Long-term effects of repeated N fertilization and straw application in a jack pine forest. 1. Twenty-two-year growth response

1995 ◽  
Vol 25 (12) ◽  
pp. 1978-1983 ◽  
Author(s):  
G.F. Weetman ◽  
L.C. Dallaire ◽  
R. Fournier
Keyword(s):  
Growth Response ◽  
Volume Growth ◽  
Jack Pine ◽  
N Fertilization ◽  
Long Term Effects ◽  
Foliar N ◽  
Significant Difference ◽  
Data Volume ◽  
Repeated Applications

Sample plots in a 45-year-old jack pine (Pinusbanksiana Lamb.) stand were fertilized six times with N or N, P, and K in a 10-year period to maintain four foliar N regimes. Volume growth response 3.6% above controls was obtained by repeated applications of 56 kg N•ha−1 associated with the target foliar N concentration of 1.4%. Application of 1344 kg N•ha−1 over 10 years killed trees and reduced growth. Growth response lasted 3 to 5 years after the application of 336 kg N•ha−1 and 7 to 9 years after the applications of 672 and 1344 kg N•ha−1. Additions of P and K with N did not produce a significant difference in growth, based on diameter data. Volume growth response to a single application of straw was similar to that obtained by repeated N additions, and lasted for 11 years.

Long-term effects of repeated N fertilization and straw application in a jack pine forest. 3. Nitrogen availability in the forest floor

1995 ◽  
Vol 25 (12) ◽  
pp. 1991-1996 ◽  
Author(s):  
C.E. Prescott ◽  
B.E. Kishchuk ◽  
G.F. Weetman
Keyword(s):  
Nitrogen Availability ◽  
Jack Pine ◽  
N Fertilization ◽  
Ground Vegetation ◽  
N Availability ◽  
Net N Mineralization ◽  
Long Term Effects ◽  
Forest Floors ◽  
Straw Application

A long-term increase in N availability was evident in higher rates of net N mineralization and lower C/N ratios in jack pine (Pinusbanksiana Lamb.) forest floors that received 672 kg N•ha−1 in six applications or a single application of straw. There was no evidence of increased N availability in plots that received P and K in addition to N. Litter N concentrations were higher in N-fertilized and straw-treated plots, but rates of C mineralization and litter decomposition were not increased. Additions of N in repeated small applications or in conjunction with readily decomposable C in straw likely resulted in high retention of N in the ecosystem. The long-term increase in N availability was attributed to increased recycling of N, retention of added N in the ecosystem, and reductions in the ericaceous ground vegetation.

scholarly journals Transitional Cell Carcinomas of the Urinary Tract in a Colony of Beagle Dogs

1989 ◽  
Vol 26 (6) ◽  
pp. 455-461 ◽  
Author(s):  
K. J. Nikula ◽  
S. A. Benjamin ◽  
G. M. Angleton ◽  
A. C. Lee
Keyword(s):  
Urinary Tract ◽  
Transitional Cell ◽  
Clinical Signs ◽  
Conclusive Evidence ◽  
Whole Body ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Significant Difference ◽  
Microscopic Features

Gross and light microscopic features of transitional cell carcinomas (TCC) of the urinary tract were examined in Beagle dogs used for the study of the long-term effects of low-dose, whole-body, 60Co gamma radiation. Thirty-eight cases of TCC occurred among 990 dogs that were from 0 to 14 years of age. There was no conclusive evidence of a radiation effect. The 38 TCC were equally divided between male and female dogs, but there was a significant difference in the sex distribution of urethra-origin TCC. Eleven males had a primary urethral TCC compared to only two females. There was no significant difference between the urethra-origin and bladder-origin TCCs in the number of tumors that caused clinical signs, metastasized, or that contributed to the death of the dog. All cases of urethral TCC in male dogs occurred in the prostatic urethra. The majority of these cases were not recognized to be neoplasms at gross necropsy, but microscopic examination revealed the TCC. Our findings differ from previous reports stating that TCC occurs more frequently in female than male dogs, and they especially differ from reports claiming that urethra-origin TCC is predominately a disease of female dogs.

scholarly journals Effects of experimental nitrogen deposition on peatland carbon pools and fluxes: a modelling analysis

2015 ◽  
Vol 12 (1) ◽  
pp. 79-101 ◽  
Author(s):  
Y. Wu ◽  
C. Blodau ◽  
T. R. Moore ◽  
J. Bubier ◽  
S. Juutinen ◽  
...  
Keyword(s):  
Ecosystem Respiration ◽  
Model Performance ◽  
Net Ecosystem Exchange ◽  
N Fertilization ◽  
N Deposition ◽  
Competitive Advantages ◽  
Long Term Effects ◽  
N Content ◽  
Modelling Analysis

Abstract. Nitrogen (N) pollution of peatlands alters their carbon (C) balances, yet long-term effects and controls are poorly understood. We applied the model PEATBOG to explore impacts of long-term nitrogen (N) fertilization on C cycling in an ombrotrophic bog. Simulations of summer gross ecosystem production (GEP), ecosystem respiration (ER) and net ecosystem exchange (NEE) were evaluated against 8 years of observations and extrapolated for 80 years to identify potential effects of N fertilization and factors influencing model behaviour. The model successfully simulated moss decline and raised GEP, ER and NEE on fertilized plots. GEP was systematically overestimated in the model compared to the field data due to factors that can be related to differences in vegetation distribution (e.g. shrubs vs. graminoid vegetation) and to high tolerance of vascular plants to N deposition in the model. Model performance regarding the 8-year response of GEP and NEE to N input was improved by introducing an N content threshold shifting the response of photosynthetic capacity (GEPmax) to N content in shrubs and graminoids from positive to negative at high N contents. Such changes also eliminated the competitive advantages of vascular species and led to resilience of mosses in the long-term. Regardless of the large changes of C fluxes over the short-term, the simulated GEP, ER and NEE after 80 years depended on whether a graminoid- or shrub-dominated system evolved. When the peatland remained shrub–Sphagnum-dominated, it shifted to a C source after only 10 years of fertilization at 6.4 g N m−2 yr−1, whereas this was not the case when it became graminoid-dominated. The modelling results thus highlight the importance of ecosystem adaptation and reaction of plant functional types to N deposition, when predicting the future C balance of N-polluted cool temperate bogs.

IMMEDIATE AND LONG-TERM EFFECTS OF INSECTICIDE APPLICATION ON PARASITOIDS IN JACK PINE STANDS IN QUEBEC

1972 ◽  
Vol 104 (2) ◽  
pp. 263-270 ◽  
Author(s):  
Peter W. Price
Keyword(s):  
Relative Abundance ◽  
Jack Pine ◽  
Ground Vegetation ◽  
Long Term Effects ◽  
Aerial Application ◽  
Insecticide Application ◽  
Number Of Species ◽  
Adult Parasitoid ◽  
Pine Stands

AbstractParasitoid populations were sampled before, and for 4 years following, an aerial application of the insecticide phosphamidon to control a sawfly outbreak. Adult parasitoid mortality was high because of spraying, but a reservoir of parasitoids in host cocoons remained to repopulate the treated areas. In moister sites the number of species decreased and their relative abundance changed, but moderate numbers of parasitoids remained 4 years after spraying. In a dry site with little ground vegetation, none of the species present before spraying remained by the fourth year.

scholarly journals Deep Planting Has No Short- or Long-Term Effect on the Survival and Growth of White Spruce, Black Spruce, and Jack Pine

2011 ◽  
Vol 28 (3) ◽  
pp. 146-151 ◽  
Author(s):  
Alain Paquette ◽  
Jean-Pierre Girard ◽  
Denis Walsh
Keyword(s):  
Black Spruce ◽  
White Spruce ◽  
Jack Pine ◽  
Eastern Canada ◽  
Planting Depth ◽  
Early Results ◽  
Significant Difference ◽  
Negative Effect ◽  
Tukey Honestly Significant Difference

Abstract Although studies in the past have reported that the deeper planting of conifers has no effect on seedling performance, most planting guidelines in use today still recommend that seedlings be planted to the rootcollar. Past studies were mostly observational, used bareroot seedlings, and often reported early results from just one or two depths of planting treatments. Most of the results available regarding planting depth for boreal species are anecdotal, although they are planted by the hundreds of millions every year. The present study reports no short-term (1 year) or long-term (15 to 19 years) negative effect of planting depth on the survival and height and diameter growth of black spruce, white spruce, and jack pine seedlings over three large, replicated experiments in the boreal forest of eastern and northern Quebec (eastern Canada). Four different depth treatments were compared, from manual planting at the rootcollar to the deepest mechanical planting treatment at 10 cm or more, making this the largest, longest-lasting study of its kind. Although, as expected, important differences in growth were present between species, all three commonly planted conifers reacted similarly to the planting depth treatments (no effect). This result can in part be attributed to an almost perfect control of frost heaving in the deepest two treatments. Planting depth effects were assessed using analysis of variance, multiple Tukey honestly significant difference, and uncorrected pairwise one-tailed t-tests to increase the probability of detecting a negative effect. Absolute differences and effect sizes (generally small and often positive with greater depths) were also analyzed.

Long term effects of tillage practices and N fertilization in rainfed Mediterranean cropping systems: durum wheat, sunflower and maize grain yield

2016 ◽  
Vol 77 ◽  
pp. 166-178 ◽  
Author(s):  
Giovanna Seddaiu ◽  
Ileana Iocola ◽  
Roberta Farina ◽  
Roberto Orsini ◽  
Giuseppe Iezzi ◽  
...  
Keyword(s):  
Grain Yield ◽  
Durum Wheat ◽  
Cropping Systems ◽  
N Fertilization ◽  
Long Term Effects ◽  
Tillage Practices ◽  
Maize Grain Yield ◽  
Maize Grain

scholarly journals Short- and Long-Term Reduction of Door-to-Needle Time in Thrombolysis for Acute Stroke

2016 ◽  
Vol 44 (3) ◽  
pp. 255-260 ◽  
Author(s):  
Bing Yu Chen ◽  
Aimen Moussaddy ◽  
Mark R. Keezer ◽  
Yan Deschaintre ◽  
Alexandre Y. Poppe
Keyword(s):  
Computed Tomography ◽  
Intracerebral Hemorrhage ◽  
Acute Stroke ◽  
Hospital Treatment ◽  
Long Term Effects ◽  
Symptomatic Intracerebral Hemorrhage ◽  
Significant Difference ◽  
Clinical Benefits ◽  
Short And Long Term

AbstractBackground: More timely administration of tissue plasminogen activator (alteplase) for patients with acute ischemic stroke yields greater clinical benefits. We implemented door-to-needle (DTN) time reduction strategies at our center and evaluated their short- and long-term effects on in-hospital treatment delays and clinical outcomes. Methods: Strategies, including stroke team prenotification, direct computed tomography transfer, not routinely waiting for laboratory results and alteplase delivery on the computed tomography table, were implemented in June 2013. We included all thrombolysed patients admitted directly to our hospital between January 2012 and March 2015. In-hospital delays and symptomatic intracerebral hemorrhage rates were compared between patients pre- and postmodification, and the latter period was divided into early (first 6 months) and late (beyond 6 months) phases to assess the durability of our modifications. Results: Forty-eight individuals were treated premodification compared with 58 postmodification. The median DTN time was reduced from 75 to 46 minutes (p<0.0001). The median DTN time in the early and late postmodification phases was not significantly different (41 vs 46 minutes, p=0.4085). There was no significant difference in rates of symptomatic intracerebral hemorrhage (4.2 vs 1.7%, p=0.361) or stroke mimics (2.1 ves 5.2%, p=0.625) Conclusions: We were able to decrease our DTN time for acute stroke thrombolysis by implementing relatively simple modifications and these improvements persisted over time.

Long-term effects of N fertilization on cropping and growth of olive trees and on N accumulation in soil profile

2009 ◽  
Vol 31 (4) ◽  
pp. 223-232 ◽  
Author(s):  
R. Fernández-Escobar ◽  
L. Marin ◽  
M.A. Sánchez-Zamora ◽  
J.M. García-Novelo ◽  
C. Molina-Soria ◽  
...  
Keyword(s):  
Soil Profile ◽  
N Fertilization ◽  
Long Term Effects ◽  
N Accumulation ◽  
Olive Trees

A 10-year tree and stand response of jack pine to urea fertilization and low thinning

1984 ◽  
Vol 14 (1) ◽  
pp. 44-50 ◽  
Author(s):  
Arthur Groot ◽  
Kenneth M. Brown ◽  
Ian K. Morrison ◽  
J. E. Barker
Keyword(s):  
Form Factor ◽  
Growth Response ◽  
Volume Growth ◽  
Basal Area ◽  
Growing Season ◽  
Jack Pine ◽  
Positive Effects ◽  
Stand Thinning ◽  
Urea Fertilization

This study examined the 10-year effects of a light (20% basal area removed) low thinning and urea fertilization (336 kg N/ha) on a 45-year-old Pinusbanksiana Lamb. stand. Thinning had no effect other than salvaging potential mortality, while fertilization resulted in an average annual gross volume growth response of about 2 m3 ha−1 year−1. Volume growth response to fertilization was greatest in the largest diameter trees, and continued until 10 years after treatment. Growth response did not begin until the second growing season after treatment. There were indications that fertilization had positive effects on form factor.

scholarly journals Oncological and quality of life outcomes following extralevator versus standard abdominoperineal excision for rectal cancer

2017 ◽  
Vol 99 (5) ◽  
pp. 402-409 ◽  
Author(s):  
D Kamali ◽  
A Sharpe ◽  
A Musbahi ◽  
A Reddy
Keyword(s):  
Quality Of Life ◽  
Rectal Cancer ◽  
Abdominoperineal Excision ◽  
Long Term Effects ◽  
Recurrence Rates ◽  
Oncological Outcomes ◽  
Significant Difference

INTRODUCTION There is increasing and conflicting research debating the oncological benefits of extralevator abdominoperineal excision (ELAPE) compared with standard abdominoperineal excision (SAPE). However, there is very little in the literature on the long-term effects on patients’ wellbeing following the two procedures. The aim of this study was to determine the oncological outcomes and long-term quality of life (QoL) of patients at two hospitals having undergone ELAPE or SAPE. METHODS Consecutive patients with rectal cancer who underwent either ELAPE or SAPE between January 2009 and June 2015 at a single centre were analysed. Oncological outcomes were determined by histology and follow-up imaging. QoL data were obtained prospectively using the QLQ-C30 and QLQ-CR29 questionnaires. RESULTS A total of 48 patients (36 male, 12 female; 27 ELAPE, 21 SAPE) were reviewed. The mean age was 67.4 years and the median follow-up duration was 44 months (range: 6–79 months). Four patients (2 ELAPE, 2 SAPE) developed local recurrence. Rates of distant metastasis were similar (ELAPE: 11%, SAPE: 14%). There was no significant difference in mean global health status score (ELAPE: 77.3, SAPE: 65.3). Impotence was the most frequently reported problem (mean symptom scores of 89.7 and 78.8 for ELAPE and SAPE respectively). CONCLUSIONS This is the largest study with the longest follow-up period that compares QoL after ELAPE with that after SAPE. Although more radical in nature, ELAPE did not demonstrate any significant impact on QoL compared with SAPE. There was no significant difference in long-term oncological outcome between the groups. Impotence remains a significant problem for all patients and they should be well informed of this risk prior to surgery.

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