Nutrient changes and release during decomposition of leaf litter in a Himalayan oak–conifer forest

1984 ◽  
Vol 62 (9) ◽  
pp. 1824-1831 ◽  
Author(s):  
Uma Pandey ◽  
J. S. Singh
Keyword(s):  
Leaf Litter ◽  
Water Soluble ◽  
Conifer Forest ◽  
Cedrus Deodara ◽  
Litter Bags ◽  
Absolute Increase ◽  
Absolute Mass ◽  
The Absolute ◽  
Nutrient Changes ◽  
Quercus Floribunda

Changes in nitrogen, calcium, water-soluble compounds, and total available carbohydrate in decomposing leaf litter of six tree and one shrub species, enclosed in nylon net bags and placed in a mixed oak conifer forest, were examined for a period of 487 days. The concentration of nitrogen increased during decomposition in all litter species. This increase was up to threefold in Aesculus indica, Quercus floribunda, and Quercus leucotrichophora. In most species the absolute increase in nitrogen mass was observed when decomposition had progressed up to 213 days. However, in Daphne cannabina and Ilex dipyrena, the absolute mass of nitrogen was never greater than the initial mass at any stage of decomposition. The absolute mass of calcium in litter bags generally declined with time. The concentration of water-soluble compounds and of total available carbohydrates varied from species to species; both these constituents, however, continually decreased with the progress of decomposition. Within 1 year, the release of nitrogen, water-soluble compounds, and total available carbohydrates was 100% in D. cannabina, A. indica, and I. dipyrena. In Cedrus deodara, Q. floribunda, and Q. leucotrichophora about 50% of total nitrogen input to the forest floor as litter fall was released by decomposition. In Cupressus torulosa only 14% of nitrogen falling as leaf litter was released during a period of 1 year.

scholarly journals Leaf Litter Decomposition of Two Central Himalayan Oaks

2015 ◽  
Vol 10 (2) ◽  
pp. 509-516 ◽  
Author(s):  
Kirtika Padalia ◽  
Rajendra Parihaar ◽  
Nidhi Bhakuni ◽  
Bhawana Kapkoti
Keyword(s):  
Weight Loss ◽  
Leaf Litter ◽  
Rate Coefficient ◽  
Climatic Factors ◽  
Average Weight ◽  
Oak Forest ◽  
Litter Bags ◽  
Litter Bag ◽  
Quercus Floribunda ◽  
Quercus Leucotrichophora

The study was conducted in two natural oak forest of Nainital (Uttarakhand) India, during 2012-2013 to determine the weight loss pattern in leaf litter of two Central Himalayan Oaks (i.e., Quercus leucotrichophora A. Camus. and Quercus floribunda Lindl.) with the help of litter bag technique. The present study concluded that weight loss proceeded throughout the study period and relatively higher within 60 days after the placement of litter bags into the soil. Among these two species, higher weight loss observed in Q. floribunda as compared to Q. leucotrichophora across both the sites. Within 365 days, average weight loss observed about 60% in Q. leucotrichophora and 62% in Q. floribunda. Decay rate coefficient rate ranged from 0.0596- 0.0014 for Q. leucotrichophora while it varies from 0.0558 to 0.0013 for Q. floribunda. The monthly relative decomposition rate (RDR) ranged between 0.0598-0.0014 g/g/day and 0.0208-0.0050 g/g/day for Q. leucotrichophora and Q. floribunda, respectively. Climatic factors (rainfall, temperature and relative humidity) also influenced the rate of decomposition.

Ants accelerate litter decomposition in a Costa Rican lowland tropical rain forest

2012 ◽  
Vol 28 (5) ◽  
pp. 437-443 ◽  
Author(s):  
Terrence P. McGlynn ◽  
Evan K. Poirson
Keyword(s):  
Mass Loss ◽  
Leaf Litter ◽  
Litter Decomposition ◽  
Rain Forest ◽  
Costa Rican ◽  
Tropical Rain Forests ◽  
Rain Forests ◽  
Food Web Structure ◽  
Litter Bags ◽  
Lowland Rain Forest

Abstract:The decomposition of leaf litter is governed, in part, by litter invertebrates. In tropical rain forests, ants are dominant predators in the leaf litter and may alter litter decomposition through the action of a top-down control of food web structure. The role of ants in litter decomposition was investigated in a Costa Rican lowland rain forest with two experiments. In a mesocosm experiment, we manipulated ant presence in 50 ambient leaf-litter mesocosms. In a litterbag gradient experiment, Cecropia obtusifolia litter was used to measure decomposition rate constants across gradients in nutrients, ant density and richness, with 27 separate litterbag treatments for total arthropod exclusion or partial arthropod exclusion. After 2 mo, mass loss in mesocosms containing ants was 30.9%, significantly greater than the 23.5% mass loss in mesocosms without ants. In the litter bags with all arthropods excluded, decomposition was best accounted by the carbon: phosphorus content of soil (r2 = 0.41). In litter bags permitting smaller arthropods but excluding ants, decomposition was best explained by the local biomass of ants in the vicinity of the litter bags (r2 = 0.50). Once the microarthropod prey of ants are permitted to enter litterbags, the biomass of ants near the litterbags overtakes soil chemistry as the regulator of decomposition. In concert, these results support a working hypothesis that litter-dwelling ants are responsible for accelerating litter decomposition in lowland tropical rain forests.

scholarly journals Post-fire consequences for leaf breakdown in a tropical stream

2019 ◽  
Vol 31 ◽  
Author(s):  
Renan de Souza Rezende ◽  
Cristiano Queiroz de Albuquerque ◽  
Andrezza Sayuri Victoriano Hirota ◽  
Paulo Fernandes Roges Souza Silva ◽  
Ricardo Keichi Umetsu ◽  
...  
Keyword(s):  
Leaf Litter ◽  
Fungal Biomass ◽  
Mesh Size ◽  
Fire Effects ◽  
Dry Mass ◽  
Tropical Stream ◽  
Fire Event ◽  
Litter Bags ◽  
Fine Mesh ◽  
Post Fire Effects

Abstract Aim Wildfire is a natural pulsed disturbance in landscapes of the Savannah Biome. This study evaluates short-term post-fire effects on leaf litter breakdown, the invertebrate community and fungal biomass of litter from three different vegetal species in a tropical stream. Methods Senescent leaves of Inga laurina, Protium spruceanum and Rircheria grandis (2 ± 0.1 g dry mass) were individually placed in litter bags (30 × 30 cm: 10 mm coarse mesh and 0.5 mm fine mesh) and submerged in the study stream before and after fire. Replicate bags (n = 4; individually for each species, sampling time, fire event and mesh size) were then retrieved after 20 and 40 days and washed to separate the invertebrates before fire event and again immediately after fire. Disks were cut from leaves to determine ash-free dry mass, while the remaining material was oven-dried to determine dry mass. Results The pre-fire mean decomposition coefficient (k = -0.012 day-1) was intermediate compared to that reported for other savannah streams, but post-fire it was lower (k = -0.007 day-1), due to decreased allochthonous litter input and increased autochthones production. Intermediate k values for all qualities of litter post-fire may indicate that fire is equalizing litter quality in the stream ecosystem. The abundance of scrapers was found to be more important than fungal biomass or shredder abundance, probably due to their functioning in leaf fragmentation while consuming periphyton growing on leaf litter. Conclusions Theses results indicate that fire can modify the relationships within decomposer communities in tropical stream ecosystems.

COMPARATIVE EVALUATION OF THE USE OF FEED WITH DIFFERENT PROTEIN CONTENT FOR GROWING PILENGAS UNDER CONTROLLED CONDITIONS

2020 ◽  
Author(s):  
D.S. Tazhbaeva ◽  
◽  
M.V. Kovalenko ◽  
Keyword(s):  
Trace Elements ◽  
Protein Content ◽  
Comparative Evaluation ◽  
High Protein ◽  
Absolute Increase ◽  
Controlled Conditions ◽  
The Absolute ◽  
Protein Feed ◽  
Minerals And Trace Elements

Linear-weight indicators of pilengas growth were analyzed when using feed with different protein content. When fed with granulated high – protein feed (52%), the absolute increase was 8.7 g, and the average daily increase was 0.29 g/day. Feed with a protein content of 45% showed less growth results (absolute-4.4 g, average daily-0.15 g/day). This result is due to the high content of protein, fat, vitamins, minerals and trace elements.

Abstract WMP51: Risk and Timing of of Ischemic Stroke Following Acute Myocardial Infarction

Stroke ◽  
2017 ◽  
Vol 48 (suppl_1) ◽  
Author(s):  
Alexander E Merkler ◽  
Gino Gialdini ◽  
Santosh Murthy ◽  
Shadi Yaghi ◽  
Babak Navi ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Ischemic Stroke ◽  
Stroke Risk ◽  
Absolute Risk ◽  
Absolute Increase ◽  
Risk Increase ◽  
Immortal Time Bias ◽  
Acute Mi ◽  
The Absolute

Background: Acute myocardial infarction (MI) has long been reported as a risk factor for ischemic stroke, but the magnitude and duration of risk remains uncertain. Methods: We performed a crossover-cohort study using inpatient and outpatient claims data from a nationally representative 5% sample of Medicare beneficiaries from 2008 through 2014. We identified all patients ≥66 years of age with a first-recorded hospitalization for acute MI. The primary outcome was ischemic stroke. All predictors and outcomes were defined using previously validated ICD-9-CM codes. To exclude stroke that may have been due to percutaneous coronary intervention, we included only cases of ischemic stroke that occurred after discharge from the MI hospitalization. We compared the risk of ischemic stroke in successive 4-week periods during the 12 weeks after MI versus the corresponding 4-week periods 1 year later. To avoid immortal time bias, we limited our cohort to patients who remained alive and insured throughout the 15 month study period. Odds ratios (OR) and absolute risk differences were calculated using the Mantel-Haenszel estimator for matched data. Results: We identified 22,798 patients with an acute MI in whom the mean age was 77.4 (±7.9) years and 50.3% were women. In the 12 weeks after discharge, 216 patients (0.95%) developed a stroke, as compared to 21 (0.09%) patients in the corresponding 12-week period 1 year later. The absolute increase in stroke risk was 0.45% (95% confidence interval [CI], 0.36-0.55%) in the first 4 weeks after acute MI compared to the 4-week time period 1 year later, corresponding to an OR of 18.2 (95% CI, 8.1-50.6). The absolute risk increase was 0.24% (95% CI, 0.16-0.31%) during weeks 5-8 (OR, 8.7; 95% CI, 4.0-22.6) and 0.17% (95% CI, 0.10-0.23%) during weeks 9-12 (OR, 5.8; 95% CI, 2.7-14.1). Conclusions: Acute MI is associated with a substantially elevated short-term risk of ischemic stroke. This risk was independent of periprocedural stroke risk in the setting of coronary reperfusion therapies.

Decomposition of Populustremuloides leaf litter accelerated by addition of Alnuscrispa litter

1989 ◽  
Vol 19 (5) ◽  
pp. 674-679 ◽  
Author(s):  
Barry R. Taylor ◽  
William F. J. Parsons ◽  
Dennis Parkinson
Keyword(s):  
Mass Loss ◽  
Leaf Litter ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Rocky Mountain ◽  
Litter Type ◽  
Litter Bags ◽  
Mass Losses ◽  
Mixed Litter ◽  
Aspen Forest

Decomposition of a slow-decaying litter type is expected to be faster in the presence of a nutrient-rich, fast-decaying litter type, but this effect has never been conclusively demonstrated for deciduous leaves. In a Rocky Mountain aspen forest, we followed decomposition of leaf litter of trembling aspen (Populustremuloides), a relatively slow-decomposing, nutrient-poor species, and green alder (Alnuscrispa), a nutrient-rich, faster-decomposing species, as well as a mixture of the two, for 2 years. Mass losses over the first winter were greatest for aspen alone, probably as a result of loss of solubles, but the mass loss rate overall was lowest for aspen (k = −0.191/year) and greatest for alder (k = −0.251/year). Mass loss rate for mixed litter (k = −0.245/year) was much closer to the rate for alder than for aspen, demonstrating a marked acceleration of mass loss rates in the mixed-litter bags. At these rates, 95% mass loss would be achieved by aspen, alder, and mixed litter in 14.5, 11.5, and 11.6 years, respectively.

scholarly journals Contributions of organic matter and nutrients via leaf litter in an urban tropical dry forest fragment

2018 ◽  
Vol 66 (2) ◽  
pp. 571 ◽  
Author(s):  
Jeiner Castellanos-Barliza ◽  
Juan Diego León-Peláez ◽  
Rosalba Armenta-Martínez ◽  
Willinton Barranco-Pérez ◽  
William Caicedo-Ruíz
Keyword(s):  
Organic Matter ◽  
Leaf Litter ◽  
Tropical Dry Forest ◽  
Soil Surface ◽  
Dry Forest ◽  
Litter Production ◽  
Forest Fragment ◽  
Litter Bags ◽  
One Year ◽  
Degraded Ecosystems

The litterfall and decomposition represent the main transfer of organic matter and nutrients from the vegetation to the soil surface and determine positive trajectories in the process of rehabilitating and restoring degraded ecosystems. The aim of this study was to evaluate the contributions of organic materials and nutrients through the characterization of fine litter in an urban dry forest fragment. Litter production was monitored for one year by collecting 29 traps (0.5 m2). To evaluate leaf nutrient resorption, green leaves were collected from 5-10 individuals that represented the dominant tree species. Litter-bags (20 x 20 cm, 2 mm pore) were used for six months to evaluate the decomposition of leaf litter. Annual fine litter production was found to be 8 574 kg ha-1, with the Cordia alba species contributing the most leaf litter (1 134 kg ha-1) and nutrients (N: 6.16; P: 0.21; Ca: 4.72; Mg: 0.47; K: 1.27 kg ha-1). Decomposition rates (k constant) followed the decreasing order: C. alba (k: 4.6) > Machaerium milleflorum (k: 3.5). M. milleflorum and Albizia niopoides presented a pattern of rapid N and P release in the first 30 days, with more than 80 % and 60 % released from M. milleflorum and C. alba, respectively, by the end of the experiment. The litterfall monitoring carried out in this urban dry forest fragment revealed some important aspects of the functioning of an ecosystem as seriously threatened as the tropical dry forest. Rev. Biol. Trop. 66(2): 571-585. Epub 2018 June 01. 

scholarly journals Desert leaf litter decay: Coupling of microbial respiration, water-soluble fractions and photodegradation

2018 ◽  
Vol 24 (11) ◽  
pp. 5454-5470 ◽  
Author(s):  
Thomas A. Day ◽  
Michael S. Bliss ◽  
Alexander R. Tomes ◽  
Christopher T. Ruhland ◽  
René Guénon
Keyword(s):  
Leaf Litter ◽  
Microbial Respiration ◽  
Water Soluble ◽  
Litter Decay ◽  
Soluble Fractions
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