Distribuição espacial de famílias botânicas em parcela de floresta ombrófila mista e suas relações com Araucariaceae na flona de São Francisco de Paula, RS

Abstract

The aims of this work were to analyze the spatial distribution of the most abundant botanical families in the area of Araucaria Forest and its relations with the Araucariaceae, in the National Forest of São Francisco de Paula, RS. For this purpose, the spatial position of the trees measured in the Forest Inventory carried out in a 1 ha plot (100 x 100 m) in the years of 2001 and 2017 was used, by the Ripley K function and geostatistics. The spatial distribution of the Aquifoliaceae, Euphorbiaceae, Lauraceae, Myrtaceae and Sapindaceae was aggregated and of the Araucariaceae and Flacourtiaceae the completely random pattern predominated in the two dates analyzed. Araucariaceae have been shown to have an associated spatial distribution with the botanical families Aquifoliaceae, Lauraceae and Myrtaceae (from approximately 20m), while the pattern of complete spatial independence was observed with the families Euphorbiaceae, Flacourtiaceae and Sapindaceae. Geostatistics, reflected the association pattern of the bivariate point process for the relationship between the Araucariaceae and the Aquifoliaceae and between the Araucariaceae and the Lauraceae, in the two dates studied. The same behavior of the bivariate point process was not observed for the relation of Araucariaceae and Myrtaceae. Araucariaceae and Flacourtiaceae obtained satisfactory variographic adjustment in the study years, disagreeing with the marked point process of complete spatial independence at most of the analysis distances. Araucariaceae and Euphorbiaceae had good variographic adjustment for the year 2001 and low quality in 2017, while the relationship between Araucariaceae and Sapindaceae, given by the labor variable did not allow to find stability in the semivariance in the years of study. It was observed that only 30.47% of the plot did not suffer alterations in the spatial distribution of the individuals of the botanical families studied between the years of study. The removal of trees modified to a greater degree the relationship between the Araucariaceae and the families Aquifoliaceae, Euphorbiaceae, Flacourtiaceae and Myrtaceae, while the entry of trees produced greater changes in the relationship between Araucariaceae and Lauraceae and between Araucariaceae and Sapindaceae.