AvaliaÃÃo dos impactos de sistemas de manejo sustentÃvel na diversidade e estrutura da flora de um cerrado sensu stricto. / Evaluation of sustainable management system impacts in the diversity and structure of flora of a savanna senso strictu.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

A floristic survey was accomplished in 30 ha of savanna senso strictu submitted to 10 treatments (removal of 50. 60. 70 and 80% of basal area, these with reduction of 20% in the value of the quotient of De Liocourt; removal of 50; 60; 70 and 80% of basal area, with addition of 20% in the value of the quotient of De Liocourt; and clear cut and the control area), before the implantation of the treatments and seven years after the interventions. The objectives were to evaluate the effect of different levels of intervention in the floristic composition of the timber vegetation, seven years after the intervention in the area; to study the behavior of the diversity and equability; to determine the floristic similarity between the two measurements; to establish the pattern of the height and diameter frequency distribution; analyzed the distribution adherence, for the test of Kolmogorov-Smirnov; to determine the existence or not of structural similarity among measurements, and to analyze the diameter and height distribution in the different treatments. All trees with BBH≥15.70 cm were inventoried, total height and BBH measured and dead trees counted. In the measurement of 2004, 7389 individuals distributed in 74 species, 57 genera and 34 families, numbers on average 11, 2 and 10% had been found greater, respectively, that the numbers gotten in the first measurement. The floristic diversity appraised by Shannon and Simpson varied from 2.825 (treatment 10) to 3.160 (treatment 2), from 0.112 (treatment 6) to 0.06 (treatment 8), respectively. The equability test presented values varying from 0.827 (treatment 8) to 0.733 (treatment 6). Through the Paired T test it was possible to also detect significant differences between the two measurements for floristic diversity and for number of species. However for equability the test was not significant. The floristic similarity of the treatments measured by the Sorensen method varied from 0.747 (treatment 1) to 0.841 (treatment 8). The average basal area was of 7.890 mÂ/ha in the measurement of 2004, about 18.75% lower than the value verified before the interventions in the area. Through the Paired T test, it was verified that for the number of individuals, basal area and average DAP, that the test was significant showing that, in average terms, these parameters had suffered alterations with the interventions effect in the area. Through the rate of net change it was possible to verify that for DA, FA and IVI occurred additions and decreases in all treatments between the two measurements. However for occurred a decrease in all treatments, showing that the vegetation had not yet recovered in terms of basal area. Through the Kolmogorov-Smirnov test it was possible to detect respectively that the biggest discrepancies in the height distributions and diameter had occurred in treatments 2 and 9. However 8 and the control treatments had presented practically the same distributions in height and diameter, respectively, in the two measurements.

ASSUNTO(S)

intervention cerrado sensu stricto manejo florestal phytossociology management system intervenÃÃo fitossociologia diversidade florÃstica manejo florestal savanna senso strictu floristic diversity

ACESSO AO ARTIGO

Documentos Relacionados