Variation in the chemical composition of green leaves and leaf litters from three deciduous tree species growing on different soil types   总被引：2，自引：0，他引：2  

T. Sariyildiz  J.M. Anderson 《Forest Ecology and Management》2005,210(1-3):303-319

The chemical composition of green leaves and leaf litters of sweet chestnut (Castanea sativa), oak (Quercus robur) and beech (Fagus sylvatica) were determined for 26 sites grouped into high fertility (HF) and low fertility (LF) soils according to base saturation and N-mineralization potentials. Measurements were made of total carbon, acid detergent fibre (ADF), Klason lignin, holo-cellulose, sugar constituents of hemicellulose and phenylpropanoid derivatives of lignin, and nutrient concentrations (N, Ca, P, Mg, K and Mn). Leaf and litter constituents varied within and between species according to soil groups, but beech showed contrasting responses to oak and chestnut. Beech leaves had lower ADF, lignin and cellulose on HF soils than LF soils, whereas oak and chestnut leaves had higher ADF, lignin and cellulose on HF than the LF soils. Conversely, the same constituents in beech leaf litter were higher on HF soils than LF soils, but lower in oak and chestnut leaf litter on HF soils than LF soils. The phenylpropanoid derivatives of lignin and sugar constituents of hemicellulose also showed similar variations in relation to soil groups with contrasting patterns for in leaves and litters. Re-absorption of N from leaves before litter fall was negatively correlated with soil N mineralization potential for beech (highest on LF soils) but showed an unexpected, positive relationship for oak and chestnut (highest on HF soils). These intra-specific differences of leaf and litter chemistry in relation to soil fertility status are unprecedented and largely unexplained. The observed patterns reflect phenotypic responses to soil type that result in continuum of litter quality, within and between tree species, that have been shown in related studies to significantly influence litter decomposition rates.  相似文献   

Variations in dark respiration and mitochondrial numbers within needles of Pinus radiata grown in ambient or elevated CO2 partial pressure     

Griffin KL  Anderson OR  Tissue DT  Turnbull MH  Whitehead D 《Tree physiology》2004,24(3):347-353

Within-leaf variations in cell size, mitochondrial numbers and dark respiration rates were compared in the most recently expanded tip, the mid-section and base of needles of Pinus radiata D. Don trees grown for 4 years in open-top chambers at ambient (36 Pa) or elevated (65 Pa) carbon dioxide partial pressure (p(CO2)a). Mitochondrial numbers and respiratory activity varied along the length of the needle, with the highest number of mitochondria per unit cytoplasm and the highest rate of respiration per unit leaf area at the base of the needle. Regardless of the location of the cells (tip, middle or basal sections), needles collected from trees grown in elevated p(CO2)a had nearly twice the number of mitochondria per unit cytoplasm as those grown in ambient p(CO2)a. This stimulation of mitochondrial density by growth at elevated p(CO2)a was greater at the tip of the needle (2.7 times more mitochondria than in needles grown in ambient CO2) than at the base of the needle (1.7 times). The mean size of individual mitochondria was unaffected either by growth at elevated p(CO2)a or by position along the needle. Tree growth at elevated p(CO2)a had a variable effect on respiration per unit leaf area, significantly increasing respiration in the tip of the needles (+25%) and decreasing respiration at the mid-section and base of the needles (-14% and -25%, respectively). Although a simple relationship between respiration per unit leaf area and mitochondrial number per unit cytoplasm was found within each CO2 treatment, the variable effect of growth at elevated p(CO2)a on respiration along the length of the needles indicates that a more complex relationship must determine the association between structure and function in these needles.  相似文献   

Electrophysiological responses of <Emphasis Type="Italic">Thaumetopoea pityocampa</Emphasis> females to host volatiles: implications for host selection of active and inactive terpenes     

Q.-H.?Zhang  F.?SchlyterEmail author  A.?Battisti  G.?Birgersson  P.?Anderson 《Journal of pest science》2003,76(4):103-107

Volatiles from newly cut branches with needles of Pinus sylvestris L. were collected with headspace sampling technique, and then identified and quantified by combined gas chromatographic-mass spectrometry (GC-MS). The response of antennae of the female pine processionary moth, Thaumetopoea pityocampa, to these volatiles was recorded by coupled gas chromatographic-electroantennographic detection (GC-EAD). Surprisingly, the most common and major monoterpene hydrocarbons (MT), α-pinene, 3-carene, and β-pinene were antennally inactive. Female antennae responded strongly only to four minor MT components, myrcene, β-phellandrene, trans-β-ocimene, and terpinolene. Weaker, but repeatable responses were also found to limonene, cis-β-ocimene, and γ-terpinene. Further EAD recordings with two synthetic MT mixtures supported our findings from the natural material. When separating the two enantiomers of limonene by running different synthetic MT mixtures, the EAD response was found only to the(?)-enantiomer, but not to the opposite (+)-enantiomer. EAD-responses were also found to some less volatile compounds, such as sesquiterpenes (SqT), active at ng-levels. The sensitivity and specificity of the antenna to a select number of active host MTs and SqTs suggest that these play a role in the host selection process of T. pityocampa females.  相似文献   

Biodiversity management approaches for stream–riparian areas: Perspectives for Pacific Northwest headwater forests,microclimates, and amphibians     

Deanna H. Olson  Paul D. Anderson  Christopher A. Frissell  Hartwell H. Welsh Jr.  David F. Bradford 《Forest Ecology and Management》2007

Stream–riparian areas represent a nexus of biodiversity, with disproportionate numbers of species tied to and interacting within this key habitat. New research in Pacific Northwest headwater forests, especially the characterization of microclimates and amphibian distributions, is expanding our perspective of riparian zones, and suggests the need for alternative designs to manage stream–riparian zones and their adjacent uplands. High biodiversity in riparian areas can be attributed to cool moist conditions, high productivity and complex habitat. All 47 northwestern amphibian species have stream–riparian associations, with a third being obligate forms to general stream–riparian areas, and a quarter with life histories reliant on headwater landscapes in particular. Recent recognition that stream-breeding amphibians can disperse hundreds of meters into uplands implies that connectivity among neighboring drainages may be important to their population structures and dynamics. Microclimate studies substantiate a “stream effect” of cool moist conditions permeating upslope into warmer, drier forests. We review forest management approaches relative to headwater riparian areas in the U.S. Pacific Northwest, and we propose scenarios designed to retain all habitats used by amphibians with complex life histories. These include a mix of riparian and upslope management approaches to address the breeding, foraging, overwintering, and dispersal functions of these animals. We speculate that the stream microclimate effect can partly counterbalance edge effects imposed by upslope forest disturbances, hence appropriately sized and managed riparian buffers can protect suitable microclimates at streams and within riparian forests. We propose one approach that focuses habitat conservation in headwater areas – where present management allows extensive logging – on sensitive target species, such as tailed frogs and torrent salamanders that often occur patchily. Assuming both high patchiness and some concordance among the distribution of sensitive species, protecting areas with higher abundances of these animals could justify less protection of currently unoccupied or low-density habitats, where more intensive forest management for timber production could occur. Also, we outline an approach that protects juxtaposed headwater patches, retaining connectivity among sub-drainages using a 6th-field watershed spatial scale for assuring well-distributed protected areas across forested landscapes. However, research is needed to test this approach and to determine whether it is sufficient to buffer downstream water quality and habitat from impacts of headwater management. Offering too-sparse protection everywhere is likely insufficient to conserve headwater habitats and biodiversity, while our alternative targeted protection of selected headwaters does not bind the entire forest landscape into a biodiversity reserve.  相似文献   

Naturally Occurring Ehrlichia ewingii and Mycoplasma sp. Co‐Infection in a Goat          下载免费PDF全文

K. Meichner  B.A. Qurollo  K.L. Anderson  C.B. Grindem  M. Savage  E.B. Breitschwerdt 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2015,29(6):1735-1738

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Cryopreservation of Piau‐Breed Wild Boar Sperm: Assessment of Cooling Curves and Centrifugation Regimes          下载免费PDF全文

HH Shiomi  RO Pinho  DMA Lima  JB Siqueira  MCR Santos  EV Costa  PS Lopes  SEF Guimarães  JD Guimarães 《Reproduction in domestic animals》2015,50(4):545-553

This study aimed to assess the effects of different cooling curves and centrifugation regimes used in cryopreservation protocols on the post‐thaw viability of Piau‐breed wild boar (Sus scrofa) sperm using in vitro assessment tests. Two centrifugations (800  g for 10 min and 2400  g for 3 min) and two cooling curves (conventional cooling using nitrogen vapour – freezing 1 and automated cooling using a programmed freezing machine – freezing 2) were tested. Therefore, the treatments were divided into M3 – centrifugation at 2400  g for 3 min and freezing 2; M10 – centrifugation at 800  g for 10 min and freezing 2; R3 – centrifugation at 2400  g for 3 min and freezing 1; and R10 – centrifugation at 800  g for 10 min and freezing 1. No significant differences (p > 0.05) between treatments occurred post‐thawing regarding the total sperm motility means recorded. The mean values of the different treatments were not different from each other regarding the supravital staining (SV), hypo‐osmotic test (HO), sperm–egg binding assay or sperm morphology. This study showed that both the cooling curve and the centrifugation regime affected the quality of post‐thaw sperm, and centrifugation for shorter times and cooling curves using automated cooling are the most suitable for minimizing sperm injury.  相似文献   

Survey of farmer knowledge and attitudes to endemic disease management in South Australia,with a focus on bovine viral diarrhoea (bovine pestivirus)          下载免费PDF全文

SR Lanyon  ML Anderson  MP Reichel 《Australian veterinary journal》2015,93(5):157-163

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An abattoir survey of equine dental abnormalities in Queensland,Australia          下载免费PDF全文

T Chinkangsadarn  GJ Wilson  RM Greer  CC Pollitt  PS Bird 《Australian veterinary journal》2015,93(6):189-194

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Effect of premedication and other factors on the occurrence of acute transfusion reactions in dogs          下载免费PDF全文

Joshua A. Bruce DVM  Lisa Kriese‐Anderson MS  PhD  Ashley M. Bruce MS  PhD  Jennifer R. Pittman DVM  DACVECC 《Journal of Veterinary Emergency and Critical Care》2015,25(5):620-630

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Distribution and Diversity of Salmonella Strains in Shipments of Hatchling Poultry,United States, 2013          下载免费PDF全文

G. G. Habing  S. E. Kessler  D. F. Mollenkopf  T. E. Wittum  T. C. Anderson  C. Barton Behravesh  L. A. Joseph  M. M. Erdman 《Zoonoses and public health》2015,62(5):375-380

Multistate outbreaks of salmonellosis associated with live poultry contact have been occurring with increasing frequency. In 2013, multistate outbreaks of salmonellosis were traced back to exposure to live poultry, some of which were purchased at a national chain of farm stores (Farm store chain Y). This study was conducted at 36 stores of Farm store chain Y and was concurrent with the timing of exposure for the human outbreaks of salmonellosis in 2013. We used environmental swabs of arriving shipment boxes of hatchling poultry and shipment tracking information to examine the distribution, diversity and anti‐microbial resistance of non‐typhoidal Salmonella (NTS) across farm stores and hatcheries. Isolates recovered from shipment boxes underwent serotyping, anti‐microbial resistance (AMR) testing and pulsed‐field gel electrophoresis (PFGE). Postal service tracking codes from the shipment boxes were used to determine the hatchery of origin. The PFGE patterns were compared with the PFGE patterns of NTS causing outbreaks of salmonellosis in 2013. A total of 219 hatchling boxes from 36 stores in 13 states were swabbed between 15 March 2013 and 18 April 2013. NTS were recovered from 59 (27%) of 219 hatchling boxes. Recovery was not significantly associated with species of hatchlings, number of birds in the shipment box, or the presence of dead, injured or sick birds. Four of the 23 PFGE patterns and 23 of 50 isolates were indistinguishable from strains causing human outbreaks in 2013. For serotypes associated with human illnesses, PFGE patterns most frequently recovered from shipment boxes were also more frequent causes of human illness. Boxes positive for the same PFGE pattern most frequently originated from the same mail‐order hatchery. Only one of 59 isolates was resistant to anti‐microbials used to treat Salmonella infections in people. This study provides critical information to address recurrent human outbreaks of salmonellosis associated with mail‐order hatchling poultry.  相似文献