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Showing 1 to 20 of 274 for “"shrubs"”.
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Leaf galls in our native trees and shrubs
… my attention to those or our native trees and shrubs. Upon looking up the literature on this subject, it will be found that in nearly all cases, either the gall is described fully and mere mention made or the agent concerned in its production, or vice versa. This state of things is most …
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Facilitation of Yucca brevifolia recruitment by Mojave Desert shrubs
… found growing under the canopy of other woody shrubs. This pattern of recruitment did not vary by canyon or elevation. Thirty-five species of perennial shrubs were identified in the study areas and sixteen of these were found in association with at least one Y. brevifolia seedling. However, …
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Rodent effects on shrubs in a Mojave Desert shrub community
The mounds created by many species of Dipodomys (kangaroo rats) are long-term modifications of the the soil chemical and physical environment which have been shown to increase both the diversity and abundance of annuals in the deserts of the Southwestern United States. I characterized shrub …
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CHANGES IN LEAF MORPHOLOGY, PHOTOSYNTHESIS AND NITROGEN CONTENT IN TWO COASTAL SHRUBS
… that facilitate expansion of two common shrubs, Morella cerifera and Baccharis halimifolia in coastal environments. The purpose of my study was to investigate the physiological and structural changes that occur as leaves age. Photosynthesis, incident light, chlorophyll, and leaf C:N …
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Extending Plant-Plant Facilitation Theory to Pollinators: Do Desert Shrubs Act as Magnets?
… literature, 2) to determine whether desert shrubs act as magnets for pollinators, and 3) extend the study of shrubs as magnets by exploring reciprocitytesting whether the floral island they facilitate in their understory can also act as a double magnet for pollinators. Video and in-situ …
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The competitive dynamics of two Protea shrubs growing in a mixed fynbos stand
Patterns of segregation among Protea species were investigated. Interspecific competition was studied as a cause of these patterns. Two different methods were used for measuring competition in a mixed stand of P. lepidocarpodendron and P. corona/a growing on the Cape Peninsula. These were the …
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Effects of defoliation on regrowth and carbon budgets of three semi-arid Karoo shrubs
… removal were studied for the following karoo shrubs: Osteospermum sinuatum, a dwarf deciduous shrub with fleshy leaves, Pteronia pallens, a dwarf evergreen shrub with sclerophyllous leaves and Ruschia spinosa, a dwarf evergreen shrub with succulent leaves. Defoliation adversely affected both …
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Rooting for the Home Team: Arbuscular Mycorrhizas and Root Traits in Native and Invasive Woody Shrubs
… of phylogenetically paired native and invasive shrubs from a common garden, plants were grown under high and low nutrient conditions, as well as with or without live soil inoculum containing AMF propagules. I used biomass data to assess if natives or invaders had different mycorrhizal growth …
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Diel patterns of insect herbivory and plant secondary metabolites in understory shrubs on Barro Colorado Island
Plants produce a broad diversity of secondary metabolites as defenses against herbivory. In response, herbivorous insects have evolved a diversity of behavioral and biochemical counter-adaptations to these defenses. Despite that a significant portion of leaf area removal by insects in the tropics …
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Shrubs as Sentinels of Ordnance Contamination: Using Plant Physiology and Remote Sensing to Detect TNT in Soils
Methods for rapid, safe and effective detection of unmapped buried ordnance are vital to the protection of humans and environmental quality throughout the world. This study aimed to investigate the use of phytosensing and to understand the physiological response of woody plants to …
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Analysing the influence of TNT on Southern African trees grass and shrubs using in-situ hyperspectral data
… five species of grasses and four species of shrubs, and leaf-clip readings were taken at regular intervals with a field spectrometer. Statistical correlation testing of seven plant health indices (red-edge position, first derivative reflectance, normalised difference water index, moisture …
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The Influence of Dense Understory Shrubs on the Ecology of Canopy Tree Recruitment in Southern Appalachian Forests
… Analysis of resource competition between shrubs and seedlings indicated that seedling performance and survivorship was a negative function of R. maximum density. Open-canopy light availability, nitrogen content in the organic horizon (litter and humus), and soil nutrient availability were …
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An examination of facilitative interactions between shrubs and local desert organisms within the desert ecosystems of southern California
… studies, specifically those with foundational shrubs within drylands. However, little has been done to analyze how the density of shrubs influence the frequency of these interactions. Here, I aim to establish shrub density as a crucial measure in ecology and facilitative interactions. I begin …
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The Role That Asexual Reproduction Plays in the Regeneration of Tropical Piper Shrubs: Habitat Differences and Genetic Consequences
Asexual reproduction is a common, but little explored characteristic of many tropical plants with a variety of life-histories and habitat requirements. My dissertation research examined the ecological correlates and population genetic consequences of asexual reproductive success in five …
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The influence of water and light on the physiology and spatial distributions of three shrubs in the Southern Appalachian Mountains
In order to understand vegetational gradients which develop in response to environmental gradients, the physiological capabilities of each species must be examined in relation to the observed environmental gradient. The distributions of three temperate zone shrub species which occupy different …
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Spatio-temporal distribution of grass and shrubs at the ecotone between an arid grassland and succulent shrubland : ecological interactions and the influence of soils
… the current distribution of grasses and shrubs along the ecotone, and to determine how this vegetation has changed over the past 20 years.
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The effects of shrub removal and grazing on vegetation and soils in a shrub-encroached Australian woodland
… and climate. Areas heavily encroached by shrubs are generally regarded as degraded, and this view is largely based on the fact that shrubs reduce pastoral productivity. There have been many attempts to remove shrubs in pastoral systems using chemical, biological and mechanical techniques …
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Demography and leaf physiology of Cornus drummondii in response to disturbance in tallgrass prairie
… and increased grazing intensity. Clonal shrubs are of particular concern because of their ability to spread via vegetative reproduction and resprout after fire. The demographic mechanisms that underlie shrub responses to climate history and disturbance are unknown. Here, I measured ramet …
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The Effect of Three Postemergence Grass Herbicides on Quackgrass (Agropyron Repens (L.) Beauv.) and Selected Ornamental Shrubs, Ground Covers, and Bedding Plants (fluazifop-P-Butyl, Sethoxydim, Quizalofop-Ethyl, Dpx-Y6202)
Applications of 0.28 kg ai/ha fluazifop-p-butyl + Surfactant WK 0.25% (by. vol), 0.56 kg ai/ha sethoxydim + crop oil concentrate 1%, and 0.56 kg ai/ha DPX-Y6202 + Surfactant WK 0.25% to Agropyron repens shoots interfered with cyto- and karyokinesis of the rapidly expanding leaves within two days …
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