The purpose of this study is to conduct a scientometric analysis of the global climate change (GCC) literature to identify the patterns, trends and biases in this research field. Data were obtained using the Thomson ISI database. A total of 5,444 articles on GCC were recorded, showing a temporal increase in the number of articles (r = 0.84; P < 0.0001). Most the articles look at the impact of climate change on geophysical variables, humans and vegetation. Few studies look at fungi, amphibians or reptiles (H = 24.6; P < 0.0001, N = 27). Principal component analysis revealed a temporal difference in the keywords associated with each article. In the first years we observed that the most frequent keywords indicated worry about the main causes of global climate change, but this shifted in more recent years towards keywords indicating concern with the effects of climate change on biodiversity. We argue that this scientometric study can help guide future climate change research and contribute to our understanding of several poorly studied areas.

No abstract

In this study, we determined the temporal trends of publications by Brazilian authors on phytoplankton and compared these trends to those of other Latin American countries as well as to the 14 countries ranking ahead of Brazil in terms of scientific publication. To do this, we investigated phytoplankton studies published in an international database (Thomson-ISI). The data showed that Brazil plays an important role among other Latin American countries in the publication of these studies. Moreover, the trend of studies published on phytoplankton in Brazil was similar to trends recorded in the developed countries of the world. We conclude that studies can be more deliberately targeted to reduce national and international asymmetries by focusing on projects with large spatial scales and projects that concentrate on less-studied geographic regions, thus encouraging increased productivity in remote areas of the country. Associated with this is a necessary increase in high-impact journal publications, increasing the quantity and quality of Brazilian scientific studies on phytoplankton and, consequently, their global visibility.Keywords: Brazil, global rating, latin america, scientometrics. Produção científica brasileira sobre estudos fitoplanctônicos: determinantes nacionais e comparações internacionais ResumoEsse estudo teve por objetivo determinar a tendência temporal das publicações sobre fitoplâncton de autores brasileiros e comparar essa tendência com outros países latino-americanos, bem como aos 14 principais países em termos de publicação científica. Para isso, investigou-se artigos sobre fitoplâncton disponível em uma base de dados internacionais (Thomson-ISI). A tendência da produção científica de autores brasileiros foi superior a maioria dos países latinoamericanos. Além disso, essa tendência foi similar ao dos países desenvolvidos do mundo. Conclui-se que futuros estudos devem buscar reduzir as assimetrias nacionais e internacionais, concentrando trabalhos em grandes escalas espaciais e em regiões geográfica menos estudadas, incentivando assim, o aumento da produtividade em áreas remotas do país. Associado a isso, destaca-se a importância de aumento de publicações de brasileiros em revistas de alto impacto, aumentando a quantidade e qualidade dos estudos científicos brasileiros sobre o fitoplâncton e, consequentemente sua visibilidade internacional.Palavras-chave: Brasil, taxa global, américa-latina, cienciometria.

Understanding variability in the composition of aquatic assemblages requires a multiscale perspective, since processes operating at different spatial scales (from regional to local) drive the community assembly. Here, the relative importance of environmental variables on fish species composition in streams of the Brazilian savanna (Cerrado) is assessed and quantified at local and landscape scales. The importance of both local and landscape environmental variables in structuring fish assemblages was supported. Local variables explained a substantially higher amount of variance of fish assemblages than landscape variables. However, the shared explanation indicate that landscape variables had a complementary effect. The streams sampled were mostly headwaters at similar altitudes and with similar watershed sizes, so the sensitivity of the fish assemblages, even to small landscape gradients, is highlighted. Maintaining these important instream habitat characteristics close to natural conditions seems to be essential for conserving stream fish species, and for this, the landscape context should be taken into account. Considering the near‐pristine condition of the streams studied, these findings can be used as a reference for further studies addressing the effects of human modifications on stream fish biodiversity of the Cerrado.

Understanding how assemblages are structured in space and the factors promoting their distributions is one of the main goals in Ecology, however, studies regarding the distribution of organisms at larger scales remain biased towards terrestrial groups. We attempt to understand if the structure of stream fish metacommunities across a Neotropical ecoregion (Upper Paraná-drainage area of 820,000 km 2) are affected by environmental variables, describing natural environmental gradient, anthropogenic impacts and spatial predictors. For this, we obtained 586 sampling points of fish assemblages in the ecoregion and data on environmental and spatial predictors that potentially affect fish assemblages. We calculated the local beta diversity (Local Contribution to Beta Diversity, LCBD) and alpha diversity from the species list, to be used as response variables in the partial regression models, while the anthropogenic impacts, environmental gradient and spatial factors were used as predictors. We found a high total beta diversity for the ecoregion (0.41) where the greatest values for each site sampled were located at the edges of the ecoregion, while richer communities were found more centrally. All sets of predictors explained the LCBD and alpha diversity, but the most important was dispersal variables, followed by the natural environmental gradient and anthropogenic impact. However, we found an increase in the models' prediction power through the shared effect. Results suggest that environmental filters (i.e. environmental variables such as climate, hydrology and anthropogenic impact) and dispersal limitation together shape fish assemblages of the Upper Paraná ecoregion, showing the importance of using multiple sets of predictors to understand the processes structuring biodiversity distribution.

ABSTRACT-The economic and scientific interest in Hancornia speciosa (mangabeira) has been growing in recent years, mainly due to the marketing of fruit and extraction of natural compounds with high pharmacological potential. In this study, a scientometric survey about mangabeira was carried out in order to promote and direct future studies on the species. As a result, low scientific productivity associated with this species was found, with only 131 articles published in the last 69 years. In addition, this study identified some trends in bibliographic production on mangabeira, among them: the increasing number of articles over the years; scientific dissemination in nationwide journals; the main focus of this study is associated with agronomic studies; the experimental approach is more frequent and usually associated with populations of restricted geographical distribution; and the scientific production is mainly from education institutions. Furthermore, this study also allowed the identification of some gaps in knowledge about mangabeira, among them the difficulty in describing and characterizing botanical lines; lack of analysis of the genetic diversity of widely distributed populations; lack of management and conservation projects for the species; lack of description of cultivation, collection and preservation techniques of fruits; and lack of identification of natural compounds responsible for its pharmacological activity. It is expected that the data generated in this study will serve to direct future studies on H. speciosa. Index terms: mangabeira, native fruit, scientometrics. ESTADO DA ARTE DA LITERATURA CIENTÍFICA SOBREHancornia speciosa: TENDÊNCIAS E LACUNAS RESUMO-O interesse econômico e científico sobre Hancornia speciosa (mangabeira) vem crescendo nos últimos anos, devido principalmente à comercialização de seu fruto e extração de compostos naturais com alto potencial farmacológico. Neste estudo, foi realizado um levantamento cienciométrico sobre a mangabeira, com o objetivo de fomentar e direcionar futuras pesquisas sobre a espécie. Como resultado, verificou-se a baixa produtividade científica a respeito da espécie, com a publicação de apenas 131 artigos nos últimos 69 anos. Além disso, o presente estudo identificou algumas tendências na produção bibliográfica sobre a mangabeira, com destaque para: o aumento do número de artigos ao longo dos últimos anos; o fato de a divulgação científica ser realizada principalmente em revistas de âmbito nacional; a abordagem experimental ser mais frequente do que a abordagem teórico-descritiva; os trabalhos experimentais serem geralmente associados às populações de distribuição geográfica restrita; e a produção científica ser proveniente, principalmente, de Instituições de Ensino Superior. Por outro lado, este estudo também permitiu a identificação de algumas lacunas no conhecimento sobre a mangabeira, entre as quais se destacam: a dificuldade em descrever e caracterizar as linhagens botânicas; a falta de análise da diversidade genética de populações de ampla dist...

Aim: Chlorophyll-a may be directly influenced by local variables and/or indirectly by land use and cover, once landscape modifications change limnological variables, which in turn affect the primary productivity of aquatic environments, e.g., streams. Therefore, the objective of this study was to determine the relative importance of the local and landscape environmental components and assess the direct and indirect effects of these variables on sestonic chlorophyll-a concentration in 30 Cerrado streams (Santa Teresa River basin). Results All aquatic environments were oligotrophic during the study period. Only the local variables were important to explain chlorophyll-a variation (R2 = 0.27; P = 0.04). In addition, the path analysis showed that all variables used in the analysis influenced chlorophyll-a concentration more directly than indirectly. Conductivity was the most important variable to directly influence chlorophyll-a, followed by turbidity. Conclusion The large amount of remnant native vegetation in the basin indicates that the region studied is well preserved, which may explain the greater importance of local variables and the low effect of the landscape in explaining chlorophyll-a variation.

The Cerrado (Brazilian savanna) is the second largest Brazilian biome and is considered a biodiversity hotspot, for presenting high endemism and being under intense threat. This study aimed at highlighting publication trends on the Cerrado, detecting possible gaps and indicating future directions for scientific studies on this biome. We searched for articles between 1991 and 2012 in the journal database of the Institute for Scientific Information (ISI). We observed a significant increase in the number of articles throughout the years of the evaluated period (r=0.89; P<0.001), demonstrating an increasing interest of the scientific community in the Cerrado. Largely addressed issues were related to biodiversity (64.75%), followed by abiotic environment (13.38%) and agricultural crops (11.21%). In addition, 10.65% addressed both biodiversity and abiotic environment jointly. The most studied taxonomic group was plants (42%), followed by fungi (18%) and insects (12%). Fishes presented a lower number of studies (0.6%). The main gaps concern the few studies dealing with abiotic aspects and freshwater organisms, such as fishes, and also a low increment in the number of articles on invertebrates, except insects. Based on these gaps, we suggest that future studies must be especially directed towards aquatic environments and their biodiversity.