scholarly journals Transport and consumption of organic detritus in a neotropical limestone cave

2012 ◽  
Vol 41 (1) ◽  
Author(s):  
Marconi Souza Silva ◽  
Leopoldo Ferreira de Oliveira Bernardi ◽  
Rogério Parentoni Martins ◽  
Rodrigo Lopes Ferreira
Keyword(s):  
Organic Matter ◽  
Energy Flow ◽  
Organic Detritus ◽  
Coarse Particulate Organic Matter ◽  
Limestone Cave ◽  
Photosynthetic Organisms ◽  
Plant Matter ◽  
Detritus Processing ◽  
Allochthonous Resources ◽  
Subterranean Environment

Caves are permanently aphotic environments, a fact that precludes the occurrence of photosynthetic organisms. In these systems the resource is allochthonous, coming mainly from the surrounding epigean environment, being imported by physical and biological agents. Even knowing about the importance of the organic allochthonous resources in caves, little is known of their importation and processing. The present work had as an objective, the measuring the coarse particulate organic matter processing and import rates in the subterranean environment. The cave studied was Lapa da Fazenda Extrema I, limestone cave, located in Brazilian savanna biome. Through bimonthly collections, it was observed that the organic detritus penetrated into the cave in low amounts in dry season and high amounts in rainy season. The processing of the organic plant matter in the aquatic hypogean environment was moderate (K-day=0.025), in the epigean environment the processing was predominantly slow (K-day =0.0104). The detritus commonly brought to the interior of the cave were large woods (58.18 g/day), followed by leaves and fragmented material (12.76 g/day), fruits and seeds (0.0069 g/day), animal carcasses (0.002 g/day) and roots (0.001 g/day). The highest richness and abundances of invertebrates were found in the same periods in which there were the highest rates of organic matter import to the cave.Keywords: cave, detritus processing, energy flow.

scholarly journals Lipid biomarkers in Holocene and glacial sediments from ancient Lake Ohrid (Macedonia, Albania)

2010 ◽  
Vol 7 (11) ◽  
pp. 3473-3489 ◽  
Author(s):  
J. Holtvoeth ◽  
H. Vogel ◽  
B. Wagner ◽  
G. A. Wolff
Keyword(s):  
Organic Matter ◽  
Lipid Biomarkers ◽  
Lake Ohrid ◽  
Labile Organic Matter ◽  
Glacial Sediments ◽  
Plant Matter ◽  
Lipid Biomarker ◽  
First Results ◽  
Near Shore

Abstract. Organic matter preserved in Lake Ohrid sediments originates from aquatic and terrestrial sources. Its variable composition reflects climate-controlled changes in the lake basin's hydrology and related organic matter export, i.e. changes in primary productivity, terrestrial plant matter input and soil erosion. Here, we present first results from lipid biomarker investigations of Lake Ohrid sediments from two near-shore settings: site Lz1120 near the southern shore, with low-lying lands nearby and probably influenced by river discharge, and site Co1202 which is close to the steep eastern slopes. Variable proportions of terrestrial n-alkanoic acids and n-alkanols as well as compositional changes of ω-hydroxy acids document differences in soil organic matter supply between the sites and during different climate stages (glacial, Holocene, 8.2 ka cooling event). Changes in the vegetation cover are suggested by changes in the dominant chain length of terrestrial n-alkanols. Effective microbial degradation of labile organic matter and in situ contribution of organic matter derived from the microbes themselves are both evident in the sediments. We found evidence for anoxic conditions within the photic zone by detecting epicholestanol and tetrahymanol from sulphur-oxidising phototrophic bacteria and bacterivorous ciliates and for the influence of a settled human community from the occurrence of coprostanol, a biomarker for human and animal faeces (pigs, sheep, goats), in an early Holocene sample. This study illustrates the potential of lipid biomarkers for future environmental reconstructions using one of Europe's oldest continental climate archives, Lake Ohrid.

Effects of tributary size on the resource supply and physical habitat at tributary junctions along two mainstem rivers

2020 ◽  
Vol 77 (8) ◽  
pp. 1393-1408
Author(s):  
David A. Tavernini ◽  
John S. Richardson
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Main Stem ◽  
Spatiotemporal Variability ◽  
Physical Habitat ◽  
Resource Concentration ◽  
Coarse Particulate Organic Matter ◽  
Substrate Size ◽  
High Concentrations ◽  
Diel Period

Tributary junctions are regarded as ecologically important due to unique habitat present; however, there is limited understanding of the drivers of habitat attributes at these locations. Using six sites across two mainstem rivers, we tested whether tributary size relative to main stem governs the strength and direction of response of substrate size, stream temperature, and nutrient and coarse particulate organic matter (CPOM) concentration. We found that only phosphorus and CPOM concentration showed a significant relationship with relative tributary size. Small tributaries contributed high concentrations, whereas concentrations in larger tributaries resembled the main stem. Often, tributary exports were enough to increase the resource concentration in the main stem by 40%. Substrate coarsened by ∼60% downstream of tributaries. Temperature asynchrony was observed, where tributaries contributed water between 2.8 °C cooler to 1.9 °C warmer than the main stem within one diel period. Our results highlight the importance of small tributaries for whole network functioning. However, large spatiotemporal variability revealed how habitat attributes are highly context-dependent in these locations and may be difficult to predict in both scientific and management settings.

scholarly journals Coarse particulate organic matter in the interstitial zone of three French headwater streams

2012 ◽  
Vol 48 (3) ◽  
pp. 303-313 ◽  
Author(s):  
Julien Cornut ◽  
Arnaud Elger ◽  
Axel Greugny ◽  
Maelys Bonnet ◽  
Eric Chauvet
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Headwater Streams ◽  
Coarse Particulate Organic Matter

THE BOTTOM SEDIMENTS OF LAKE LAUZON, MONTCALM COUNTY, PROVINCE OF QUEBEC: I. CHEMICAL AND PHYSICAL INVESTIGATIONS

1952 ◽  
Vol 30 (4) ◽  
pp. 219-242 ◽  
Author(s):  
Herman Kleerekoper ◽  
F. Grenier
Keyword(s):  
Organic Matter ◽  
Bottom Sediments ◽  
Surface Sediments ◽  
Microscopical Study ◽  
Wood Fibers ◽  
Loss On Ignition ◽  
Average Chemical Composition ◽  
Organic Detritus ◽  
Total N ◽  
Plant Detritus

Macroscopic, microscopic and chemical examinations of 287 bottom samples collected in Lake Lauzon, Montcalm County, P.Q. by means of core sampler, combination sounding weight and Ekman dredge showed that most of the bottom of the lake is covered with dark brown to blackish sludge whose thickness varies from 3.5 to more than 350 mm. It is of semiliquid nature but becomes colloidal in well defined areas. The suspensions contain hydrogen sulphide. The water content varied between 31 and 95%. The highest loss on ignition observed was 75.0%, in the deeper parts of the lake. The ratio varies [Formula: see text] between 15.0 and 64.7. It is estimated that lignin accounts for half of the organic matter of the surface bottom deposits. Nitrogen varies between 0.00 and 1.68%. Samples with high loss on ignition contained also the higher amounts of nitrogen. The ratio [Formula: see text] varies between 0.00 and 3.09. There was no correlation between the location of the sample in the lake and this ratio. Silica content is closely related to depth and to position in relation to the shore. In the deepest part (24.4 m.), 32.7% was found. One sample contained 82.4% silica. Calcium varied between 0.34 and 1.69% in the surface sediments. There is no correlation between depth and calcium content. The ratio Ca/Mg varies between 1.55 and 29.0. In half of the samples it was between 2 and 4. Samples with a higher ratio (above 20) contained slightly more nitrogen than the average for all samples (0.04). Phosphorus varied between traces and 0.42%. Samples with higher loss on ignition contained generally the highest amount of phosphorus, although some exceptions were observed. A large part of the phosphorus in the surface sediments seemed to be in organic form. There was no apparent correlation between iron and phosphorus contents. About one-third of the samples contained more than 1% iron. Values for this element varied between 0.19 and 3.87%. The average chemical composition in % dry weight of all surface bottom sediments was: loss on ignition 45.6; crude lignin 17.08; ashes 54.4; total N 0.94; SiO2 46.0; Al2O3 7.11; Ca 0.87; Mg 0.21; total P 0.14; total Fe 1.02; percentage of water 84.9. For a chemical and microscopical study of the subsurface strata, 128 cores were taken. The bacteriology of these samples was described elsewhere. The surface layer of sludge is underlain by different layers which were classified as amorphous organic matter, nonfibrous plant detritus, fibrous plant detritus, sandy organic detritus, sandy clay, fine sand and coarse sand. A profile of the lake bottom was prepared to a depth of about 40 cm. Chemical analyses were carried on for the surface samples. A study was made of the relative abundance in all samples of diatoms, sponge spicules, pollen grains, wood fibers, remains of mosses, plankton and tubes of worms.

Hydrologic and Riparian Influences on the Import and Storage of Coarse Particulate Organic Matter in a Prairie Stream

1988 ◽  
Vol 45 (4) ◽  
pp. 655-665 ◽  
Author(s):  
Martin E. Gurtz ◽  
G. Richard Marzolf ◽  
Keith T. Killingbeck ◽  
David L. Smith ◽  
J. Vaun McArthur
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Riparian Vegetation ◽  
River Continuum Concept ◽  
Hydrologic Regime ◽  
River Continuum ◽  
Coarse Particulate Organic Matter ◽  
Continuum Concept ◽  
And Storage ◽  
Prairie Stream

The hydrologic regime and zonation of riparian vegetation influenced the quantity and quality of coarse particulate organic matter (CPOM; >1 mm) stored in the channel and upper bank of a prairie stream. In a 5.4-km intermittent reach of the South Branch of Kings Creek on Konza Prairie, Kansas, total annual import was lowest in headwater reaches and increased downstream. Total storage of benthic CPOM in the dry channel and on the bank before the flow period was highest in the fourth- and fifth-order gallery forest zone (999 g ash-free dry mass∙m−2) and less in upstream reaches (320–341 g∙m−2). These longitudinal patterns of CPOM annual import and storage (before the flow period) were opposite those predicted by the river continuum concept for streams draining forested regions. Following flow, headwater channels had more CPOM (291 g∙m−2) than downstream reaches. On the bank, storage was always highest in downstream reaches. Composition of CPOM both in the channel and on the bank varied with changes in riparian vegetation; grass tissues dominated in headwater channels, while wood and leaves of trees and shrubs were more abundant downstream. During the flow period, storage of CPOM increased only in headwater channels, where retention was high despite the lack of woody debris. In this intermittent prairie stream, benthic CPOM may not contribute consistently to the terrestrial/aquatic linkages that are suggested in the river continuum concept because of (1) a paucity of large CPOM sources (e.g. trees, shrubs) in the upper reaches and (2) a hydrologic regime that reduces the amount, as well as the predictability, of stored CPOM. The biota of prairie streams must have opportunistic food gathering and reproductive strategies to take advantage of variable food resources in a flow environment that is itself very unpredictable.

scholarly journals Environmental heterogeneity affects input, storage, and transformation of coarse particulate organic matter in a floodplain mosaic

2012 ◽  
Vol 75 (3) ◽  
pp. 335-348 ◽  
Author(s):  
Simone Daniela Langhans ◽  
Urs Richard ◽  
Janine Rueegg ◽  
Urs Uehlinger ◽  
Peter Edwards ◽  
...  
Keyword(s):  
Organic Matter ◽  
Particulate Organic Matter ◽  
Environmental Heterogeneity ◽  
Coarse Particulate Organic Matter
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