Phytosociology of the arboreal component and floristic of one remnant of cerrado stricto sensu contiguous to agriculture area in eastern region of Federal District, Brazil

Abstract

Since the 1970s the eastern region of the Federal District (DF), Brazil, has been occupied by large agricultural crops, and today there are few remnants of native vegetation. In a reserve of about 85 ha of cerrado stricto sensu located in that region
(15°45’13”– 15°45’30” S, 47°33’55”– 47°32’60” W), adjacent to agricultural areas, a floristic collecting program was carried out between 2009 and 2011. In 2010, we conducted a phytosociological survey of the
arboreal component, randomly allocating 10 plots of 20 m x 50 m. We sampled all individuals with diameter ≥ 5cm measured at 30 cm of soil. In the floristic inventory we found 251 species, 157 genera and 59 families. Fabaceae, Malpighiaceae and Asteraceae were the richest families. Shrubs predominated followed by trees, subshrubs, herbs, vines and hemiparasites. In the phytosociology we sampled 72 species, 53 genera and 33 families. Fabaceae and Vochysiaceae were the richest families. The density of live plants was 1.584 ind./ha, with a basal area of 13,96 m²/ha. Excluding the group of dead plants (the highest IV), the 12 most important species accounted for 50.8% of community IV, and the most important species were Qualea parviflora and Q. grandiflora. Despite the high species richness, diversity was low (H’ = 3.18, J’ = 0.74) when compared to other areas. Although disturbed and immersed into an agricultural matrix, the studied reserve still harbors floristic elements common to better preserved areas in the DF and its surroundings, and conserves species
whose populations are locally extinct elsewhere.