Decomposition of Bauhinia purpurea leaf litter in a polluted and unpolluted Hong Kong waterway

1992 ◽  
Vol 70 (5) ◽  
pp. 1061-1070 ◽  
Author(s):  
D. W. T. Au ◽  
I. J. Hodgkiss ◽  
L. L. P. Vrijmoed
Keyword(s):  
Leaf Litter ◽  
Heterotrophic Bacteria ◽  
Seasonal Pattern ◽  
Oxygen Demand ◽  
Ash Content ◽  
Litter Bags ◽  
Forest Stream ◽  
Key Words Decomposition ◽  
Exponential Decay Model ◽  
Bauhinia Purpurea

Decomposition of Bauhinia purpurea L. leaves in litter bags submerged in the Tai Po Kau Forest Stream (TPKFS) and the Lam Tsuen River (LTR) was investigated during the winter of 1988 and the summer of 1989. At every collection, temperature, pH, turbidity, dissolved oxygen, and biological oxygen demand (BOD5) were measured. In winter, the organically enriched LTR was categorized as polluted based on BOD5, turbidity, and heterotrophic bacteria counts, whereas the TPKFS was always relatively clean. Weight loss of leaf litter at both sites was very rapid when compared with published values and exhibited a distinct seasonal pattern. The decomposition rate of leaf litter (using the single exponential decay model) varied linearly with mean water temperature. Carbon content of the leaf litter decreased during decomposition and was, as expected, negatively correlated with the percent ash content. Except in the first 2 weeks, the nitrogen content of decomposing leaf litter decreased with time at a rate correlated with the abundance of heterotrophic bacteria in winter leaf litter (insufficient data were available in summer). Based on the results of the winter study only, the decomposition of leaf litter seems to be suppressed in the polluted river. Key words: decomposition, carbon, nitrogen, water pollution, heterotrophic bacteria.

Fungi and cellulolytic activity associated with decomposition of Bauhinia purpurea leaf litter in a polluted and unpolluted Hong Kong waterway

1992 ◽  
Vol 70 (5) ◽  
pp. 1071-1079 ◽  
Author(s):  
D. W. T. Au ◽  
I. J. Hodgkiss ◽  
L. L. P. Vrijmoed
Keyword(s):  
Leaf Litter ◽  
Geotrichum Candidum ◽  
Aquatic Hyphomycetes ◽  
Cellulolytic Activity ◽  
Mucor Racemosus ◽  
Trichoderma Spp ◽  
Complementary Sequence ◽  
Forest Stream ◽  
Bauhinia Purpurea

A survey of fungal succession on decomposing Bauhinia purpurea L. leaves in the unpolluted Tai Po Kau Forest Stream (TPKFS) and the animal waste polluted Lam Tsuen River (LTR) was carried out during the winter of 1988 and the summer of 1989. In situ cellulolytic activity of the TPKFS leaf litter was also investigated. Most of the 28 aquatic hyphomycete species found were cosmopolitan or frequently reported in temperate regions. Clavariopsis aquatica De Wildeman, Lunulospora cymbiformis Miura, and Flagellospora penicillioides Ingold were the dominant species at both sites. Among the 49 geofungi species recorded, lymaphilic species were commonly observed in the polluted LTR (e.g., Geotrichum candidum Link ex Leman, Fusarium oxysporum Schlecht, and Mucor racemosus Fres.) and lymaxenes in the TPKFS (e.g., Humicola spp., Trichoderma spp. and Gliocladium roseum Bain.). Species richness of aquatic hyphomycetes was higher in the TPKFS (27 species) than in the polluted LTR (14 species), whereas for the associated geofungi, it was higher in the LTR (35 species) than in the TPKFS (28 species). Conidial production was also higher in the TPKFS. Aquatic hyphomycetes and geofungi showed a complementary sequence of dominance in winter and summer, respectively, in the clean TPKFS. Higher cellulolytic activity occurred in the winter than the summer leaf litter. Key words: aquatic hyphomycetes, geofungi, leaf litter, pollution, cellulolytic activity.

scholarly journals Bacterial (9A2H) enhancement alters the nematode community structure and decomposition pathway of amended nutrient-limited soil

2020 ◽  
Vol 21 (10) ◽  
Author(s):  
DEMA R. LUCKYANA ◽  
I G. A. AYU RATNA PUSPITASARI ◽  
Ardhini R Maharning
Keyword(s):  
Community Structure ◽  
Food Web ◽  
Decomposition Rate ◽  
Heterotrophic Bacteria ◽  
Community Response ◽  
Nematode Community ◽  
Litter Bags ◽  
Litter Bag ◽  
Exponential Decay Model ◽  
Decomposition Pathway

Abstract. Luckyana DR, Puspitasari IGAAR, Maharning AR. 2020. Bacterial (9A2H) enhancement alters the nematode community structure and decomposition pathway of amended nutrient-limited soil. Biodiversitas 21: 4813-4820. This study examined the influence of paddy litter amendment and bacterial enhancement of nutrient-limited soil on the nematode community structure and investigated the decomposition rate of the litter due to the treatment. We applied a microcosm-based approach using sand as the medium, including the following treatments: no-bacteria, 9A-autotrophic-bacteria, 2H-heterotrophic-bacteria, and 9A-2H-mix-bacteria, with five replicates. The litter bag experiment and exponential decay model estimated the litter decomposition rate in the microcosm. The soil samples and litter bags were retrieved after days 21, 42, and 63. The structure, enrichment, channel index (CI), and canonical correspondence analysis were employed to investigate the nematode community response. Bacterial enhancement shifted the nematode community and the soil food web toward the dominant bacterial pathway by day 63 (CI: 0), with a slightly less structured food web that was supported by bacterivorous nematodes mostly related to available nutrients. These changes coincided with soil organic carbon and nitrogen increases over time. Our experiments showed that paddy litter amendment and the 9A, 2H, and 9A-2H-mix bacterial enhancements improved nutrient-limited soil, according to the analysis of the nematode community, its composition, and the food web conditions determining nutrient mobility and availability. However, these factors have no impact on the litter decay rate.

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.

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 Seasonal Pattern of Decomposition and N, P, and C Dynamics in Leaf litter in a Mongolian Oak Forest and a Korean Pine Plantation

Forests ◽  
2014 ◽  
Vol 5 (10) ◽  
pp. 2561-2580 ◽  
Author(s):  
Jaeeun Sohng ◽  
Ah Han ◽  
Mi-Ae Jeong ◽  
Yunmi Park ◽  
Byung Park ◽  
...  
Keyword(s):  
Leaf Litter ◽  
Seasonal Pattern ◽  
Oak Forest ◽  
Korean Pine ◽  
Pine Plantation ◽  
C Dynamics ◽  
Korean Pine Plantation ◽  
Mongolian Oak

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 Hydrothermal Carbonization as a Strategy for Sewage Sludge Management: Influence of Process Withdrawal Point on Hydrochar Properties

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2890 ◽  
Author(s):  
Fabio Merzari ◽  
Jillian Goldfarb ◽  
Gianni Andreottola ◽  
Tanja Mimmo ◽  
Maurizio Volpe ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Oxygen Demand ◽  
Hydrothermal Carbonization ◽  
Volatile Matter ◽  
Ash Content ◽  
Process Conditions ◽  
Conventional Activated Sludge ◽  
Phosphorous Content ◽  
Sewage Sludge Management ◽  
Ph Decrease

Conventional activated sludge systems, still widely used to treat wastewater, produce large amounts of solid waste that is commonly landfilled or incinerated. This study addresses the potential use of Hydrothermal Carbonization (HTC) to valorize sewage sludge residues examining the properties of hydrochars depending on HTC process conditions and sewage sludge withdrawal point. With increasing HTC severity (process residence time and temperature), solid yield, total Chemical Oxygen Demand (COD) and solid pH decrease while ash content increases. Hydrochars produced from primary (thickened) and secondary (digested and dewatered) sludge show peculiar distinct properties. Hydrochars produced from thickened sludge show good fuel properties in terms of Higher Heating Value (HHV) and reduced ash content. However, relatively high volatile matter and O:C and H:C ratios result in thermal reactivity significantly higher than typical coals. Both series of carbonized secondary sludges show neutral pH, low COD, enhanced phosphorous content and low heavy metals concentration: as a whole, they show properties compatible with their use as soil amendments.

Phenological changes in a Sumatran rain forest

1986 ◽  
Vol 2 (4) ◽  
pp. 327-347 ◽  
Author(s):  
C. P. Van Schaik
Keyword(s):  
Leaf Litter ◽  
Rain Forest ◽  
Seasonal Pattern ◽  
Dry Season ◽  
Wet Season ◽  
Phenological Changes ◽  
Young Leaves ◽  
Fig Trees ◽  
One Year ◽  
Made In

ABSTRACTPhenological observations were made in a Sumatran rain forest during three years (1980–1982). Phenological changes followed a consistent seasonal pattern. The abundance of young leaves and the fall of leaf litter peaked between December and February (first dry season); flowers were most abundant between January and April (first dry and first wet sea son), and ripe fruits in July-August (the second dry season). The fruit of strangling fig trees showed peaks in April and October, both wet season months. Within the study area there was variation in both the phase and the amplitude of the phenological cycles. One year, 1981, displayed mast flowering and fruiting. The observations indicate that the conditions for production were better during the mast year, a finding that facilitates our understanding of the evolution of mast fruiting.

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