Dynamics of Tree Population Structure After Disturbance of Araucaria Forest Remnants

Abstract This study aimed at evaluating and compare the changes from 2012 to 2016 in the structure and floristic composition of a remnant Araucaria Forest. The entry and mortality rates were 2.2% year-1 and 6.9% year-1, respectively. Among the most represented species, those with the greatest yearly increases in their numbers were Sebastiania brasiliensis, Eugenia uniflora, and Allophylus sp. Average mortality density was 498 ind ha-1, and was particularly high for the following species: Casearia decandra (representing 32.3% of total mortality), Eugenia sp. (27.2%), Cinnamodendron dinisii (24.5%), and Lithraea brasiliensis (25.2%). The pioneer species represented 8.33% of income and 29.17% mortality, and secondary species composed 33.33% and 62.50% of income and mortality, respectively. Climax species accounted for 8.33% of income and did not contribute to mortality. The high tree mortality observed in the present study can be attributed, among others factors, to the effects of natural disturbance that occurred in the period.