Abel Augusto Conceição

Plant species richness and ecosystem multifunctionality in global drylands

Global Ecosystem Analysis The relationship between species richness and the functional properties of their ecosystems has often been studied at small scales in experimental plots. Maestre et al. (p. 214; see the Perspective by Midgley) performed field measurements at 224 dryland sites from six continents and assessed 14 ecosystem functions related to carbon, nitrogen, and phosphorus cycling. Positive relationships were observed between perennial plant species richness and ecosystem functionality. The relative importance of biodiversity was found to be as large as, or larger than, many key abiotic variables. Thus, preservation of plant biodiversity is important to buffer negative effects of climate change and desertification in drylands, which collectively cover 41% of Earths land surface and support over 38% of the human population. Plant species richness is positively related to ecosystem multifunctionality in drylands at a global scale. Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and the buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report here on a global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth’s land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality and always included species richness as a predictor variable. Our results suggest that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands.

Ilhas de vegetação em afloramentos de quartzito-arenito no Morro do Pai Inácio, Chapada Diamantina, Bahia, Brasil

ABSTRACT – (Islands of vegetation on quartzite-sandstone outcrops, Pai Inacio Mountain, Chapada Diamantina, Bahia, Brazil).Islands of vegetation on rocky surfaces were studied on two plateaus at Pai Inacio Mountain (41°28’; 12°27’S) in the ChapadaDiamantina. Both plateaus have quartzite-sandstone outcrops interspersed with sandy, acidic soils at the summit between 1,100 and1,170 meters above sea level, with a well-defined dry season. Islands are defined as clumps of one or more species of vascular plantscompletely surrounded by a rocky surface devoid of vascular plants. The study included 39 vegetation islands of different sizes on eachplateau, with 63 herb and shrub species, of which 22 are common to both plateaus. Liliopsida species had the highest abundance,frequency and dominance, with Velloziaceae, Cyperaceae, Orchidaceae, Bromeliaceae, and Guttiferae families predominating on bothplateaus. The chamaephyte life-form was also predominant. Similar species richness was detected on both plateaus, with most of theislands composed of up to five species. Four species groups were revealed using UPGMA and Jaccard´s similarity index, two groupswith species typical of sunlit islands, one group with species from shadier sites, and a fourth composed of more generalist species. The

Massive post-fire flowering events in a tropical mountain region of Brazil: high episodic supply of floral resources

The species Vellozia sincorana L.B.Sm. & Ayensu is key to biodiversity conservation in the tropical mountain region of Brazil. The massive post-fire flowering of this endemic species provides a large, episodic supply of floral resources, mostly nectar, to animals.

Rupestrian Grassland Vegetation, Diversity, and Origin

Rupestrian grasslands (campos rupestres) are tropical landscapes consisting of a mosaic of herbaceous and shrubby physiognomies on quartzite or ironstone that occur in highlands , usually above 900 m. These landscapes encompass a high diversity of habitats , under different environmental conditions, such as on rock outcrops dominated by desiccation-tolerant species, as well as grasslands and shrublands dominated by resprouter species. Therefore, water availability is one of the most significant selective pressures on rock outcrops, while fire is more important on grasslands and shrublands. Poaceae and Velloziaceae are the two dominant plant families in terms of cover area. There is predominance of hemicryptophytes, chamaephytes, and phanerophytes. Autochory is the main dispersal syndrome and contributes to high plant endemism. Floristic and vegetation structural patterns are affected by geology, geography, habitat, and disturbance. Rupestrian grasslands are Old Stable Landscapes and high specialization, phylogenetic conservatism, and low dispersal ability characterize most lineages in these landscapes. Rather than plant refuges during the warmer and moister Pleistocene interglacial periods, highlands have probably worked as refuges for fire-sensitive lineages since the expansion of fire-prone savannas (cerrados) in the late Tertiary. Most lineages from these mountain ranges then diversified during the Quaternary as rupestrian grasslands were finely fragmented by fire-prone landscapes. The fragmented and rich biodiversity in rupestrian grasslands is naturally vulnerable to anthropogenic disturbances. Therefore, protected areas even if small, scattered along the whole landscape, will help to protect them for a while. However, areas suitable for rupestrian grasslands will probably be greatly reduced in the next few decades as seasonality increases. This scenario calls for immediate ex situ conservation measures.

Fire in Rupestrian Grasslands: Plant Response and Management

Plant communities and species composing rupestrian grassland complexes within Brazilian savannas show varied responses to fire, and display similarities with other fire-prone ecosystems. Shallow, nutrient-poor soils subjected to severe water stress favor grasslands which carry fire in a landscape punctuated or crossed by rocky outcrops, riverine forests and other forest patches that act as barriers to fire. The long-term fire regime in these physiognomies is largely unknown, but, in post-European colonization times, the use of fire to livestock (cattle) pastures management and arson, most commonly in the dry season, have dominated the fire dynamics of these ecosystems. Several traits of rupestrian grassland plant species allow them to survive some fire regimes and/or take advantage of the post-burn environment, suggesting an ancient role of fire in their evolution and in defining agricultural practices. Fire management must consider the intrinsic heterogeneity and socioeconomic complexities of rupestrian grasslands landscapes. Evaluation and adaptation of strategies, ranging from protecting target areas from fire to applying prescribed patchy burning, and guaranteeing dialogue regarding people’s needs, practices and knowledge, like those related to cattle raising and everlasting flowers harvesting, must be assured for the accomplishment of biodiversity conservation and sustainability goals. Decision-makers are encouraged to work in partnership with ecologists, policy-makers, and local communities, in an adaptive management approach.

What are the most important factors determining different vegetation types in the Chapada Diamantina, Brazil?

A transect was used to examine the environmental and biological descriptors of a compact vegetation mosaic in the Chapada Diamantina in northeastern Brazil, including the floristic composition, spectrum of plant life forms, rainfall, and soil properties that defined areas of cerrado (Brazilian savanna), caatinga (seasonally dry tropical forest thorny, deciduous shrub/arboreal vegetation) and cerrado-caatinga transition vegetation. The floristic survey was made monthly from April/2009 to March/2012. A dendrogram of similarity was generated using the Jaccard Index based on a matrix of the species that occurred in at least two of the vegetation types examined. The proportions of life forms in each vegetation type were compared using the chi-square test. Composite soil samples were analyzed by simple variance (ANOVA) to examine relationships between soil parameters of each vegetation type and the transition area. The monthly precipitation levels in each vegetation type were measured and compared using the chi-square test. A total of 323 species of angiosperms were collected distributed in 193 genera and 54 families. The dendrogram demonstrated strong difference between the floristic compositions of the cerrado and caatinga, sharing 2% similarity. The chi-square test did not demonstrate any significant statistical differences between the monthly values of recorded rainfall. The organic matter and clay contents of the soilsin the caatinga increased while sand decreased, and the proportions of therophyte, hemicryptophyte, and chamaephyte life forms decreased and phanerophytes increased. We can therefore conclude that the floristic composition and the spectrum of life forms combined to define the cerrado and caatinga vegetation along the transect examined, with soil being the principal conditioning factor determining the different vegetation types, independent of precipitation levels.

A new acicular-leaved species of Sauvagesia (Ochnaceae) from Chapada Diamantina, Bahia, Brazil

A new species of Sauvagesia is described and illustrated under the name Sauvagesia paniculata. This new species is morphologically similar to the acicular-leaved species of the subsect. Vellozianae. However, S. paniculata can be clearly differentiated from the other acicular-leaved species by the paniculate inflorescence. Other diagnostic characters of S. paniculata include the shorter pedicel and longer leaves. This new species seems to be narrowly endemic to the “campo rupestre” vegetation in the Esbarrancado mountain range of Mucugê, in the Chapada Diamantina, Bahia, Brazil.ResumoUma nova espécie de Sauvagesia é descrita e ilustrada sob o nome Sauvagesia paniculata. Esta nova espécie é morfologicamente similar às espécies da subsect. Vellozianae que apresentam folhas aciculares. No entanto, S. paniculata é claramente diferenciada das demais espécies de folhas aciculares por possuir inflorescência paniculada. Outros caracteres diagnósticos de S. paniculata são o pedicelo mais curto e as folhas maiores. Esta nova espécie parece ser endêmica restrita da vegetação de campo rupestre da Serra do Esbarrancado em Mucugê, Chapada Diamantina, Bahia, Brasil.

Composição florística e fisionomia de floresta estacional semidecídua submontana na Chapada Diamantina, Bahia, Brasil

This study surveyed floristic composition and physiognomy of an area of submontane seasonal semi-deciduous forest and examine floristic relationships on the Chapada Diamantina. Angiosperm species were collected monthly in 2004 and from May 2006 to August 2007. Physiognomy was characterized by the profile and species’ habit. A total of 117 species belonging to 85 genera and 49 families were identified. Some of the more species-rich taxa are recurrent in other forests in Brazil, especially the families Fabaceae, Myrtaceae, Lauraceae and Apocynaceae, and the genera Ocotea, Myrcia, Casearia and Inga. The canopy consists of trees 10-16m tall, such as Micropholis gardneriana (Sapotaceae) and Pogonophora schomburgkiana (Euphorbiaceae) with 26-meter-tall emergents. The sub-canopy is located approximately 6-9 m above the forest floor and contains most of the tree species. The understory is composed mostly of saplings of the species that form the upper strata, species of the families Rubiaceae and Melastomataceae and Parodiolyra micrantha (Poaceae). Comparing with other forests showed taxa previously found on the Chapada Diamantina, indicating greater consistency and greater richness of the tree component on the Chapada: Myrtaceae, Fabaceae, Anacardiaceae, Apocynaceae, Sapotaceae, Simaroubaceae, Calyptranthes, Pouteria, Simarouba, Tapirira, Clusia, Miconia, Myrcia and Protium. The study indicated a distinction between Submontane Seasonal Forest and other forest formations on the Chapada, showing the need for more floristic and structural studies there.

Variações locais na riqueza florística em duas ecorregiões de caatinga

Resumo de caatinga do nordeste brasileiro ocorre principalmente sobre dois tipos de substrato principais: sobre solos derivados do embasamento cristalino pre-cambriano e sobre a cobertura arenosa das bacias sedimentares. Evidencias recentes tem demonstrado variacoes na dinâmica, estrutura e composicao floristica da caatinga desses dois macroambientes, o que fundamenta a necessidade de estudos com enfoque nas diferencas floristicas entre esses diferentes substratos. O presente estudo floristico das ecorregioes de caatinga, Depressao Sertaneja Meridional e Raso da Catarina, no municipio de Tucano, Bahia, e de especial interesse porque neste municipio ocorrem esses dois substratos em escala geografica local, permitindo ampliar o conhecimento sobre a heterogeneidade do Dominio da Caatinga. Neste trabalho e apresentado um inventario floristico de 14 localidades nestas duas ecorregioes da Caatinga. Em conjunto, as caatingas amostradas apresentaram uma alta riqueza floristica em comparacao com outras areas no nordeste do Brasil. Foram coletadas 450 especies, 288 generos e 82 familias. A maior riqueza em especies foi das Leguminosae, seguida por Euphorbiaceae. Nas localidades sobre substrato derivado do embasamento cristalino ocorreram 226 especies, enquanto nas de substrato arenoso ocorreram 284 especies. A proporcao de especies em comum entre esses dois tipos de substrato foi de apenas 13%. Diferencas em composicao floristica reforcam a hipotese de duas biotas distintas associadas aos dois principais tipos de substrato, que compoem a vegetacao da caatinga. Palavras-chave: floresta sazonalmente seca, Depressao Sertaneja Meridional, Raso da Catarina, semiarido brasileiro.

Ethnobotany and Harvesting Impacts on Candombá (Vellozia aff. sincorana), A Multiple Use Shrub Species Endemic to Northeast Brazil1

Ethnobotany and Harvesting Impacts on Candombá ( Vellozia aff. sincorana ), A Multiple Use Shrub Species Endemic to Northeast BrazilThis study assessed the relationship between knowledge, use, and harvesting impacts on Vellozia aff. sincorana L.B.Sm. & Ayensu (Velloziaceae) populations. The species has a dracaenoid habit and is endemic to the Chapada Diamantina National Park (NPDC), state of Bahia, in northeastern Brazil. We interviewed 37 key informants from local rural communities in the vicinity of the NPCD, who cited six types of use for the species’ pseudostems, which were grouped into four categories: fuel, magical–religious, technology, and trade. Presently, the pseudostems are used mostly to light wood stoves (fuel). Men had greater knowledge about this species compared to women, which is probably due to the historical use of these plants in rudimentary mining activities in the past, which were performed almost exclusively by men. Informants did not identify preferred spots for harvesting, but they did report areas with a higher density of plants with the desired qualities—larger pseudostems. We also studied the population structures of V. aff. sincorana in six areas under contrasting harvest levels (low vs. high harvesting pressure). We found a significantly lower density of plants in high harvested areas compared to low harvested areas. In contrast, harvest did not significantly change the population distribution in size classes, indicating that recruitment is not impaired by harvesting. Although presently V. aff. sincorana harvesting is only performed in a non–commercial scale, harvesting of this strictly endemic species persists in local communities. Therefore, local ecological knowledge and practices should be taken into account to help conserve this and other species in the region, as it is the case for other protected areas and regions, especially in the tropics.Etnobotânica e Impactos da coleta do Candombá (Vellozia aff. sincorana), uma espécie de múltiplos usos endêmica do Nordeste do BrasilInvestigamos a relação entre conhecimento, uso e impactos do extrativismo em populações de Vellozia aff. sincorana L.B.Sm. & Ayensu (Velloziaceae). Esta espécie dracenóide é endêmica do Parque Nacional da Chapada Diamantina (PNCD), Bahia, Brasil. As entrevistas semiestruturadas foram realizadas com 37 informantes–chave de comunidades rurais que vivem no entorno do PNCD. Identificamos seis tipos de uso para a espécie, que foram agrupadas em quatro categorias: fogo, mágico–religioso, tecnologia e comércio. Atualmente os pseudocaules desta espécie são usados apenas para iniciar fogo em fogões a lenha. Os homens detiveram maior conhecimento sobre a espécie em comparação com as informantes do sexo feminino, o que é provavelmente devido ao uso histórico da espécie durante as atividades rudimentares de mineração, realizadas exclusivamente por homens. Não foram declarados pontos preferenciais para a colheita ainda em prática, embora haja procura por áreas com maior densidade de plantas com as qualidades desejadas (pseudocaules com maiores diâmetros). Adicionalmente, a estrutura populacional da espécie foi caracterizada em seis áreas com diferentes níveis de colheita (baixa vs. alta pressão de extrativismo). Encontramos densidades significativamente menores de plantas em áreas de alta pressão de colheita em comparação com áreas de baixa pressão de colheita. Em contraste, a colheita não alterou significativamente a distribuição dos indivíduos em classes de tamanho entre as populações, indicando que a colheita não prejudica o recrutamento de novos indivíduos. Apesar de, atualmente, a colheita de V. aff. sincorana ser realizada apenas em escala não–comercial, a atividade persiste e é mantida nas comunidades locais. Portanto, o conhecimento e as práticas ecológicas locais devem ser levados em conta para ajudar a conservar essa e outras espécies na região, assim como ocorre em outras regiões e áreas protegidas, especialmente em regiões tropicais.