Acrocomia aculeata is a native palm distributed widely throughout Brazil that is used in a diverse array of products from the food industry to biodiesel oil production. This study uses nine microsatellite loci to assess the genetic diversity, spatial genetic structure (SGS), and mating system of A. aculeata. A total of 200 samples were collected from four populations (Fusquinha-FU, Padre Josimo-PJ, Gleba XV-GB, and Amparo-AM), in São Paulo State, Brazil. We also collected fruits from 20 randomly selected seed trees in the FU population to assess mating patterns, for a total of 246 genotyped embryos. We identified a total of 103 alleles and all loci were polymorphic. The average observed heterozygosity ( H o ) ranged from 0.410 (AM) to 0.531 (FU) and expected heterozygosity ( H e ) ranged from 0.547 (PJ) to 0.615 (GB). The average fixation index ( F ) ranged from 0.043 to 0.254 for FU and AM populations, respectively. The coancestry coefficient ( xy ) was significant up to 38 m in PJ the population and 71 m in AM. Individual palm outcrossing rates were predominantly high ( t m = 0.985) and the paternity correlation ( r p (m) = 0.02) was significantly low, indicating a high probability of the occurrence of half-sibs.Compared to other palm species, the studied populations show high levels of genetic diversity. Our results confirm that A. aculeata is primarily allogamous, with no significant paternity correlation, and seeds should be harvested from at least 40 trees to ensure high levels of genetic diversity in seed collection programs.

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Araucaria angustifolia is an endangered species with more than 97% of its natural populations extinct. Logging of the species in the few remaining natural populations is highly restricted, though not readily accepted by farmers and logging companies. Consequently, political pressures have emerged for a return to logging of the species. Assessing the sustainability of such logging requires studies of a range of impacts on the remaining populations, including their genetic viability. We investigated the effect of selective logging on genetic diversity, intrapopulation spatial genetic structure (SGS), effective population size (Ne), and pollen and seed dispersal in three A. angustifolia permanent sample blocks established in a remnant of Araucaria Forest in Brazil. In these sample blocks, three logging intensities were applied (LI: 18.4, 31.4, and 32.3% of trees). Microsatellite analysis was performed for all adult and juvenile trees pre- and post-logging saplings. After selective logging, the greatest loss of alleles and the greatest decrease in Ne were observed from the highest LI. Logging increased SGS, while the distance and patterns of pollen and seed dispersal were different for both pre- and post-logging scenarios, with pollen dispersed over greater distances than seed. Pollen dispersal distance post-logging and seed dispersal distance pre- and post-logging decreased with the increased distance between parents. After logging, Ne reduced from 27.7 (LI = 31.4%) to 28.8 (LI = 18.4%) and 39.5% (LI = 32.3%), and some alleles were lost. Despite this, the loss of these alleles may be compensated for in subsequent generations, considering that logging resulted in changes such as an increase in the rate and distance of pollen immigration. Under the conditions evaluated in this study, selective logging of A. angustifolia is not adequate. To achieve truly sustainable forest logging, new rules that combine higher minimum DBH, lower logging intensity, and longer cutting cycles must be adopted. Furthermore, extensive genetic studies must be performed before logging any individual from a natural population.

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Dicksonia sellowiana is the only Brazilian tree fern in the Dicksoniaceae family. Due to the exploitation of its caudex for the manufacture of pots for plants, the species is endangered. The objective of this research was to analyze the spatial distribution of D. sellowiana in the araucaria forest. To obtain data, 37 sample units with 10 × 50 m each were evaluated and systematically distributed in 25-hectar permanent plots installed in the Irati National Forest. All tree ferns above 1.30 m in total height were identified and measured. To analyze the spatial distribution, three aggregation indices were used, while the total volume and the commercial volume were estimated using volumetric models. The density and population structure in height classes were calculated. The species has an average density of 83 individuals per hectare. Through the evaluation of the indices, it was verified that the species has an aggregated pattern. The estimates were 19.87 m3 .ha-1 for total volume and 11.82 m3 ha-1 for commercial volume, with more than 60% of these volumes concentrated in heights of 3.30 m to 6.30 m, which is about 40% of the population.