35Aim: We aimed to assess the contribution of marginal habitats to the tree species 36 richness of the Mata Atlântica (Atlantic Forest) biodiversity hotspot. In addition, we 37 aimed to determine which environmental factors drive the occurrence and 38 distribution of these marginal habitats. Brazil where it largely occurs, stretches for over 3,500km across equatorial, tropical 73 and subtropical latitudes, and is renowned worldwide for being one of the 35 74 biodiversity hotspots for conservation prioritisation (Myers et al., 2000). Its 75 importance is also demonstrated by its designation as one of the five primary 76 vegetation 'Domains' of Brazil (IBGE, 1993; Ab'Sáber, 2003), the others being the The prevailing land cover of these bordering Domains are semi-arid thorn woodlands distribution of rain forest species in the Atlantic Domain, which at its harshest 88 extremes give rise to distinct habitats (one for each factor), referred to as marginal 89 habitats. Therefore, the rain forest is placed by Scarano (2009) (Galindo-Leal et al., 2003; Tabarelli et al., 2004; 2005; Joly et al., 2014 203The data were originally compiled from an extensive survey of published and 217It also excludes checklists with low species richness (< 20 species), because this is 218 often due to low sampling/collecting efforts, which results in poor descriptive power. 219This study used a subset of tree inventories from the NTT database, The distribution of the sites in the ordination space yielded by NMDS (Fig. 3a waterlogged soils at positive scores (tropical riverine forests). 377The floristic composition of marginal habitats is not simply a nested subset of 378 the more species rich rain forest. The turnover component accounts for most of the 379 floristic dissimilarity of each marginal habitat in relation to rain forests (Fig. 4). 380Nestedness is higher than the turnover component in very few cases (i.e., few The forward selection procedure retained 13 environmental variables in the 390 model to explain the variation in tree species composition (Table 1). In partitioning 391 the variation explained by the retained environmental and spatial predictors, we 392 found that the environmental fraction explained 27% of the variation, 5% of which 393 was independent of spatial autocorrelation (P < 0.01). The environmental predictors 394could not account for a spatially structured variation of 12% (P < 0.01), and 61% of 395 the variation remained unexplained (see discussion for more details). 396The harshest extremes of the retained environmental variables (Table 1) rock outcrops (including campos rupestres) from all others vegetation types (Fig. 3a). 404Within the rock outcrop habitat, the frequency of frost was associated with the forests and tropical riverine forests (Figs. 2b and 3b). At the harshest extreme of the 414 drought-stress gradient (Fig. 3b) Fig. S1). Because the overall floristic dissimilarity between cloud forests and rain 430forests was relatively low (Fig. 3), we assessed the rates of endemism con...

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.Keywords: flora, aquatic plants, floodplain, savanna, vereda. Diversidade de macrófitas aquáticas do Pantanal e alta bacia ResumoEsta é uma breve revisão sobre o estado do conhecimento sobre as macrófitas aquáticas e os principais tipos de vegetação do Pantanal brasileiro e da alta bacia. A flora da planície inundável é de aproximadamente 280 espécies, com escasso endemismo. Na alta bacia, as áreas úmidas do Cerrado (veredas) e nascentes em calcário têm flora distinta do Pantanal, com o dobro da riqueza de espécies. Como um caso representativo de ambientes aquáticos influenciados por inundação fluvial, são apresentados alguns dados primários do Parque Nacional do Pantanal mato-grossense e da Reserva Acurizal associada, analisando-se a similaridade florística entre tipos de vegetação aquática e comentandose os problemas de conservação na região, onde foi observado que a espécie Panicum elephantipes Nees é uma das poucas nativas que competem com a invasora Urochloa arrecta (Hack. ex T. Durand & Schinz) Morrone & Zuloaga.Palavras-chave: flora, plantas aquáticas, campo úmido, savana, vereda.

SUMMARYAppropriate legislation based on in-depth ecological evidence is essential for ecosystem conservation. Wetland areas in the Brazilian Cerrado hotspot are facing difficulties in terms of status under environmental law: only those wetlands with the palm Mauritia flexuosa (veredas) are recognized as protected. Comprehensive fieldwork in central-western Brazil (72 50-m transects) coupled with both exploratory and confirmatory analyses showed that communities with (MP) and without (MA) M. flexuosa are similar in terms of the floristics and ecology. The results demonstrate that the analysed wetlands are part of a continuum, in which a gradual replacement of species and community structure occurs without a pattern related to physiognomy. Considering such floristic and structure patterns when legally defining the ecosystem would promote a more comprehensive and realistic view of the ecosystem's characteristics and functions, and result in laws with a stronger scientific support. Conservationists should further examine the lack of consistent separation of plant community attributes between the MP and MA areas, and reconsider the scientific definition of veredas.

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.

Esta é uma breve revisão de alguns trabalhos recentes sobre diversidade de plantas aquáticas do Pantanal, da planície de inundação do Rio Paraná e de outras áreas úmidas de Mato Grosso do Sul, com algumas considerações florísticas. As áreas extra-planícies dos dois grandes rios são nascentes, veredas, campos úmidos, covais e varjões dos cerrados e da floresta estacionai, além de águas cristalinas de Bonito. A planície do Rio Paraná tem a menor área e 153 espécies, o Pantanal, com a maior área, tem 280 espécies, enquanto as demais pequenas áreas de cabeceiras e veredas têm mais do que o dobro da riqueza do Pantanal. São citadas algumas das espécies principais, exclusivas e invasoras atuais e potenciais como Hydrilla e a nova Urochloa humidicola cv. Tupi.