scholarly journals Plant species invasion effects on litter dynamics in subtropical streams

2020 ◽  
Vol 32 ◽  
Author(s):  
Lucas Eugenio Fontana ◽  
Rozane Maria Restello ◽  
Tanise Luisa Sausen ◽  
Luiz Ubiratan Hepp
Keyword(s):  
Organic Matter ◽  
Riparian Vegetation ◽  
Riparian Zones ◽  
Native Vegetation ◽  
Allochthonous Organic Matter ◽  
Plant Resources ◽  
One Year ◽  
Forest Streams ◽  
Hovenia Dulcis ◽  
Native Organic Matter

Abstract Aim We evaluated the effect of the presence of Hovenia dulcis Thunb. (Rhamnaceae) in riparian zones on the organic matter dynamics of small subtropical streams. Methods We conducted this study in three subtropical Atlantic Forest streams with different densities of H. dulcis in riparian vegetation located in southern Brazil. In each stream, we quantified the input of allochthonous organic matter for one year using buckets (area: 0.04 m2/bucket) suspended about 1 m from the streambed in three different sections (15 buckets/stretch = 45 buckets/stream). Monthly, the plant material retained in the buckets was collected individually, dried (40±5 °C/72 h), identified (native litter together and H. dulcis litter alone) and weighed. Results The largest input of native organic matter occurred during the winter months (~55 g.m-2), ranging from ~31 g.m-2 (summer) to ~46 g.m-2 (spring) over the year. The input of H. dulcis organic matter was concentrated in the autumn (~56 g.m-2) and summer (~28 g.m-2), being scarce in the other seasons (~3 g.m-2 in the spring and winter). Only the contribution of native organic matter was associated with precipitation. Contrary to that observed with native vegetation (input of organic matter related with rainfall), H. dulcis input was related to the phenology of the species, which is deciduous, with leaf fall strongly marked, occurring especially during the autumn. Conclusions When present at high densities (dominant), the presence of H. dulcis in riparian stream vegetation makes the supply of allochthonous plant resources scarce at some periods of the year, altering the energy availability in these ecosystems and, potentially, the functioning of subtropical streams.

Dissolved organic matter as P source for biofilms in two contrasting low-order streams

2019 ◽  
Vol 193 (2) ◽  
pp. 131-142
Author(s):  
Verónica Díaz-Villanueva
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Deciduous Forest ◽  
Spatial Scales ◽  
Algal Species ◽  
Community Level ◽  
Nutrient Concentrations ◽  
Organic Substrates ◽  
One Year ◽  
Forest Streams

Forest streams receive large amounts of leaves whose leachates are an important source of dissolved organic matter (DOM), providing not only carbon but also organic nutrients to the microbial communities in streams. I carried out a field study to evaluate the effect of different DOM concentrations on the biofilm structure and functional traits in two similar forest streams belonging to the same catchment. I compared biofilm biomass and nutri- ent content throughout one year, algal species composition, and biofilm community-level physiological profiles in two streams with different DOM concentration and aromaticity. Dissolved nutrient concentrations were higher in the stream with higher DOM concentration, with a concomitant higher biofilm biomass, and there was also a temporal pattern, with higher values during the autumn. Phosphorus content in biofilms was also higher in the high DOM stream, coincidently with a higher capacity of the community to utilize organic P source (glucose-1-P) as a substrate. In contrast, the biofilms from the stream with lower DOM concentrations preferentially used N-organic substrates (amino acids and amines). These results reveal that the biofilms of forest streams make use of organic matter nutrients, so that streams with different DOM loads may differ in biofilm biomass due to changes in both bacterial and autotrophic biomass. In addition, biofilm dynamics may be related to forest phenology, as the highest OM input in this deciduous forest is represented by tree leaves, which supply DOM through leachates, and in particular, with P-rich leachates. In conclusion, different DOM concentrations in two nearby streams led to differences in the community-level physiological profile, as has been previously demonstrated at larger spatial scales in oceans, lakes and along larger rivers.

scholarly journals Dynamics of allochthonous organic matter in a tropical Brazilian headstream

2006 ◽  
Vol 49 (6) ◽  
pp. 967-973 ◽  
Author(s):  
José Francisco Gonçalves Júnior ◽  
Juliana Silva França ◽  
Marcos Callisto
Keyword(s):  
Organic Matter ◽  
Species Composition ◽  
Particulate Organic Matter ◽  
Riparian Vegetation ◽  
Riparian Zone ◽  
Allochthonous Organic Matter ◽  
Allochthonous Input ◽  
Coarse Particulate Organic Matter ◽  
Litter Input ◽  
And Storage

The species composition of the riparian vegetation and the seasonal contribution of input and storage of fine and coarse particulate organic matter were assessed in a 3rd order stretch. Fourteen tree species in the riparian zone were identified, with 3 species contributing with 68% of total litter input: Miconia chartacea Triana (43%), Miconia cyathanthera Triana (16%) and Erythroxylum pelletarianum St. Hil (9%). The allochthonous input of coarse particulate organic matter (CPOM) was composed mainly by leaves (over 50%). Species composition and the contribution of each plant species biomass for vertical, lateral and soil inputs and benthic stocks varied along the study period. The maximum values found in September, November and December coincided with the beginning of the rainy season. There were no differences between the allochthonous vertical and lateral inputs of CPOM to the stream. Differently to other studies, this result was probably due to the peculiar composition of stream’s riparian vegetation at Serra do Cipó.

Pilot-plant experiments for improvement of polluted canal/klong water by rock-bed filtration

1997 ◽  
Vol 35 (8) ◽  
pp. 83-90
Author(s):  
Shigeo Fujii ◽  
Chiaki Niwa ◽  
Mitsuo Mouri ◽  
Ranjna Jindal
Keyword(s):  
Organic Matter ◽  
Pilot Plant ◽  
Horizontal Flow ◽  
Removal Mechanism ◽  
Soluble Organic Matter ◽  
Filter Media ◽  
Canal Water ◽  
Rock Bed ◽  
One Year ◽  
Filtration Technique

Applicability of the rock-bed filtration technique was investigated through pilot-plant experiments in Bangkok, Thailand. Polluted canal water was used as horizontal flow influent to two reactor channels filled with rocks. During one year operation, HRT, filter media, and aeration mode, were changed in several runs. The results showed that 1) the rock-bed filtration with aeration and the HRT more than 6 h can successfully improve polluted klong water by reducing the pollutants (e.g. 60-120mg/L of SS to 20-40 mg/L and 15-30 mg/L of BOD to 5-20 mg/L); 2) main removal mechanism seems to be the sedimentation resulting from the settleability enhanced by aeration, and the biofilm attached onto rocks also works in the reduction of soluble organic matter; 3) a combination of three rock sizes arranged in descending order showed best results; 4) longer HRT (13 h) produces better effluent but is not so effective if it exceeds 9 hours; 5) 60-70% of sediment IL was decomposed in a year, and porosity in rock beds reduced approximately 16%.

Sources and distribution of allochthonous organic matter in surface sediment from the Seomjin River to the southern inner shelf of Korea

2017 ◽  
Vol 52 (4) ◽  
pp. 489-499
Author(s):  
Adegoke Olugboyega Badejo ◽  
Sangmin Hyun ◽  
Wonnyon Kim ◽  
Se-Jong Ju ◽  
Bareum Song
Keyword(s):  
Organic Matter ◽  
Surface Sediment ◽  
Allochthonous Organic Matter ◽  
Inner Shelf ◽  
Seomjin River

Bacterial decomposition of allochthonous organic matter in shallow subtropical lakes

2021 ◽  
Vol 26 (4) ◽  
Author(s):  
Pâmela R. Gayer ◽  
Pablo S. Guimarães ◽  
Edélti F. Albertoni ◽  
Luiz U. Hepp
Keyword(s):  
Organic Matter ◽  
Allochthonous Organic Matter ◽  
Subtropical Lakes ◽  
Bacterial Decomposition

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 Copepods act as omnivores in a (sub)tropical reservoir: Implication for the top-down effect on phytoplankton

2018 ◽  
Vol 77 (2) ◽  
Author(s):  
Qiuqi Lin ◽  
Liang Peng ◽  
Yang Yang ◽  
Bo-Ping Han
Keyword(s):  
Organic Matter ◽  
Trophic Position ◽  
Zooplankton Community ◽  
Nitrogen Isotope ◽  
Terrestrial Organic Matter ◽  
Tropical Reservoir ◽  
Cascading Effect ◽  
Cladoceran Species ◽  
Grazing Effect ◽  
One Year

Tropical reservoirs in China receive a high input of organic matter from surrounding watersheds and this represents a significant resource for zooplankton consumers. Copepods are often the dominant zooplankton group in the tropical systems. Whether copepods tend to be omnivorous and their potential cascading effect on phytoplankton are subjects of debate. We used stable carbon and nitrogen isotope analyses to elucidate the allochthony and trophic positions of two copepod species (Phyllodiaptomus tunguidus and Mesocyclops thermocyclopoides) and one cladoceran species (Diaphanosoma orghidani) over a one-year period in a tropical oligo-mesotrophic reservoir in China. We assumed the filter-feeding D. orghidani was herbivorous and we used it as a baseline indicator of δ15N to estimate the trophic position of the two copepods. P. tunguidus and M. thermocyclopoides had an average trophic level that was 0.7 and 0.5 higher, respectively, than that of D. orghidani. M. thermocyclopoides showed seasonal differences in trophic position and an increase in trophic position with rising temperatures, whereas P. tunguidus remained omnivorous throughout the year. All three zooplankton species had a much higher degree of allochthony in the flood season than in the dry season, and their allochthony was positively related to the allochthony of the particulate organic matter input. The two copepods’ omnivorous behavior suggests their allochthony was primarily linked to microbial food web based on the input of terrestrial organic matter. The chlorophyll a to total phosphorus ratio was much higher when P. tunguidus dominated the zooplankton community than when D. orghidani dominated. The ratio was positively related to the ratio of omnivorous adult copepods to cladoceran biomass but not to the zooplankton:phytoplankton biomass ratio. Our results suggest that copepods tended to be omnivorous and relied heavily on allochthonous material in the study reservoir. The indirect cascading effect is likely to be stronger than the direct grazing effect, resulting in a positive effect of copepods on the phytoplankton.

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