Estrutura e diversidade florística das diferentes fisionomias de Cerrado e suas correlações com o solo na Estação Ecológica de Jataí, Luiz Antônio, SP.
Abstract
Jataí Ecologycal Station, located at Luiz Antonio city, has a great habitat diversity spread
from strict aquatic environments, like rivers, creeks and lakes, to wetlands and flood plains,
till vegetation kinds free from flooding. The following steps were adopted to this work: 1)
mapping and characterizing different phytophysiognomies found at Jataí Ecologycal Station,
and determining each physiognomy area; 2) carrying out a floristic survey; 3) carrying out the
phytossociological survey of Cerrado existing physiognomies at the area; 4) characterizing
granullometrically and chemically the soil under each plot; 5) comprehending existing
correlations among Cerrado soil and phytophisiognomies recorded. The following working
hypothesis were tested: 1) There are different phytophysiognomical kinds of vegetations at
Jataí Ecologycal Station, occupying distinct areas. Null hypothesis Jataí Ecologycal Station
is physiognomically homogeneous. 2) Floristic composition and structure of different
physiognomies at Jataí Ecologycal Station are correlated with granullometrical and chemical
features of the soil. Null hypothesis There is no correlation between soil characteristics and
phytophysiognomies. To evaluate these hypothesis, phytophysiognomies mapping, vegetation
analysis, soil analysis and soil versus vegetation correlation analysis were carried out. Based
on photointerpretatives analysis and on field survey, eight phytophysiognomies classes were
determined ( cerradão , regenerating cerrado, semi-deciduous forest, flood plain vegetation,
campo sujo , cerrado stricto sensu , Pinus and Eucalyptus reflorestation). Most of the Jataí
Ecologycal Station (60,72% or 5471,8 ha) has cerradão as principal vegetation. To the
phytosociologycal survey, 2631 individuals were sampled at cerradão , being 1229 in the
lower layer (0,25ha; 4.916 ind./ha) and 1412 in the upper layer (1ha). A total of 118 species
were identified in the cerradão two layers. In the cerrado stricto sensu , 642 individuals
were recorded, being 190 in the lower layer (0,25ha; 760 ind./ha) and 452 in the upper layer
(1ha). A number of 50 species were identified in the two cerrado stricto sensu
phytofisiognomies layers. The diversity index (H ), considering the two studied vegetation
types, was 3,44 (70,45% equitability). Indexes were 3,20 in the cerradão (67,08%
equitability) and 2,99 in the cerrado stricto sensu (76,43% equitability). In the upper layer
of the cerradão , the basal area was 18,37m2/ha, and cerrado stricto sensu was 4,20m2/ha.
Statistical analysis showed that cerradão and stricto sensu cerrado phytophysiognomies are
distinct according to chemical and granulometrical soil properties. Granulometrical features
seemed to be important environmental variables to distinguish the two studied
phytophysiognomies. Based on the obtained results, it is believed that soil has an indirect
correlation on species density and on vegetal physiognomies occurency at studied area.