Anderson Cássio Sevilha

Diversity, floristic and structural patterns of cerrado vegetation in Central Brazil

The cerrado has been identified as one of the richest and most threatened biomes of the world, but few phytogeographical studies have been undertaken in the region. A total of 70 land systems based on climate, landscape and soils have been identified in the region, but it remains to be seen if the distribution and structure of the plant communities support these divisions. The aim of this work was to compare the floristic and structural similarity of cerrado sensu stricto within and between three physiographic units, named Pratinha, Veadeiros and São Francisco, which contain six land systems in central Brazil and cover 10 degrees of latitude and five degrees of longitude. The woody vegetation of 15 selected sites of the cerrado sensu stricto physiognomy was surveyed under a standardized methodology. The number of species per site varied from 55 to 97, with most sites having around 60 to 70 species, and Shannon´s diversity indices ranged from 3.44 to 3.73, with most sites around 3.5 suggesting high alpha diversity. Sørensen´s floristic similarity index was high, with all Figures above 0.5 between the sites in the same land system in each physiographic unit but low between sites in different land systems in the Veadeiros. Czekanowski similarity indices were lower than Sørensen’s in the comparisons due to a high structural differentiation between the sites. There is a large overlap in species occurrence in the sites but the size of their populations is very different at each site. Therefore, the high beta diversity is mostly due to differences in abundance of species between sites. The sites were separated by physiographic units, considering the first three divisions of TWINSPAN classification. The first axis of DCA ordination showed a gradient going from the cerrado on deep soils in Pratinha, through to those on sandy soils in São Francisco and ending on the shallower soils of the Veadeiros. Land systems conformed well with the floristic and structural variations of the vegetation, indicating their potential use in designing a network of conservation areas in the cerrado region and as a basis for decision-making on management.

Germinação de espécies arbóreas de floresta estacional decidual do vale do rio Paranã em Goiás após três tipos de armazenamento por até 15 meses

Seed dispersal in tropical deciduous forests occurs mostly in the dry season and germination at the onset of the rainy season. The delay of the first rains and dry spells are major mortality factors in dry forest regions. Storing seeds to plant during the constant rains could increase germination and seedling survival. We investigated the germination percentage of deciduous forest tree species after being stored i) at -20 °C and -196 °C (liquid nitrogen), and ii) at natural conditions for three and 15 months. Seeds of 19 tree species of deciduous forests of Parana river basin, Goias state, were collected from August to October 2005. Two experiments were run: i) storage for three and 15 months in brown bags at environmental temperature, ii) storage for 72 hours at -20 °C cameras, liquid nitrogen (-196 °C) and a control. Storage at environmental temperature decreased germination of only two species after three months, Cordia trichotoma (73 to 38%) and Copaifera langsdorffii (85 to 65%). Three species decreased germination after 15 months (Cordia trichotoma, 73 to 5%; Cavanillesia arborea, 77% to 12%; and Anadenanthera colubrina, 93% to 76%) and two species, Aspidosperma pyrifolium and Tabebuia impetiginosa, lost completely their germination. Temperatures -20 and -196 °C decreased germination of only one species each, Tabebuia impetiginosa (90 to 70%) and Aspidosperma pyrifolium (90 to 43%), respectively. In general, environmental temperature storage up to 15 months and -20 and -196 °C storage were efficient to preserve seed germinability of many dry forest tree species from Parana river basin. These are feasible options to ex situ conservation and to increase germination for direct seeding strategies of restoration.

A comparative study of fatty acids profile of Passiflora seed from Brazilian savana

ABSTRACT- There is more 580 species of passion fruit in the world; the majority is native from Tropical and Subtropical America, especially from Brazil. Breeding programs use a small part of genetic resources available, because the potential of this material is not sufficiently characterized. The objective of this work was the characterization of lipids content and fatty acids profile present in the seeds of 03 species of wild native passion fruit (Passiflora cincinnata, P. setacea e P. nitida) using commercial passion fruit (P. edulis) as reference. Total lipids were extracted with petroleum ether in Soxhlet extractor. The profile of methyl esters was characterized by gas chromatograph using flame ionization detector. The seeds of P. setacea showed higher content of oil (31.2-33.5 %), followed by P. nitida (29.5-32.3 %) and P. cincinnata (16.7-19.2 %). The P. setacea oil presented 64.7% of linoleic, 10.2% of palmitic and 19.7% of oleic acid. P. nitida presented myristic (0.6%), palmitic (15.3%), palmitoleic (2.0%), oleic (24.8%), linoleic (51.7%) and a not common acid in other Passiflora specie, the lauric acid (0.4%); P. cincinnata showed oleic (11.0%), palmitic (10.2%) and linoleic acid (74.3%). Linoleic acid was predominant in all evaluated species. All species presented vaccenic acid (0.3-0.6 %), described for first time in Passiflora genus.Index terms: passion seed, oil, gas chromatography, fatty acid, Savanna.

Estimativas de área basal e uso do relascópio de bitterlich em amostragem de Floresta Estacional Decidual

The Deciduous Seasonal Forest of the Northeast region of the state of Goias is one of the few types of forest formations in the Cerrado biome, which may occur in areas of limestone outcrops. Generally it has a higher biomass of tree species than the contiguous cerrado. This study was carried out in an undisturbed area of forest (Flor Ermo Farm) and in others four areas of disturbed forests: Formosa, Tracadal, Manguinha and Conceicao Mocambo Farm. The study aimed to estimate the basal area and the sampling intensity needed to use Bitterlich´s relascope in the deciduous forests. Estimates of basal area of the plots ranged from 23 to 24 m²/ha in the disturbed forests up to a maximum of 29.3 m²/ha in the undisturbed one. Forests with high disturbance showed very small variation of the standard deviation curve for the sampled points when compared to the area with low disturbance level. For a confidence level of 95% estimate of the mean, 20 sampling points with the relascope can be enough to sample the basal area in this kind of vegetation.

Recruitment of Dry Forest Tree Species in Central Brazil Pastures

Despite its importance as a wealthy source of unique biodiversity (Janzen 1988) and that it covers 42% of the tropical vegetation worldwide (Murphy and Lugo 1995), the dry forest is the most endangered terrestrial ecosystem and one of the least protected (Scariot and Sevilha 2005). In Central America for example, less than 1% of the original 500,000 km2 is preserved in conservation units (Janzen 1988, Sanchez-Azofeifa et al. 2003). In Brazil, the seasonal deciduous forests—a type of dry forest—covers 27,367,815 ha (3.21%) of the territory, from which 1,072,946 ha (3.9%) are protected by conservation units. Among conserved areas of deciduous dry forest, only 117,980 ha (0.43%) are in conservation units of restricted use as national parks and biological reserves. Most of the conservation units (402,456 ha or 1.47%) allow limited economic use of the land and natural resources. There is no information of the conservation unit assigned in official database for 552,509 ha (2.02%) of dry forests (Sevilha et al. 2004). Dry forests occur in many soil classes. In Brazil they occur in at least 13 soil classes of the Brazilian Soil Classification (Scariot and Sevilha 2005), but deciduous dry forests occur predominantly in rich soils. There are many valuable trees used for timber. These forests are the main targets of farmers, who log the trees and sell the timber to acquire financial resources to establish farms. In Central Brazil, where some of the most important remnants of dry forests of the country occur (Fig. 11.1), most of the area originally occupied by dry forests has been replaced by pasture composed by exotic grass in extensive farmlands on rich soils. Recommendations have been made for the creation of new conservation units, but given the high degree of landscape fragmentation any new conservation unit will contain significant proportion of its area covered by pasture and forest fragments with different levels of disturbance caused by logging, cattle grazing, fire and invasive species. Thus, in this scenario it is fundamental to understand the mechanisms of tree regeneration in pasture fields to address vegetation recovery and use this information to facilitate forest regeneration. There are four to five times more studies on the natural regeneration of rainforests than on dry forests, and even less on restoration (Vieira and Scariot 2006a). Taking into account the threat level, the lack of conservation units, the lack of information