Serviços ecossistêmicos da palmeira nativa “macaúba” (Acrocomiaaculeata)

Abstract

Macaúba - Acrocomia aculeata (Arecaceae) has been extensivelystudied as a nature-based solution to mitigate the effects of climate change. The primary objective of this thesis was to contribute to the evaluation of theecosystem services provided by the macaúba palm. Chapter 1 comprised aliterature review focusing on various biological aspects of the species, including population genetics and plant breeding, interactions with otherorganisms, biological functioning of different parts of the plant, historical andcurrent interactions with humans, and ecosystem services explored thus far. Chapter 2 presented a forest inventory, with a specific emphasis on carbonassessment, conducted in a commercial macaúba plantation in Olaria, MG. Thirty-three 400 m² plots were randomly established, and measurementswere taken, including circumference at breast height and total height, amongother attributes. An allometric equation tailored for this species was utilized toestimate carbon. Variability in dendrometric attributes within the sampledpopulation was observed. The recorded carbon stock in the 24-hectarecommercial plantation was 1,778.34 tons of CO2eq., with a sampling error of 23.96%. Chapter 3 involved modeling the distribution of macaúba for both thepresent and the future. Bioclimatic variables, along with environmental factorssuch as vegetation, soil classification, soil pH, and organic matter content, were incorporated. Multiple algorithms were applied, and different global circulation models were employed to project future scenarios. The model findings confirmed previous studies regarding the current suitability of macaúba habitats. Significant expansion of the species was noted in variousgreenhouse gas emission scenarios, with minimal retractions in its current suitable areas. Chapter 4 focused on evaluating the soil microbiological community using molecular markers and fluorescence in situ hybridization of selected taxa. Soils in pastures intercropped with macaúba were comparedwith those in non-intercropped pastures, considering the topography, including hilltops, slopes, and lowlands. Microorganism density significantlydiffered between intercropped and non-intercropped pastures, indicating anincrease in microorganism density in intercropped pastures. The relief wasfound to influence microorganism density and diversity, with lowlands in intercropped pastures showing higher diversity indices, likely due to thepresence of macaúba and the influence of surface runoff. These resultsunderscore the value of macaúba as a promising agronomic innovation of native origin, capable of enhancing Brazil's gross domestic product whilecontributing to ongoing efforts in climate change resilience and mitigation.