Traditional Knowledge of açaí (Euterpe precatoria Mart. - Arecaceae) usage in the Sustainable Development Reserve - RDS Piagaçu Purus – Amazonas - Brazil

— The historical reciprocity among traditional populations and the usage of biodiversity in natural environments have outlined the Amazon as one of the richest and most complex socio-ecological systems on the planet. Conservation Units (CU’s) are effective strategies to protect biodiversity, although the simple creation does not guarantee its efficiency. Conservation depends on the integration between ecological and social aspects of the forest peoples and the management of institutions involved with the use and protection of biodiversity and environment. In this context, Non-Timber Forest Products (NFTPs) are important elements in the culture and subsistence of traditional populations and can represent significant sources of income. Specifically, the açaí palm (Euterpe precatoria) is one of the species that stands out in the Amazon, with high cultural and economic values. Given the importance of the species, this research was carried out using traditional knowledge associated with this palm tree, along with residents of three communities of the RDS Piagaçu Purus, to identify and evaluate the uses of parts of the plant of greatest interest to local communities. Within a two-months period, in 2006, information on the diversity of uses and knowledge of the species were collected. It was applied the method of qualitative-quantitative exploratory research, surveying primary and secondary information. The results showed the great potential of açaí usage, especially the fruit, which is consumed in the form of wine and the root, in popular medicine, indicating that the species is a key resource for families subsistence besides its high economic and social potential.


INTRODUCTION
Planted and native forests offer diversified, high-quality timber and non-timber forest products to the market, with the possibility of developing other products that, when valued, can improve the quality traditional populations life (LAY, 2008).
Traditional populations are local populations, whose knowledge comes from wisdom about the elements of nature and its dynamics, which are used as a means of survival. The indigenous peoples, quilombolas, riverside dwellers, artisanal fishermen and many other local rural communities, have territoriality in the context of The historical reciprocity between traditional populations and the use of timber and non-timber products in the natural environment outlined the Amazon, as one of the richest and most complex socio-ecological systems on the planet. Therefore, the conservation of this biome depends on the integration between the ecological and the social aspects of the inhabitants, management of sustainability-concerned institutions, protection of biodiversity and the ancestral knowledge, regarding the use of Non-Timber Forest Products -NTFP's.
NTFP's are a cultural element of great importance for traditional populations and can be considered a significant source of income for them. According to Takeda (2015), the exploitation of forest resources has always played a relevant role in society and the economy, being more intense in tropical countries, which encourage the generations of jobs and income, promoting the development of rural infrastructure and the provision of social services, among others.
In addition to the ecological and economic importance of NTFPs, the literature has increasingly demonstrated the nutritional richness of plants present in the eating habits of traditional populations. Some authors, having theorized and analyzed eating habits of globalized society, show the unawareness and mischaracterization of traditional and regional cuisine with the increase in consumption of industrialized food, which has impacted the nutritional status of urban populations (CERDA, 2014). Other authors also highlight that there are few works that emphasize the plant diversity consumed by Amazonian populations. However, it is remarkable the contribution in a diet that plants, especially wild and cultivated, represent in terms of micronutrients and macronutrients (DUFOUR et al., 2016). In fact, the Amazonian species used in cooking have greater visibility, as is the case of açaí, which has nutritional properties that put the specie in the market spotlight.
The national and international recognition of açaí, as a source of antioxidants makes it the target of investments and research, which grow every year and also makes it a reference within natural resources for new products and technologies, bringing forth the importance of antioxidant compounds that are present in a large part of the Brazilian flora (SOZO et al., 2016).
The açaí tree is native to the Amazon region of Brazil, being one of several species of plants that make up the traditional set of forest products grown in the Amazon estuary floodplain. At the height of the canopy, purple fruits grow in bunches and hand-harvested by collector-farmers.
Açaí is one of the most important forest products in Brazil (MATOS et al, 2017;NOBRE, 2017). Data from 2017 indicate that 93.1% of Brazilian açaí production comes from the species Euterpe oleraceae ("açaí-do-Pará"), naturally restricted to the eastern Amazon (IBGE, 2018). But the supply of açaí by the species E. precatoria has been growing exponentially year by year (IBGE, 2018). Intriguingly enough, until 2018 the species was not considered a source of açaí pulp by Brazilian legislation, which recognized açaí pulp only as the one extracted from E. oleraceae (BRAZIL, 2018). Brazil produces about 220,000 tons of açaí of extractive origin. From those, about 50,000 tons came from E. precatoria, and the activity generates an income of just over US$ 150 millions/year (IBGE 2018).
In Brazil, three species of açaí palms are well known: E. oleracea -native of Pará and Amapá states, which are responsible for most of its commercial production; E. precatoria -native of Amazonas; and, E. edulis -native of the Atlantic Forest, which was much exploited in an unsustainable way for palm heart extraction. The açaí chain involves extractivists, producers, intermediaries, processing industries and artisanal açaí beaters (people who process açaí in and artisanal way), being of crucial importance to generate income to an expressive group of families of small producers (TAVARES and HOMMA, 2015). This study was developed in order to collect and analyze information on the social and ecological aspects of the use and commercialization of natural resources by riverine communities in the central Amazon, specifically the açaí (Euterpe precatoria). The objective was to generate basic scientific knowledge in the extractive development by the social organization of residents in the State Reserve of Sustainable Development Piagaçu-Purus (RDS-PP), municipality of Beruri in the state of Amazonas.

II. MATERIAL AND METHOD AREA OF STUDY
This study took place in the months of November 2006 and February 2007, in two riverside communities located in areas of terra-firme forests of Lake Ayapuá (Pinheiros and Uixi) and one of Lake Uauaçu in the lower course of the Beruri, State of Amazonas, Brazil. (Figure 1). In these communities, açaí extractivism is one of the main income source practices of the communities.

Data collection
The communities in Lake Ayapuá are called Divino Espírito Santo (Pines) and Nossa Sra. do Livramento (Uixí), and there is also São João do Uauçu, in Lake Uauaçu.
For the collection and analysis of information on the social and ecological aspects of the use and commercialization of natural resources in those communities, it was developed forms and conducted interviews to cover the aspects (1) general information; (2) use of plant species; and (3) commercialization of products.

Sampling areas establishment
The phytosociological data of occurrence and distribution pattern of "açaizais", in the community areas, were obtained through a floristic inventory in 60 sample plots, with 20 x 20 meters each, totaling 24,000 m 2 delimited and inventoried.
Twenty sample plots were installed, randomly distributed, in 8 hunting spots in each community. They were distant from each other in approximately half an hour, traveling by boat and far from the headquarters.
In the center of each plot was set sub-plots of 5 x 5m, for the survey of natural regeneration, as used by Marangon et al., (2008), in a semidecidual seasonal forest fragment, and also by Machado (2018), in which was studied the forest dynamics of areas in natural regeneration with different degrees of disturbance. The center of each plot was identified with a 1.20-meter-high wooden stake.
A main trail, with an extension of 100 meters, was opened in the central part of each secondary forests (capoeira) in each community. The secondary forests are the result of a natural process of vegetation regeneration. The plots were installed on the sides of the main trail, on the distance of 20 meter, to minimize the effect of the trail's edge on the vegetation structure in the studied plot.
The total height of each tree was measured with a 5 meters long pole, with identification of each meter.

III. RESULTS AND DISCUSSION
Literature lists the species of seeded plants that grow in the Amazon forest at an elevation lower than or equal to 1,000m, excluding savannas and dry forests. In the three communities, 66 species occurred in secondary forests. The açaí, occurring in a frequency of 50% in the 15 and 30-year-old secondary forests (  Açaí is an important and traditional fruit present in the diet of riverine populations and commonly consumed along with cassava flour and sources of protein, such as fish and shrimp. The State Department of Agriculture of Pará (SAGRI) listed the by-products that can be obtained from the pulp and seeds, informing that, the pulp represents 15% of the total weight of the fruit and can be used in the manufacture of ice cream, liquor, jam, nectar, jelly, among others (SAGRI, 2011).
Similarly, to other species and products, the management of açaí is a complex activity, given that it consists of several stages, ranging from community organization to manufacturers training, as well as special post-harvest care of the fruits and market notions.
Thus, in order to a community to be successful in the management of açaí, it is necessary to have a group of interested families, training the harvesters to climb the palm tree safely, providing good hygiene conditions for the fruits handling soon after harvest, good outlet conditions (by vehicle, boat, railroad branch and others) and the right destination or buyer for the production ( However, to facilitate the work of the harvesters and without climbing the palm, the INPA in Manaus, Am, has developed tools for the collection of clusters of 20 species of palm trees in the Amazon. The tools have simple technology for easy handling and were made with materials easily found on the market. In order to allow collections of tall palm trees, mechanisms were developed for support, stability and balance of the stem. People or companies interested in acquiring PALMHASTE, can contact COETI / INPA, by e-mail ceti@inpa.gov.br.

Açaí population structure in a secondary forest (capoeira)
E. precatoria plants with DBH (Chest Height Diameter) equal to or less than 5 cm (seedlings), occurred in a greater proportion in relation to adults. The number of seedlings and young plants was 5 times greater than the number of adults. These results coincide with those of Rocha (2004) in forests known as lowland and upland "baixio / terra-firme".
However, in a secondary forest with canopy above 30 m in the Amazon, in the municipality of Manaquiri, Castro (2000) found 232 fertile individuals on one hectare. Interviewees from the three communities reported 66 species as ones stemming from secondary forest. The açaí had the frequency of 50% in secondary forest aged 15 and 30 years (Table 1).
Of the ten types of fruit most consumed in the communities, six was from palm trees. Among these, four was used to prepare a thick drink known as "vinho" (wine), which can be consumed immediately or a day after preparation. Cassava flour and sugar may be added. These data show the importance of açaí both as a food and income source for rural Amazonian communities (SACRAMENTO et al., 2015).
Among the species mentioned by residents and community members, many are medicinal plants and are used in combination or not with other species to cure diseases, especially the açaí root (E. precatoria). All residents interviewed consumed açaí wine as part of their diet.

The evolution of açaí production in the Northern Region of Brazil
The production of most NTFP is concentrated in the northern region, with an emphasis on the açaí (93.1%). In 2015, some extractivist products presented positive variation productions when compared to that obtained in 2014. Açaí in this case was the most expressive in absolute values due to the growing demand for the product, increasing 9% when compared to the previous year (IBGE, 2016 In the state of Amazonas, the NTFP's segment receives support from the Institute of Sustainable Agricultural and forestry development of the state of Amazonas (IDAM), along with organizations, associations and cooperatives of extractivists. In 2018, 3,435 family farmers/rural producers were said to be assisted in good management practices: extraction, collection, storage, processing and marketing, in activities related to Brazil nuts, açaí, rubber, piassava, as well as andiroba and copaíba oils, with the production of approximately 25,000 tons of extractive products (IDAM, 2018).

Marketing
The extractivism practiced in secondary forest, by the inhabitants of the communities, also serves for the commercialization of products such as straw, fruits and others.
Açaí used by residents of these communities, 16% of respondents sell the fruit or pulp. The commercialization of the fruit is carried out sporadically and by few families, thus being considered of little importance. Açai is transported by regional boats to the municipalities of Codajás and Beruri.
In the communities of RDS Piagaçu-Purus, the sale of açaí was concentrated in a smaller number of community members, according to the seasonal variation. However, market pressures could cause a super exploitation above the rate of the resources renewal, but this does not happen because the traditional populations of the Amazon culturally produce for their own subsistence.
Thus, the use and trade of these resources is fundamental for the families' subsistence and is also associated with the commercial relations network which presents barter as the main base.
The barter transaction in the 3 communities continues to have striking characteristics, such as nonmonetary commercialization in the exploitation relationship between salespeople and customers.
The commercialization relies on the merchant known as "regatão", which means river trader, who does not have fixed customers or that does not require exclusivity, even if some community members deliver their whole production to this marketing agent. Therefore, Sacramento et al. (2015) regard it important to highlight, in this context, the relevance of açaí as a source of income for rural Amazonian communities.

IV. CONCLUSION
The diagnosis with residents of traditional communities of RDS Piagaçu Purus, in the state of Amazonas, shows that the species of açaí (E. precatoria) is especially important as food, medicine and a source of economic income for the families of the Conservation Units.
The use of açaí fruit, mainly consumed in the form of wine, and the roots in popular medicine, indicates that the species is a fundamental natural resource in the subsistence of families and has high potential for local economic development.
A determining factor for the production of açaí, in general, is the availability of young male labor, since the collection of the fruits depends directly on the climbing of the palm stem, to reach the brunches and with the use of equipment craft called "peconha", which depends on skill and physical effort, but with the risk of accident.
To improve the açai fruit collection process, it is necessary to invest in regular training in harvesting and to encourage the purchase of safety equipment.
Alternatively, mechanization of the harvest is indicated, in areas planted or not, with motorized artifacts or with collection equipment, which can prevent the climb of the palm stem, to harvest the fruits with less risk of accidents.