Resume

• 2007

  Muhlenberg College

  University of Colorado Colorado Springs

  Massachusetts College of Liberal Arts

  Rocky Mountain Biological Laboratory

  Muhlenberg College

  Rocky Mountain Biological Laboratory

  Crested Butte

  CO

  Coordinator of Undergraduate Research

  Assistant Professor

  Colorado Springs

  Colorado Area

  University of Colorado Colorado Springs

  Massachusetts College of Liberal Arts

• 2002

  Doctor of Philosophy (PhD)

  Dissertation research

  'Genetic and Evolutionary Consequences of Harvest in American Ginseng

  Panax quinquefolius.'

  Environmental Biology

  West Virginia University

• 1999

  Bachelor of Science (BS)

  Environmental and Forest Biology

  State University of New York College of Environmental Sciences and Forestry

• Emily H. Mooney: Research Pages

  Panax

  Emily H. Mooney: Research Pages

  Rocky Mountain Biological Laboratory | Rocky Mountain Biological Laboratory

  Rocky Mountain Biological Laboratory * P.O. Box 519 Crested Butte

  CO 81224 * (970) 349-7231

  RMBL | Rocky Mountain Biological Laboratory

  Genetics

  Evolutionary Biology

  Conservation Biology

  Ecology

  Scientific Writing

  Biology

  Plant Identification

  Statistics

  Molecular Genetics

  Research

  Grant Writing

  Science

  Higher Education

  Effects of Light Environment on Recovery from Harvest and Antibacterial Properties of Oshá Ligusticum porteri (Apiaceae)

  Robert Blessin

  Wild-harvested medicinal plants collected from different light environments may show differential recovery from harvest. Also

  plants growing in open and shaded habitats may allocate resources differently to defense. Since defensive compounds are biologically active

  this difference may lead to variation in medicinal properties. We designed an experiment to test the hypothesis that light environment will affect both the ability of populations to recover from harvest and the medicinal properties of Ligusticum porteri (Apiaceae). L. porteri is a wild-harvested plant found in both high-elevation meadows and forest understories. Surveys in 2010 documented differences in population structure between light environments

  with fewer flowering stalks in the understory. In 2012

  we harvested plants in plots within five sites across varying light (PAR) levels at three different intensities: 0%

  50%

  and 100% of ramets collected. We monitored regrowth in these plots over two years. We also tested the medicinal properties of methanol root extracts of L. porteri from the harvested plots using disc-diffusion assays. We found that L. porteri was able to regrow leaves following even intensive harvest (100%)

  although these were smaller than in control (0%) plots. Harvest significantly reduced the number of flowering stalks

  changing population structure. While light did not impact the ability to regrow following harvest

  it did influence antibacterial activity. The ability to inhibit Bacillus cereus decreased in extracts from plants harvested from high light environments

  which follows plant defense theory. Altogether

  harvest sustainability in L. porteri is equivocal among the light environments examined in this study

  although some medicinal properties vary. L. porteri populations can recover from harvest through vegetative regrowth.

  Effects of Light Environment on Recovery from Harvest and Antibacterial Properties of Oshá Ligusticum porteri (Apiaceae)

  Jennifer Chandler

  Jessica B. Turner

  Sara Souther

  Mary Ann Furedi

  Martha Van der Voort

  Anne E. Lubbers

  James B. McGraw

  American ginseng (Panax quinquefolius L.) is an uncommon to rare understory plant of the eastern deciduous forest. Harvesting to supply the Asian traditional medicine market made ginseng North America's most harvested wild plant for two centuries

  eventually prompting a listing on CITES Appendix II. The prominence of this representative understory plant has led to its use as a phytometer to better understand how environmental changes are affecting many lesser-known species that constitute the diverse temperate flora of eastern North America. We review recent scientific findings concerning this remarkable phytometer species

  identifying factors through its history of direct and indirect interactions with humans that have led to the current condition of the species. Harvest

  deer browse

  and climate change effects have been studied in detail

  and all represent unique interacting threats to ginseng's long-term persistence. Finally

  we synthesize our current understanding by portraying ginseng's existence in thousands of small populations

  precariously poised to either escape or be drawn further toward extinction by the actions of our own species.

  Ecology and conservation of ginseng (Panax quinquefolius) in a changing world

  Norris Muth

  Erin Jo Tiedeken

  Theoretically

  induced defenses should be prevalent within low resource environments like the forest understory where constitutive defenses would be costly. Also

  the induced response should be stronger when the herbivore is a generalist rather than a specialist

  which often have mechanisms to avoid or overcome plant defenses. These ideas have been previously tested for herbaceous species

  and we examined these predictions in Lindera benzoin (spicebush)

  a common woody shrub of the eastern deciduous forest. Lindera benzoin plants in contrasting light environments served as control plants or were subjected to one of four treatments: application of jasmonic acid

  clipping

  herbivory by the specialist Epimecis hortaria (tulip tree beauty) and herbivory by the generalist Spodoptera exigua (beet armyworm). Following treatment

  we assessed induced responses by measuring leaf chemistry (C/N ratio

  protein content

  and peroxidase activity)

  and by using insect bioassays with E. hortaria larvae. We found no difference in peroxidase activity between light environments in controls

  plants treated with clipping or jasmonic acid. In plants subject to insect herbivory

  peroxidase activity was greater in shade plants than in sun plants. The magnitude of this increase in the shade varied between the herbivores

  with a 32 fold increase in plants exposed to the generalist S. exigua and a 9 fold increase in plants exposed to the specialist E. hortaria. Leaves from shade plants had more protein and lower C/N ratios than leaves from sun plants

  regardless of induction treatment. In control plants

  E. hortaria larvae consumed more leaf biomass and achieved greater final weights in the sun than in the shade

  but these differences disappeared with induction treatments were applied. These results are among the first to show rapid induction in a woody plant

  and different levels of induction with light environments and with specialist versus generalist herbivores.

  Differential induced response to generalist and specialist herbivores by Lindera benzoin (Lauraceae) in sun and shade

  Plants display photosynthetic plasticity in response to variation in light environment

  and the extent of this plasticity often varies with genotype. Herbivory may also covary with light environment as a result of light-induced changes in photosynthetic traits. For example

  greater levels of photoprotective phenolic compounds in high-light environments may reduce host quality to herbivores. We investigated intraspecific variation in photosynthetic responses to light and its consequences for herbivory in the understory shrub

  Lindera benzoin (Lauraceae). We transplanted five plants from eight populations (N = 240) into three replicate sun and shade common gardens. Two years after transplantation

  we tested for population × light environment interactions in six photosynthesis-related responses: specific leaf area

  water content

  chlorophyll content

  chlorophyll fluorescence (F0)

  maximum quantum yield (Fv/Fm)

  and total phenolics. We assessed seasonal herbivory and consumption by a specialist lepidopteran herbivore (Epimecis hortaria). This allowed us to test for (1) population-specific patterns of photosynthetic acclimation and photoinhibition

  (2) population-specific production of phenolics in response to photoinhibition

  and (3) population-specific photosynthetic responses that contribute to population × light environment interactions in herbivory. Total phenolics and minimum chlorophyll fluorescence (F0) were significant covariates with herbivory

  but their effects depended on light environment and population of origin. High-light environments eliminated differences among populations in how these leaf variables affected herbivory

  while population-specific relationships were apparent in the shade. Analysis of total phenolics revealed that they were likely induced by photoinhibition

  but that this response varied among the populations we assessed. Our results suggest that herbivores could affect evolution of photosynthetic plasticity in L. benzoin.

  Population-specific responses to light influence herbivory in the understory shrub Lindera benzoin

  Benjamin Hixon

  Annie Arbuthnot

  Alberto Aparicio

  Nisse Goldberg

  Karen Beard

  David Marsh

  Martha Hoopes

  BioScience

  Abstract: Answering large-scale questions in ecology can involve time-consuming data compilation. We show how networks of undergraduate classes can make these projects more manageable and provide an authentic research experience for students. With this approach

  we examined the factors associated with plant species richness in US national wildlife refuges. We found that the richness of harmful invasive plants and the richness of native plants were positively correlated in mainland refuges but negatively correlated in island refuges. Nonnative richness and invasive richness were also positively correlated with colonization pressure as indicated by nonnative richness around each refuge. Associations between refuge characteristics and invasive plants varied substantially among regions

  with refuge area and habitat diversity important predictors of invasion in some regions but not in others. Our results serve to identify the refuges that are most susceptible to plant invasion and demonstrate the potential value of a new model for education and research integration.

  Invasive Plants in Wildlife Refuges

  Genetic differentiation between sun and shade habitats in populations of Lindera benzoin.

  Marten Edwards

  Differences in selection patterns among habitats can alter the distribution of genetic diversity even when this is estimated with neutral markers. For plants

  light is an essential resource that can influence both abiotic and biotic components of habitat. We examined genetic differentiation between sun and shade habitats in Lindera benzoin L. (Spicebush)

  a perennial understory shrub. Genetic diversity of 127 plants from sun and shade habitats in two populations of L. benzoin was determined using 12 polymorphic microsatellite markers. We analyzed patterns of genetic diversity using analysis of molecular variance (AMOVA)

  and we assessed correlation between genetic and geographic distance using Mantel tests. We found (1) low levels of differentiation among populations (F ST = 0.028)

  (2) little evidence of genetic structure within populations due to isolation-by-distance

  and (3) some evidence of habitat-based genetic differentiation. Specifically

  the AMOVA showed a small (0.5%) but significant portion of overall variation could be explained by differences between habitats. The overall low levels of differentiation we saw were likely a result of extensive gene flow in this dioecious

  bird-dispersed species.

  Genetic differentiation between sun and shade habitats in populations of Lindera benzoin.

  James McGraw

  Replicate harvest simulations were conducted in a large natural population of Panax quinquefolius L.␣(Araliaceae) to determine the selective effects of harvest. We investigated how minimum size requirements and the influence of size on apparency to human harvesters could result in preferential removal of large plants. To determine which plants were encountered in the large population

  harvesters were tracked using GPS as they searched for every legally harvestable

  adult plant they could find. Plants were assigned stage-specific fitness measures based on their contributions to population growth rate (λ) under three demographically based harvest regimes: no harvest

  harvest and harvest removing seeds. Plant size was codified into a size-index equal to the product of total leaf area and stem height. Heterogeneity of slopes was tested to determine if the selection gradients (β) describing the relationship between fitness and size varied among the three harvest regimes. Harvest differentially reduced the fitness of larger plants in one of four individual harvest simulations. The combined harvest simulation significantly altered the selection regime for size in the population of juvenile and adult (harvestable) plants. Seed removal by harvesters intensified fitness declines for larger plants. Because larger plants contribute most to population growth

  the selective effects of harvest could result in a shift in the evolutionary dynamics of this species with significant conservation implications.

  Alteration of selection regime resulting from harvest of American ginseng

  Panax quinquefolius L.

  Climate change can influence the abundance of insect herbivores through direct and indirect mechanisms. In this study

  we evaluated multitrophic drivers of herbivore abundance for an aphid species (Aphis helianthi) in a subalpine food web consisting of a host plant (Ligusticum porteri)

  mutualist ants and predatory lygus bugs (Lygus spp.). We used a model-selection approach to determine which climate and host plant cues best predict year-to-year variation in insect phenology and abundance observed over 6 years. We complemented this observational study with experiments that determined how elevated temperature interacts with (1) host plant phenology and (2) the ant-aphid mutualism to determine aphid abundance. We found date of snowmelt to be the best predictor of yearly abundance of aphid and lygus bug abundance but the direction of this effect differed. Aphids achieved lower abundances in early snowmelt years likely due to increased abundance of lygus bug predators in these years. Elevating temperature of L. porteri flowering stalks reduced their quality as hosts for aphid populations. However

  warming aphid colonies on host plants of similar quality increased population growth rates. Importantly

  this effect was apparent even in the absence of ants. While we observed fewer ants tending colonies at elevated temperatures

  these colonies also had reduced numbers of lygus bug predators. This suggests that mutualism with ants becomes less significant as temperature increases

  which contrasts other ant-hemipteran systems. Our observational and experimental results show the importance of multitrophic species interactions for predicting the effect of climate change on the abundances of herbivores

  Multitrophic interactions mediate the effects of climate change on herbivore abundance

  James McGraw

  Size-selective harvest occurs not only in some animal species in the wild

  but in some plant species. Panax quinquefolius

  a perennial plant of eastern North America

  is one such species. As harvest of this species is fatal

  there is potential for evolutionary change if selected traits are heritable. In this study

  we compared traits potentially affected by selection among 12 populations with different harvest pressures. We used the recovery pattern of an experimentally harvested population to develop an index of harvest pressure: the proportion of seedlings and juveniles. Age was related to leaf area

  sympodium (stem) height

  and reproduction in populations across a range of harvest indices (HI = 0.4122-0.9583). We detected variation among populations with different harvest indices in the age-leaf area relationship in 2006. A 10-y-old plant would have 30% less leaf area in a population with high harvest pressure (HI = 0.9) than in a population with low harvest pressure (HI = 0.4). Similar results were observed with sympodium height in 2005 and 2006. Reproductive plants in populations with higher harvest indices had reduced seed set

  likely due to Allee effects. A separate

  related study showed that leaf area differences were maintained among plants from 8 populations 4 to 5 y after transplantation to a common environment. Reduced growth rates in populations with higher harvest pressure may be the outcome of appearance-mediated selection.

  Relationship between age

  size

  and reproduction in populations of American ginseng

  Panax quinquefolius (Araliaceae)

  across a range of harvest pressures

  Kailen A. Mooney

  Annika S. Nelson

  Cheryl Sandrow

  Chadwick V. Tillberg

  Species abundance is typically determined by the abiotic environment

  but the extent to which such effects occur through the mediation of biotic interactions

  including mutualisms

  is unknown. We explored how light environment (open meadow vs. shaded understory) mediates the abundance and ant tending of the aphid Aphis helianthi feeding on the herb Ligusticum porteri. Yearly surveys consistently found aphids to be more than 17-fold more abundant on open meadow plants than on shaded understory plants. Manipulations demonstrated that this abundance pattern was not due to the direct effects of light environment on aphid performance

  or indirectly through host plant quality or the effects of predators. Instead

  open meadows had higher ant abundance and per capita rates of aphid tending and

  accordingly

  ants increased aphid population growth in meadow but not understory environments. The abiotic environment thus drives the abundance of this herbivore exclusively through the mediation of a protection mutualism.

  Abiotic mediation of a mutualism drives herbivore distribution

  James McGraw

  For rare plants

  self-pollination and inbreeding can increase in small populations

  while unusual levels of outcrossing can occur through restoration efforts. To study both inbreeding and outcrossing

  we performed experimental pollinations using Panax quinquefolius (American ginseng)

  a wild-harvested plant with a mixed mating system. For inbreeding

  plants were either cross-pollinated within the population or self-pollinated

  which resulted in a higher proportion of seeds from self-pollinated flowers. For outcrossing

  wild plants were either cross-pollinated within the population or with cultivated plants from West Virginia or Wisconsin. Offspring of all crosses were followed for 4 yr. Two-yr-old seedlings from self-pollination had 45% smaller leaf areas and 33% smaller heights relative to those from cross-pollination. Leaf area is a positive predictor of longer-term survival in wild populations. Our results suggest inbreeding depression

  which is unexpected in this self-fertile species. Seedlings from crosses with cultivated plants had 127% greater leaf area and 165% greater root biomass relative to outcrosses within the population. The accelerated growth suggests genetic differences between wild and cultivated populations

  but outbreeding depression may not appear until later generations. Assessment of the ultimate fitness consequences of introducing cultivated genotypes requires monitoring over longer time periods.

  Effects of self-pollination and outcrossing with cultivated plants in small natural populations of American ginseng

  Panax quinquefolius (Araliaceae)

  Emily

  Mooney