Relative Importance of Seed-Bank and Post-Disturbance Seed Dispersal on Early Gap Regeneration in a Colombian Amazon Forest

We analysed the germination of seeds after their passage through the digestive tract of small floodplain fishes. Samples were collected in five open flooded fields of the northern Pantanal in March 2011. All fishes were sacrificed and their intestinal contents were removed. The fecal material was weighed and stored at 4°C in a GF/C filter wrapped in aluminum foil. The material was then transferred to a receptacle containing sterilised soil from the sampling area. The fecal samples were kept in a germination chamber for 68 days and then transferred to a greenhouse for another 67 days. We collected a total of 45 fish species and 1014 individuals which produced a total amount of 32g of fresh fecal mass and 11 seedlings. We were able to identify six seedlings: two Banara arguta, two Steinchisma laxa, one Hymenachne amplexicaulis and one Luziola sp.. The fish species that produced samples with seedlings were Astyanax assuncionensis, Metynnis mola, Plesiolebias glaucopterus, Acestrorhyncus pantaneiro and Anadoras wendelli. With the exception of B. arguta the remaining plant species and all fish species were not known to be associated with the seed dispersal process of these plants. We found a ratio of 0.435 seedlings.g–1 of fresh fecal material, which is 100 times higher than the amount of seedlings encountered in fresh soil mass (92,974 grams) in seed bank studies conducted in the same study area. In particular, Astyanax assuncionensis and Metynnis mola were among the most frequent and most abundant fish taxa in the area. Together with the high seed concentration in the fish fecal material, this evidence allows us to conclude that such fish species may play an important role in seed dispersal in the herbaceous plants of the Pantanal.

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Mineralogy and chemistry of archaeological ceramic fragments from archaeological Dark Earth site in Colombian Amazon

Rem Revista Escola de Minas ◽

10.1590/s0370-44672011000100002 ◽

2011 ◽

Vol 64 (1) ◽

pp. 17-23 ◽

Cited By ~ 6

Author(s):

Marcondes Lima da Costa ◽

Gaspar Morcote Rios ◽

Mônia Maria Carvalho da Silva ◽

Glayce Jholy da Silva ◽

Uliana Molano-Valdes

Keyword(s):

Brazilian Amazon ◽

Chemical Characteristics ◽

Amazon Forest ◽

X Ray Diffraction ◽

Aluminium Phosphate ◽

X Ray ◽

Clay Matrix ◽

Archaeological Ceramic ◽

Colombian Amazon ◽

Grey Colour

Several Archaeological Dark Earth (ADE) sites have been already found in the Colombian Amazon forest showing high content of archaeological ceramic fragments similarly to those in the Brazilian Amazon represented by Quebrada Tacana site. Their fragments are yellow to grey colour, display a burned clayey matrix which involves fragments of cariapé and coal and ash particles, besides grains of quartz and micas. The clay matrix is made of metakaolinite, quartz, and some mica flakes, chlorite and sepiolite. Cariapé and cauixi spicules are constituted of cristobalite, which is also the main mineral component of the coal and ashes. Although not detected by X-ray diffraction, the phosphate minerals should be present, since the contents of phosphor reach up to 2.90 Wt.% P2O5. Possibly it occurs as aluminium-phosphate, since Ca contents fall below 0.1 Wt.%. These mineralogical and chemical characteristics allow to correlate these ceramic fragments with those found in the ADE in Brazil and reinforce phosphor as an important chemical component, which indicates human activity by the daily use of pottery all over the Amazon region.

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Seed bank, seed dispersal and vegetation cover: Colonization along a newly‐created river channel

Journal of Vegetation Science ◽

10.1111/j.1654-1103.2006.tb02490.x ◽

2006 ◽

Vol 17 (5) ◽

pp. 665-674 ◽

Cited By ~ 66

Author(s):

A.M. Gurnell ◽

A J. Boitsidis ◽

K. Thompson ◽

N J. Clifford

Keyword(s):

Seed Dispersal ◽

Seed Bank ◽

Vegetation Cover ◽

River Channel

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Residues of sweet sorghum promotes suppression of weeds in sugarcane rotation

Australian Journal of Crop Science ◽

10.21475/ajcs.20.14.04.p1903 ◽

2020 ◽

pp. 565-573

Author(s):

Paulo Roberto Fidelis Giancotti ◽

Mariluce Pascoína Nepomuceno ◽

Juliana de Souza Rodrigues ◽

Micheli Yamauti ◽

José Valcir Fidelis Martins ◽

...

Keyword(s):

Seed Bank ◽

Vegetation Cover ◽

Sweet Sorghum ◽

Crop Residues ◽

Soil Seed Bank ◽

Cyperus Rotundus ◽

Relative Importance ◽

Raphanus Raphanistrum ◽

Velvet Bean ◽

Allelopathic Potential

Sorghum is an important crop to plant in rotation with sugarcane. This is mainly because both are inputs for the ethanol industry. Crop residues of sweet sorghum promote suppression of weed re-infestation, avoiding weed interference to the sugarcane crop due to the strong allelopathic potential of sorghum. In order to determine the suppressive effects of sorghum crop residues on weeds, a field experiment was carried out. Seven vegetation covers were used as options for crop rotation with sugarcane. The treatments were sweet sorghum, velvet bean, sunflower, soybean, sugar cane, fallow, and an area without cover. The experiment was randomized blocks with four replications of 27 m2 plots. The weed community of each plot was evaluated by phytosociological indexes at 60 and 120 days after the formation of vegetation cover. The composition of soil seed bank was also evaluated. The weeds with the highest indexes of relative importance during the evaluations were Cyperus rotundus, Raphanus raphanistrum and Parthenium hysterophorus. The diversity of the weed community, estimated by relative importance indexes, was lower in the area with velvet bean as soil cover. Sorghum, velvet bean and sunn hemp covers reduced the soil seed bank compared to the fallow treatment and the treatment without vegetation cover. Crop residues of sweet sorghum and velvet bean provide a decrease in weed infestation in field, and the weed suppression period can last up to 120 days during the dry season.

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