Padrões fenológicos e de endemismo da flora das Campinaranas da Reserva de Desenvolvimento Sustentável do Uatumã, Amazônia Central

Abstract

The Amazonian Campinaranas are characterized by having predominantly sandy, heavily leached, acidic, and low fertility soils. This ecosystem can experience in the same year physiological drought during the dry season and the flooding of the root system during the wet season. These characteristics act as an environmental filter for the establishment of species, resulting in a specialized flora, with many endemisms. Although many authors point to a high level of specialist species, recent studies show a higher proportion of generalists. This is a matter of debate, even more in a context of scarcity of field studies, and the numerous taxa not yet described in this ecosystem. Furthermore, the phenology of these ecosystems is almost unknown. Questions about the vegetative and reproductive phenophases behave in the face of these environmental characteristics across the different phytophysiognomies remain unanswered. In this thesis, I investigate the pattern of endemisms, the phenological responses of the community, and phytophysiognomies of the Campinaranas of the Uatumã Sustainable Development Reserve. Additionally, it analyzed the relationship of phytophysiognomies with environmental variables on a regional (rainfall, temperature, photoperiod) and local scale (soil water tension, groundwater level). For analyzing the pattern of endemisms and the characterization of the different phytophysiognomies. Were sampled 12 plots of Campinarana of 50 x 50 m trying to sample the greatest physiognomic variation. The species list generated through systematic field collections was compared with collections deposited in herbariums and other published inventories to classify the species as specialists in white-sand, specialists in oligotrophic habitats, and generalists. Six different phytophysiognomies of Campinarana were characterized, with the differentiation between them palpated mainly in the gradient of the groundwater level, the structure, and the variation of species composition. Were found a total of 167 species belonging to 117 genera and 50 families. Fabaceae was the most representative, followed by Rubiaceae and Chrysobalanaceae. Only 30.5% of the species were exclusive to Campinaranas, Thus, although there are many endemic species, most are generalist. Regarding the phenological patterns, the plots were monitored monthly for 21 months. In each plot, a tensiometer was installed to evaluate the soil water tension and a level logger to evaluate the groundwater level. The results showed that at the community level, the phenology presents low seasonality and synchrony. Although there are variations according to the phenophase considered. On the other hand, even on a local scale, marked differences were observed between the phenological strategies of the different phytophysiognomies. For example, the leaf fall, and leaf flush were more seasonal and synchronous when compared to the flowering and fruiting phenophases. Phytophysiognomies with intermediate conditions of water availability showed greater synchrony and seasonality for the reproductive phenophases and leaf fall. Though, phytophysiognomies with lower water availability throughout the year showed greater synchrony and seasonality for the leaf flush. The climatic variables influenced the phenology depending on the phenophase and phytophysiognomy considered. In addition, there was an effect of the interaction between climatic variables on the phenophases. During monthly monitoring, it was possible to collect the majority of Campinarana fertile species. These records generated a guide with more than 400 photos and about 180 species. This wide range of records and collections made it possible to identify a new species belonging to the Clusiaceae family. We provide illustrations, ecological characteristics, a distribution map, and a conservation status assessment. In addition, was discussited taxonomic characters and compared them with those of other related species. The new species was named Tovomita cornuta Demarchi & L. Marinho, an epithet due to the small protuberances present on the fruits that are similar to horns, one of the main morphological characteristics that differentiate it from others in the same genus. Accessing the conservation status of the species showed that it is naturally rare, with only four areas of occurrence, two of which are in highly impacted areas, all in Campinaranas within the state of Amazonas. Thus, the species was classified as critically endangered. The present thesis uses different approaches to generate complementary information, constituting an important tool to substantiate conservation and management strategies in Campinarana ecosystems.