Tjiurutue M.C.,University of Massachusetts Amherst |
Tjiurutue M.C.,University of Namibia |
Sandler H.A.,UMass Cranberry Experiment Station |
Kersch-Becker M.F.,University of Campinas |
And 2 more authors.
Oecologia | Year: 2017
Interactions between species can have cascading effects that shape subsequent interactions. For example, herbivory can induce plant defenses that affect subsequent interactions with herbivores, pathogens, mycorrhizae, and pollinators. Parasitic plants are present in most ecosystems, and play important roles in structuring communities. However, the effects of host herbivory on parasitic plants, and the potential mechanisms underlying such effects, are not well known. We conducted a greenhouse study to ask whether gypsy moth (Lymantria dispar) damage, host cultivar, and their interaction affected preference of the stem parasite dodder (Cuscuta spp.) on cranberry hosts (Vaccinium macrocarpum). We then assessed the mechanisms that could underlie such effects by measuring induced changes in phytohormones and secondary compounds. We found that damage by gypsy moths delayed dodder attachment by approximately 0.3 days when dodder stems were added 2 days after damage, and reduced attachment by more than 50% when dodder stems were added 1 week after host plant damage. Gypsy moth damage significantly increased jasmonic acid (JA) levels, total volatile emissions, and the flavonol, quercetin aglycone, suggesting possible mechanisms underlying variation in dodder ability to locate or attach to hosts. Dodder preference also differed between cranberry cultivars, with the highest attachment on the cultivar that had significantly lower levels of total volatile emissions and total phenolic acids, suggesting that volatile composition and phenolics may mediate dodder preference. Our results indicate that herbivory can reduce subsequent attachment by a highly damaging parasitic plant, demonstrating the potential importance of early damage for shaping subsequent species interactions. © 2017 Springer-Verlag GmbH Germany
Barber N.A.,Northern Illinois University |
Milano N.J.,University of Massachusetts Amherst |
Milano N.J.,Cornell University |
Kiers E.T.,VU University Amsterdam |
And 4 more authors.
Journal of Ecology | Year: 2015
There is a widespread recognition that above- and below-ground organisms are linked through their interactions with host plants that span terrestrial subsystems. In addition to direct effects on plants, soil organisms such as root herbivores can indirectly alter interactions between plants and other community members, with potentially important effects on plant growth and fitness. We manipulated root herbivory by Acalymma vittatum in Cucumis sativus to determine indirect effects on arbuscular mycorrhizal fungi, leaf herbivory, the leaf pathogen downy mildew and pollinators. We also manipulated pollen receipt by plants to determine whether root herbivory reduced plant reproduction through changes in pollinator visitation. Overall, root herbivory had strong net negative effects on plant growth and fitness, with 34% reductions in both leaf and fruit production by high root damage levels relative to control, despite reduced infection by downy mildew. High root herbivory also reduced floral visitation by 39%, apparently due to lower flower production, as flower size and scent were unaffected. Above-ground herbivory was not affected by root herbivores. Although root herbivory reduced pollinator visits, pollen receipt manipulations had no effect on fruit set, indicating that reduced pollinator service did not affect plant reproduction. Synthesis. Root herbivory had indirect effects on a range of community members, including mutualists and antagonists both above- and below-ground. Although reduced pathogen infection associated with root herbivory would be expected to benefit plants, root herbivory had an overall strong negative effect on plant growth and reproduction, indicating that direct negative effects over-rode any potential indirect benefits. Soil organisms such as root herbivores can indirectly alter interactions between plants and other community members. Here, root damage had indirect effects on a range of community members, including mutualists and antagonists both above- and below-ground. However, direct negative effects of root herbivory were more important for reducing plant growth and fitness. © 2015 British Ecological Society.
PubMed | Elms College, UMass Cranberry Experiment Station, Cornell University and University of Massachusetts Amherst
Type: Journal Article | Journal: Journal of chemical ecology | Year: 2016
Parasitic plants are common in many ecosystems, where they can structure community interactions and cause major economic damage. For example, parasitic dodder (Cuscuta spp.) can cause up to 80-100% yield loss in heavily infested cranberry (Vaccinium macrocarpon) patches. Despite their ecological and economic importance, remarkably little is known about how parasitic plants affect, or are affected by, host chemistry. To examine chemically-mediated interactions between dodder and its cranberry host, we conducted a greenhouse experiment asking whether: (1) dodder performance varies with cranberry cultivar; (2) cultivars differ in levels of phytohormones, volatiles, or phenolics, and whether such variation correlates with dodder parasitism; (3) dodder parasitism induced changes in phytohormones, volatiles, or phenolics, and whether the level of inducible response varied among cultivars. We used five cranberry cultivars to assess host attractiveness to dodder and dodder performance. Dodder performance did not differ across cultivars, but there were marginally significant differences in host attractiveness to dodder, with fewer dodder attaching to Early Black than to any other cultivar. Dodder parasitism induced higher levels of salicylic acid (SA) across cultivars. Cultivars differed in overall levels of flavonols and volatile profiles, but not phenolic acids or proanthocyanidins, and dodder attachment induced changes in several flavonols and volatiles. While cultivars differed slightly in resistance to dodder attachment, we did not find evidence of chemical defenses that mediate these interactions. However, induction of several defenses indicates that parasitism alters traits that could influence subsequent interactions with other species, thus shaping community dynamics.
Barber N.A.,University of Massachusetts Amherst |
Barber N.A.,Northern Illinois University |
Adler L.S.,University of Massachusetts Amherst |
Theis N.,Elms College |
And 3 more authors.
Ecology | Year: 2012
Herbivores affect plants through direct effects, such as tissue damage, and through indirect effects that alter species interactions. Interactions may be positive or negative, so indirect effects have the potential to enhance or lessen the net impacts of herbivores. Despite the ubiquity of these interactions, the indirect pathways are considerably less understood than the direct effects of herbivores, and multiple indirect pathways are rarely studied simultaneously. We placed herbivore effects in a comprehensive community context by studying how herbivory influences plant interactions with antagonists and mutualists both aboveground and belowground. We manipulated early-season aboveground herbivore damage to Cucumis sativus (cucumber, Cucurbitaceae) and measured interactions with subsequent aboveground herbivores, root-feeding herbivores, pollinators, and arbuscular mycorrhizal fungi (AMF). We quantified plant growth and reproduction and used an enhanced pollination treatment to determine if plants were pollen limited. Increased herbivory reduced interactions with both antagonists and mutualists. Plants with high levels of early herbivory were significantly less likely to suffer leaf damage later in the summer and tended to be less attacked by root herbivores. Herbivory also reduced pollinator visitation, likely due to fewer and smaller flowers, and reduced AMF colonization. The net effect of herbivory on plant growth and reproduction was strongly negative, but lower fruit and seed production were not due to reduced pollinator visits, because reproduction was not pollen limited. Although herbivores influenced interactions between plants and other organisms, these effects appear to be weaker than the direct negative effects of early-season tissue loss. © 2012 by the Ecological Society of America.
Theis N.,Elms College |
Barber N.A.,Northern Illinois University |
Gillespie S.D.,Simon Fraser University |
Hazzard R.V.,University of Massachusetts Amherst |
Adler L.S.,University of Massachusetts Amherst
American Journal of Botany | Year: 2014
Premise of the study: Floral traits play important roles in pollinator attraction and defense against floral herbivory. However, plants may experience trade-offs between conspicuousness to pollinators and herbivore attraction. Comparative studies provide an excellent framework to examine the role of multiple traits shaping mutualist and antagonist interactions. Methods: To assess whether putative defensive and attractive traits predict species interactions, we grew 20 different Cucur-bitaceae species and varieties in the field to measure interactions with pollinators and herbivores and in the greenhouse to assess trait variation. Cucurbits are characterized by the production of cucurbitacins, bitter nonvolatile terpenoids that are effective against generalist herbivores but can attract specialist beetles. We determined whether plant traits such as cucurbitacins predict herbivore resistance and pollinator attraction using an information-theoretic approach. Key results: Mutualists and floral antagonists were attracted to the same cucurbit varieties once they flowered. However, rather than cucurbitacin concentration, we found that the size of the flower and volatile emissions of floral sesquiterpenoids explained both pollinator and floral herbivore visitation preference across cucurbit taxa. This pattern held across cucurbit taxa and within the Cucurbita genus. Conclusions: Surprisingly, floral sesquiterpenoid volatiles, which are associated with direct defense, indirect defense, and attraction, rather than defense traits such as cucurbitacins, appeared to drive interactions with both pollinators and floral herbivores across cucurbit taxa. Identifying the relevant plant traits for attraction and deterrence is important in this economically valuable crop, particularly if pollinators and floral herbivores use the same plant traits as cues. © 2014 Botanical Society of America.
PubMed | Elms College, University of Massachusetts Amherst, Simon Fraser University and Northern Illinois University
Type: Journal Article | Journal: American journal of botany | Year: 2014
Floral traits play important roles in pollinator attraction and defense against floral herbivory. However, plants may experience trade-offs between conspicuousness to pollinators and herbivore attraction. Comparative studies provide an excellent framework to examine the role of multiple traits shaping mutualist and antagonist interactions.To assess whether putative defensive and attractive traits predict species interactions, we grew 20 different Cucurbitaceae species and varieties in the field to measure interactions with pollinators and herbivores and in the greenhouse to assess trait variation. Cucurbits are characterized by the production of cucurbitacins, bitter nonvolatile terpenoids that are effective against generalist herbivores but can attract specialist beetles. We determined whether plant traits such as cucurbitacins predict herbivore resistance and pollinator attraction using an information-theoretic approach.Mutualists and floral antagonists were attracted to the same cucurbit varieties once they flowered. However, rather than cucurbitacin concentration, we found that the size of the flower and volatile emissions of floral sesquiterpenoids explained both pollinator and floral herbivore visitation preference across cucurbit taxa. This pattern held across cucurbit taxa and within the Cucurbita genus.Surprisingly, floral sesquiterpenoid volatiles, which are associated with direct defense, indirect defense, and attraction, rather than defense traits such as cucurbitacins, appeared to drive interactions with both pollinators and floral herbivores across cucurbit taxa. Identifying the relevant plant traits for attraction and deterrence is important in this economically valuable crop, particularly if pollinators and floral herbivores use the same plant traits as cues.
Sens J.-M.,Nicholls State University |
Fonseca A.J.,Elms College
Technical Services Quarterly | Year: 2013
Academic librarians have embraced patron-driven acquisitions (PDA) without asking the tough, critical questions about the literature that champions it, which often stretches the boundaries of logical analysis in its conclusions. Realizing what is at stake, in this article the authors ask the skeptical questions that should be considered before buying into the idea of PDA as the panacea for all circulation and budget ills. The goal of the authors is to foster pause for thought and to cause academic librarians to read more carefully the literature for its logical lapses. Since no true dialogue on PDA seems to exist, this is offered as a starting point. © 2013 Copyright Taylor and Francis Group, LLC.
Rivers A.,Regional Mental Health Center |
Wickramasekera I.E.,Naropa University |
Pekala R.J.,Coatesville Medical Center |
Rivers J.A.,Elms College
American Journal of Clinical Hypnosis | Year: 2016
This study examined the levels of empathy and absorption of individuals who regularly play fantasy and science fiction role-playing games. A hypothesis was developed that higher levels of empathy would be found in individuals who fantasy role-play based upon previous research in hypnosis such as J. R. Hilgard’s (1970) imaginative involvement hypothesis, research into the “fantasy prone” personality type (Wilson & Barber, 1981), and the empathic involvement hypothesis (Wickramasekera II & Szlyk, 2003). The participants in the current study were 127 fantasy role-players who volunteered and completed the Davis Interpersonal Reactivity Index (empathy) and the Tellegen Absorption Scale (absorption). The results demonstrated that those who play fantasy role-playing games scored significantly higher than the comparison group on the IRI scale of empathy, confirming the hypothesis that fantasy role-players report experiencing higher levels of empathic involvement with others. Correlational analysis between the measures demonstrated a significant positive correlation between empathy and absorption (r = .43, p < .001). These results collectively suggest that fantasy role-players have a uniquely empathically-imaginative style. The results also confirm and extend previous findings on the relationship between empathy and absorption as predicted by the Empathic Involvement Hypothesis (Wickramasekera II & Szlyk, 2003). Copyright © American Society of Clinical Hypnosis.
Grady A.M.,Personal Touch Home Care |
Grady A.M.,Elms College
Home Healthcare Nurse | Year: 2014
The Latino population is the fastest growing ethnically diverse group in the United States, but U.S. healthcare studies report poorer health status in this population than in non-Latinos. Using Campinha-BacoteÊs Inventory for Assessing the Process of Cultural Competence Among Healthcare Professionals - Revised (IAPCC-R, 2003), a single-session pilot educational program to enhance culturally responsive home care nursing to Latinos resulted in a 27% increase in the nurse participant cultural competency levels. Copyright © 2014 Lippincott Williams & Wilkins.
Schrauf C.M.,Elms College
Nephrology nursing journal : journal of the American Nephrology Nurses' Association | Year: 2011
When individuals with chronic kidney disease require ongoing assistance with activities of daily living and disease management, the consistent care provided by family caregivers often averts the need for institutional placement These caregivers may experience physical and mental burden when supports are not in place to provide occasional help and relief In some states, public programs have been developed to provide assistance to family caregivers, such as respite care, caregiver training, and tax credits. However, policies among the states are not consistent. This study identified factors that have influenced the development of family caregiver-friendly policies and programs in two study states, Connecticut and New Jersey. The case study method used in this research utilized data from informant interviews, document review, and observation of select meetings and hearings to identify 11 factors or themes that impacted public policy development benefiting family caregivers. Two primary factors, state fiscal environment/philosophy and advocacy, were found to be critical to the policymaking process. Based on these findings, specific measures are described that nephrology nurses can take to help influence adoption of policies benefiting caregivers. In addition, information to help caregivers access available programs through agencies, organizations, and informational Web sites is identified.