Difference between revisions of "Astrocaryum jauari"

Astrocaryum jauari is more frequent in the palm igapós Rio Negro, in the Brazilian Amazon, measuring around 20 meters in height, is rarely found isolated and often forming clumps of 4-6 individuals of different sizes, coming from a single rhizome. The fruit abscission occurs during the peak of the floods and the beginning of the receding waters, which are eaten by fish. The palm has commercial value being extracted from it for about 20 years, until 1998, was the basis of the industrial production of palm in Central Amazonia. This study aimed to investigate the dynamics of biomass production and seasonal fruit of A. jauari in relation to flood levels of its occurrence and its implications in terms of the dispersion and local distribution of this palm. Systematic studies were conducted at the Ecological Station doArquipélago Anavilhanas, for a total area of 5,000 m sq. survey, this determined the relative density of A. jauari regarding the level and duration of annual flooding. Fruit production was monitored weekly biomass was determined. Data on fish were obtained through collection, interviews and literature. A. jauari occurs at the uppermost parts of the lower floodplain, inundated 270 to 340 days / year. 125 specimens of A. jauari were sampled in this 5,000 m sq., equivalent to a density of 250 ind / ha. in Anavilhanas. Only mature plants directly exposed to light produced fruits, each stem 4 bunches per year, with about 90 cm in length, and 106 fruits per bunch. Each fruit weighed on average 17 g, equivalent to the production of 6.60 kg / palm / year (fresh weight). 16 fish species exploit the fruits of this palm, 10 possible dispersers, among them 3 as predators. The absence of structures for floating when the propagules in the water sink and, if conditions are hypoxic, rotting occurs to the fruit and seed. All seeds were collected floating rotten, discarding the hydrochory as dispersal strategies and, pointing to ictiocoria as a mechanism for colonization of new habitats by A. jauari. The high caloric content and vitamin A can be attractive to search this resource by fish. In flooded portions for short periods the fruit can accumulate near adult plant (barochory) or sliding on the relief virtue of its weight, possibly with the aid of moving water (barochory sliding +), increasing the local density of the plant. The species occurring in the same age distribution A. jauari have hydrochoric ictiocoria as strategies and prevailing dispersion, and high tolerance to prolonged periods of flooding. In the main area of extraction of the species in the past, in the municipality of Barcelos, plant density also varied greatly between islands, but with densities greater than those found in this study, ranging from 250 to 2000 ind / ha. At this site, one worker could topple and pre-clean palms in full up to 90 (months of May, June) and about 25 in the ebb (December, January). The yield per tree, 0.5 to 1 can of processed palm. Assuming an average number of 10 employees in the area, 900 to 250 palms are exploited daily, which may correspond to the first 0.5 ha. overturned. Considering the thickness of the palm and fruit production calculated for the islands Anavilhanas, which was 165 kg, the extraction without replacement planting would mean the exclusion of this feature to the fish fauna of the archipelago, with negative consequences for the population and for regional íctico trade.

Astrocaryum jauari is the most frequent Palm in the flood plains (wetland) of the Rio Negro in the Brazilian Amazonia. It grows to 20 m of height and is rarely found isolated. More commonly, 4-6 Individuals of different sizes stand together, which originate from the same rhizome. Fruit abscission Occurs at highest water levels and dispersal by fish Occurs. The palm has commercial value: until 1998, for 20 years this palm was the basis of the industrial production in Central Amazonia. In the present study, seasonal dynamics and biomass of fruit production in A. jauari are Described in relation to annual water level and flood duration. Systematic studies were Performed at the Ecological Station of the Anavilhanas Archipelago, with an inventory area covering 5,000 m sq.. Fruit production was at Monitored weekly intervals and biomass was determined. Data on the fishes was Obtained by recording collection in the field and by interviews of local people. A. jauari Occurs from the higher levels to the Lowest in the flooding gradient, being waterlogged up to 270-340 days / year. 125 specimens of A. jauari were sampled in the 5,000 m sq., Which Is equivalent to a density of 250 ind / ha. in the Anavilhanas. Only adult trees Which were Directly exposed to light produced fruits. 16 species of fish feed on the fruits of A. jauari. Ten of these cur As Possible dispersers, 3 the predators. The high contents of vitamine A may be attractive for the fishes. Since the fruits have poor floatation, hydrochoric dispersal Does Not Occur and the seeds succumb to the hypoxic conditions under water. In habitats with short periods of flooding, the fruits may be Accumulated near the adult plant (barochory). Other trees occurring in the habitats colonized by A. jauari have hydrochoric ichthyochoric and dispersal syndromes and show high flooding tolerance. In the main area of extractivism of the past, in the Municipality Barcelos, the density of the species varied between the islands, and had densities between 250 and 2000 ind / ha. Here, Could one worker fell up to 90 palms at high water (May, June) and up to 25 in the low water period (december, january). For each tree, 0.5 to 1 bin of processed "palm" is produced. Assuming the mean number of ten workers in the area, 250 to 900 palms are Exploited per day, Corresponding to 1-0.5 ha. forest destroyed. If we consid the densities of the palm and its productivity Calculated for the Anavilhanas the islands (whcih was 165 kg), extractivism without replacement of new palm trees implies the fast extinction and exclusion of this ressource for the ichthyofauna of the archipelago with all Consequences for the local people. (Borchsenius, F. 1998)/Palmweb.

Uses: The trunk is used for posts (wooden columns) for housing, artifacts & handicrafts, simple burden baskets are is made from the petioles. Utensils and Tools, Cloth and accessories from the leaf.