Fire seasonality plays a limited role in the reproduction of Anacardium humile A. St.-Hil. in a tropical savanna.

Anthropogenic fires are an increasing threat to tropical savannas and their plant populations. In the Brazilian Cerrado, human-made fires at the end of the dry season are replacing natural fires at the beginning of the dry season. Critically, these late burns occur under more intense climate variables. Here, we aimed to understand the potential role of fire seasonality on individuals of Anacardium humile, a widespread Cerrado species of cultural and economic importance. We conducted two prescribed burnings, one at the beginning of the dry season (early burning) and one at the end of the dry season (late burning) when climate variables were remarkably different. We assessed the reproductive responses of A. humile individuals over 4 years and compared individuals from the fire treatments with those from an unburned area (control). The reproductive phenology of A. humile varied over time and was influenced by climate variables. The seasons of different burning had similar impacts on the reproductive phenology of A. humile, and this impact lasted for at least 4 years. While A. humile populations do not depend on fire for reproduction, they produced more flowers and fruits for up to 2 years with the fire treatments. We provide empirical evidence of the role of climate variables on the phenology of A. humile and demonstrate the importance of considering the role of time after fire events. The similar responses of A. humile to fire seasonality show that Cerrado fire management can be more complex than previously thought.

Trends and biases in global scientific literature about ecological niche models.

Recently, ecological niche models have been employed to investigate the potential geographical distribution of species. However, it is necessary to analyze the vast number of publications on this topic to understand the trends and biases of research using ecological niche models (ENMs). Therefore, this study aims to investigate trends in the scientific literature regarding studies on ENMs. For the quantitative analysis of the literature on ENMs, we performed a search in the Thomson ISI (Web of Science) database between 1991 and 2013. The search identified 3042 papers containing preselected keywords in either the title or abstract. The results showed that the number of papers has increased over the years (r=0.77, P<0.001), with a sharp increase in recent years, highlighting the widespread use of the ENMs. There was an increase in the diversity of journals that published papers about ENMs (r=0.97, P<0.001). The research was conducted in different countries, predominantly the United States of America (550 papers), and the most commonly used method was the Maximum Entropy method (312 papers). Regarding the taxonomic group, most research has been conducted on plants (402 papers, or 28.36% of the total). There was no relationship between the modeling method used and the taxonomic group studied (χ2=4.8, P=0.15). Finally, the wide availability of biological, environmental and computational resources has elicited the broad use of tools for ENMs. Despite the conceptual discussions of the ENMs, this method is currently the most effective way to evaluate the potential geographical distribution of species, and to predict the distribution under different environmental conditions (i.e., future or past scenarios).

Trends and biases in global scientific literature about ecological niche models / Tendências e vieses na literatura científica mundial sobre modelos de nicho ecológico

Abstract Recently, ecological niche models have been employed to investigate the potential geographical distribution of species. However, it is necessary to analyze the vast number of publications on this topic to understand the trends and biases of research using ecological niche models (ENMs). Therefore, this study aims to investigate trends in the scientific literature regarding studies on ENMs. For the quantitative analysis of the literature on ENMs, we performed a search in the Thomson ISI (Web of Science) database between 1991 and 2013. The search identified 3042 papers containing preselected keywords in either the title or abstract. The results showed that the number of papers has increased over the years (r=0.77, P<0.001), with a sharp increase in recent years, highlighting the widespread use of the ENMs. There was an increase in the diversity of journals that published papers about ENMs (r=0.97, P<0.001). The research was conducted in different countries, predominantly the United States of America (550 papers), and the most commonly used method was the Maximum Entropy method (312 papers). Regarding the taxonomic group, most research has been conducted on plants (402 papers, or 28.36% of the total). There was no relationship between the modeling method used and the taxonomic group studied (χ2=4.8, P=0.15). Finally, the wide availability of biological, environmental and computational resources has elicited the broad use of tools for ENMs. Despite the conceptual discussions of the ENMs, this method is currently the most effective way to evaluate the potential geographical distribution of species, and to predict the distribution under different environmental conditions (i.e., future or past scenarios).

Resumo Recentemente, modelos de nicho têm sido empregados para investigar a distribuição geográfica potencial de espécies. Porém, é necessário analisar a vasta quantidade de publicações sobre o referido tema, a fim de compreender as tendências e vieses das pesquisas que usam modelos de nicho ecológico (MNEs). Portanto, esse trabalho tem por objetivo investigar as tendências da literatura científica de trabalhos sobre MNEs. Para a análise quantitativa das publicações sobre MNEs, foi realizada uma busca na base de dados Thomson ISI (Web of Science), entre o período de 1991 a 2013. A pesquisa agrupou 3042 documentos que continham nas palavras-chave, no título ou no resumo os termos selecionados para a busca. Os resultados mostraram que de forma geral o número de artigos tem aumentado ao longo dos anos (r=0,77, P<0,001), com um acentuado crescimento nos anos mais recentes, destacando o amplo uso de MNEs. Ao longo dos anos percebeu-se um aumento da diversidade de revistas que publicam sobre o assunto (r=0,97, P<0,001). As pesquisas têm sido desenvolvidas em diferentes países, com predomínio dos Estados Unidos (550 artigos) e o método mais utilizado foi o de Máxima Entropia (312 artigos). Quanto ao grupo taxonômico, a maioria dos estudos tem ocorrido com plantas (402 artigos ou 28,36% do total de artigos). Não houve relação entre método de modelagem e grupo taxonômico (χ2=4,8, P=0,15). Por fim, a ampla disponibilidade de dados biológicos, ambientais e recursos computacionais tem propiciado um amplo uso de MNEs. Apesar das discussões conceituais sobre MNEs, o método atualmente é o mais eficaz para conhecer a distribuição geográfica potencial das espécies e ainda projetar essa distribuição sob diferentes condições ambientais (i.e. cenários futuros, passado).

Trends and biases in global scientific literature about ecological niche models

Abstract Recently, ecological niche models have been employed to investigate the potential geographical distribution of species. However, it is necessary to analyze the vast number of publications on this topic to understand the trends and biases of research using ecological niche models (ENMs). Therefore, this study aims to investigate trends in the scientific literature regarding studies on ENMs. For the quantitative analysis of the literature on ENMs, we performed a search in the Thomson ISI (Web of Science) database between 1991 and 2013. The search identified 3042 papers containing preselected keywords in either the title or abstract. The results showed that the number of papers has increased over the years (r=0.77, P 0.001), with a sharp increase in recent years, highlighting the widespread use of the ENMs. There was an increase in the diversity of journals that published papers about ENMs (r=0.97, P 0.001). The research was conducted in different countries, predominantly the United States of America (550 papers), and the most commonly used method was the Maximum Entropy method (312 papers). Regarding the taxonomic group, most research has been conducted on plants (402 papers, or 28.36% of the total). There was no relationship between the modeling method used and the taxonomic group studied (2=4.8, P=0.15). Finally, the wide availability of biological, environmental and computational resources has elicited the broad use of tools for ENMs. Despite the conceptual discussions of the ENMs, this method is currently the most effective way to evaluate the potential geographical distribution of species, and to predict the distribution under different environmental conditions (i.e., future or past scenarios).

Resumo Recentemente, modelos de nicho têm sido empregados para investigar a distribuição geográfica potencial de espécies. Porém, é necessário analisar a vasta quantidade de publicações sobre o referido tema, a fim de compreender as tendências e vieses das pesquisas que usam modelos de nicho ecológico (MNEs). Portanto, esse trabalho tem por objetivo investigar as tendências da literatura científica de trabalhos sobre MNEs. Para a análise quantitativa das publicações sobre MNEs, foi realizada uma busca na base de dados Thomson ISI (Web of Science), entre o período de 1991 a 2013. A pesquisa agrupou 3042 documentos que continham nas palavras-chave, no título ou no resumo os termos selecionados para a busca. Os resultados mostraram que de forma geral o número de artigos tem aumentado ao longo dos anos (r=0,77, P 0,001), com um acentuado crescimento nos anos mais recentes, destacando o amplo uso de MNEs. Ao longo dos anos percebeu-se um aumento da diversidade de revistas que publicam sobre o assunto (r=0,97, P 0,001). As pesquisas têm sido desenvolvidas em diferentes países, com predomínio dos Estados Unidos (550 artigos) e o método mais utilizado foi o de Máxima Entropia (312 artigos). Quanto ao grupo taxonômico, a maioria dos estudos tem ocorrido com plantas (402 artigos ou 28,36% do total de artigos). Não houve relação entre método de modelagem e grupo taxonômico (2=4,8, P=0,15). Por fim, a ampla disponibilidade de dados biológicos, ambientais e recursos computacionais tem propiciado um amplo uso de MNEs. Apesar das discussões conceituais sobre MNEs, o método atualmente é o mais eficaz para conhecer a distribuição geográfica potencial das espécies e ainda projetar essa distribuição sob diferentes condições ambientais (i.e. cenários futuros, passado).