success of an invasive species: Alliaria petiolata (Brassicaceae)garlic mustard. J. Torrey Bot. Soc. 138: 418-433. 2011.-Successful biological invasion requires correspondence between invader functional traits and their utility in novel environments. We focused on specific phenological and ecophysiological characteristics of an herbaceous biennial, Alliaria petiolata, related to its successful invasion of deciduous forest groundlayers in eastern North America. We tested for phenological separation between A. petiolata and native groundlayer species during spring of its second year, when the plant accumulates 91% of its total biomass, and assessed importance of availability of high irradiance before tree canopy closure on growth and reproductive output. We experimentally shaded plants in situ during three intervals: Early: before native groundlayer was well developed (3 March-20 April), Mid: 21 April to tree canopy closure (18 May), and Late: after canopy closure to 29 May. We measured maximum photosynthetic rates (A max) in early (13-14 April) and late (22-26 May) spring. Alliaria petiolata began rapid growth and reached maximum cover earlier than most native groundlayer species. Shading effect on plant growth and resource allocation to vegetative growth and reproduction varied depending upon timing and duration of shading. Comparison of treatments differing by being shaded or unshaded in only one of three intervals showed that unshaded plants consistently had significantly higher production than shaded plants only during the Early interval. Greatest A max occurred in early spring (13-14 April), when ground layer irradiance was high. Success of A. petiolata in invading this community is likely related to phenological niche separation and temporal availability of resources not available to most native species in early spring.
Usefulness of native prairie and domesticated grasses in revegetating strip mine spoil and produc... more Usefulness of native prairie and domesticated grasses in revegetating strip mine spoil and producing biomass was examined on 30-year old, recontoured spoil banks located near Canton, Illinois. Grasses were planted in the spring and fall on strip mine spoil and spoil amended with 333 MT/ha of dry sewage sludge. By the end of the second growing season, indiangrass [Sorghastrum nutans (L.) Nash] produced more biomass than the other warm-season grasses, switchgrass (Panicum virgatum L.) and little bluestem [Schizachyrium scoparium (Michx.) Nash], on the unamended plots, and no warm-season grasses survived on the sludge amended plots. Warm-season grasses were able to compete with weedy species on unamended sites, but two cool-season grasses, reed canarygrass (Phalaris arundinacea L.) and Kentucky 31 tall fescue (Festuca arundinacea Schreb.), produced more biomass on amended sites than on unamended sites.
Vegetation ecology and change in terrestrial ecosystems
American Journal of Botany, 2013
• Premise of the study: Invasive species are nonnative species that enter novel environments, est... more • Premise of the study: Invasive species are nonnative species that enter novel environments, establish sustained populations, and can negatively impact native species. Here we assess a potential weakness of invasive species (genetic load) and show how species might overcome genetic barriers. Colonization of novel habitats by invasive species typically involves few individuals, exposing populations to founder effects. We empirically tested a central Illinois population of an invasive biennial plant, Alliaria petiolata , for evidence of a founder effect by assessing the pattern of genetic load. • Methods: To estimate genetic load, we assayed offspring from three cross types (self-pollinated, outcrossed within-and between-populations) in a greenhouse. Vegetative and reproductive traits were measured on fi rst-year plants grown with or without intraspecifi c competition. • Key results: We found substantial genetic load in this population of A. petiolata, which can mostly be attributed to genetic drift (founder effect) and not inbreeding depression. Between-population heterosis was expressed more than inbreeding depression under intraspecifi c competition. • Conclusions: Inbreeding may be adaptive for A. petiolata in its introduced range by providing reproductive assurance, with limited inbreeding load. Nevertheless, most of the genetic load in this population of A. petiolata is due to fi xation of deleterious alleles. Drift load is expected, given that this population is near the edge of its continuous geographic range in highly fragmented habitats, and gene fl ow between isolated populations is likely highly limited. Preventing additional introduction and movement of propagules between isolated local populations should reduce heterosis and A. petiolata competitiveness.
Intraspecific Competition in the Invasive, Biennial Garlic Mustard and the Response of Native Vegetation to Garlic Mustard Removal
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Papers by Roger C. Anderson