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For accurate interpretations of palaeopalynological data, it is important to understand the influence of the current vegetation composition and characteristics on the formation of the palynological assemblage recorded in artificial or natural pollen traps. Therefore, in this study, modern pollen rain was characterized using artificial pollen traps under different ecological conditions and climatic seasons in Trilha da Mata Lake, Carajás North Ridge, southeastern Amazonia. The collection of pollen rain data comprises the total period from September 2015 to August 2016. There were two periods of low rainfall (September to December 2015 and May to August 2016) and one period of high rainfall (January to April 2016). The first two periods were represented by a predominance of canga vegetation pollen relative to forest pollen. Under dry conditions, the associations among the taxa Aparisthmium/Alchornea, Myrcia and Bellucia dichotoma were considered important for forest ecosystems, while those among Pleroma, Hyptis parkeri, Borreria and Perama carajensis were considered important for canga ecosystems. Under wet conditions, the forests were well represented by Schefflera, Anthurium lindmanianum, Pseudopiptadenia suaveolens and Glycydendron, and the most represented canga vegetation in the pollen rain were Poaceae undif., Miconia, M. acutistipula var. ferrea and Psychotria. Aparisthmium/Alchornea and Poaceae undif. Aparisthmium/Alchornea was related to periods of low water availability, and Poaceae undif. was associated with marshy or flooded environments. Thus, an increase in the influx of Poaceae undif. pollen grains was determined by variations in the extension of flooded areas, indicating an increase in the amount of rainfall and not the opposite case. Thus, future studies on vegetation reconstruction must consider modern pollen assemblages to precisely determine paleoenvironmental and paleoclimate conditions during sediment deposition.

Honey pollen samples of Melipona seminigra pernigraMoure & Kerr 1950 sampled between 2017 and 2019 from experimental apiaries installed in campo rupestre on canga (CRC) vegetation of the Serra dos Carajás aimed to evaluated seasonal floral availability of undisturbed and mining-influenced areas. Around one hundred pollen types were identified mainly belonging to Fabaceae, Myrtaceae and Euphorbiaceae (31, 6 and 5 species, respectively). Mining area presented the highest pollen richness, almost twice those identified in the undisturbed areas. 80% of the pollen types are rare with concentrations ≤ 2,000 pollen grains/10 g, while the remaining were the most abundant, frequent and the primary bee sources. These latter correspond mostly to native plants species such as Tapirira guianensis Aubl., Protium spp., Aparisthmium cordatum (A.Juss.) Baill., Mimosa acutistipula var. ferrea Barneby, Periandra mediterranea (Vell.) Taub., Miconia spp., Pleroma carajasense K.Rocha, Myrcia splendens (Sw.) DC., Serjania spp. and Solanum crinitum Lam. All pollen types were identified during both seasons, but higher concentration values are related to the dry period (June-September). The statistical analysis of the pollen data indicated that there was no significant difference between undisturbed and mining-influenced areas, since primary bee sources of this study are widespread used in revegetation of mined areas.

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Serra dos Carajás harbors a unique open plant community in Amazonia, known as canga vegetation, with several endemic species coexisting with the potential threat of large-scale iron ore mining. In this sense, Convolvulaceae occur in a wide variety of canga geoenvironments with multiple flower visitors, but the scarcity of data on its pollen morphology prevents the correct association between Convolvulaceae species with floral visitors, as well as the precise identification of their habitats throughout the Quaternary. Therefore, this study aims to contribute to the taxonomic knowledge and refinement of the identification of insect-plant networks of endangered plants, including Ipomoea cavalcantei. Pollen grains were examined by light and scanning electron microscopy (LM and SEM, respectively), and the morphological parameters obtained were statistically analyzed using principal component analysis. Therefore, all species were differentiated based on aperture types and exine ornamentation. The set of morphological characters indicated that echinae morphology, easily identified under LM, was effective for the identification of Ipomoea species. This work represents the first robust pollen database for a precise identification at the species level of Convolvulaceae from southeastern Amazonian cangas.

The pollen content of honey samples collected in the years 2017 and 2019 from experimental apiaries of Melipona seminigra pernigra Moure & Kerr 1950 installed in campo rupestre on canga (CRC) vegetation of the Serra dos Carajás, southeastern Amazonia, was analyzed to understand the local variability of floral resources occurring on natural and disturbed areas. Around one hundred pollen types were identified mainly belonging to Fabaceae, Myrtaceae and Euphorbiaceae (31, 6 and 5 types, respectively). The N5 mine presented the highest pollen richness with 95 pollen types identified, almost twice of those identified in the other areas, including the better preserved ones. Eighty percent of the pollen types are rare with concentrations ≤ 2,000 pollen grains/10 g; the remaining types are the most abundant and frequent, and are considered the primary bee sources (PBS). PBS correspond mostly to native plants such as Tapirira guianensis Aubl., Protium spp., Aparisthmium cordatum (A.Juss.) Baill., Mimosa acutistipula var. ferrea Barneby, Periandra mediterrânea (Vell.) Taub., Miconia spp., Pleroma carajasense K.Rocha, Myrcia splendens (Sw.) DC., Serjania spp. and Solanum crinitum Lam. All pollen types were identified during both seasons, but higher pollen concentration are related to the dry period (June-September). The statistical analysis indicated that there was no significant difference in honey pollen data between the natural and disturbed areas since the plant species considered as PBS in this work are intensively used in revegetation of degraded area (RDA) processes by mining activities.

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