DECOMPOSITION OF LEAF LITTER IN THE BRAZILIAN CERRADO, CERRADÃO AND FOREST ENVIRONMENTS IN THE AMAZON, BRAZIL

The soils of the Amazon region, despite being under one of the densest forests in the world, are mostly characterized by low nutrient availability, with litter being the main nutrient input route. The present work aimed to evaluate the litter decomposition in forest, Cerrado and Cerradão environments in the Amazon. The litter decomposition rate was estimated by mass loss analysis using litter bags. The collections were performed at intervals of 30, 60, 90, 120, 150, 180, 210, 240, 270 and 300 days, with four replications. Once collected, the material contained in each litter bag was placed to dry to obtain the dry mass. And so, the remaining mass percentage, the decomposition rates (k) and the half-life time (t1/2) are estimated. During the studied period, the Cerrado environment presented the lowest constant k (0.0017 g g-1 day-1) and consequently longer half-life (407 days). The monthly deposition in Cerrado input ranged from Mgha-1mother1 (June to September). Among the evaluated environments, the forest presented the highest decomposition speed and Cerrado presented the lowest one. It was evidenced that the decomposition process for all studied environments occurred with greater intensity in the rainy season.

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Litter decomposition studies using mesh bags: spillage inaccuracies and the effects of repeated artificial drying

Canadian Journal of Botany ◽

10.1139/b74-278 ◽

1974 ◽

Vol 52 (10) ◽

pp. 2157-2163 ◽

Cited By ~ 18

Author(s):

Roger Suffling ◽

David W. Smith

Keyword(s):

Litter Decomposition ◽

Field Experiments ◽

Experimental Results ◽

Old Field ◽

Decomposition Rates ◽

Litter Bags ◽

Litter Bag ◽

Modified Method ◽

Mesh Bags ◽

Source Of Error

A modified method of measuring litter decomposition using mesh bags is suggested in which the bags are reused during several time increments. The chief objections to this method are that litter may be lost through spillage and that repeated artificial drying may affect decomposition rates. Experimental results are presented to show that spillage represents a significant source of error with finely divided litter, even using conventional litter bag methods. A method for handling litter bags is suggested in which corrections may be made for spillage. In a second experiment it was found that decomposition rates were not significantly altered by repeated artificial drying of old-field litter so that repeated drying of litter in field experiments may be valid.

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Species Diversity Induces Idiosyncratic Effects on Litter Decomposition in a Degraded Meadow Steppe

Frontiers in Environmental Science ◽

10.3389/fenvs.2021.582409 ◽

2021 ◽

Vol 9 ◽

Author(s):

Iqra Naeem ◽

Talal Asif ◽

Xuefeng Wu ◽

Nazim Hassan ◽

Liu Yiming ◽

...

Keyword(s):

Species Diversity ◽

Litter Decomposition ◽

Incubation Time ◽

Soil Surface ◽

Leymus Chinensis ◽

Natural Ecosystem ◽

Litter Bags ◽

Litter Bag ◽

Decomposition Dynamics ◽

Litter Mixing

Litter decomposition is a fundamental path for nutrient cycling in a natural ecosystem. However, it remains unclear how species diversity, including richness and evenness, affects the decomposition dynamics in the context of grassland degradation. Using a litter bag technique, we investigated the litter-mixing effects of two coexisting dominant species (Leymus chinensis Lc and Phragmites australis Pa), as monocultures and mixtures with evenness (Lc:Pa) from M1 (30:70%), M2 (50:50%), and M3 (70:30%), on decomposition processes over time (60 and 365 days). The litter bags were placed on the soil surface along a degradation gradient [near pristine (NP), lightly degraded (LD), and highly degraded (HD)]. We found that 1) mass loss in mixture compositions was significantly and positively correlated with initial nitrogen (N) and cellulose contents; 2) litter mixing (richness and evenness) influenced decomposition dynamics individually and in interaction with the incubation days and the degradation gradients; 3) in a general linear model (GLM), nonadditive antagonistic effects were more prominent than additive or neutral effects in final litter and nutrients except for carbon (C); and 4) in nutrients (C, N, lignin) and C/N ratio, additive effects shifted to nonadditive with incubation time. We speculated that the occurrence of nonadditive positive or negative effects varied with litter and nutrients mass remaining in each degraded gradient under the mechanism of initial litter quality of monoculture species, soil properties of experimental sites, and incubation time. Our study has important implications for grassland improvement and protection by considering species biodiversity richness, as well as species evenness.

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Effects of water content and mesh size on tea bag decomposition

10.1101/2020.11.15.384016 ◽

2020 ◽

Author(s):

Taiki Mori ◽

Ryota Aoyagi ◽

Hiroki Taga ◽

Yoshimi Sakai

Keyword(s):

Water Content ◽

Large Scale ◽

Mixed Forest ◽

Mesh Size ◽

Decomposition Rates ◽

Litter Bags ◽

Essential Information ◽

Litter Bag ◽

Rooibos Tea ◽

Water Contents

AbstractThe tea bag method was developed to provide uniform litter bags that enable comparison of organic matter decomposition rates on a large scale. However, it remains uncertain whether tea bag decomposition in response to wetness is representative of that of natural litters. We performed incubation experiments to examine whether the effect of soil water on tea bag decomposition becomes inhibitory at higher water contents, as was demonstrated in natural leaf litters. In addition, we performed field studies in a mixed forest and cedar plantation in Japan to compare two litter bag mesh sizes: 0.25-mm mesh, the size previously used by a major manufacturer of tea bags (Lipton), and nonwoven bags with mesh sizes finer than 0.25 mm, which are currently produced by Lipton. Both green tea and rooibos tea exhibited higher decomposition rates at higher water contents, but decomposition was inhibited at the highest water content, consistent with conceptual models of natural litters. The nonwoven tea bags did not show lower decomposition rates, despite the finer mesh size. Rather, the nonwoven rooibos tea bags exhibited slightly higher decomposition rates than the 0.25-mm mesh bags in the cedar plantation, possibly due to a greater abundance of microorganisms that decompose litters in the nonwoven bags, due to the decrease in predation by mesofauna. Our findings provide essential information for future studies of tea bag decomposition.

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Biochar addition affected nutrient leaching and litter decomposition rates in boreal sandy soils

Agricultural and Food Science ◽

10.23986/afsci.89559 ◽

2020 ◽

Vol 29 (4) ◽

Author(s):

Sanna Saarnio ◽

Riitta Kettunen

Keyword(s):

Litter Decomposition ◽

Agricultural Soils ◽

Fine Sand ◽

Nutrient Leaching ◽

N Leaching ◽

Decomposition Rates ◽

Litter Bags ◽

Total N ◽

Nutrient Analyses ◽

Total P

Effects of biochar addition on litter decomposition rates, nutrient leaching and soil moisture were tested in two boreal agricultural soils; a sandy till and a medium fine sand. Three litter bags were buried in soil basins, which were stored in the dark for 31 and 19 weeks in the sandy till experiment and medium fine sand experiment, respectively. Once per each temperature period, the soil was saturated in order to collect excess water for nutrient analyses. Biochar increased the decomposition rate of N-rich litter but did not affect the decomposition of N-poor litter. PO43--P and NO2--N were released from the biochar to the leached water and thus leaching of PO43--P, NO2--N and total P was increased in the soil with the finer texture. However, biochar retained water after heavy irrigation and leaching of PO43--P and total P was not increased on the coarser soil. Although pure biochar adsorbed NH4+-N from nutrient solutions, NH4+-N leaching from both soil types was generally not affected by biochar. Leaching of nitrate NO3--N and total N was decreased on both soils due to retention by the biochar.

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LITTER DECOMPOSITION IN Rhizophora sp. MANGROVE STANDS OF VARYING PLANTING AGES

TROPICAL WETLAND JOURNAL ◽

10.20527/twj.v2i1.19 ◽

2016 ◽

Vol 2 (1) ◽

pp. 8-14

Author(s):

Anang Kadarsah

Keyword(s):

Litter Decomposition ◽

Environmental Conditions ◽

Decomposition Rate ◽

Half Life ◽

Life Time ◽

Dry Weight ◽

Mangrove Ecosystem ◽

Litter Decomposition Rate ◽

Decomposition Coefficient ◽

Decomposition Efficiency

Information about litter decomposition in Rhizophora Sp. mangrove stands of different planting ages is very important to find out the main factors affecting the whole information on structure and function of mangrove ecosystem and to improve mangrove management in the future. The objective of this study was to determine the litter decomposition in Rhizophora sp. mangrove stands of varying planting ages, with a case study in Subang Regency, West Java Province. Comparisons of litter decomposition were taken from five stands of planting ages (4 years, 12 years, 21 years, 29 years, and 38 years old). Four parameters of litter decomposition compared were dry weight of litter, decomposition rate, litter decomposition coefficient, and half-life time. The observation on Rhizophora Sp. mangrove stands was conducted in three plots of 10 m x 10 m. The results show that the litter decomposition parameters, especially dry weight of litter, decomposition rate, litter decomposition coefficient, and half-life time, were different on each planting age of Rhizophora sp. mangrove stands. The fastest time for litter decomposition was found in 12 years old of Rhizophora Sp. stands with the achievement for 90 days of observation and the decomposition efficiency of 100%. Meanwhile, the slowest was found in 38 years old of Rhizophora Sp. mangrove stands with more than 120 days, and the litter decomposition efficiency was about 97.84%. Environmental conditions (soil and water conditions, nitrogen content, and soil fauna) play a major role on its differentiation. It can be concluded that the litter decomposition in Rhizophora sp. mangrove stands of varying planting ages change over time because of the environmental conditions, but the complexity of the relation between ages is not always apparent.

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Litter decomposition in coastal hemlock stands: impact of nitrogen fertilizers on decay rates

Canadian Journal of Forest Research ◽

10.1139/x83-017 ◽

1983 ◽

Vol 13 (1) ◽

pp. 116-121 ◽

Cited By ~ 14

Author(s):

Ranjit S. Gill ◽

Denis P. Lavender

Keyword(s):

Litter Decomposition ◽

Forest Floor ◽

Calcium Nitrate ◽

Decay Rates ◽

Nitrogen Fertilizers ◽

Western Hemlock ◽

Decomposition Rates ◽

Litter Bags ◽

Coated Urea ◽

Qualitative Measure

Urea, gypsum-coated urea, and calcium nitrate fertilizers differentially affected indigenous rates of litter decomposition on the forest floor for coastal stands of western hemlock (Tsugaheterophylla (Raf.) Sarg.). These differences were most pronounced during the first 6 months after fertilization. Urea and gypsum-coated urea both stimulated the rates of litter decomposition, although the effect of gypsum-coated urea was more gradual. In contrast, calcium nitrate somewhat retarded existing decomposition rates during the first 6 months; after 12 months, it had little or no impact. The significant (P < 0.05) positive correlation of percentage of lignin in litter with time renders it an important qualitative measure of decomposition rates in studies utilizing litter bags.

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Decomposition rate of cereal straw as affected by soil placement

Soil Research ◽

10.1071/sr07085 ◽

2008 ◽

Vol 46 (2) ◽

pp. 152 ◽

Cited By ~ 19

Author(s):

D. Curtin ◽

G. S. Francis ◽

F. M. McCallum

Keyword(s):

Crop Residues ◽

Soil Layer ◽

Soil Surface ◽

Decomposition Rates ◽

Straw Decomposition ◽

Litter Bags ◽

Litter Bag ◽

Residue Contact ◽

Co2 Output ◽

Soil Residue

Decomposition rates for crop residues have generally been estimated based on data obtained using buried litter bags. Because of limited soil–residue contact, the litter bag technique may not adequately simulate decomposition when residues are mixed through the soil. In field microplots, decomposition of wheat (Triticum aestivum) and barley (Hordeum vulgare) straw (autumn-incorporated at a rate of 7 t/ha) mixed through the 0–0.20 m soil layer was compared with straw decomposition in fibreglass bags (4-mm mesh) buried at a depth of 0.20 m. A surface-placed straw treatment and a no-straw control were included for comparison. Emissions of CO2 were monitored from the incorporated straw treatments and undecomposed straw was recovered after 158 days (mean soil temperature during the trial period was 8°C at 0.10 m). Emissions of CO2 from the soil‐mixed straw treatment were generally greater than from the buried bag treatment in the 2 months following incorporation. Output of CO2-C over the first 73 days averaged 83 g/m2 for the soil-mixed straw treatment compared with 61 g/m2 for the litter bag treatment and 34 g/m2 for the no-straw control. Over the entire trial, CO2-C attributable to straw (CO2-C output from straw-treated plots minus CO2-C emitted from the control) was 66% greater for soil‐mixed straw than for litter bag straw, indicating that within soil placement can have a strong and persistent effect on straw decomposition. Straw type had a small but significant (P < 0.05) effect on CO2 output (barley > wheat). Straw mass loss during the trial averaged 66% for soil-mixed straw, 32% for litter bag straw, and 13% for straw placed on the soil surface. The low recovery of soil‐mixed straw is partly due to difficulty of extracting small (<2 mm) residue fragments from the soil; however, such fragments could legitimately be considered part of the soil organic matter. The results confirm that straw that is well distributed through the soil may decompose more rapidly than would be anticipated from litter bag measurements.

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Decomposition of tree litter: Interaction between inherent quality and environment

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d200722 ◽

2019 ◽

Vol 20 (7) ◽

Author(s):

SYIFA RACHMAWATI ◽

TITUT YULISTYARINI ◽

KURNIATUN HAIRIAH

Keyword(s):

Home Environment ◽

Litter Quality ◽

Life Time ◽

Litter Layer ◽

Decomposition Rates ◽

Litter Bags ◽

Litter Weight ◽

Tree Litter ◽

Mature Stands ◽

Inherent Quality

Abstract. Rachmawati S, Yulistyarini T, Hairiah K. 2019. Decomposition of tree litter: Interaction between inherent quality and environment. Biodiversitas 20: 1946-1952. Litter layers protect forest soils, but may not be appreciated in recreation sites such as the Purwodadi Botanical Gardens (PBG), East Java, Indonesia. We quantified litter decomposition rates in mature stands of three tree species: mahogany (Swietenia macrophylla), angsana/narra (Pterocarpus indicus), and bungur/crape myrtle (Lagerstroemia thorelii). To separate inherent litter quality and stand-level environmental factors (such as microclimate, soil), decomposition rates were quantified for each species across all three stands. A possible interaction on decomposition rates is known as ‘home-field advantage’ (HFA). Litter-weight loss from TSBF-standard litter bags was observed at 0, 1, 2, 4, 8 and 12 weeks after litter bags were installed to estimate the half-life time (t50). We also solicited visitor views on the presence of a thick litter layer on garden floor. Decomposition of angsana (t50=48 weeks) was 15% faster at its ‘own home’ than in ‘neighbors home’. No significant HFA effects were found in bungur/crape myrtle litter that decomposed slower in its home environment, while mahogany decomposition was independent of location. Generally, PBG visitors knew the benefits of litter and were not bothered by its presence; litter increased the attractiveness for visitors to enjoy their happy days under the shade of trees in a ‘tropical autumn’.

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Covalent Complexes Between Low Molecular Weight Heparin Fragments and Antithrombin III – Inhibition Kinetics and Turnover Parameters

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657333 ◽

1983 ◽

Vol 49 (02) ◽

pp. 109-115 ◽

Cited By ~ 4

Author(s):

M Hoylaerts ◽

E Holmer ◽

M de Mol ◽

D Collen

Keyword(s):

Molecular Weight ◽

Half Life ◽

Low Molecular Weight Heparin ◽

Antithrombin Iii ◽

Factor Xa ◽

Life Time ◽

Low Molecular Weight ◽

High Affinity ◽

Plasma Half Life ◽

Covalent Complex

SummaryTwo high affinity heparin fragments (A/r 4,300 and M, 3,200) were covalently coupled to antithrombin III (J. Biol. Chem. 1982; 257: 3401-3408) with an apparent 1:1 stoichiometry and a 30-35% yield.The purified covalent complexes inhibited factor Xa with second order rate constants very similar to those obtained for antithrombin III saturated with these heparin fragments and to that obtained for the covalent complex between antithrombin III and native high affinity heparin.The disappearance rates from plasma in rabbits of both low molecular weight heparin fragments and their complexes could adequately be represented by two-compartment mammillary models. The plasma half-life (t'/j) of both low Afr-heparin fragments was approximately 2.4 hr. Covalent coupling of the fragments to antithrombin III increased this half-life about 3.5 fold (t1/2 ≃ 7.7 hr), approaching that of free antithrombin III (t1/2 ≃ 11 ± 0.4 hr) and resulting in a 30fold longer life time of factor Xa inhibitory activity in plasma as compared to that of free intact heparin (t1/2 ≃ 0.25 ± 0.04 hr).

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Simultaneous optimization of activity and stability of xylose reductase from D. nepalensis NCYC 3413 using statistical experimental design

Protein and Peptide Letters ◽

10.2174/0929866527666201103145246 ◽

2020 ◽

Vol 27 ◽

Author(s):

Shwethashree Malla ◽

Sathyanarayana N. Gummadi

Keyword(s):

Half Life ◽

Specific Activity ◽

Enzyme Stability ◽

Reductase Activity ◽

Xylose Reductase ◽

Life Time ◽

Economic Feasibility ◽

Simultaneous Optimization ◽

Physical Parameters ◽

Statistical Experimental Design

Background: Physical parameters like pH and temperature play a major role in the design of an industrial enzymatic process. Enzyme stability and activity are greatly influenced by these parameters; hence optimization and control of these parameters becomes a key point in determining the economic feasibility of the process. Objective: This study was taken up with the objective to optimize physical parameters for maximum stability and activity of xylose reductase from D. nepalensis NCYC 3413 through separate and simultaneous optimization studies and comparison thereof. Method: Effects of pH and temperature on the activity and stability of xylose reductase from Debaryomyces nepalensis NCYC 3413 were investigated by enzyme assays and independent variables were optimised using surface response methodology. Enzyme activity and stability were optimised separately and concurrently to decipher the appropriate conditions. Results: Optimized conditions of pH and temperature for xylose reductase activity were determined to be 7.1 and 27 ℃ respectively, with predicted responses of specific activity (72.3 U/mg) and half-life time (566 min). The experimental values (specific activity 50.2 U/mg, half-life time 818 min) were on par with predicted values indicating the significance of the model. Conclusion: Simultaneous optimization of xylose reductase activity and stability using statistical methods is effective as compared to optimisation of the parameters separately.

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