Mapeando a perda de diversidade florística na Amazônia brasileira em função do desmatamento histórico e futuro

Abstract

Digital information on the occurrence of species in time and space is essential for scientific and conservation purposes, but is generally incomplete and tends to degrade over time. In regions such as the Amazon, where large areas have already been deforested, existing knowledge may not represent current conditions. Here, we explore: (1) To characterize how complete and accurate are the plant data for Brazilian Amazonia available on free access platforms; (2) Investigate when and where botanical records occurred over time; (3) Evaluate how much floristic diversity has been degraded by historical and future deforestation. We compiled records of species occurrences of the Magnoliopsida class for the Brazilian Amazon region from three free access databases. We calculate the completeness of the temporal and spatial records available in the region and how their distribution is affected by deforestation, past and future. Of the total of 608,451 records belonging to the Brazilian Amazon, approximately 38% of the records remained with complete information, based on the criteria established in this study. All sample units with records totaled 3,227, 10% were floristic samples containing at least two records. After the influence of historical deforestation (until 2016), we lost 49 sampled areas / areas with a value of completeness ≥ 0.5, in areas in the northwest and central Brazilian Amazon. In the future deforestation scenario (2050), we will not have representative sample units in the Brazilian Amazon, according to the data used in this study. Sample areas without knowledge with the digitally available data correspond to 42% of the total, and approximately 12% were areas with floristic diversity lost in the current deforestation scenario. We need to know more about floristic diversity in non-sampled or low collection areas such as indigenous lands and areas that will be lost. The local and regional scientific community, together with the international community, should assess how comprehensive and accurate the available data are for mitigating biodiversity impacts.