Santiago José Elías Velazco

Florística e Fitossociologia de uma Floresta Estacional Semidecidual, Reserva Privada Osununú-Misiones, Argentina

This survey was conducted in a fragment of Semideciduous Seasonal Forest (Misiones, Argentina) in order to analyze the phytosociological variable of tree species by means of area stratification according to geomorphology. Initially, based on the slope and through photointerpretation, the area was compartmentalized in lowland, hillsides with intermediate slopes and high slopes, and highlands. Within each compartment, three plots composed of four 100 m2 sub-units were allocated; totaling 48 sub-units, where all trees with circumference at breast height ≥ 10 cm were included, and soil depth and slope were measured. Sampling comprised 72 species, 59 genera, and 31 families. Variations were detected regarding species and importance values obtained according to the topographic gradient. In the Canonical Correspondence Analysis, the coverage values of species showed significant correlation with the parameters of soil depth and slope.

Florística e Fitossociologia de uma Floresta Estacional Semidecidual, Reserva Privada Osununú-Misiones, Argentina / Floristic and Phytosociology in a Semideciduous Seasonal Forest - Osununú Private Reserve, Misiones, Argentina

This survey was conducted in a fragment of Semideciduous Seasonal Forest (Misiones, Argentina) in order to analyze the phytosociological variable of tree species by means of area stratification according to geomorphology. Initially, based on the slope and through photointerpretation, the area was compartmentalized in lowland, hillsides with intermediate slopes and high slopes, and highlands. Within each compartment, three plots composed of four 100 m2 sub-units were allocated; totaling 48 sub-units, where all trees with circumference at breast height ≥ 10 cm were included, and soil depth and slope were measured. Sampling comprised 72 species, 59 genera, and 31 families. Variations were detected regarding species and importance values obtained according to the topographic gradient. In the Canonical Correspondence Analysis, the coverage values of species showed significant correlation with the parameters of soil depth and slope.

Cerrados in Argentina? Structure, diversity and biogeography of the woody component of a savanna in the Misiones Province

The Teyú Cuaré field, in Misiones province, Argentina, has been renowned for its flora and physiognomy, which led researchers to indicate that it could be a relict of Cerrado biome. We analyzed the floristic structure of the woody component of a savanna community in this site, and discussed the processes that could contribute to the permanence of this vegetation type over time. Perimeter and height of all woody individuals ≥ 10 cm of perimeter at soil height were collected in 12 square plots (400 m each one). We found 15 families and 17 species in our site and compared the woody flora surveyed at this site with the flora of other Cerrado areas from Brazil and Paraguay. Leptolobium elegans had the highest importance value. The woody flora of the area is closely related to the Cerrado areas from Paraná state in Brazil and Canindeyú and Amambay in Paraguay. This site probably reflects old open physiognomies which were predominant in Misiones and Southern of Brazil in the late Pleistocene and middle Holocene. We inferred that the permanence of open physiognomies at Teyú Cuaré is probably related to mechanisms that act at different levels, such as geological, edaphic, anthropic, and fire disturbance.

GERMINATION AND SEEDLINGS DEVELOPMENT OF THE THREATENED SPECIES Quillaja brasiliensis

Fil: Velazco, Santiago Jose Elias. Universidade Federal do Parana; Brasil. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet - Nordeste. Instituto de Biologia Subtropical. Instituto de Biologia Subtropical - Nodo Puerto Iguazu | Universidad Nacional de Misiones. Instituto de Biologia Subtropical. Instituto de Biologia Subtropical - Nodo Puerto Iguazu; Argentina

Using worldwide edaphic data to model plant species niches: An assessment at a continental extent

Ecological niche modeling (ENM) is a broadly used tool in different fields of plant ecology. Despite the importance of edaphic conditions in determining the niche of terrestrial plant species, edaphic data have rarely been included in ENMs of plant species perhaps because such data are not available for many regions. Recently, edaphic data has been made available at a global scale allowing its potential inclusion and evaluation on ENM performance for plant species. Here, we take advantage of such data and address the following main questions: What is the influence of distinct predictor variables (e.g. climatic vs edaphic) on different ENM algorithms? and what is the relationship between the performance of different predictors and geographic characteristics of species? We used 125 plant species distributed over the Neotropical region to explore the effect on ENMs of using edaphic data available from the SoilGrids database and its combination with climatic data from the CHELSA database. In addition, we related these different predictor variables to geographic characteristics of the target species and different ENM algorithms. The use of different predictors (climatic, edaphic, and both) significantly affected model performance and spatial complexity of the predictions. We showed that the use of global edaphic plus climatic variables generates ENMs with similar or better accuracy compared to those constructed only with climate variables. Moreover, the performance of models considering these different predictors, separately or jointly, was related to geographic properties of species records, such as number and distribution range. The large geographic extent, the variability of environments and the different species’ geographical characteristics considered here allowed us to demonstrate that global edaphic data adds useful information for plant ENMs. This is particularly valuable for studies of species that are distributed in regions where more detailed information on soil properties is poor or does not even exist.