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Results 301 - 350 of 667
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Fry Heidi R C - - 2008
Trees in an urban forest are highly valued because they have esthetic appeal, provide shade, and improve air quality. During the past 5 yr (2002-2006) in St. John's, Newfoundland and Labrador, Canada, the elm spanworm, Ennomos subsignaria (Hübner) (Lepidoptera: Geometridae), has reached outbreak densities. Each year, hundreds of trees have ...
Yoshimoto Teppei - - 2008
The technical establishment of boar sperm cryopreservation is indispensable for effective breeding of the scarce Okinawan native pig Agu. The objective of the present study was to determine whether ascorbic acid 2-O-alpha-glucoside (AA-2G), a stable ascorbate derivative, is capable of improving the quality of cryopreserved Agu spermatozoa. Ejaculated Agu sperm ...
André Frédéric - - 2008
The effects of meteorological variables and local canopy characteristics on throughfall chemistry were investigated within a mixed oak-beech stand during the leafed and the leafless seasons. Throughfall was collected after each rain event in 12 structural units delimited by three neighbouring trees each. For each investigated ion (H+, Mg2+, Ca2+, ...
Dominy Nathaniel J - - 2008
There has been little previous work on the toughness of the laminae of monocots in tropical lowland rain forest (TLRF) despite the potential importance of greater toughness in inhibiting herbivory by invertebrates. Of 15 monocot families with >100 species in TLRF, eight have notably high densities of fibres in the ...
Veraart, Annelies J.
Browsing may lead to an induced resistance or susceptibility of the plant to the herbivore. We tested the effect of winter browsing by Eurasian beavers (Castor fiber L., 1758) on food quality of holme willows (Salix dasyclados Wimm.) in and after the following growth season. Shrubs were pruned in February, ...
Maier Chris A - - 2008
We examined effects of a first nitrogen (N) fertilizer application on upper-canopy needle morphology and gas exchange in approximately 20-m-tall loblolly pine (Pinus taeda L.) exposed to elevated carbon dioxide concentration ([CO(2)]) for 9 years. Duke Forest free-air CO(2) enrichment (FACE) plots were split and half of each ring fertilized ...
de Magalhães Erismann Norma - - 2008
Photosynthetic limitations under moderate water deficit were evaluated in 'Valência' orange trees grafted on three different rootstocks, in pots. Net CO(2) assimilation rate (A (N)), stomatal conductance (g (s)), and photosystem II (PS II) operating efficiency (F'(q)/F'(m)) in response to changing intercellular CO(2 ) partial pressure (C (i)) were analyzed ...
Zug, George R
Bufo marinus was introduced into the New Guinea region in the late 1930s. Its present distribution in Papua New Guinea is mapped. In the Port Moresby area, the population of Bufo marinus is capable of reproduction at any time of the year. Sampling at a rain forest and a savanna ...
Moultrie Tom A - - 2008
Stalled fertility declines have been identified in several regions across the developing world, but the current conceptualization of a stalled fertility decline is poorly theorized and does not lend itself to objective measurement. We propose a more rigorous and statistically testable definition of stalled fertility decline that can be applied ...
Teixeira Diva C - - 2008
Huanglongbing (HLB), an insect-transmitted disease of citrus, known for many years in Asia and Africa, has appeared in the state of São Paulo State (SSP), Brazil, in 2004, and the state of Florida, USA, in 2005. HLB endangers the very existence of citrus, as trees infected with the bacterial pathogen, ...
Funsani, S; ;
People living near Dzalanyama Forest Reserve in Lilongwe District of Central Malawi collect various forest products throughout the year. This paper quantifies the contribution of fuel wood as a non-timber forest product (NTFP) to income and food security of the households surrounding the Dzalanyama Forest Reserve. A sample of 150 ...
Degabriel Jane L - - 2008
Many regard the concentrations of nitrogen (N), tannins and plant cell wall constituents (fibre) as key indicators of food quality and habitat suitability for browsing herbivores; yet there is no method for measuring their combined effects. We have developed a simple in vitro assay for measuring the effects of tannins ...
Meinzer Frederick C - - 2008
The physiological mechanisms responsible for reduced extension growth as trees increase in height remain elusive. We evaluated biophysical constraints on leaf expansion in old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. Needle elongation rates, plastic and elastic extensibility, bulk leaf water (Psi(L)) and osmotic (Psi(pi)) potential, bulk tissue yield threshold and ...
Yee Wee L - - 2008
A study was conducted to determine the abundance of potential foods and the feeding substrates and behaviors of the western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), in 2005, 2006, and 2007 in central Washington state. Aphid colonies with honeydew, a presumed food source for flies, were not seen ...
Ji Xiufeng - - 2008
Alkylresorcinols (ARs) are bioactive compounds occurring in many members of the Poaceae, likely at or near the surface of various organs. Here, we investigated AR localization within the cuticular wax layers of rye (Secale cereale) leaves. The total wax mixture from both sides of the leaves was found to contain ...
Waring, Richard H.
Structure and function of the Coniferous Forest Biome organization -- A systematic framework for modeling and studying the physiology of a coniferous forest ecosystem -- Nutrient cycling in 37- and 450-year-old Douglas-fir ecosystems -- Estimating evapotranspiration from forests by meteorological and lysimetric methods -- Canopy food chain in a coniferous ...
Hukkanen Anne - - 2008
The main arctic bramble ( Rubus arcticus) cultivars are susceptible to downy mildew ( Peronospora sparsa), which seriously threatens the cultivation. The efficiency of Aliette, Euparen M, phosphite-containing Phosfik, Phostrol, Farm-Fos-44, and Kaliumfosfiet, as well as Bion was evaluated in the greenhouse. Fewer symptoms and less Peronospora DNA were found ...
Warner J C - - 2008
Zoonotic pathogens such as Salmonella can cause gastrointestinal illness if they are ingested with food. Foods such as salads pose a greater risk because they are consumed raw and have been the source of major outbreaks of disease from fresh produce. The novel light microscopy methods used in this study ...
I.S. Travlos
This study was conducted in order to evaluate the allelopathic potential of marama bean (<I>Tylosema esculentum</I> (Burch) A. Schreib), a drought-avoider legume of Africa, which produces seed and tubers with potential for use as human food and animal fodder. Fresh, senesced and decaying leaves from marama were evaluated for their ...
Broberg, Emilia
The wild boar is a reintroduced game species in Sweden which has become a problem species because of damage on crops and causing traffic accidents. This is a comparative study with the aim to answer the following questions: (i) which habitat sites are most frequently visited by wild boar (ii) ...
Bylesjö Max - - 2008
An increased understanding of leaf area development is important in a number of fields: in food and non-food crops, for example short rotation forestry as a biofuels feedstock, leaf area is intricately linked to biomass productivity; in paleontology leaf shape characteristics are used to reconstruct paleoclimate history. Such fields require ...
Jazy Hamid Dehghanzadeh - - 2007
An experiment was conducted during 2004-2006 at the Agricultural Research Station, Islamic Azad University, Khorasgan Branch, Isfahan, Iran. The purpose of this study was to evaluate the effects of irrigation regimes on growth indices of three bread wheat (Triticum aestivum L.) genotypes. A split plot layout with a randomized complete ...
Brown, Gregory G.
Thesis (M.S.)--Humboldt State University, Natural Resources: Wildlife, 2007
Straw N A - - 2007
A survey of 801 poplar trees in central east England in 1999 demonstrated a correlation between crown dieback and infestation by hornet clearwing moth (Sesia apiformis), induced by a period of drought in 1995-1996. To determine whether trees colonised by S. apiformis would subsequently deteriorate and die or whether they ...
Ponce Georgina - - 2008
Directed growth of roots in relation to a moisture gradient is called hydrotropism. The no hydrotropic response (nhr1) mutant of Arabidopsis lacks a hydrotropic response, and shows a stronger gravitropic response than that of wild type (wt) in a medium with an osmotic gradient. Local application of abscisic acid (ABA) ...
Burgess Kevin S - - 2008
Hybrid fertilizations can have negative demographic effects on taxa by usurping ovules that would otherwise give rise to nonhybrid offspring. The consequent reduction in conspecific matings may be exaggerated in rare taxa and constitutes a fertility cost that has rarely been quantified. Here, the effect of interspecific mating was estimated ...
Rodriguez Clara I - - 2007
Spermatogenesis in mammals necessitates an extensive remodeling and loss of many cellular organelles and proteins as the spermatozoa undergo maturation. The removal of proteins and organelles depends on the ubiquitin-proteasome pathway. Here we show that the E3 ubiquitin ligase Herc4, though ubiquitously expressed in all tissues, is most highly expressed ...
Yang Fan - - 2007
The improvement of spinach growth is proved to relate to N2 fixation by nano-anatase TiO2 in this study. The results show that all spinach leaves kept green by nano-anatase TiO2 treatment and all old leaves of control turned yellow white under culture with N-deficient solution. And the fresh weight, dry ...
Pradhan Surendra K - - 2007
Human urine was used as a fertilizer in cabbage cultivation and compared with industrial fertilizer and nonfertilizer treatments. Urine achieved equal fertilizer value to industrial fertilizer when both were used at a dose of 180 kg N/ha. Growth, biomass, and levels of chloride were slightly higher in urine-fertilized cabbage than ...
Koch, Paul
The problems associated with habitat loss and habitat fragmentation are larely responsible for a decline in biodiversity around the world, yet there are relatively few studies targeting declining populations to determine which aspects of resource availability actually limit population size. The endangered south-eastern Red-tailed Black Cockatoo Calyptorhychus banksii graptogyne is ...
Siritunga Dimuth - - 2007
For cassava to become a safe and acceptable crop, it is necessary to reduce the cyanogen levels in cassava foods. While this objective can be achieved by processing procedures, recent findings have shown that it is also possible to achieve it by suppression of cyanogen synthesis or by accelerating cyanogen ...
Bakker Jonathan D - - 2007
Long-term studies can broaden our ecological understanding and are particularly important when examining contingent effects that involve changes to dominance by long-lived species. Such a change occurred during the last century in Southwestern (USA) ponderosa pine (Pinus ponderosa) forests. We used five livestock grazing exclosures established in 1912 to quantify ...
Wittig Victoria E - - 2007
The surface concentration of ozone ([O(3)]) has risen from less than 10 ppb prior to the industrial revolution to a day-time mean concentration of approximately 40 ppb over much of the northern temperate zone. If current global emission trends continue, surface [O(3)] is projected to rise a further 50% over ...
Sato, Takeaki
ABSTRACT I assessed the influence of microhabitat variables on the abundance and spatial structure of small mammals across three types of forest, deciduous (Colonial Point), hardwood-pine (the Burn Plots) and cedar swamp (Reese’s Swamp), at the University of Michigan Biological Station (UMBS), in Cheboygan County, northern lower Michigan. Traps have ...
Kuemmerle Tobias - - 2007
Forests provide important ecosystem services, and protected areas around the world are intended to reduce human disturbance on forests. The question is how forest cover is changing in different parts of the world, why some areas are more frequently disturbed, and if protected areas are effective in limiting anthropogenic forest ...
Knepp Rachel G - - 2007
To understand how the increase in atmospheric CO2 from human activity may affect leaf damage by forest insects, we examined host plant preference and larval performance of a generalist herbivore, Antheraea polyphemus Cram., that consumed foliage developed under ambient or elevated CO2. Larvae were fed leaves from Quercus alba L. ...
Crook D J - - 2007
In the Ozark Mountains of northern Arkansas and southern Missouri, an oak decline event, coupled with epidemic populations of red oak borer (Enaphalodes rufulus Haldeman), has resulted in extensive red oak (Quercus spp., section Lobatae) mortality. Twenty-four northern red oak trees, Quercus rubra L., infested with red oak borer, were ...
Bosu Paul P - - 2007
Seedlings of three elm species with variable susceptibility to the elm leaf beetle (Pyrrhalta luteola Müller) (Coleoptera: Chrysomelidae) were subjected to three water stress treatments (no stress, low stress, and high stress) in a greenhouse experiment. The species tested were Ulmus pumila L. (Siberian elm = highly susceptible), U. parvifolia ...
Kunkel Brian A - - 2007
Pecan foliage is attacked by three species of aphids [Monellia caryella (Fitch), Melanocallis caryaefoliae (Davis), and Monelliopsis pecanis Bissell], resulting in damage that can reduce tree nut yield. In this study, we assayed the ovipositional response of the green lacewing Chrysoperla rufilabris (Burmeister) to M. caryella and M. caryaefoliae at ...
Pullakhandam Raghu - - 2007
The leaves and pods of the drumstick tree are used as food and medicine in some Asian and African countries. Although relatively high concentrations of beta-carotene and lutein have been reported in the leaves, the bioavailability of these carotenoids from this source is unknown. We have analyzed the digestive stability ...
Feng Yu-Long - - 2007
The general-purpose genotype hypothesis and the hypothesis of the evolution of invasiveness predict that invasive species are characterized by particular traits that confer invasiveness. However, these traits are still not well-defined. In this study, ecophysiological traits of eight populations of the invasive shrub Buddleja davidii from a wide range of ...
Cesari Andreina - - 2007
OBJECTIVE: To evaluate the in vitro spermicidal activity of Solanum tuberosum aspartic proteinases (StAPs) on bovine and human sperm. DESIGN: Controlled laboratory study. SETTING: Three research laboratories at a university of biologic science. ANIMAL(S) AND DONOR(S): Frozen semen from five Aberdeen Angus bulls and six proven fertile men volunteers. INTERVENTION(S): ...
LIAO, Wen-bo
The Sichuan Hill Partridge (Arborophila rufipectus   ) requires successional broadleaf forest and their populations have declined as a result of fragmentation of endemic bird areas in subtropical forest in the mountains of southwestern China. In this paper, habitat utilization of the Sichuan Hill Partridge was studied in replanted broadleaf ...
Ragusa-Netto J - - 2007
The genus Pyrrhura includes small to medium-sized parakeets, which inhabit both low and dry alongside tall rainforests, mainly in South America. Pyrrhura molinae is still common, year round, in the markedly seasonal forests of western Brazil. This parakeet, as well as most Neotropical parrots, continues to be poorly understood. Hence, ...
Tavakol E - - 2007
This research was conducted to evaluate some of the drought resistance criteria at seedling stage in wheat. A factorial experiment in a Completely Randomized Design (CRD) was used with two factors consisted of stress levels (0, -5 and -8 bar) using PEG 6000 and genotypes (10 genotypes of bread wheat; ...
Irwin Mitchell T - - 2007
Forest fragmentation is thought to threaten primate populations, yet the mechanisms by which this occurs remain largely unknown. However, fragmentation is known to cause dietary shifts in several primate species, and links between food resource distribution and within-group spatial dynamics are well documented. Thus, fragmentation has the potential to indirectly ...
Nyquist B - - 2007
In this paper, we present a model for source-sink population dynamics where the locations of source and sink habitats change over time. We do this in the context of the population dynamics of the North American red squirrel, Tamiasciurus hudsonicus, within a forest environment subject to harvesting and regrowth. Harvested ...
Iwai Noriko - - 2007
In aquatic food webs consumers can affect other members of the web by releasing nutrients as a result of their feeding activity. There is increasing evidence of these positive effects on primary producers, but such nutrient regeneration can also affect detritivores, by favoring the activities of detritus-associated microbes. We examined ...
Herbinger K - - 2007
Three-year-old beech (Fagus sylvatica) seedlings growing in containers were placed into the sun and shade crown of a mature beech stand exposed to ambient (1 x O(3)) and double ambient (2 x O(3)) ozone concentrations at a free-air exposure system ("Kranzberg Forst", Germany). Pigments, alpha-tocopherol, glutathione, ascorbate, and gas exchange ...
Beres B L - - 2007
The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), has reached outbreak status at most locations in the southern Canadian prairies. Solid-stemmed wheat, Triticum aestivum L., cultivars, which are less susceptible to damage, remain the primary management option. This article quantifies the effect of wheat stem sawfly damage on grain ...
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