Calibration of thermal dissipation sap flow probes for ring- and diffuse-porous trees   总被引：2，自引：0，他引：2  

Bush SE  Hultine KR  Sperry JS  Ehleringer JR 《Tree physiology》2010,30(12):1545-1554

Thermal dissipation probes (the Granier method) are routinely used in forest ecology and water balance studies to estimate whole-tree transpiration. This method utilizes an empirically derived equation to measure sap flux density, which has been reported as independent of wood characteristics. However, errors in calculated sap flux density may occur when large gradients in sap velocity occur along the sensor length or when sensors are inserted into non-conducting wood. These may be conditions routinely associated with ring-porous species, yet there are few cases in which the original calibration has been validated for ring-porous species. We report results from laboratory calibration measurements conducted on excised stems of four ring-porous species and two diffuse-porous species. Our calibration results for ring-porous species were considerably different compared with the original calibration equation. Calibration equation coefficients obtained in this study differed by as much as two to almost three orders of magnitude when compared with the original equation of Granier. Coefficients also differed between ring-porous species across all pressure gradient conditions considered; however, no differences between calibration slopes were observed for data collected within the range of expected in situ pressure gradients. In addition, dye perfusions showed that in three of the four ring-porous species considered, active sapwood was limited to the outermost growth ring. In contrast, our calibration results for diffuse-porous species showed generally good agreement with the empirically derived Granier calibration, and dye perfusions showed that active sapwood was associated with many annual growth rings. Our results suggest that the original calibration of Granier is not universally applicable to all species and xylem types and that previous estimates of absolute rates of water use for ring-porous species obtained using the original calibration coefficients may be associated with substantial error.  相似文献   

Understanding fisheries credit systems: potentials and pitfalls of managing catch efficiency          下载免费PDF全文

Maria C Van Riel  Simon R Bush  Paul A M van Zwieten  Arthur P J Mol 《Fish and Fisheries》2015,16(3):453-470

Following implementation in a range of other resource sectors, a number of credit‐like systems have been proposed for fisheries. But confusion exists over what constitutes these nascent ‘fisheries credit’ systems and how they operate. Based on a review of credit systems in other sectors, this study fills this gap by defining how credit systems function and what credits add to prevailing fisheries management. In doing so, we distinguish ‘mitigation’ and ‘behavioural’ fishery credits. Mitigation credits require resource users to compensate for unsustainable catches of target species, by‐catch species or damaging practices on the marine environment by investing in conservation in a biologically equivalent habitat or resource. Behavioural credit systems incentivize fishers to gradually change their fishing behaviour to more sustainable fishing methods by rewarding them with, for instance, extra fishing effort to compensate for less efficient but more sustainable fishing methods. The choice of credit system largely depends on the characteristics of specific fisheries and the management goals agreed upon by managers, scientists and the fishing industry. The study concludes that fisheries credit systems are different but complimentary to other forms of management by focusing on ‘catchability’ or gear efficiency in addition to effort or catch quota, affecting overall economic efficiency by setting specific goals as to how fish are caught. Credit systems therefore incentivize specific management interventions that can directly improve stock sustainability, conserve habitat and endangered species, or decrease by‐catch.  相似文献   

Suspected choledochal cyst in a domestic shorthair cat     

Elisa J. Best  Damien J. Bush  Charlotte Dye 《Journal of Feline Medicine and Surgery》2010,12(10):814-817

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The Use of Compound B-Mode Ultrasound in Abdominal Disease of Animals     

A. Everette  James  F. O. Osterman  R. M. Bush  T. Sheehan  G. Novak  D. Wight  R. C. Sanders 《Veterinary radiology & ultrasound》1976,17(3):106-112

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MEDICINE     

B.M. Bush 《The Journal of small animal practice》1977,18(11):706-706

Treatment of Acute Diarrhoea in Adult Human Patients. Cummings , J. (1977) Prescribed J. 17 , 27.  相似文献   

Induced Spawning of Nassau Grouper Epinephelus striatus     

John W.  Tucker  Jr. J. Eugene  Parsons Gina C.  Ebanks Phillippe G.  Bush 《Journal of the World Aquaculture Society》1991,22(3):187-191

Nassau grouper Epinephelus striurus females ovulated 48–51 h after the first of two intramuscular injections of human chorionic gonadotropin given 24 h apart (usually 0.7 IU/gram body weight). Typical spawns contained 400,000–600,000 eggs. With fresh milt and clean water, fertilization rate was 85 and 86%. Survival from fertilization to first feeding for six spawns was 73–94%.  相似文献   

Yersiniosis in captive exotic mammals.     

G B Baskin  R J Montali  M Bush  T J Quan  E Smith 《Journal of the American Veterinary Medical Association》1977,171(9):908-912

Within a 2 1/2-month period, Yersinia pseudotuberculosis infection occurred in 3 blesbok (Damaliscus dorcas), 1 dik-dik (Madoqua kirkii), and 1 giant anteater (Myrmecophaga tridactyla) at the National Zoological Park, Washington, DC. Lesions consisted of fibrinonecrotic enteritis and peritonitis, mesenteric lymphadenitis, and embolic pyogranulomatous lesions in the liver, spleen, and lungs. Feed contaminated with the feces of wild rats and pigeons was thought to be the source of infection.  相似文献   

Essential features of the treatment of chronic renal failure in the dog     

B M Bush 《The Journal of small animal practice》1971,12(10):569-574

The consequences of chronic renal failure are enumerated and the recommended measures for mitigating them are described. Treatments vary according to whether the disease is in the compensated or terminal phase. Résumé. On énumère les conséquences des maladies rénales chroniques et on décrit les mesure recommandées pour les atténuer. La traitements varient selon que la maladie se trouve au stade compensé ou terminal. Zusammenfassung. Die Folgen chronischen Nierenversagens werden aufgezählt und die empfohlenen Massnahmen zu ihrer Linderung beschrieben. Die Behandlung richtet sich danach, ob die Krankheit sich in der Kompensationsoder terminalen Phase befindet.  相似文献   

The role of ocean-atmosphere interactions in tropical cooling during the last glacial maximum     

ABG Bush  SGH Philander 《Science (New York, N.Y.)》1998,279(5355):1341-1344

A simulation with a coupled atmosphere-ocean general circulation model configured for the Last Glacial Maximum delivered a tropical climate that is much cooler than that produced by atmosphere-only models. The main reason is a decrease in tropical sea surface temperatures, up to 6 degrees C in the western tropical Pacific, which occurs because of two processes. The trade winds induce equatorial upwelling and zonal advection of cold water that further intensify the trade winds, and an exchange of water occurs between the tropical and extratropical Pacific in which the poleward surface flow is balanced by equatorward flow of cold water in the thermocline. Simulated tropical temperature depressions are of the same magnitude as those that have been proposed from recent proxy data.  相似文献   

Molecular markers reveal low genetic diversity in Casuarina equisetifolia clonal plantations in South China     

Yu  Wei  Zhang  Yong  Xu  Xiuyu  Zhong  Chonglu  Wei  Yongcheng  Meng  Jingxiang  Chen  Yu  Li  Zhen  Bush  David 《New Forests》2020,51(4):689-703

New Forests - Casuarina equisetifolia is planted extensively in clonally-established coastal shelterbelts in South China. During the last decade, the plantations have been severely attacked by...  相似文献