Lomatogonium gaurgopalii sp. nov., a new species of Gentianaceae from Sikkim Himalaya, is described and illustrated. It can be distinguished from its morphologically closest relative, Lomatogonium cherukurianum S.K.Dey & D.Maity, mainly by its robust habit, longer internodes, much larger creamy yellow flower and much larger floral parts; the presence of many hairs in an inverted semilunar arrangement behind the filament bases; and its larger, narrowly ovoid to narrowly ellipsoid ovary. Lomatogonium gaurgopalii is also unique in having pollen grains with striate-reticulate exine ornamentation without perforations.

Tropical montane cloud forests (TMCFs) are characterised principally by frequent immersion in ground-level clouds, which influences their structure. This study aimed to characterise TMCFs in Serra do Papagaio State Park, Minas Gerais State, Southeast Brazil, and to test the hypothesis that TMCF areas can be highly heterogeneous by comparing the tree species composition and structural parameters of 10 TMCF patches in the studied landscape. TMCFs of Serra do Papagaio State Park are of particular interest for conservation, because they contain important populations of threatened tree species.

This study investigated the structure, diversity and composition of the regenerating shrub-tree species community along a stretch of riparian vegetation in relation to environmental heterogeneity. In the Environmental Protection Area of Pandeiros River, southeastern Brazil, the regenerating stratum on 70 plots (25 m2) divided into four groups according to their soil characteristics and natural barriers was sampled. For each plot observations were made of variables related to several soil properties, canopy openness and flooding regime. In addition to the traditional calculation of phytosociological parameters and diversity, a canonical correspondence analysis (CCA) to examine the existing relationships between environmental variables and species distribution was performed. The families with the highest species richness were Fabaceae and Myrtaceae and the species with the highest importance value indices were Zygia latifolia, Tapirira guianensis, Butia capitata, Bauhinia rufa and Hirtella gracilipes. The CCA largely confirmed the groups that were originally proposed. The stretch of riparian vegetation studied was highly heterogeneous with regard to both the abiotic variables tested and floristic structure and composition.

Vegetation analysis reveals that the Themeda quadrivalvis tall-grass savannah in Oman, southern Arabia, forms a clearly defined belt with strong edaphic and geomorphological characteristics. The newly described association Desmodio gangetico-Themedetum quadrivalvis ass. nov. is interpreted as an impoverished easternmost outlier of the East African savannah.

Large areas of the Himalayas have become severely deforested although little has been published about the extent of this problem in the closed Kingdom of Bhutan. A preliminary survey was undertaken during 1983. Without detailed information or accurate maps, LANDSAT 2 imagery was used to prepare a sampling stratification and to plot the distribution of defined vegetation types after sampling and analysis. Eleven forest noda are described in relation to their habitats, and area and timber volume estimates given. Deforestation pressures are discussed.

Floristic and structural comparisons and a numerical classification were performed to identify the priority areas for conservation of genetic resources in central Brazil. The main type of woody vegetation, cerrado sensu stricto (savanna woodland with 10–60% tree cover), was sampled under a uniform methodology in six selected sites (total sample of 6 ha) scattered in a physiographic unit called the Pratinha Plateau located between 15–20° S and 46–49° W. A total of 6971 trees belonging to 139 species and 42 families was measured. Each site had a combination of 50–80 species and approximately 30 families but only 22 species from 14 families were common to all sites. Similarity decreased with distance, indicating the existence of geographical gradients as the physical characteristics were relatively uniform and the soils were dystrophic at all sites. The most dissimilar sites, in the localities of Patrocínio-MG and Paracatu-MG were recommended for the establishment of conservation units. The already existent conservation units arc all clumped in the Federal District and are not enough to protect the genetic heritage of the plateau. Floristics and phytosociological surveys based on land system zoning were recommended as useful tools in planning conservation areas at a regional level to preserve the maximum biodiversity.

A species checklist is presented for a stretch of the seasonally flooded Macal River in the Cayo District of Belize, together with preliminary phytosociological data for the primary riverine communities. A total of 229 species were recorded in the seasonally flooded riparian zone, representing 7% of the flora of Belize. Results of quantitative sampling indicate that Inga vera subsp. vera dominates the river corridor. Other important woody associates include Cuphea calophylla, C. utriculosa, Calyptranthes bartlettii, C. lindeniana, Lindenia rivalis, Pleuranthodendron lindenii, Calliandra tergemina and Nectandra salicifolia. One of the most significant threats to riparian vegetation in the region is the Chalillo Dam upstream of the study site. The current work provides baseline floristic and ecological data for this threatened riparian habitat and documents the structure and composition of vegetation that exists downstream from the dam before its construction.

The study was carried out on the gallery forest of the Bacaba stream situated in the Municipal Ecological Reserve ‘Mário Viana’ (14°43′S, 52°21′W) in Nova Xavantina, Eastern Mato Grosso, Brazil. Three sections of the gallery (upper, middle and lower) running downstream and differing in slope were surveyed by stratified sampling. Fortyseven nested 10m × 10m plots were analysed in each section, giving a total sampling area of 1.41ha overall. All trees or lianas ≥ 15cm girth at breast height were recorded and a total of 129 species belonging to 105 genera and 47 families were found. Diversity was high, with the Shannon index ranging from 3.84 nats/individual in the lower section to 4.08 in the middle section. The most important families (IVI) were Caesalpiniaceae (upper and middle sections) and Arecaceae (lower section), and the most important species were Diospyros obovata (upper section), Hymenaea courbaril var. stilbocarpa (middle section) and Mauritia flexuosa (lower section). Morisita and Sørensen indices of similarity were calculated. The floristic composition was complex and included species in common with a number of Brazilian forest types and with cerrado (savanna), as well as many widespread species, but stronger links with Amazonian forests could be detected. This is to be expected since the area lies in the ecotonal zone of the cerrado and Amazonian forest biomes and the Bacaba stream itself is a tributary of the Mortes–Araguaia–Amazon river system.

The floristic composition, structure, soil fertility and leaf nutrient concentrations were analysed in a monodominant forest of Brosimum rubescens Taub. located in the Areões Xavante Indigenous Reserve (14°34′S, 51°58′W). The area lies in the ecotone between Amazonian forest and cerrado in the municipality of Água Boa, Mato Grosso State, Brazil. Sixty nested plots (10 × 10m each) were located in a representative portion of the forest, giving a total sampling area of 0.6ha (40 × 150m). A total of 609 trees ≥ 5cm dbh belonging to 57 species, 46 genera and 32 families were present. The most important family was Moraceae, with B. rubescens as the dominant species with a relative dominance of 59%. The diameter distribution of B. rubescens was unbalanced, indicating an episodic recruitment that could lead to future changes in the forest structure. The high basal area per hectare of B. rubescens indicates the possibility of sustainable logging for commercial exploitation. Analysis of composite soil samples collected from the surface layer (0–10cm) of each of the 60 plots did not indicate any significant gradients in fertility within the area sampled. Mean soil pH was 4.6 and the availability of essential nutrients was very low (0.22cmol(+) kg−1 K, 0.048cmol(+) kg−1 Ca, 0.167cmol(+) kg−1 Mg, and 1.5mg kg−1 P). The higher availability of Mg in the soils in comparison with Ca was a feature observed in other monodominant forests in the Amazon region, as well as in other parts of the world. Analysis of foliar samples showed that the dominant species, B. rubescens, maintained higher foliar concentrations of K, Ca and Mg than other species in the forest. This probably indicates a competitive advantage for this species. Also, the higher concentrations of Mg in the soil did not affect its uptake of Ca or K.