Maximum decomposition limits of forest litter types: a synthesis

1996 ◽  
Vol 74 (5) ◽  
pp. 659-672 ◽  
Author(s):  
Björn Berg ◽  
Maj-Britt Johansson ◽  
Gunnar Ekbohm ◽  
Charles McClaugherty ◽  
Flora Rutigliano ◽  
...  
Keyword(s):  
Litter Decomposition ◽  
Forest Litter ◽  
Limit Values ◽  
Limit Value ◽  
Needle Litter ◽  
Linear Relationships ◽  
Asymptotic Function ◽  
Linear Regressions ◽  
Negative Linear Relationship

We used long-term litter decomposition data to estimate final decomposition levels using an asymptotic function. The estimated final limit values for decomposition were compared with available chemical data for the different litter types. A total of 41 limit values were estimated from as many different decomposition studies, and 20 different litter types were incubated in eight different forest systems. The limit values estimated varied with litter type. They ranged from about 35 to about 100% decomposition and were linearly related to the initial litter concentrations of N, Mn, and Ca in the newly shed litter. For these three nutrients, there are causal relationships to lignin degradation and to the lignin-degrading microbial community. Using all available data, we made simple and multiple linear regressions and obtained a negative linear relationship between limit value and initial N concentration ([Formula: see text]; n = 41; p < 0.001). For needle litter alone, we obtained a better relationship ([Formula: see text]; n = 23; p < 0.001). Manganese concentrations in litter gave a positive relationship ([Formula: see text]; n = 25; p < 0.001), with a clear improvement when needle litter was tested for alone ([Formula: see text]; n = 16; p < 0.001). Calcium alone gave a barely significant relationship. When combining nutrients in multiple linear relationships we obtained high R2 values, indicating that the models were good. Thus for all sites and litter types, N, Mn, and Ca combined gave an [Formula: see text] value of 0.640 with n = 25 (p < 0.001). All needle litters combined gave an [Formula: see text] of 0.745 (n = 16; p < 0.001). The significance of this finding is discussed. Keywords: litter decomposition, limit values, maximum decomposition, nitrogen, manganese, calcium.

Estimated nitrogen concentrations in humus based on initial nitrogen concentrations in foliar litter: a synthesis. XII. Long-term decomposition in a Scots pine forest

2000 ◽  
Vol 77 (12) ◽  
pp. 1712-1722
Author(s):  
Björn Berg ◽  
Ryszard Laskowski ◽  
Amalia Virzo Santo
Keyword(s):  
Linear Relationship ◽  
Limit Values ◽  
Significant Linear Relationship ◽  
Limit Value ◽  
N Concentration ◽  
Linear Relationships ◽  
Significant Difference ◽  
Nitrogen Concentrations ◽  
Scots Pine Forest

The final (limit) values for litter decomposition were estimated and, by extrapolating a linear relationship between accumulated litter mass loss and litter N concentration, the N concentration at the limit value (Nlimit) was estimated. The values for Nlimit were compared with those of the A01 layer (Nhumus) and of newly shed litter (Ninit). No difference was found between the A01 and A02 layers when their N concentrations were compared with the values for Nlimit. There was a highly significant linear relationship between Nlimit and Ninit (R2 = 0.769 and p < 0.001). Likewise, there was a highly significant linear relationship between Nhumus and Ninit. When these two linear relationships were compared, there was no significant difference in slope, while there was a significant difference in the intercepts of 6.76 and 7.25 mg·g-1 for Nhumus and Ninit, respectively. Thus, for a given site in our investigation, the estimated value for N concentration in humus would be 6.8% lower than the measured one.

scholarly journals Using crop analysis in the precision nutrient supply system of maize

2012 ◽  
pp. 183-186
Author(s):  
Zoltán Izsáki
Keyword(s):  
Grain Yield ◽  
Nutrient Supply ◽  
Limit Values ◽  
Leaf Analysis ◽  
Yield Level ◽  
Limit Value ◽  
P Concentration ◽  
Maize Leaves ◽  
K Concentration

The effect of the N, P and K supplies of soil on the grain yield and N, P and K status of maize was studied in a long-term mineral fertilisation experiment between 2001 and 2008 and nutrient supply limit values were determined to plant analysis. Based on the interaction between the N concentrtion of maize leaves measured at the beginnig of tasseling and grain yield, the satisfactory limit value of N supply to reach 10–14 t ha-1 yield was between 2.0–4.0%. Leaf analysis at the beginning of tasselling indicated that better P and K supplies were associated with a higher P and K concentration in the maize leaves. Correlation analysis on the P concentration of the maize leaves and the grain yield showed that at a grain yield level of 10–14 t ha-1 a P concentration of 0.20–0.37% represented a satisfactory P supply level. The satisfactory K supply limit value to reach 10–14t ha-1 grain yield was 1.5–2.6%.

Factors influencing limit values for pine needle litter decomposition: a synthesis for boreal and temperate pine forest systems

2010 ◽  
Vol 100 (1-3) ◽  
pp. 57-73 ◽  
Author(s):  
B. Berg ◽  
M. P. Davey ◽  
A. De Marco ◽  
B. Emmett ◽  
M. Faituri ◽  
...  
Keyword(s):  
Litter Decomposition ◽  
Pine Forest ◽  
Pine Needle ◽  
Limit Values ◽  
Factors Influencing ◽  
Needle Litter

scholarly journals Foliar Litter Decomposition: A Conceptual Model with Focus on Pine (Pinus) Litter—A Genus with Global Distribution

ISRN Forestry ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-22 ◽  
Author(s):  
Björn Berg
Keyword(s):  
Tree Species ◽  
Late Phase ◽  
Global Distribution ◽  
Pine Needle ◽  
Limit Values ◽  
Enhancing Effect ◽  
Limit Value ◽  
Needle Litter ◽  
Three Phase ◽  
Similarities And Differences

The genus Pinus encompasses c 120 species and has a global distribution. Today we know more about the decomposition of pine needle litter than litter from any other genus. This paper presents a developed conceptual three-phase model for decomposition, based on pine needle litter, starting with newly shed litter and following the process until a humus-near stable residue. The paper focuses on the mass-loss dynamics and factors regulating the process in the early phase, the late one, and the humus-near phase. For the late phase, the hampering influence of N and the rate-enhancing effect of Mn on the decomposition are given extra attention. Empirical factors related to the limit value/stable residue are discussed as well as the decomposition patterns and functions for calculating limit values. The climate-related litter concentrations of N and Mn are discussed as well as their possible influence on the size of the stable residue, which may accumulate and sequester carbon, for example, in humus layers. The sequestration of carbon in humus layers is discussed as well as the effect of tree species on the process. Although the paper focuses on litter of pine species, there are comparisons to studies on other litter genera and similarities and differences are discussed.

scholarly journals Study of size-segregated particle (PM1, PM2,5, PM10) concentrations over Greece

2013 ◽  
Vol 10 (2) ◽  
pp. 132-139 ◽  
Keyword(s):  
Regional Scale ◽  
Monitoring Network ◽  
Quality Standard ◽  
Anthropogenic Source ◽  
Data Sets ◽  
Limit Values ◽  
Back Trajectories ◽  
Dust Transport ◽  
Limit Value

This study reports particulate matter levels of various size fractions (PM10, PM2.5, and PM1) and identify their controlling factors, in various locations over Greece. It combines long-term data sets involving particle concentrations as measured in the island of Crete in the Eastern Mediterranean and the Greater Area of Athens. Measurements were carried out in various sites at urban (Central Athens and Heraklion, Crete), suburban (Lykovrissi, Athens) and natural background (Finokalia, Crete) locations, for a time period extending from 2004 to 2006. Size-segregated mass measurements of 3 sizes (PM10, PM2.5 and PM1) are reported. The EU annual limit value of 40 μg m-3 for PM10 was exceeded on a yearly basis at both of measurement sites in Athens, while frequent exceedances of the 24-h limit value of 50 μg m-3 were recorded. Concentration levels of PM2.5 and PM1 were also found elevated, when regarded in perspective to either existing limit values (for PM2.5) or levels reported for other large metropolitan areas (for PM1). In addition even at the background station of Finokalia in Crete, average PM10 concentrations exceeded 30 μg m-3. Moreover, at the same station, average concentrations of PM2.5, notably exceed 15 μg m-3 (a characteristic value, relative to the USEPA PM2.5 air quality standard). At all sites coarse particles have been found to comprise a noteworthy portion of total PM10 particles (with PM2.5/PM10 ratios ranging between 45-60%), while fine particle mass concentrations heavily relied on those of particles in the submicron range (PM1/PM2.5 ratios spanning between 55-75%). The short and long-term temporal variability of each fraction were examined and spatial associations were statistically analyzed, in an attempt to identify possible affinities in particle level profiles, effective over a larger regional scale. It has been observed that at several instances, severe particle episodes recorded in the region of Crete have largely affected the Greek mainland and have triggered a response to the monitoring network in Athens. Special focus has been given to events of dust transport from N. Africa, which is found to be more frequent during spring and fall, and during which the PM10 limit value of 50 μg m-3 is violated and concentrations of even finer particle fractions are affected. Air mass back trajectories were studied, for episode days during dust transport events. Data of particle chemical composition were utilized, contributing to an initial identification and characterization of major natural and anthropogenic source types, which determine particle concentrations.

The analysis of the results of a rotation experiment on the use of straw and fertilizers

1953 ◽  
Vol 43 (1) ◽  
pp. 77-88 ◽  
Author(s):  
H. D. Patterson
Keyword(s):  
Present Experiment ◽  
Treatment Effects ◽  
Standard Errors ◽  
Methods Of Analysis ◽  
Seasonal Factors ◽  
Long Term Experiments ◽  
The Mean ◽  
Linear Regressions

An experiment, designed to test different ways of using straw with fertilizers, and involving a three course rotation of crops, was carried out at Rothamsted between 1933 and 1951. The methods of analysis developed for this experiment are described in the present paper and demonstrated using yields of potatoes.Treatment effects of interest are given by the mean yields over all years and the linear regressions of yield on time. These estimates are straightforward but the evaluation of their errors is complicated by the existence of correlations due to the recurrence of treatments on the same plots. Further complications are introduced when, as frequently happens in long-term experiments, treatment effects show real variation from year to year. A method is given for estimating standard errors which include a contribution from this variation.The various relationships between yields and the uncontrolled seasonal factors can also be examined; in the present experiment there is some indication that the effects of treatments on yields of potatoes are influenced by the dates of planting.In other circumstances the analysis requires modifications, some of which are briefly considered.

scholarly journals Nitrogen Addition Significantly Affects Forest Litter Decomposition under High Levels of Ambient Nitrogen Deposition

PLoS ONE ◽  
2014 ◽  
Vol 9 (2) ◽  
pp. e88752 ◽  
Author(s):  
Li-hua Tu ◽  
Hong-ling Hu ◽  
Gang Chen ◽  
Yong Peng ◽  
Yin-long Xiao ◽  
...  
Keyword(s):  
Nitrogen Deposition ◽  
Litter Decomposition ◽  
Forest Litter ◽  
Nitrogen Addition

Feedback interactions between needle litter decomposition and rhizosphere activity

Oecologia ◽  
2004 ◽  
Vol 139 (4) ◽  
pp. 551-559 ◽  
Author(s):  
Jens-Arne Subke ◽  
Volker Hahn ◽  
Giovanna Battipaglia ◽  
Sune Linder ◽  
Nina Buchmann ◽  
...  
Keyword(s):  
Litter Decomposition ◽  
Needle Litter
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