scholarly journals Bryosphere Loss Impairs Litter Decomposition Consistently Across Moss Species, Litter Types, and Micro-Arthropod Abundance

Ecosystems ◽  
2021 ◽  
Author(s):  
Roger Grau-Andrés ◽  
David A. Wardle ◽  
Paul Kardol
Keyword(s):  
Litter Decomposition ◽  
Boreal Forests ◽  
Terrestrial Ecosystems ◽  
Minor Role ◽  
Decomposition Rates ◽  
Moss Species ◽  
Key Driver ◽  
A Minor ◽  
Positive Effect ◽  
Arthropod Abundance

AbstractThe bryosphere (that is, ground mosses and their associated biota) is a key driver of nutrient and carbon dynamics in many terrestrial ecosystems, in part because it regulates litter decomposition. However, we have a poor understanding of how litter decomposition responds to changes in the bryosphere, including changes in bryosphere cover, moss species, and bryosphere-associated biota. Specifically, the contribution of micro-arthropods to litter decomposition in the bryosphere is unclear. Here, we used a 16-month litterbag field experiment in two boreal forests to investigate bryosphere effects on litter decomposition rates among two moss species (Pleurozium schreberi and Hylocomium splendens), and two litter types (higher-quality Betula pendula litter and lower-quality P. schreberi litter). Additionally, we counted all micro-arthropods in the litterbags and identified them to functional groups. We found that bryosphere removal reduced litter decomposition rates by 28% and micro-arthropod abundance by 29% and led to a colder micro-climate. Litter decomposition rates and micro-arthropod abundance were uncorrelated overall, but were positively correlated in B. pendula litterbags. Bryosphere effects on litter decomposition rates were consistent across moss species, litter types, and micro-arthropod abundances and community compositions. These findings suggest that micro-arthropods play a minor role in litter decomposition in the boreal forest floor, suggesting that other factors (for example, micro-climate, nutrient availability) likely drive the positive effect of the bryosphere on decomposition rates. Our results point to a substantial and consistent impairment of litter decomposition in response to loss of moss cover, which could have important implications for nutrient and carbon cycling in moss-dominated ecosystems.

Decomposition of Douglas-fir and red alder wood in clear-cuttings

1986 ◽  
Vol 16 (4) ◽  
pp. 822-831 ◽  
Author(s):  
Robert L. Edmonds ◽  
Daniel J. Vogt ◽  
David H. Sandberg ◽  
Charles H. Driver
Keyword(s):  
Small Diameter ◽  
Soil Surface ◽  
Douglas Fir ◽  
Dominant Factor ◽  
Minor Role ◽  
Wood Decomposition ◽  
Decomposition Rates ◽  
Red Alder ◽  
A Minor ◽  
The University

Decomposition rates of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and red alder (Alnusrubra Bong.) wood (simulating logging residues) were determined in clear-cuttings at the Charles Lathrop Pack Experimental Forest of the University of Washington, which is located approximately 120 km south of Seattle, WA. The influence of diameter (1–2, 4–6, and 8–12 cm), vertical location (buried, on the soil surface, and elevated), season of logging (summer and winter), aspect (north and south), and wood temperature, moisture, and chemistry on wood decomposition rates were determined. Red alder wood decomposed faster (k = 0.035–0.517 year−1) than Douglas-fir wood (k = 0.006–0.205 year−1). In general, buried wood decomposed faster than surface wood, which decomposed faster than elevated wood. Small diameter wood generally decomposed faster than larger diameter wood. Aspect and season of logging had little influence on decomposition rates. Moisture and temperature were the dominant factors related to Douglas-fir wood decomposition, with initial chemistry playing a minor role. Initial wood chemistry, particularly soda solubility, was the dominant factor related to red alder wood decomposition.

Toads (Bufo bankorensis) influence litter chemistry but not litter invertebrates and litter decomposition rates in a subtropical forest of Taiwan

2007 ◽  
Vol 23 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Ching-Yu Huang ◽  
Chiao-Ping Wang ◽  
Ping-Chun Lucy Hou
Keyword(s):  
Litter Decomposition ◽  
Terrestrial Ecosystems ◽  
Subtropical Forest ◽  
Decomposition Rates ◽  
North East ◽  
Ecological Roles ◽  
Litter Invertebrates ◽  
Species Specific ◽  
And Control ◽  
Predatory Arthropods

Few studies have been conducted to investigate ecological roles of litter amphibians in forest ecosystems. In this study, ten field enclosures (3 m × 2 m × 0.4 m) were used to evaluate effects of the toad Bufo bankorensis on the abundance of litter invertebrates (microbivores, fragmenters and predatory arthropods) and litter decomposition rates in a subtropical forest of southern Taiwan. Litterbags collected from toad and control (toad-excluded) enclosures were analysed for the communities and abundances of litter invertebrates and decay loss during this decomposition study from September to December 2001. The presence of B. bankorensis significantly changed phosphorus concentrations in the litter, but not the densities of litter invertebrates (microbivores, fragmenters and predatory arthropods) or rates of litter decomposition. These results were not consistent with previous studies, which have shown that Plethodon cenereus in a temperate forest of north-east USA and Eleutherodactylus coqui in a tropical rain forest of Puerto Rico significantly changed decomposition rates. We suggest that ecological roles of ground-dwelling amphibians may be species-specific and vary with different terrestrial ecosystems.

scholarly journals Effects of Simulated Nitrogen Deposition on Leaf-Litter Decomposition and Nutrient Release of A Cold Temperate Coniferous Forest in Jiaozi Snow Mountain National Nature Reserve, Southwest China

2021 ◽  
Author(s):  
jiyou yuan ◽  
zhiyun Ouyang ◽  
Yirong SU ◽  
Yun Wang
Keyword(s):  
Ammonium Nitrate ◽  
Nitrogen Deposition ◽  
Litter Decomposition ◽  
Coniferous Forest ◽  
Nutrient Release ◽  
Terrestrial Ecosystems ◽  
High Nitrogen ◽  
Decomposition Rates ◽  
Nitrogen Treatments ◽  
Over Time

Abstract Purpose Litter decomposition is a key process of nutrient cycling in terrestrial ecosystems, an important part of the global carbon budget, and deeply affected by global atmospheric nitrogen deposition. However, the effects of different forms of N addition on litter decomposition and nutrient release are unclear in a cold temperate coniferous forest in a subtropical Chinese plateau. Methods Three N sources (NH4)2SO4, NaNO3, and NH4NO3 were used in the gradient N deposition method. Each N source was divided into four treatments, from low to high, they were CK (control 0 kg N·hm− 2·a− 1), low N (low-N 5 kg N·hm− 2·a− 1), medium n (medium-N 15 kg N·hm− 2·a− 1), high N (high-30 kg N·hm− 2·a− 1), and each treatment repeated three times. Results After two years, the litter decomposition rates of low and medium ammonium nitrate treatments were the fastest as compared to the control, while high and low ammonium nitrate treatments were the slowest. Under the same nitrogen deposition conditions, the litter decomposition rates of low nitrogen treatments were higher than high nitrogen treatments. The order of litter decomposition rates was ammonium nitrate > ammonium sulfate > sodium nitrate. Nitrogen deposition decreased the amount of C in litter leaves but increased N and P levels slightly. Phosphorus changes over time were more complex than C and N over time. Conclusions These results showed that high nitrogen deposition in the future could increase litter decomposition rates and delay the nutrient release, which may be beneficial to improve soil carbon sequestration.

scholarly journals Tea Bag Index to Assess Carbon Decomposition Rate in Cranberry Agroecosystems

Soil Systems ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 44
Author(s):  
Wilfried Dossou-Yovo ◽  
Serge-Étienne Parent ◽  
Noura Ziadi ◽  
Élizabeth Parent ◽  
Léon-Étienne Parent
Keyword(s):  
Litter Decomposition ◽  
Green Tea ◽  
Decomposition Rate ◽  
Terrestrial Ecosystems ◽  
Carbon Accumulation ◽  
N Leaching ◽  
Decomposition Rates ◽  
Rooibos Tea ◽  
Tea Bag Index ◽  
Stabilization Factor

In cranberry production systems, stands are covered by 1–5 cm of sand every 2–5 years to stimulate plant growth, resulting in alternate layers of sand and litter in soil upper layers. However, almost intact twigs and leaves remain in subsurface layers, indicating a slow decomposition rate. The Tea Bag Index (TBI) provides an internationally standardized methodology to compare litter decomposition rates (k) and stabilization (S) among terrestrial ecosystems. However, TBI parameters may be altered by time-dependent changes in the contact between litter and their immediate environment. The aims of this study were to determine the TBI of cranberry agroecosystems and compare it to the TBI of other terrestrial ecosystems. Litters were standardized green tea, standardized rooibos tea, and cranberry residues collected on the plantation floor. Litter decomposition was monitored during two consecutive years. Added N did not affect TBI parameters (k and S) due to possible N leaching and strong acidic soil condition. Decomposition rates (k) averaged (mean ± SD) 9.7 × 10−3 day−1 ± 1.6 × 10−3 for green tea, 3.3 × 10−3 day−1 ± 0.8 × 10−5 for rooibos tea, and 0.4 × 10−3 day−1 ± 0.86 × 10−3 for cranberry residues due to large differences in biochemical composition and tissue structure. The TBI decomposition rate (k) was 0.006 day−1 ± 0.002 in the low range among terrestrial ecosystems, and the stabilization factor (S) was 0.28 ± 0.08, indicating high potential for carbon accumulation in cranberry agroecosystems. Decomposition rates of tea litters were reduced by fractal coefficients of 0.6 for green tea and 0.4 for rooibos tea, indicating protection mechanisms building up with time in the tea bags. While the computation of the TBI stabilization factor may be biased because the green tea was not fully decomposed, fractal kinetics could be used as additional index to compare agroecosystems.

The Effect of Path Length and Display Size on Memory for Spatial Information

2012 ◽  
Vol 59 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay
Keyword(s):  
Path Length ◽  
Potential Role ◽  
Spatial Information ◽  
Recall Performance ◽  
Minor Role ◽  
Length Effect ◽  
Serial Memory ◽  
Fixed Reference ◽  
A Minor

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

Use of Different Tissue Thromboplastins in the Control of Anticoagulant-Therapy

1958 ◽  
Vol 02 (05/06) ◽  
pp. 462-480 ◽  
Author(s):  
Marc Verstraete ◽  
Patricia A. Clark ◽  
Irving S. Wright
Keyword(s):  
Prothrombin Time ◽  
Anticoagulant Therapy ◽  
Factor Vii ◽  
Rabbit Brain ◽  
Minor Role ◽  
Rabbit Lung ◽  
Coagulation Mechanism ◽  
Time Test ◽  
The One ◽  
A Minor

SummaryAn analysis of the results of prothrombin time tests with different types of thromboplastins sheds some light on the problem why the administration of coumarin is difficult to standardize in different centers. Our present ideas on the subject, based on experimental data may be summarized as follows.Several factors of the clotting mechanism are influenced by coumarin derivatives. The action of some of these factors is by-passed in the 1-stage prothrombin time test. The decrease of the prothrombin and factor VII levels may be evaluated in the 1-stage prothrombin time determination (Quick-test). The prolongation of the prothrombin times are, however, predominantly due to the decrease of factor VII activity, the prothrombin content remaining around 50 per cent of normal during an adequate anticoagulant therapy. It is unlikely that this degree of depression of prothrombin is of major significance in interfering with the coagulation mechanism in the protection against thromboembolism. It may, however, play a minor role, which has yet to be evaluated quantitatively. An exact evaluation of factor VII is, therefore, important for the guidance of anticoagulant therapy and the method of choice is the one which is most sensitive to changes in factor VII concentration. The 1-stage prothrombin time test with a rabbit lung thromboplastin seems the most suitable method because rabbit brain preparations exhibit a factor VII-like activity that is not present in rabbit lung preparations.

Produktivkraft als Versprechen

2016 ◽  
Vol 46 (185) ◽  
pp. 621-638 ◽  
Author(s):  
Christian Siefkes
Keyword(s):  
Private Consumption ◽  
Minor Role ◽  
Progressive Reduction ◽  
Internal Forces ◽  
A Minor

The ‘Fragment on Machines’ from Marx’s Grundrisse is often cited as an argument that the internal forces of capitalism will lead to its doom. But the argument that the progressive reduction of labor must doom capitalism lacks a proper foundation, as a comparison with the ‘Schemes of Reproduction’ given in Capital II shows. The latter, however, aren’t fully convincing either. In reality, more depends on the private consumption of capitalists than either model recognizes. Ultimately, most can be made of the ‘Fragment on Machines’ by reading it not as an exposure of capitalism’s internal contractions, but as a discussion of a possible communist future where labor (or work) will play but a minor role.

Effects of Myo-inositol Alone and in Combination with Seleno-Lmethionine on Cadmium-Induced Testicular Damage in Mice

2019 ◽  
Vol 12 (4) ◽  
pp. 311-323 ◽  
Author(s):  
Salvatore Benvenga ◽  
Antonio Micali ◽  
Giovanni Pallio ◽  
Roberto Vita ◽  
Consuelo Malta ◽  
...  
Keyword(s):  
Structural Changes ◽  
Natural Antioxidants ◽  
Minor Role ◽  
Positive Role ◽  
Testosterone Levels ◽  
Tnf Α ◽  
Testicular Lesions ◽  
A Minor ◽  
Immunohistochemical Analyses

Background: Cadmium (Cd) impairs gametogenesis and damages the blood-testis barrier. Objective: As the primary mechanism of Cd-induced damage is oxidative stress, the effects of two natural antioxidants, myo-inositol (MI) and seleno-L-methionine (Se), were evaluated in mice testes. Methods: Eighty-four male C57 BL/6J mice were divided into twelve groups: 0.9% NaCl (vehicle; 1 ml/kg/day i.p.); Se (0.2 mg/kg/day per os); Se (0.4 mg/kg/day per os); MI (360 mg/kg/day per os); MI plus Se (0.2 mg/kg/day); MI plus Se (0.4 mg/kg/day); CdCl2 (2 mg/kg/day i.p.) plus vehicle; CdCl2 plus MI; CdCl2 plus Se (0.2 mg/kg/day); CdCl2 plus Se (0.4 mg/kg/day); CdCl2 plus MI plus Se (0.2 mg/kg/day); and CdCl2 plus MI plus Se (0.4 mg/kg/day). After 14 days, testes were processed for biochemical, structural and immunohistochemical analyses. Results: CdCl2 increased iNOS and TNF-α expression and Malondialdehyde (MDA) levels, lowered glutathione (GSH) and testosterone, induced testicular lesions, and almost eliminated claudin-11 immunoreactivity. Se administration at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression, maintained GSH, MDA and testosterone levels, structural changes and low claudin-11 immunoreactivity. MI alone or associated with Se at 0.2 or 0.4 mg/kg significantly reduced iNOS and TNF-α expression and MDA levels, increased GSH and testosterone levels, ameliorated structural organization and increased claudin-11 patches number. Conclusion: We demonstrated a protective effect of MI, a minor role of Se and an evident positive role of the association between MI and Se on Cd-induced damages of the testis. MI alone or associated with Se might protect testes in subjects exposed to toxicants, at least to those with behavior similar to Cd.

Extraction of strontium and barium salts by the nitrobenzene solution of dicarbolide in the presence of glymes

1985 ◽  
Vol 50 (3) ◽  
pp. 581-599 ◽  
Author(s):  
Petr Vaňura ◽  
Emanuel Makrlík
Keyword(s):  
Stability Constants ◽  
Organic Phase ◽  
Equilibrium Constants ◽  
Minor Role ◽  
Nitrobenzene Solution ◽  
Ligand Structure ◽  
Stability Constants Of Complexes ◽  
Separation Factors ◽  
The Stability ◽  
A Minor

Extraction of microamounts of Sr2+ and Ba2+ (henceforth M2+) from the aqueous solutions of perchloric acid (0.0125-1.02 mol/l) by means of the nitrobenzene solutions of dicarbolide (0.004-0.05 mol/l of H+{Co(C2B9H11)2}-) was studied in the presence of monoglyme (only Ba2+), diglyme, triglyme, and tetraglyme (CH3O-(CH2-CH2O)nCH3, where n = 1, 2, 3, 4). The distribution of glyme betweeen the aqueous and organic phases, the extraction of the protonized glyme molecule HL+ together with the extraction of M2+ ion and of the glyme complex with the M2+ ion, i.e., ML2+ (where L is the molecule of glyme), were found to be the dominating reactions in the systems under study. In the systems with tri- and tetraglymes the extraction of H+ and M2+ ions solvated with two glyme molecules, i.e., the formation of HL2+ and ML22+ species, can probably play a minor role. The values of the respective equilibrium constants, of the stability constants of complexes formed in the organic phase, and the theoretical separation factors αBa/Sr were determined. The effect of the ligand structure on the values of extraction and stability constants in the organic phase is discussed.

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