Vali Joana Pott

Aquatic macrophyte diversity of the Pantanal wetland and upper basin.

This is a short review of the state of the art concerning diversity of aquatic macrophytes and the main aquatic vegetation types in the Brazilian Pantanal wetland and upper watershed. There are ca. 280 species of aquatic macrophytes on the Pantanal floodplain, with scarce endemism. On the upper watershed, Cerrado wetlands (veredas) and limestone springs have a distinct flora from the Pantanal, with twice the species richness. As a representative case of aquatic habitats influenced by river flood, some primary data are presented for the Pantanal Matogrossense National Park and associated Acurizal Preserve, analysing the floristic similarity among aquatic vegetation types. We comment on problems of conservation and observe that Panicum elephantipes Nees is one of the few natives to compete with the invasive Urochloa arrecta (Hack. ex T. Durand & Schinz) Morrone & Zuloaga.

Antimicrobial activity of some medicinal plants from the cerrado of the central-western region of Brazil

Ethanol extracts from six selected species from the Cerrado of the Central-Western region of Brazil, which are used in traditional medicine for the treatment of infectious diseases and other medical conditions, namely Erythroxylum suberosum St. Hil. (Erythroxylaceae), Hyptis crenata Pohl. ex Benth. (Lamiaceae), Roupala brasiliensis Klotz. (Proteaceae), Simarouba versicolor St. Hil. (Simaroubaceae), Guazuma ulmifolia Lam. (Sterculiaceae) and Protium heptaphyllum (Aubl.) March. (Burseraceae), as well as fractions resulting from partition of these crude extracts, were screened in vitro for their antifungal and antibacterial properties. The antimicrobial activities were assessed by the broth microdilution assay against six control fungal strains, Candida albicans, C. glabrata, C. krusei, C. parapsilosis, C. tropicalis and Cryptococcus neoformans, and five control Gram-positive and negative bacterial strains, Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. Toxicity of the extracts and fractions against Artemia salina was also evaluated in this work. All plants investigated showed antimicrobial properties against at least one microorganism and two species were also significantly toxic to brine shrimp larvae. The results tend to support the traditional use of these plants for the treatment of respiratory and gastrointestinal disorders and/or skin diseases, opening the possibility of finding new antimicrobial agents from these natural sources. Among the species investigated, Hyptis crenata, Erythroxylum suberosum and Roupala brasiliensis were considered the most promising candidates for developing of future bioactivity-guided phytochemical investigations.

Structure of pond vegetation of a vereda in the Brazilian Cerrado

This is the first report on aquatic macrophytes in ponds of veredas (palm swamps) in the Cerrado (Brazilian savanna). We studied a pond in a vereda in Terenos, Mato Grosso do Sul state, central-western Brazil, during drought and flood periods to assess plant community structure and the relationship between species distribution and water depth. Sampling was carried out in five permanent transects, along which we placed sampling units of 1 m2 quadrats every 5 m. We estimated visually the relative cover of each species, bare ground, dead matter, and exposed water. We also measured water depth. We recorded 77 species of 49 genera and 31 families. The number of species varied between seasons, and in the rainy season the amphibious life form was predominant. The richest families were Poaceae (15 species), Cyperaceae (11), Asteraceae (4) and Lentibulariaceae (4). The richest genera were Rhynchospora (4), Utricularia (4), Eleocharis (4), Aeschynomene (3), Bacopa (3), Ludwigia (3) and Panicum (3). We found six new occurrences for the cerrado. Eleocharis acutangula had the highest relative cover (rainy and dry seasons), followed by Bacopa reflexa (rainy season), Paspalum lenticulare (rainy and dry seasons), Leersia hexandra (rainy and dry seasons), and Sagittaria rhombifolia (rainy season). Some species were distributed mainly at shallower depths, others occurred in deeper water, whereas some species varied greatly in terms of depth. Heliotropium filiforme and Ludwigia nervosa were found only in the dry season. In the rainy season, as expected, the exclusive species were mostly true aquatics.

Structure of aquatic vegetation of a large lake, western border of the Brazilian Pantanal

Studies on Neotropical aquatic macrophytes have increased in recent decades, however species richness in wetlands of South America is far from being fully known. In addition, studies having an ecological approach are scarce in the Pantanal. Rapid assessments are essential for gaining knowledge of the biodiversity in the region. This study was performed in five sites of the Baía do Castelo, the western border of the Brazilian Pantanal, which included wild-rice patches, floating mats and floating meadows. At each site, plots of 0.5 × 0.5 m were set (n = 137), species of aquatic macrophytes were identified, their coverage was measured and the plot depth was estimated. We recorded 57 species in 26 families, of which Poaceae was the richest. The most frequent and abundant species was Commelina schomburgkiana; the second most frequent was Oryza latifolia,followed by Leersia hexandra, Enydra radicans and Pityrogramma calomelanos. The latter species was second in cover, followed by Pontederia rotundifolia, Eichhornia azurea, E. crassipes and Enydra radicans. These five species and C. schomburgkiana (the most abundant) together represent more than half of the coverage on the lake. Pontederia rotundifolia, Ludwigia helminthorrhiza, Pistia stratiotes, E. azurea, E. crassipes, Enydra radicans and Panicum elephantipes were strongly associated with deeper areas, while Oryza latifolia, Leersia hexandra and Salvinia auriculata were prevalent in shallow areas. Pityrogramma calomelanos, Ludwigia nervosa, Ipomoea alba, Cayaponia podantha, Polygonum acuminatum, Rhynchanthera novemnervia and Ludwigia leptocarpa were highly correlated with floating meadows. The structure of the habitat, natural dynamics and zonation of aquatic vegetation in the Baía do Castelo seems to be influenced by a variation in water levels, which promotes spatial segregation, most likely due to competition and/habitat preference.

Hippeastrum angustifolium Pax (Amaryllidaceae): first record for a biodiversity hotspot in the Mato Grosso do Sul, Brazil

Hippeastrum angustifolium Pax a bulbous perennial in the family Amaryllidaceae, occurs in Argentina, Paraguay, and south-southeastern Brazil in the Pampa and Atlantic Forest domains. In this work, we present the first record of this species for the Cerrado domain in the state of Mato Grosso do Sul, Brazil. We also comment on its biology and ecology.

EFFECTS OF ENVIRONMENTAL CHARACTERISTICS ON THE RICHNESS AND COMPOSITION OF AQUATIC MACROPHYTES IN URBAN STREAMS

The aquatic macrophytes are plants that contribute to aquatic ecosystem with its distribution and abundance determined, among others factors, by water level and velocity, eutrophication, anthropogenic pressure and luminosity. We describe the richness and composition of species aquatic macrophytes in two small basins of Dourados city, Mato Grosso do Sul State, Brazil and their relationship with environmental characteristics. The floristic survey was performed in 16 sites, the aquatic-paludal macrophytes found were recorded as well as some physical and chemical variables and degradation level of streams through Rapid Assessment Protocol-PAR. A Non-Metric Multidimensional Scaling Analysis (NMDS) was performed to investigate differences in species composition and richness among the sampled sites. We recorded 79 plant species, distributed in 33 families. The richest family was Cyperaceae. We observed that PAR was the main descriptor of species richness and composition of aquatic macrophytes in urban streams analyzed, altered stream stretches present higher species richness and life forms, such as Salvinia biloba, Utricularia gibba, Elanthium bolivianun, Rotala Mexicana. On the other hand, impacted portions presented lower richness, being represented by amphibian species of the families Cyperaceae and Poaceae, such as Cyperus alternifolius, Urochloa arrecta and Pennisetum purpureum. Key-Words: Urbanization, conservation and floristic survey.

Nymphaeaceae, Nymphaea belophylla Trickett: new state record

We report the first record of Nymphaea belophylla for the Pantanal wetland in the State of Mato Grosso do Sul, Brazil, being the southernmost record of this waterlily. It is one of the seven neotropical species of this genus in the Pantanal. We collected N. belophylla during a study on seasonality of herbaceous species composition in a remote area of the Paraguay river floodplain, what reinforces the importance of floristic surveys to improve knowledge on species distribution.