Impacts of agricultural management practices on C sequestration in forest-derived soils of the eastern Corn Belt   总被引：7，自引：0，他引：7  

W. A. Dick  R. L. Blevins  W. W. Frye  S. E. Peters  D. R. Christenson  F. J. Pierce  M. L. Vitosh 《Soil & Tillage Research》1998,47(3-4):235-244

Soil organic matter has recently been implicated as an important sink for atmospheric carbon dioxide (CO₂). However, the relative impacts of various agricultural management practices on soil organic matter dynamics and, therefore, C sequestration at spatial scales larger than a single plot or times longer than the typical three year experiment have rarely been reported. Results of maintaining agricultural management practices in the forest-derived soils of the eastern Corn (Zea mays L.) Belt states of Kentucky, Michigan, Ohio and Pennsylvania (USA) were studied. We found annual organic C input and tillage intensity were the most important factors in affecting C sequestration. The impact of rotation on C sequestration was primarily related to the way it altered annual total C inputs. The removal of above-ground plant biomass and use of cover crops were of lesser importance. The most rapid changes in soil organic matter content occurred during the first five years after a management practice was imposed with slower changes occurring thereafter. Certain management practices, e.g. no-tillage (NT), increased the soil's ability to sequester atmospheric CO₂. The impact of this sequestration will be significant only when these practices are used extensively on a large percentage of cropland and when the C-building practices are maintained. Any soil C sequestered will be rapidly mineralized to CO₂ if the soil organic matter building practices are not maintained.  相似文献   

Homeward bound: canopy cover and species identity influence non-breeding season homing success and speed in forest birds     

Jin Bai  Chelsea A.Weitekamp  Kelly Frye  Kathryn E.Sieving 《中国鸟类》2021,(2):173-180

Background: Efficient and safe movement is fundamental for wild birds to thrive in their environments. For arboreal forest animals, especially birds, canopy cov...  相似文献   

Active surveillance of pathogens from ticks collected in New York State suburban parks and schoolyards     

Qin Yuan  Sebastian G. Llanos‐Soto  Jody L. Gangloff‐Kaufmann  Joellen M. Lampman  Matthew J. Frye  Meghan C. Benedict  Rebecca L. Tallmadge  Patrick K. Mitchell  Renee R. Anderson  Brittany D. Cronk  Bryce J. Stanhope  Ava R. Jarvis  Manigandan Lejeune  Randall W. Renshaw  Melissa Laverack  Elizabeth M. Lamb  Laura B. Goodman 《Zoonoses and public health》2020,67(6):684-696

Schoolyards and suburban parks are two environments where active tick surveillance may inform local management approaches. Even in a state such as New York with a robust active tick surveillance programme operated by the state Department of Health, these settings are not routinely covered. The goal of this study was to highlight the importance of active surveillance for tick‐borne pathogens by describing their prevalence in ticks collected from schoolyards and suburban parks and to guide the use of integrated pest management in these settings. Tick dragging was performed in three regions of New York State: Long Island, the Lower Hudson Valley and the Capital Region. A total of 19 schoolyards and 32 parks were sampled. The location, habitat and weather at the time of tick collection were recorded. Ticks were speciated and tested for the presence of 17 pathogens with a novel application of nanoscale real‐time PCR. The causative agents of Lyme disease, anaplasmosis, babesiosis and Powassan virus disease were all detected from Ixodes scapularis in various sites throughout the capital region and south‐eastern counties of New York state. The most common agent detected was Borrelia burgdorferi, and coinfection rates were as high as 36%. This surveillance study also captured the first of the invasive Asian longhorned tick species, Haemaphysalis longicornis, in New York state (collected 2 June 2017). Results from this study highlight the importance of collaborative efforts and data sharing for improvement of surveillance for tick‐borne disease agents.  相似文献   

Rabies in an ocelot     

F L Frye  J P Cucuel 《Journal of the American Veterinary Medical Association》1968,153(7):789-790

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Negative contrast electron microscopic diagnosis of viruses of neonatal calf diarrhea.     

J J England  C S Frye  E A Enright 《The Cornell veterinarian》1976,66(2):172-182

Ninety-one cases of neonatal calf diarrhea were examined for viruses with negative contrast electron microscopy. Viruses were demonstrated in 41% of the cases. Reo-like viruses and corona-like viruses, and mixed virus populations were observed in 12%, 20% and 9%, respectively. Twenty-six of the cases were examined by negative contrast electron microscopy, and by virus isolation or by fluorescent antibody technique. There was an 81% agreement in obtained results. The disagreements resulted from the demonstration of a viral agent by negative contrast electron microscopy while the other techniques did not indicate a virus. The results suggest that negative contrast electron microscopy is a more sensitive diagnostic tool for demonstration of viruses associated with neonatal calf diarrhea than are viral isolation or the fluorescent antibody technique.  相似文献   

A test method based on microscopic assessments to determine curative and protectant fungicide properties against Septoria tritici     

U. A. SCHÖFL  & V. ZINKERNAGEL 《Plant pathology》1997,46(4):545-556

Glasshouse experiments to test the activity of commercial fungicides against Septoria tritici were carried out under controlled conditions. In addition to the parameter, % necrotic leaf area (NEC), used to estimate the pathogen-induced leaf damage, the number of pycnidia per leaf (PYC) was determined to quantify the pathogen itself. Curative fungicide treatments were applied 100–210 day degrees after inoculation. A high curative activity was achieved up to 170 day degrees after inoculation, whereas the treatments at 200–205 day degrees were less effective. The best curative activity was observed for epoxiconazole-based treatments, followed by slightly less active azoles in the ranking tebuconazole, cyproconazole, prochloraz and flusilazole. Greater differences between the fungicides were observed for the protectant fungicide properties, which were tested 50–350 day degrees prior to inoculation. The best persistency was observed for epoxiconazole, whereas tebuconazole, cyprocoazole, prochloraz and flusilazole showed declining activity with this ranking. Combinations of triazoles with the active ingredients kresoxim-methyl and chlorothalonil, which are known to inhibit spore germination, significantly improved the longevity of the remaining green leaf area in comparison with disease-free treatments with triazoles alone. The results obtained under glasshous conditions were compared with field studies on S. tritici development after treatments with tebuconazole to place the results in context. The comparison of the assessment parameter PYC and NEC between glasshouse and field trial showed that curative and protectant fungicide properties based on microscopic assessments of PYC in the glasshouse correlated well with results from field trials.  相似文献   

Toxicities and harzards for clinicians in small animal practice.     

S M Schuchman  F L Frye  R P Barrett 《The Veterinary clinics of North America》1975,5(4):727-735

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Malignant chromatophoroma in a western terrestrial garter snake.     

F L Frye  J D Carney  J C Harshbarger  R F Zeigel 《Journal of the American Veterinary Medical Association》1975,167(7):557-558

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Hemangiosarcoma in a horse     

F L Frye  H D Knight  S I Brown 《Journal of the American Veterinary Medical Association》1983,182(3):287-289

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管碟法测定生物效价影响因素的探讨及改进   总被引：2，自引：0，他引：2  

李凡  朱志华  姜凤丽  宋丽华  代晓静 《中国兽药杂志》2008,42(1):45-48

《中国兽药典》（2005年版）收载的兽用抗生素药品效价的微生物检定包括两种方法,即管碟法和浊度法。目前多数使用者仍以管碟法为主。管碟法作为抗生素效价测定的经典方法,具有它的优点,但此方法操作步骤复杂,试验影响因素多,需要从每个环节严格控制,才能得到与真值更为接近的结果。笔者结合日常工作实践,对管碟法测定抗生素生物效价过程中的多种影响因素进行探讨及改进,使测定条件得到了较好的控制,有利于提高效价测定结果的精密度和准确度。  相似文献