Padrão fenológico de Bertolletia excelsa Humn. & Bonpl (Castanha-da-Amazônia) na Amazônia Legal

Abstract

The Brazil nut tree (Bertolletia excelsa Humn. & Bonpl) is an important species for extractive exploration in the Amazon, being a source of income for rural and urban workers. It has a wide distribution in the terra firme forests of the Amazon, and as it is a species of great economic relevance, some studies on phenology have already been developed, as the knowledge of the different stages of plant growth and development allows the definition of sustainable use strategies. Repetitive phenological events such as fruiting, flowering and dispersal are strongly related to local biotic and abiotic conditions, and are regulated by endogenous characteristics associated with climate variations that regulate the time, intensity, duration and periodicity of events. In this context, the aim of this study was to analyze the phenological pattern of Bertolletia excelsa Humn. & Bonpl for the Legal Amazon, and check if there is any temporal pattern of fruiting, flowering and seed dispersal of the species in the region. The phenological information was obtained through a bibliometric survey of several studies (articles, theses and dissertations) on the phenology of the chestnut tree in the Amazon. By means of a presence and absence matrix (with the places where the studies were carried out in the lines and the months of occurrence of the chestnut phenophases in the columns) an ordering analysis (NMDS) was performed using the Sorensen similarity index as a method distance, to see if there is any temporal similarity of the phenophases between the states in the Legal Amazon. Envif analysis was applied to verify whether the precipitation and annual mean temperature variables are correlated with the ordination axes and with the groups formed. The fruiting of Brazil nut was persistent in the rainy season and tended to occur throughout the year in places with higher average annual rainfall. The flowering of the species occurred over a longer period in places with higher precipitation and average annual temperature (October to March), and in places with less precipitation, flowering tended to come forward (beginning in September) occurring in a shorter period (end in January). Dispersion tended to start in September, October or November, ending in March in places with higher average temperature, and tended to occur in the rainy season in places with higher average precipitation. It is noteworthy that the knowledge of the phenological patterns of the Amazon nut allows efficient decisions to be taken regarding its management. Through climatic predictability, it is possible to select better areas of Brazil nut groves, for example, those with higher annual averages of precipitation, as fruiting takes place for 12 months and flowering is extended, thus ensuring productivity throughout the year.