A meta-analysis of the effects of clearcut and variable-retention harvesting on soil nitrogen fluxes in boreal and temperate forests

2011 ◽  
Vol 41 (9) ◽  
pp. 1852-1870 ◽  
Author(s):  
Lucie Jerabkova ◽  
Cindy E. Prescott ◽  
Brian D. Titus ◽  
Graeme D. Hope ◽  
Michael B. Walters
Keyword(s):  
Inorganic Nitrogen ◽  
Meta Analysis ◽  
Field Trials ◽  
N Availability ◽  
Total N ◽  
Variable Retention ◽  
N Concentration ◽  
Clearcut Harvesting ◽  
Single Tree Selection ◽  
Gap Creation

One of the assumed advantages of variable-retention (VR) harvesting over clearcut harvesting is reduced postharvest leaching losses of nitrogen. We test this assumption by synthesizing results from long-term field trials in a meta-analysis. Overall, clearcutting significantly increased soil NO3-N concentration, NO3-N as a proportion of soluble inorganic nitrogen (SIN), N concentration in leachates, N flux, nitrification rates, and pH, but not total N, NH4-N, SIN concentration, ammonification, or N mineralization rate. The proportion of soil NO3-N in deciduous forests increased immediately and returned to preharvest levels within five years; the effect was delayed in coniferous forests, but levels remained elevated for several years. Deciduous leaf litter decomposed faster and needle litter decomposed more slowly on clearcut sites than in uncut forests. Single-tree selection caused smaller changes in NO3-N than removal of groups of trees (i.e., gap creation) and led to smaller increases in NO3-N as a proportion of SIN than clearcut harvesting. High levels of retention (>70%) were required to maintain uncut stand N-cycling characteristics. Postharvest NO3-N levels could be predicted from NO3-N availability in the uncut forests.

Post-fire forest floor development along toposequences of white spruce - trembling aspen mixedwood communities in west-central Alberta

2002 ◽  
Vol 32 (5) ◽  
pp. 892-902 ◽  
Author(s):  
T I Little ◽  
D J Pluth ◽  
I G.W Corns ◽  
D W Gilmore
Keyword(s):  
Forest Floor ◽  
Fire Disturbance ◽  
Slope Position ◽  
N Availability ◽  
Net N Mineralization ◽  
Potential Productivity ◽  
Area Index ◽  
Total N ◽  
Organic C ◽  
N Concentration

After wildfire in the boreal forest, storage of organic carbon (C) begins with the accumulation of forest floor material. Soil properties of Gray Luvisols were studied to determine the differences in development along three toposequences. Our central hypothesis is that slope position does not influence the amount of accumulated organic C and total nitrogen (N) in the forest floor. Organic C and the C/N ratio in the forest floor and in A and B horizons increased from the crest to the toe of the slope. The forest floor contributed 2.0 ± 0.4 kg C·m–2 (mean ± SE) at the crest to 3.5 ± 0.5 kg C·m–2 at the toe. Throughout the solum, the C/N ratio was lower at the top of the slope compared with the toe (p < 0.05), and there were no differences among slope positions for in situ net N mineralization rates. Leaf area index, used as a proxy for net primary productivity, was greater (p < 0.05) at the toe compared with the crest position, and it was negatively correlated with forest floor total N concentration (r = –0.35, p = 0.027). These results, from mixedwood stands approximately 90 years after the last major fire disturbance, indicate that slope position does influence forest floor organic C by horizon volume (p = 0.02), but not total N concentration (p = 0.07). Despite the apparently lower N availability at the toe position, it exhibited the greatest potential productivity.

scholarly journals Soil nitrogen application in the spring did not increase apple yield

1999 ◽  
Vol 29 (4) ◽  
pp. 645-649 ◽  
Author(s):  
Paulo Roberto Ernani ◽  
Jaques Dias
Keyword(s):  
Organic Matter ◽  
Field Trials ◽  
Fruit Yield ◽  
N Availability ◽  
Nitrogen Application ◽  
Average Yield ◽  
Normal Range ◽  
Total N ◽  
Apple Cultivars ◽  
N Requirement

Since there is no chemical method to assess N availability from field soil samples, this nutrient is still recommended based on regional field trials. This study aimed to evaluate the effect of spring application of N to the soil on fruit yield of apple cultivars. Two experiments were carried out, respectively for ‘Gala’ and ‘Fuji’. The trees, grafted on MM 106 rootstock, were planted in 1987, spaced 4.50 x 1.80m, in a clayed Oxisol (Hapludox) with 4.0% of organic matter, in Vacaria (RS), Southern Brazil. Treatments were applied annually, from the spring of 1990, in the tree row, over a 1.5-m-wide strip, as urea, and consisted of four rates of N corresponding to 0, 27.5, 55.0 and 82.5kg ha-1 in the first three years, and respectively 0, 50, 100 and 120kg ha-1 in the remaining two years. Data were collected for four years, starting at the 91/92 growing season. Application of increasing rates of N to the soil during five years had no effect on fruit yield and on concentration of N in the leaves regardless of year and cultivar. Average annual fruit yield varied from 50 to 70t ha-1 for ‘Gala’ and from 39 to 89t ha-1 for ‘Fuji’, but in the entire period the average yield was similar for both cultivars, approximately 56t ha-1. Concentration of N in the leaves was always in the normal range (2.0 to 2.5%) for ‘Fuji’, and slightly lower for ‘Gala’, but above 1.9%. Total N requirement for tree growth and fruiting, thus, came from soil organic matter decay.

Nitrogen availability and nitrate leaching from organo-mineral fertilizers

1993 ◽  
Vol 73 (2) ◽  
pp. 197-208 ◽  
Author(s):  
J. E. Richards ◽  
J.-Y. Daigle ◽  
P. LeBlanc ◽  
R. Paulin ◽  
I. Ghanem
Keyword(s):  
Nitrate Leaching ◽  
Nitrogen Availability ◽  
N Uptake ◽  
Field Trials ◽  
Mineral Fertilizers ◽  
N Availability ◽  
Pellet Size ◽  
Total N ◽  
Leaching Losses ◽  
Effective Source

Greenhouse, field and laboratory studies were conducted to determine if N availability to corn (Zea mays L.) and NO3 leaching were affected by encapsulating conventional granular fertilizer within peat pellets (organo-mineral fertilizers or OMF). In the greenhouse, total N uptake by three 6-wk crops of corn from soil fertilized with NH4NO3 was 9.1% higher than the mean from soils fertilized with OMF made with urea (OMF-urea) or with NH4NO3 (OMF-AN). Total N uptake was 5.1% higher from soils fertilized with OMF-AN than OMF-urea. Differences in total N uptake among the fertilizers were constant across crops. In two field trials, total N uptake was slightly higher (4%) from soil fertilized with commercial NH4NO3 than with OMF-AN. In a laboratory experiment, NO3 from commercial NH4NO3 fertilizer leached more readily from soil than NO3 from OMF-AN. Approximately 95% of the NO3 from commercial NH4NO3 fertilizer leached from 3-cm soil cores in the first 50 mL of leachate whereas only 26% of the NO3 contained in OMF-AN leached. In another trial, NO3 from commercial NH4NO3 fertilizer leached more deeply than NO3 from OMF-AN after application of 2.5 cm irrigation water to soil in 63-cm leaching columns. Virtually no NO3 was retained within the OMF-AN pellet after leaching, suggesting that the retention of NO3 by OMF-AN used in our work is of limited duration. The OMF is an effective source of N to crops and is less prone to NO3 leaching losses than commercial NH4NO3 fertilizer when rain occurs soon after application. More work is required to determine the effect of pellet size and composition on NO3 retention, NO3 leaching losses and crop availability of N. Key words: Nitrate leaching, corn, organo-mineral fertilizers

Temporal Discounting Across Adulthood: A Systematic Review and Meta-analysis

2020 ◽  
Author(s):  
Kendra Leigh Seaman ◽  
Sade J Abiodun ◽  
Zöe Fenn ◽  
Gregory Russell Samanez-Larkin ◽  
Rui Mata
Keyword(s):  
Age Differences ◽  
Intertemporal Choice ◽  
Meta Analysis ◽  
Empirical Work ◽  
Adult Life ◽  
Temporal Discounting ◽  
Total N ◽  
Adult Age ◽  
Adult Age Differences ◽  
Choice Tasks

A number of developmental theories have been proposed that make differential predictions about the links between age and temporal discounting; that is, the valuation of rewards at different points in time. Most empirical studies examining adult age differences in temporal discounting have relied on economic intertemporal choice tasks, which pit choosing a smaller, sooner monetary reward against choosing a larger, later one. Although initial studies using these tasks suggested older adults discount less than younger adults, follow-up studies provided heterogeneous, and thus inconclusive, results. Using an open science approach, we test the replicability of adult age differences in temporal discounting by conducting a preregistered systematic literature search and meta-analysis of adult age differences in intertemporal choice tasks. Across 37 cross-sectional studies (Total N = 104,736), we found no reliable relation between age and temporal discounting (r = -0.081, 95% CI [-0.185, 0.025]). We also found little evidence of publication bias or p-hacking. Exploratory analyses of moderators found no effect of experimental design (e.g., extreme-group vs. continuous age), incentives (hypothetical vs. rewards), amount of delay (e.g., days, weeks, months, or years), or quantification of discounting behavior (e.g., proportion of immediate choices vs. parameters from computational modeling). Additional analyses of 12 participant-level data sets found little support for a nonlinear relation between age and temporal discounting across adulthood. Overall, the results suggest that adult age is not reliably associated with individual differences in temporal discounting. We provide recommendations for future empirical work on temporal discounting across the adult life span.

Political bullshit receptivity and its correlates: a cross-cultural validation of the concept

2020 ◽  
Author(s):  
Vukašin Gligorić ◽  
Allard Feddes ◽  
Bertjan Doosje
Keyword(s):  
The Netherlands ◽  
Political Ideology ◽  
Voting Behavior ◽  
Free Market ◽  
Meta Analysis ◽  
The United States ◽  
Persuasive Communication ◽  
Lower Probability ◽  
Left Wing ◽  
Total N

Frankfurt defined persuasive communication that has no regard for truth, knowledge, or evidence as bullshit. Although there has been a lot of psychological research on pseudo-profound bullshit, no study examined this type of communication in politics. In the present research, we operationalize political bullshit receptivity as endorsing vague political statements, slogans, and political bullshit programs. We investigated the relationship of these three measures with pseudo-profound bullshit, ideology (political ideology, support for neoliberalism), populism, and voting behavior. Three pre-registered studies in different cultural settings (the United States, Serbia, The Netherlands; total N = 534) yielded medium to high intercorrelations between political bullshit measures and pseudo-profound bullshit, and good construct validity (hypothesized one-factor solution). A Bayesian meta-analysis showed that all political bullshit measures positively correlated with support for the free market, while only some positively correlated with social (political statements and programs) and economic conservatism (programs), and populism (programs). In the U.S., higher receptivity to political bullshit was associated with a higher probability that one voted for Trump (vs Clinton) in the past and higher intentions to vote for Trump (vs Biden and Sanders). In the Netherlands, higher receptivity to political bullshit predicted the intention to vote for the conservative-liberal People's Party for Freedom and Democracy. Exploratory analyses on merged datasets showed that higher receptivity to political bullshit was associated with a higher probability to vote for right-wing candidates/parties and lower probability for the left-wing ones. Overall, political bullshit endorsement showed good validity, opening avenues for research in political communication, especially when this communication is broad and meaningless.

scholarly journals Sense of Purpose in Life Is Associated with Lower Risk of Incident Dementia: A Meta-Analysis

2021 ◽  
pp. 1-10
Author(s):  
Angelina R. Sutin ◽  
Damaris Aschwanden ◽  
Martina Luchetti ◽  
Yannick Stephan ◽  
Antonio Terracciano
Keyword(s):  
Lower Risk ◽  
Meta Analysis ◽  
Random Effect ◽  
Purpose In Life ◽  
Population Based ◽  
Primary Data ◽  
Or Education ◽  
Total N ◽  
Sense Of Purpose ◽  
Incident Dementia

Background: A sense of purpose in life has been associated with healthier cognitive outcomes across adulthood, including risk of dementia. The robustness and replicability of this association, however, has yet to be evaluated systematically. Objective: To test whether a greater sense of purpose in life is associated with lower risk of dementia in four population-based cohorts and combined with the published literature. Methods: Random-effect meta-analysis of prospective studies (individual participant data and from the published literature identified through a systematic review) that examined sense of purpose and risk of incident dementia. Results: In six samples followed up to 17 years (four primary data and two published; total N = 53,499; n = 5,862 incident dementia), greater sense of purpose in life was associated with lower dementia risk (HR = 0.77, 95%CI = 0.73–0.81, p <  0.001). The association was generally consistent across cohorts (I2 = 47%), remained significant controlling for clinical (e.g., depression) and behavioral (e.g., physical inactivity) risk factors, and was not moderated by age, gender, or education. Conclusion: Sense of purpose is a replicable and robust predictor of lower risk of incident dementia and is a promising target of intervention for cognitive health outcomes.

scholarly journals Genotypic Difference in the Responses to Nitrogen Fertilizer Form in Tibetan Wild and Cultivated Barley

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 595
Author(s):  
Shama Naz ◽  
Qiufang Shen ◽  
Jonas Lwalaba Wa Lwalaba ◽  
Guoping Zhang
Keyword(s):  
Wild Barley ◽  
Growth Parameters ◽  
Inorganic Nitrogen ◽  
N Uptake ◽  
Total Soluble Protein ◽  
Organic N ◽  
Genotypic Difference ◽  
N Availability ◽  
Tibetan Wild Barley ◽  
Cultivated Barley

Nitrogen (N) availability and form have a dramatic effect on N uptake and assimilation in plants, affecting growth and development. In the previous studies, we found great differences in low-N tolerance between Tibetan wild barley accessions and cultivated barley varieties. We hypothesized that there are different responses to N forms between the two kinds of barleys. Accordingly, this study was carried out to determine the response of four barley genotypes (two wild, XZ16 and XZ179; and two cultivated, ZD9 andHua30) under 4Nforms (NO3−, NH4+, urea and glycine). The results showed significant reduction in growth parameters such as root/shoot length and biomass, as well as photosynthesis parameters and total soluble protein content under glycine treatment relative to other N treatments, for both wild and cultivated barley, however, XZ179 was least affected. Similarly, ammonium adversely affected growth parameters in both wild and cultivated barleys, with XZ179 being severely affected. On the other hand, both wild and cultivated genotypes showed higher biomass, net photosynthetic rate, chlorophyll and protein in NO3− treatment relative to other three N treatments. It may be concluded that barley undisputedly grows well under inorganic nitrogen (NO3−), however in response to the organic N wild barley prefer glycine more than cultivated barely.

Parenting Programs for Disruptive Child Behavior in China: A Meta-Analysis and Systematic Review

2021 ◽  
pp. 104973152110185
Author(s):  
Ningxuan Hua ◽  
Patty Leijten
Keyword(s):  
Child Behavior ◽  
Meta Analysis ◽  
Behavioral Approach ◽  
Parenting Programs ◽  
Behavioral Management ◽  
Total N ◽  
Chinese Families ◽  
Inconsistent Parenting ◽  
Program Effects ◽  
Disruptive Child Behavior

Purpose: To synthesize evidence of parenting program effects on disruptive child behavior in China and compare three program approaches: behavioral, relational, and cognitive. Methods: We searched five databases (four English and one Chinese) and identified 45 studies; 29 studies were included in a multilevel meta-analysis (92 effect sizes; total N total = 3,892; M child age = 6.12 years). Results: We found large overall effects on reduced disruptive child behavior ( d = −1.28, 95% CI [−1.86, −0.70], p < .001), reduced harsh and inconsistent parenting ( d = −1.70, 95% CI [−2.91, −0.49], p <.001), and improved parental warmth and positive behavioral management ( d = 2.67, 95% CI [0.41, 4.93], p <.001). Behavioral programs were more effective than relational programs (Δ d = .89, 95% CI [−1.7, −0.13], p = .034), and cognitive programs were too rare to analyze separately. Conclusions: Parenting programs for disruptive child behavior can effectively support Chinese families, especially those adopting a behavioral approach.

scholarly journals Major Adverse Cardiac Events and Mortality Associated with Electroconvulsive Therapy

2019 ◽  
Vol 130 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Andreas Duma ◽  
Mathias Maleczek ◽  
Basil Panjikaran ◽  
Harald Herkner ◽  
Theodore Karrison ◽  
...  
Keyword(s):  
Heart Failure ◽  
Pulmonary Edema ◽  
Acute Heart Failure ◽  
Electroconvulsive Therapy ◽  
Meta Analysis ◽  
Incidence Rates ◽  
Major Adverse Cardiac Events ◽  
Cardiac Events ◽  
Total N ◽  
Adverse Cardiac Events

Abstract EDITOR’S PERSPECTIVE What We Already Know about This Topic The incidence of major adverse cardiac events after electroconvulsive therapy is not known What This Article Tells Us That Is New Major adverse cardiac events and death after electroconvulsive therapy are infrequent and occur in about 1 of 50 patients and after about 1 of 200 to 500 electroconvulsive therapy treatments Background Cardiac events after electroconvulsive therapy have been reported sporadically, but a systematic assessment of the risk is missing. The goal of this study was to obtain a robust estimate of the incidence of major adverse cardiac events in adult patients undergoing electroconvulsive therapy. Methods Systematic review and meta-analysis of studies that investigated electroconvulsive therapy and reported major adverse cardiac events and/or mortality. Endpoints were incidence rates of major adverse cardiac events, including myocardial infarction, arrhythmia, pulmonary edema, pulmonary embolism, acute heart failure, and cardiac arrest. Additional endpoints were all-cause and cardiac mortality. The pooled estimated incidence rates and 95% CIs of individual major adverse cardiac events and mortality per 1,000 patients and per 1,000 electroconvulsive therapy treatments were calculated. Results After screening of 2,641 publications and full-text assessment of 284 studies, the data of 82 studies were extracted (total n = 106,569 patients; n = 786,995 electroconvulsive therapy treatments). The most commonly reported major adverse cardiac events were acute heart failure, arrhythmia, and acute pulmonary edema with an incidence (95% CI) of 24 (12.48 to 46.13), 25.83 (14.83 to 45.00), and 4.92 (0.85 to 28.60) per 1,000 patients or 2.44 (1.27 to 4.69), 4.66 (2.15 to 10.09), and 1.50 (0.71 to 3.14) per 1,000 electroconvulsive therapy treatments. All-cause mortality was 0.42 (0.11 to 1.52) deaths per 1,000 patients and 0.06 (0.02 to 0.23) deaths per 1,000 electroconvulsive therapy treatments. Cardiac death accounted for 29% (23 of 79) of deaths. Conclusions Major adverse cardiac events and death after electroconvulsive therapy are infrequent and occur in about 1 of 50 patients and after about 1 of 200 to 500 electroconvulsive therapy treatments.

Characteristics of Non-Point Source N Export via Surface Runoff from Sloping Croplands in Northeast China

2011 ◽  
Vol 347-353 ◽  
pp. 2302-2307 ◽  
Author(s):  
Hong Xiang Wang ◽  
Yi Shi ◽  
Jian Ma ◽  
Cai Yan Lu ◽  
Xin Chen
Keyword(s):  
Point Source ◽  
Surface Runoff ◽  
Rainfall Intensity ◽  
Inorganic Nitrogen ◽  
Rainfall Amount ◽  
Organic N ◽  
Dissolved Inorganic Nitrogen ◽  
Slope Gradient ◽  
N Loss ◽  
Total N

A field experiment was conducted to study the characteristics of non-point source nitrogen (N) in the surface runoff from sloping croplands and the influences of rainfall and cropland slope gradient. The results showed that dissolved total N (DTN) was the major form of N in the runoff, and the proportion occupied by dissolved inorganic nitrogen (DIN) ranged from 45% to 85%. The level of NH4+-N was generally higher than the level of NO3--N, and averaged at 2.50 mg·L-1and 1.07 mg·L-1respectively. DIN was positively correlated with DTN (R2=0.962). Dissolved organic N (DON) presented a moderate seasonal change and averaged at 1.40 mg·L-1. Rainfall amount and rainfall intensity significantly affected the components of DTN in the runoff. With the increase of rainfall amount and rainfall intensity, the concentrations of DTN, NH4+-N and NO3--N presented a decreased trend, while the concentration of DON showed an increased trend. N loss went up with an increase in the gradient of sloping cropland, and was less when the duration was longer from the time of N fertilization.fertilization.

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