Estimating stand transpiration in a Eucalyptus populnea woodland with the heat pulse method: measurement errors and sampling strategies     

Hatton TJ  Moore SJ  Reece PH 《Tree physiology》1995,15(4):219-227

Sap flow measurement techniques, such as the heat pulse (compensation) method, are practical means for estimating the water use of individual trees and are often the only reasonable alternative for measuring forest and woodland transpiration in complex heterogeneous terrain. The need to scale estimates of water use from a sample of individual stems to a stand (population) of known area may be satisfied by applying scalars of flux based on tree size or domain. We estimated the aggregate errors in applying the heat pulse technique to the estimation of stand transpiration in a poplar box (Eucalyptus populnea F.J. Muell.) woodland in southeastern Queensland, Australia, by a combination of precision analyses, experimental validation and Monte Carlo simulations of sampling errors. Errors in sap flux density measurements were approximately 13%. The potential error in the flux estimates for individual stems with stratified sampling of sap flux density with depth and bole quadrant based on four sensors was an additional 25%. Conducting wood area, diameter at 1.3 m, leaf area and domain based on Ecological Field Theory all proved excellent scalars of flux at the stand level. With a sample size of six trees stratified by diameter, coefficients of variation in scaling to the stand level were approximately 5% for any of these scalars. The greatest potential source of error in estimating stand transpiration by the heat pulse method was in the measurement of the fluxes of individual stems; scaling these measurements to a homogeneous stand of trees involved less uncertainty.  相似文献   

The integration of pasture,livestock and widely-spaced pine in South West Western Australia     

G. W. Anderson  R. W. Moore  P. J. Jenkins 《Agroforestry Systems》1988,6(1-3):195-211

This paper expands on a short voluntary presentation, by the first two authors, to the 18th IUFRO World Congress held at Ljubljana, Yugoslavia, in September 1986. It describes management procedures and incorporates biological and economic data, from a number of agro-silvo-pastoral trials in the South West of Western Australia. The integration of pine timber and livestock production is shown to have a range of economic and environmental benefits available in the long-term. Ways in which the choice of tree density, planting pattern and silvicultural regime can each be directed towards the achievement of various objectives are indicated.  相似文献   

The effect of multi-nutrient fertilization on understory vegetation nutrient concentrations in inland Northwest conifer stands     

Curtis L. VanderSchaaf  James A. Moore  James L. Kingery 《Forest Ecology and Management》2004,190(2-3):201-218

This study looked at the effects that multi-nutrient fertilization had on understory vegetation nutrient concentrations at four conifer forested locations in the inland Northwest. Multi-nutrient fertilization of conifer stands cannot only enhance the overstory species in the inland Northwest but also the understory vegetation. Determination of nutrient concentration response to fertilization treatments can provide managers the ability to better manipulate their forests for grazing and wildlife habitat. We grouped the understory vegetation into three general life forms: forbs, grasses and grass-likes, and shrubs. Multi-nutrient fertilization had little effect on nitrogen concentration across all life forms. Potassium and sulfur generally increased in concentration. Micronutrients as a whole showed less variability in response to multi-nutrient fertilization. Boron, copper, molybdenum, and zinc generally showed increases in concentrations across all life forms. We were able to conduct analyses on a selected number of understory vegetation species. Individual species showed variability in nutrient concentration response to multi-nutrient fertilization. Wildlife habitat and grazing quality were both increased and decreased following multi-nutrient fertilization. Increases in nutrient concentrations will provide more nutritious vegetation to these animals and vice versa for decreases in concentrations.  相似文献   

Age-related changes in ecosystem structure and function and effects on water and carbon exchange in ponderosa pine     

Irvine J  Law BE  Kurpius MR  Anthoni PM  Moore D  Schwarz PA 《Tree physiology》2004,24(7):753-763

As forests age, their structure and productivity change, yet in some cases, annual rates of water loss remain unchanged. To identify mechanisms that might explain such observations, and to determine if widely different age classes of forests differ functionally, we examined young (Y, approximately 25 years), mature (M, approximately 90 years) and old (O, approximately 250 years) ponderosa pine (Pinus ponderosa Dougl. ex P. Laws.) stands growing in a drought-prone region of central Oregon. Although the stands differed in tree leaf area index (LAIT) (Y = 0.9, M = 2.8, O = 2.1), cumulative tree transpiration measured by sap flow did not differ substantially during the growing season (100-112 mm). Yet when water was readily available, transpiration per unit leaf area of the youngest trees was about three times that of M trees and five times that of O trees. These patterns resulted from a nearly sixfold difference in leaf specific conductance (KL) between the youngest and oldest trees. At the time of maximum transpiration in the Y stand in May-June, gross carbon uptake (gross ecosystem production, GEP) was similar for Y and O stands despite an almost twofold difference in stand leaf area index (LAIS). However, the higher rate of water use by Y trees was not sustainable in the drought-prone environment, and between spring and late summer, KL of Y trees declined fivefold compared with a nearly twofold decline for M trees and a < 30% reduction in O trees. Because the Y stand contained a significant shrub understory and more exposed soil, there was no appreciable difference in mean daily latent energy fluxes between the Y stand and the older stands as measured by the eddy-covariance technique. These patterns resulted in 60 to 85% higher seasonal GEP and 55 to 65% higher water-use efficiency at the M and O stands compared with the Y stand.  相似文献   

Phylogeographic patterns of Armillariaostoyae in the western United States     

J. W. Hanna  N. B. Klopfenstein  M.‐S. Kim  G. I. McDonald  J. A. Moore 《Forest Pathology》2007,37(3):192-216

Nuclear ribosomal DNA regions (i.e. large subunit, internal transcribed spacer, 5.8S and intergenic spacer) were sequenced using a direct‐polymerase chain reaction method from Armillaria ostoyae genets collected from the western USA. Many of the A. ostoyae genets contained heterogeneity among rDNA repeats, indicating intragenomic variation and likely intraspecific hybridization. Intragenomic variation was verified by visually editing base‐sequence offsets in regions with insertions/deletions, and using sequence‐specific internal primers to resequence heterogeneous regions. Phylogenetic analyses with Bayesian Inference methods were used to define groups within A. ostoyae. Analysis of A. ostoyae from outside the western USA indicated the presence of a Circumboreal group of A. ostoyae that also occurs in Utah; two other phylogeographic groups were associated with the Rocky Mountain and Pacific Northwest regions of the USA. Mixed sequence types, an indication of intraspecific hybrids, were common in some geographic regions. Hybridization events may have influenced species evolution, contributing to variation in pathogenicity and virulence. The occurrence of these groups and intraspecific hybrids also indicates that paleogeography and paleoclimate may have influenced the phylogeography of A. ostoyae. In addition, other Armillaria species were examined for evolutionary relationships with the groups of A. ostoyae. These findings will provide a basis for future research relating ecological function to genetic diversity within A. ostoyae.  相似文献   

EFFECTS OF FLUID AND COMPUTED TOMOGRAPHIC TECHNICAL FACTORS ON CONSPICUITY OF CANINE AND FELINE NASAL TURBINATES          下载免费PDF全文

Raimonda Uosyte  Darren J. Shaw  Danielle A. Gunn‐Moore  Eduardo Fraga‐Manteiga  Tobias Schwarz 《Veterinary radiology & ultrasound》2015,56(5):494-502

Turbinate destruction is an important diagnostic criterion in canine and feline nasal computed tomography (CT). However decreased turbinate visibility may also be caused by technical CT settings and nasal fluid. The purpose of this experimental, crossover study was to determine whether fluid reduces conspicuity of canine and feline nasal turbinates in CT and if so, whether CT settings can maximize conspicuity. Three canine and three feline cadaver heads were used. Nasal slabs were CT‐scanned before and after submerging them in a water bath; using sequential, helical, and ultrahigh resolution modes; with images in low, medium, and high frequency image reconstruction kernels; and with application of additional posterior fossa optimization and high contrast enhancing filters. Visible turbinate length was measured by a single observer using manual tracing. Nasal density heterogeneity was measured using the standard deviation (SD) of mean nasal density from a region of interest in each nasal cavity. Linear mixed‐effect models using the R package ‘nlme’, multivariable models and standard post hoc Tukey pair‐wise comparisons were performed to investigate the effect of several variables (nasal content, scanning mode, image reconstruction kernel, application of post reconstruction filters) on measured visible total turbinate length and SD of mean nasal density. All canine and feline water‐filled nasal slabs showed significantly decreased visibility of nasal turbinates (P < 0.001). High frequency kernels provided the best turbinate visibility and highest SD of aerated nasal slabs, whereas medium frequency kernels were optimal for water‐filled nasal slabs. Scanning mode and filter application had no effect on turbinate visibility.  相似文献   

Primary pulmonary neoplasia in cats: assessment of computed tomography findings and survival          下载免费PDF全文

J. Nunley  J. Sutton  W. Culp  D. Wilson  K. Coleman  R. Demianiuk  A. Schechter  G. Moore  T. Donovan  P. Schwartz 《The Journal of small animal practice》2015,56(11):651-656

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Clinical Findings,Diagnostic Test Results,and Treatment Outcome in Cats with Spontaneous Hyperadrenocorticism: 30 Cases     

S.Y. Valentin  C.C. Cortright  R.W. Nelson  B.M. Pressler  D. Rosenberg  G.E. Moore  J.C. Scott‐Moncrieff 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2014,28(2):481-487

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Influence of Temperament Score and Handling Facility on Stress,Reproductive Hormone Concentrations,and Fixed Time AI Pregnancy Rates in Beef Heifers     

R Kasimanickam  S Schroeder  M Assay  V Kasimanickam  DA Moore  JM Gay  WD Whittier 《Reproduction in domestic animals》2014,49(5):775-782

The objectives were (i) to evaluate the effect of temperament, determined by modified 2‐point chute exit and gait score, on artificial insemination (AI) pregnancy rates in beef heifers following fixed time AI and (ii) to determine the effect of temperament on cortisol, substance‐P, prolactin and progesterone at initiation of synchronization and at the time of AI. Angus beef heifers (n = 967) at eight locations were included in this study. At the initiation of synchronization (Day 0 = initiation of synchronization), all heifers received a body condition score (BCS), and temperament score (0 = calm; slow exit and walk or 1 = excitable; fast exit or jump or trot or run). Blood samples were collected from a sub‐population of heifers (n = 86) at both synchronization initiation and the time of AI to determine the differences in serum progesterone, cortisol, prolactin and substance‐P concentrations between temperament groups. Heifers were synchronized with 5‐day CO‐Synch+ controlled internal drug release (CIDR) protocol and were inseminated at 56 h after CIDR removal. Heifers were examined for pregnancy by ultrasound 70 days after AI to determine AI pregnancy. Controlling for synchronization treatment (p = 0.03), facility design (p = 0.05), and cattle handling facility design by temperament score interaction (p = 0.02), the AI pregnancy differed between heifers with excitable and calm temperament (51.9% vs 60.3%; p = 0.01). The alley‐way with acute bends and turns, and long straight alley‐way had lower AI pregnancy rate than did the semicircular alley‐way (53.5%, 56.3% and 67.0% respectively; p = 0.05). The serum hormone concentrations differed significantly between different types of cattle handling facility (p < 0.05). The cattle handling facility design by temperament group interactions significantly influenced progesterone (p = 0.01), cortisol (p = 0.01), prolactin (p = 0.02) and substance‐P (p = 0.04) both at the initiation of synchronization and at the time of AI. Inter‐ and intra‐rater agreement for temperament scoring were moderate and good (Kappa = 0.596 ± 0.07 and 0.797 ± 0.11) respectively. The predictive value for calm and pregnant to AI was 0.87, and excited and non‐pregnant to AI was 0.76. In conclusion, the modified 2‐point temperament scoring method can be used to identify heifers with excitable temperament. Heifers with excitable temperament had lower AI pregnancy. Further, cattle handling facility design influenced the temperament and AI pregnancy.  相似文献   

Gonadotropin‐induced Puberty Does Not Impair Reproductive Performance of Gilts over Three Parities     

OHO Eckhardt  SMMK Martins  ME Pinese  FC Horta  AC Rosseto  MA Torres  AFC De Andrade  BBD Muro  CT Marino  PHM Rodrigues  AS Moretti 《Reproduction in domestic animals》2014,49(6):964-969

The aim of this study was to evaluate the reproductive performance of three parities of gilts treated or not treated with gonadotropin to induce puberty. Sixty gilts received 600 IU of equine chorionic gonadotropin (eCG) followed by 2.5 mg of porcine luteinizing hormone (LH) 72 h later. Fifty‐nine other gilts were exposed only to a mature boar for 15 min twice daily. Artificial insemination (AI) was performed at 0, 12 and 24 h after the detection of oestrus, and gestation was confirmed by ultrasound after 35 days. Sows were inseminated at the first post‐weaning oestrus. The total numbers of piglets born, piglets born alive, stillborn, mummified foetuses, as well as pregnancy and farrowing rates were evaluated for each of the three parities. Culling rates, farrowing intervals and weaning‐to‐oestrous intervals (WEI) were also analysed. Mean age at puberty and oestrous manifestation were not significantly different between treatments (p = 0.0639; 179.20 ± 17.52 compared with 173.96 ± 16.94, 91.66% compared with 94.92%) across the experimental period. However, females that underwent puberty induction showed modest increases both in the number of total pigs born and in the number of piglets born alive. In conclusion, puberty induction through exogenous gonadotropin administration in field conditions did not induce a more concentrated first oestrous manifestation, but trended to a modest increase in the number of pigs born alive in the first parity and a reduced culling rate during the first gestation.  相似文献