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Plant Growth Forms (plant + growth_form)
Selected AbstractsImpact of chemical elicitor applications on greenhouse tomato plants and population growth of the green peach aphid, Myzus persicaeENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 3 2006Anthony J. Boughton Abstract Recent advances in the understanding of plant signaling pathways have opened the way for using elicitor-induced plant resistance as a tactic for protecting plants against arthropod pests. Four common elicitors of induced responses in tomato, Lycopersicon esculentum Mill. (Solanaceae), were evaluated with regard to phytotoxicity, induction of plant defensive proteins, and effects on population growth and fecundity of a common pest, the green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae). Ethephon and methyl jasmonate (MJ) treatments caused varying degrees of phytotoxicity. Ethephon caused pronounced changes in plant growth form and severe, dose-dependent negative impacts on plant growth and flowering. Effects with MJ were milder, but still caused temporary inhibition of development, leading to smaller plants and delayed flowering. The commercial elicitors benzothiadiazole (BTH) and harpin did not cause detectable phytotoxicity. The highest doses of ethephon and MJ significantly increased leaf peroxidase (POD) levels but only MJ treatments significantly increased polyphenol oxidase (PPO) levels. BTH and harpin had no detectable effects on POD and PPO. Populations of green peach aphids grew significantly more slowly on plants treated with BTH or MJ than on control plants or plants treated with harpin or ethephon. Slowed aphid population growth on BTH-treated plants was due to significant reductions in aphid fecundity, although this was independent of changes in time to onset of reproduction or time to death. Aphid fecundity was also reduced on MJ-treated plants relative to controls, but this difference was not statistically significant, suggesting that other mechanisms are involved in slowing aphid population growth on MJ-treated plants. Growth of aphid populations on plants treated with a MJ,BTH mixture was reduced almost as much as with treatments of MJ alone, suggesting that antagonism between JA-dependant and SA-dependent plant signaling pathways is only mild with regard to induced defenses against aphids. [source] Large-scale geographical trends in fruit traits of vertebrate-dispersed temperate plantsJOURNAL OF BIOGEOGRAPHY, Issue 4 2003Arndt Hampe Abstract Aim, To assess large-scale geographical trends in the character of fleshy, vertebrate-dispersed fruits. Location, Europe between central Sweden and southern Spain. Methods, Analyses of fruit of sixty-three plant species from twenty-nine families were compiled from four regional data sets. Four structural and five chemical fruit traits were analysed intraspecifically to control rigorously for phylogenetic lineage effects. Trends were examined in relation to various biological features of the considered species. Results, Contents of soluble carbohydrate and lipids decreased markedly northwards. Fruit diameter and fresh mass peaked at the wettest site, while the pulp water content remained more constant throughout the gradient than any other fruit trait. Ash content, seed number and seed mass did not change, while the nitrogen content showed conflicting trends. No relation was detected between observed variation in fruit traits and fruit type, fruit colour, ripening season, plant growth form, leaf longevity, or geographical distribution of the considered plant species. Main conclusions, Considerable intraspecific variability exists in vertebrate-dispersed fruits on large geographical scales. Climate presumably affects particularly those traits related to carbon and water gain and storage. Most research on fruit,frugivore interactions has been carried out on small spatial scales and failed to find matchings between frugivore communities and the character of fleshy fruits. I suggest that explicitly addressed large-scale surveys on the geographical variability of fruits and their disperser assemblages are needed to elucidate their spatial patterns and to determine the extent to which fleshy fruit traits are shaped by animals and/or abiotic factors. [source] Reduced early growing season freezing resistance in alpine treeline plants under elevated atmospheric CO2GLOBAL CHANGE BIOLOGY, Issue 3 2010MELISSA MARTIN Abstract The frequency of freezing events during the early growing season and the vulnerability to freezing of plants in European high-altitude environments could increase under future atmospheric and climate change. We tested early growing season freezing sensitivity in 10 species, from four plant functional types (PFTs) spanning three plant growth forms (PGFs), from a long-term in situ CO2 enrichment (566 vs. 370 ppm) and 2-year soil warming (+4 K) experiment at treeline in the Swiss Alps (Stillberg, Davos). By additionally tracking plant phenology, we distinguished indirect phenology-driven CO2 and warming effects from direct physiology-related effects on freezing sensitivity. The freezing damage threshold (lethal temperature 50) under ambient conditions of the 10 treeline species spanned from ,6.7±0.3 °C (Larix decidua) to ,9.9±0.6 °C (Vaccinium gaultherioides). PFT, but not PGF, explained a significant amount of this interspecific variation. Long-term exposure to elevated CO2 led to greater freezing sensitivity in multiple species but did not influence phenology, implying that physiological changes caused by CO2 enrichment were responsible for the effect. The elevated CO2 effect on freezing resistance was significant in leaves of Larix, Vaccinium myrtillus, and Gentiana punctata and marginally significant in leaves of Homogyne alpina and Avenella flexuosa. No significant CO2 effect was found in new shoots of Empetrum hermaphroditum or in leaves of Pinus uncinata, Leontodon helveticus, Melampyrum pratense, and V. gaultherioides. Soil warming led to advanced leaf expansion and reduced freezing resistance in V. myrtillus only, whereas Avenella showed greater freezing resistance when exposed to warming. No effect of soil warming was found in any of the other species. Effects of elevated CO2 and soil warming on freezing sensitivity were not consistent within PFTs or PGFs, suggesting that any future shifts in plant community composition due to increased damage from freezing events will likely occur at the individual species level. [source] Predictors of plant phenology in a diverse high-latitude alpine landscape: growth forms and topographyJOURNAL OF VEGETATION SCIENCE, Issue 5 2009Marianne Iversen Abstract Question: Different plant growth forms may have distinctly different functioning in ecosystems. Association of phenological patterns with growth form will therefore help elucidate the role of phenology in an ecosystem. We ask whether growth forms of common vascular plants differ in terms of vegetative and flowering phenology, and if such phenological differences are consistent across environmental gradients caused by landscape-scale topography. Location: A high-latitude alpine landscape in Finnmark County, Norway (70°N). Methods: We assessed vegetative and flowering phenology repeatedly in five growth forms represented by 11 common vascular plant species across an altitudinal gradient and among differing slope aspects. Results: Species phenology clustered well according to growth form, and growth form strongly explained variation in both flowering and vegetative phenology. Altitude and aspect were poor predictors of phenological variation. Vegetative phenology of the growth forms, ranked from slowest to fastest, was in the order evergreen shrubs CLO-PLA: the database of clonal and bud bank traits of Central European flora,JOURNAL OF VEGETATION SCIENCE, Issue 3 2009Jitka Klime Abstract: Clonal growth of plants is mainly a result of the vegetative growth of organs hidden beneath the soil surface and producing potentially independent vegetative offspring. Clonal traits are difficult to measure due to inaccessibility of the space they inhabit and their morphological diversity. This causes great difficulties with descriptions, standardization of measurements across plant growth forms and, probably, a lack of appropriate questions that should be answered using them. The freely available CLO-PLA database (http://clopla.butbn.cas.cz/) can help to assess the roles of vegetative means of regeneration and spread in plant communities under the effect of various biotic and abiotic filters. It can serve as a source of reference on persistence traits of European temperate flora and, eventually, as a guide for trait sampling in other regions of the world. [source] Defining fallback foods and assessing their importance in primate ecology and evolutionAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2009Andrew J. Marshall Abstract Physical anthropologists use the term "fallback foods" to denote resources of relatively poor nutritional quality that become particularly important dietary components during periods when preferred foods are scarce. Fallback foods are becoming increasingly invoked as key selective forces that determine masticatory and digestive anatomy, influence grouping and ranging behavior, and underlie fundamental evolutionary processes such as speciation, extinction, and adaptation. In this article, we provide an overview of the concept of fallback foods by discussing definitions of the term and categorizations of types of fallback foods, and by examining the importance of fallback foods for primate ecology and evolution. We begin by comparing two recently published conceptual frameworks for considering the evolutionary significance of fallback foods and propose a way in which these approaches might be integrated. We then consider a series of questions about the importance of fallback foods for primates, including the extent to which fallback foods should be considered a distinct class of food resources, separate from preferred or commonly eaten foods; the link between life history strategy and fallback foods; if fallback foods always limit primate carrying capacity; and whether particular plant growth forms might play especially important roles as fallback resources for primates. We conclude with a brief consideration of links between fallback foods and primate conservation. Am J Phys Anthropol 140:603,614, 2009. © 2009 Wiley-Liss, Inc. [source]
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