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.

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

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.

99mTc-DPD SPECT/CT for localisation of inflammatory and chronic osteoarthritis of the foot and ankle

2016 ◽  
Vol 55 (04) ◽  
pp. 145-150 ◽  
Author(s):  
Lutz Freudenberg ◽  
Hinrich Wieder ◽  
Jens Stollfuss
Keyword(s):  
Bone Metabolism ◽  
Late Phase ◽  
Blood Pool ◽  
Phase Imaging ◽  
Bone Imaging ◽  
Foot And Ankle ◽  
Planar Imaging ◽  
Selective Treatment ◽  
Complex Anatomy ◽  
Three Phase

SummaryAim: The precise localisation of osteoarthritic and inflammatory changes is crucial for selective treatment planning of radiosynovectomy (RSV). The present study evaluated the diagnostic accuracy of planar bone imaging and SPECT for the detection of pathological bone metabolism and inflammation in joints of the foot and ankle, compared with SPECT/CT. Patients, methods: 39 patients (mean age 65.6 ± 11.1 years) with suspected inflammatory osteoarthritis underwent SPECT/CT of the feet. After injection of approximately 500 MBq 99mTc DPD, all patients had three-phase planar bone imaging and late-phase hybrid SPECT/CT. late-phase SPECT, and CT of the foot. Increased bone metabolism and blood-pool was assigned to the respective joint of the fore-, mid-, and hindfoot, using SPECT/CT as the reference standard. Results: Overall, SPECT had a higher sensitivity than planar imaging (0.80 vs 0.68, n.s.). The advantage of SPECT was most obvious in the anatomically complex midfoot area (0.63 vs 0.26, p < 0.05) and less obvious in the forefoot (0.85 vs 0.79, n.s.) and hindfoot (0.89 vs 0.89, n.s.). The overall concordance (Cohen`s Kappa) between SPECT/CT and planar (late-phase) imaging and SPECT was high for the forefoot and the hindfoot (planar: 0.78/0.81; SPECT 0.86/0.88) and comparatively low for the midfoot (planar: 0.27; SPECT 0.61). Conclusion: SPECT was significantly superior to planar bone imaging for the detection of joint lesions in the midfoot. The differences between SPECT and planar imaging in the fore- and hindfoot were not significant, most likely due to the inherently less complex anatomy. Compared with SPECT alone, a benefit from the use of SPECT/CT can be observed in the midfoot region where it facilitates the identification of the correct joint for RSV.

scholarly journals Similarities and differences in intrapopulation trait correlations of co-occurring tree species: consistent water-use relationships amid widely different correlation patterns

2018 ◽  
Vol 105 (9) ◽  
pp. 1477-1490 ◽  
Author(s):  
Julie Messier ◽  
Cyrille Violle ◽  
Brian J. Enquist ◽  
Martin J. Lechowicz ◽  
Brian J. McGill
Keyword(s):  
Water Use ◽  
Tree Species ◽  
Similarities And Differences ◽  
Trait Correlations

scholarly journals Aspects of arbuscular mycorrhizal fungi in an atlantic forest chronosequence parque estadual turístico do Alto Ribeira (petar), SP

2004 ◽  
Vol 4 (2) ◽  
pp. 1-15 ◽  
Author(s):  
Marcos P.M. Aidar ◽  
Rosilaine Carrenho ◽  
Carlos A. Joly
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Atlantic Forest ◽  
Tree Species ◽  
Mycorrhizal Fungi ◽  
Late Phase ◽  
Arbuscular Mycorrhizal ◽  
Diversity Indices ◽  
Mycorrhizal Colonization ◽  
Wet Season ◽  
Generic Level

Mycorrhizal colonization was assessed in roots of trees within an Atlantic Forest chronosequence, located in the southeastern of São Paulo State, Brazil, inside Tourist State Park of the High Ribeira Valley (PETAR). The phytosociological survey was carried out in three adjacent areas, all on calcareous soil, which correspond to different time intervals during which they have been left abandoned following a slash-and-burn agricultural perturbation. Early Phase (EP) with 15 years; Mid Phase (MP) with 25 years; and Late Phase (LP) with more than 36 years without clear-cut. The inventory indicated a continuum of tree species substitution, which is dominated by species of Leguminosae, especially Piptadenia gonoacantha (Mart.) J.F. Macbr. (Mimosoideae) in the earlier successional phases. Mycorrhizal colonization, estimated by the occurrence of the mycorrhizal structures in the tree species roots, diminished during the season with less rain (winter), and showed no significant differences between successional phases in the wet season (summer). Rather, the mycorrhizal colonization was correlated with occurrence of the tree’s successional status: being positively correlated with occurrence of pioneer species, and negatively correlated with late secondary species. Mycorrhizal colonization was also correlated negatively with soil organic matter and base saturation. Twenty five species of arbuscular mycorrhizal fungi belonging to four genera were identified. Six species were only identified to generic level. The species Glomus etunicatum Becker & Gerd. represented 10% of the total number of spores and occurred in all phases and seasons, while the genus Glomus represented 57% of the total of spores found in the rhizosphere. The diversity indices evaluated for the mycohrriza community were: H’ = 2.3, J’ = 0.97 and R = 4.12. These results are a contribution to the knowledge of The Atlantic Forest biodiversity and may have implications to support programs regarding rehabilitation of degraded vegetation in one of the World’s most threatened Biomes.

scholarly journals Efficiency and gases emissions with incineration of composite and one-component biofuel briquettes in room heater

2008 ◽  
Vol 53 (No. 3) ◽  
pp. 94-102 ◽  
Author(s):  
P. Jevič ◽  
P. Hutla ◽  
J. Malaťák ◽  
Z. Šedivá
Keyword(s):  
Sugar Beet ◽  
Wheat Straw ◽  
Brown Coal ◽  
Parameters Optimization ◽  
Sugar Beet Pulp ◽  
Heat Output ◽  
Limit Values ◽  
Limit Value ◽  
Solid Biofuel ◽  
Beet Pulp

In accordance with the technical standard ČSN EN 13229 “Inset appliances for heating including open fires fired by solid fuels – Requirements and test methods” was performed the basic assessment of thermal efficiency and emission parameters of prototype of combustion accumulation stove SK-2 with upper after-burning and nominal heat output of 8 kW. Verified gradually were the bio-briquettes of diameter 65 mm from mixture of wheat straw and 20% m/m of brown coal, wheat straw and 5% m/m of brown coal, wheat straw, mixture of wheat straw and 10% m/m of water and molasses solution, Ecobiopal created with the fermented blend of 33% m/m of digested clean water plant sludge and 67% m/m of wood chopped material, blend of wheat straw and 15% m/m of sugar beet pulp, mixture of timothy hay and 25% m/m of brown coal, timothy grass hay, meadow hay, mixture of meadow hay and 25% m/m of brown coal. The lowest CO emissions, when the limit value of 3000 mg/m<sup>3</sup><sub>N</sub> at 13% of O<sub>2</sub> has not been exceeded, determined for more strict 1<sup>st</sup> class and the highest efficiency at nominal heat performance, i.e. higher or equal to 70% (Class I) have been reached by the briquettes produced from mixture of wheat straw and 15% m/m of sugar beet pulp, timothy hay and mixture of meadow hay with addition of 25% m/m of brown coal. Further were measured NO<sub>x</sub> and HCl emissions. NO<sub>x</sub> values were significantly lower than limit values determined for similar combustion of solid biofuel. Higher differences of HCl emissions correlate with various Cl content in fuels. Only the wheat straw briquettes with share of 25% m/m of brown coal have exceeded the limit value by 16%. Other fuels have shown considerably lower values. The results have proved better heat-technical and emission parameters of blended briquettes and are significant also for solid biofuels and solid recovered fuels standardization as well as for increasing efficiency method detection and ecological parameters optimization including HCl emissions.

PAHs Sorption and Desorption on Soil Influenced by Pine Needle Litter-Derived Dissolved Organic Matter

Pedosphere ◽  
2014 ◽  
Vol 24 (5) ◽  
pp. 575-584 ◽  
Author(s):  
Xiu-Hong YANG ◽  
P. GARNIER ◽  
Shi-Zhong WANG ◽  
V. BERGHEAUD ◽  
Xiong-Fei HUANG ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Pine Needle ◽  
Needle Litter

scholarly journals A Human-Relevant 3D In Vitro Platform for an Effective and Rapid Simulation of Workplace Exposure to Nanoparticles: Silica Nanoparticles as Case Study

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1761 ◽  
Author(s):  
Luisana Di Cristo ◽  
Fabio Boccuni ◽  
Sergio Iavicoli ◽  
Stefania Sabella
Keyword(s):  
Silica Nanoparticles ◽  
Defense Mechanisms ◽  
Workplace Exposure ◽  
Limit Values ◽  
Limit Value ◽  
Exposure Limit ◽  
Airway Model

In this contribution, we show the suitability of a 3D airway model, when coupled with a nebulizer system, for simulating workplace exposure to nanoparticles. As a proof of concept, workplace exposure to silica nanoparticles was experimentally measured in an occupational facility where nanoparticles are produced weekly, and compared with the official limit value for bulk silica materials. These values of potential exposure were simulated in a 3D airway model by nebulizing low doses (from 0.90 to 55 µg/cm2) of silica nanoparticles over a prolonged period (12 weeks of repeated exposure, 5 days per week). Overall, the results suggest the efficiency of the defense mechanisms of the respiratory system and the clearance of the breathed silica nanoparticles by the mucociliary apparatus in accordance with the recent in vivo data. This in vitro platform shows that the doses tested may correlate with the occupational exposure limit values. Such relationship could provide regulatory-oriented data useful for risk classification of nanomaterials.

Particulate Matter in Ambient Air

2007 ◽  
Vol 4 (4) ◽  
pp. 278-288 ◽  
Author(s):  
Reinhold Görgen ◽  
Udo Lambrecht
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Human Health ◽  
Ambient Air ◽  
Limit Values ◽  
Limit Value ◽  
European Institutions ◽  
Negative Effect ◽  
Time Extension ◽  
The Eu

AbstractNumerous studies have demonstrated the negative effect of particulate matter on human health. The EU therefore introduced ambitious limit values for particulate matter (PM10) in ambient air as early as 1999: an annual limit and a daily limit that can be exceeded on up to 35 days a year. These values are binding since 2005. The daily limit is still exceeded in many cities throughout Europe. Heated debates on the future of the daily limit are taking place at all levels of the EU in the context of the negotiations on the Commission's proposal on a new Air Quality Directive. Suggestions range from allowing a compliance time extension to increasing the number of days the daily limit can be exceeded, and abolition of the daily limit value. The deliberations have not yet been concluded, but the decisive European institutions have voiced support for keeping the daily limit while at the same time extending the compliance deadline. In this article, we will make the point that the problem can most probably be solved by allowing a compliance extension of around 5 years after the new directive enters into force. This would give the competent local authorities and the EU the time necessary to intensify their measures in order to comply with the daily limit in most areas where it is currently exceeded. An increase in the number of days the limit values may be exceeded, as called for by the European Parliament (EP), would therefore amount to an unnecessary lowering of the limit value.

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