Efeitos da interação entre complexidade do substrato e mesohabitat na colonização de macroalgas lóticas
Data
2015-12-07
Autores
Guimarães, Jannie Francianne
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Resumo
A heterogeneidade espacial do habitat tem se tornado um dos temas de interesse crescente dentro do escopo ecológico, principalmente em estudos de ambientes aquáticos. Uma vez que diversos fatores contribuem para os padrões de distribuição de abundância das espécies, a estrutura física do habitat também tem apresentado uma relação significativa para explicar estes padrões. Ambientes lóticos estão sujeitos a diversas alterações estruturais ao longo do seu percurso resultando em mesohabitats tais como ambientes de remanso e corredeira. Ademais, o constante fluxo de água em ambientes lóticos não permite a formação do fitoplâncton, fazendo com que as comunidades de algas bentônicas sejam as principais produtoras de energia destes ambientes. Assim, as macroalgas filamentosas constituem uma importante fonte de alimentos para os organismos aquáticos, além da estruturação e manutenção de habitats para outros organismos. O objetivo deste trabalho foi investigar como a complexidade da superfície do substrato e a heterogeneidade gerada pelo mesohabitat influenciam os padrões de estabelecimento das comunidades de macroalgas. Para tanto, foi realizada uma experimentação em três riachos da região sul de Foz do Iguaçu/PR, onde foram inseridos substratos artificiais de concreto de 20x10x3cm com dois níveis de complexidade (mais complexo e menos complexo), em ambientes de remanso e corredeira. A amostragem foi realizada 118 dias após a montagem do experimento. A partir dos dados de riqueza e abundância amostrados foram feitas análises estatísticas: Análise de Normalidade de Shapiro-Wilk, Análise Não-Paramétrica de Mann-Whitney e Análise de Correspondência Destendenciada. Foram encontradas 10 espécies de macroalgas, sendo 40% pertencentes à divisão Chlorophyta, 20% à divisão Cyanophyta, 30% à divisão Rhodophyta e 10% à divisão Ochrophyta. Comparando a média da riqueza encontrada nos tratamentos aplicados, foi possível observar maior número de espécies em ambientes de corredeira em comparação a ambientes de remanso e maior abundância nos substratos mais complexos que nos menos complexos. O teste não-
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paramétrico Mann-Whitney mostrou que houve diferença significativa entre ambientes de remanso e corredeira tanto para dados de riqueza (U = 70; p = 0,0024), quanto para abundância (U = 76,5; p = 0,0052). Ambientes de corredeira apresentaram maior riqueza e abundância em relação a ambientes de remanso, ressaltando assim a importância da correnteza na obtenção de nutrientes e criação de microhabitats. Entretanto, não foi encontrada diferença significativa entre complexidade do substrato, tanto para riqueza (U = 157; p = 0,887), como para abundância (U = 132,5 p = 0,3311). A Análise de Correspondência Destendenciada (DCA) não apresentou nenhum padrão de composição entres os pontos amostrados. Embora não tenha sido possível testar os efeitos da interação entre o mesohabitat e a complexidade do substrato, o desenvolvimento da metodologia e os resultados obtidos no presente trabalho dá suporte a pesquisas futuras.
The habitat spatial heterogeneity has become one of the topics of growing interest within the ecological scope, especially in studies of aquatic environments. Since many factors contribute to the abundance of species distribution patterns, habitat physical structure has also shown a significant relationship to explain these patterns. In addition, these environments are subject to a number of structural changes along their course, resulting in mesohabitats such as pools and riffles environments. Moreover, the constant flow of water in lotic environments does not let the formation of phytoplankton, causing the communities of benthic algae are the main energy-producing these environments. Thus standing out filamentous macroalgae, which are an important source of food for aquatic organisms, as well as the structure and maintenance of habitats for other organisms. Hence, the aim of this study was to investigate if the substrate complexity and heterogeneity generated by mesohabitat influence patterns in macroalgae communities. To this end, an experiment in three streams of the southern region of Foz do Iguaçu / PR was performed, where they were inserted in which concrete artificial substrates 20x10x3cm with two complexity levels (more complex and less complex) in pools and riffles environments. Sampling was carried out 118 days after installation of the experiment. From the data of species richness and abundance sampled uni and multivariate statiscal analysis were made, being as Normality Analysis Shapiro-Wilk, Analysis Non-parametric Mann-Whitney and Correspondence Analysis Detrended. We found 10 species of macroalgae, with 40% belonging to the Chlorophyta division, 20% to the division Cyanophyta, Rhodophyta division to 30% and 10% to Ochrophyta division. Among them, only two were sampled exclusively on samplers and four out of samplers. Comparing the mean richnnes found in the applied treatments, we observed greater number of species in riffles environments compared to pools environments and greater abundance in the most complex substrates in relation to less complex. The non- parametric Mann-Whitney test showed that there was significant difference between pools and riffles environments for both richness data (U = 70, p = 0.0024), and for abundance (U = 76.5, p = 0, 0052). Riffles environments which present greater richness and abundance with respect to backwater environments, emphasizing the importance of the current in obtaining nutrients and light attenuation. However, there was no significant difference between smooth and rough substrate for both richness (U = 157, p = 0.887) and abundance (U = 132.5 p = 0.3311). The Correspondence Analysis Detrended (DCA) did not present any standard entres composition of the sampled points, presenting an explicability of 80.54% in total. Although it was not possible to test the effects of interaction between the mesohabitat and substrate complexity, the result obtained in this study supports further research.
The habitat spatial heterogeneity has become one of the topics of growing interest within the ecological scope, especially in studies of aquatic environments. Since many factors contribute to the abundance of species distribution patterns, habitat physical structure has also shown a significant relationship to explain these patterns. In addition, these environments are subject to a number of structural changes along their course, resulting in mesohabitats such as pools and riffles environments. Moreover, the constant flow of water in lotic environments does not let the formation of phytoplankton, causing the communities of benthic algae are the main energy-producing these environments. Thus standing out filamentous macroalgae, which are an important source of food for aquatic organisms, as well as the structure and maintenance of habitats for other organisms. Hence, the aim of this study was to investigate if the substrate complexity and heterogeneity generated by mesohabitat influence patterns in macroalgae communities. To this end, an experiment in three streams of the southern region of Foz do Iguaçu / PR was performed, where they were inserted in which concrete artificial substrates 20x10x3cm with two complexity levels (more complex and less complex) in pools and riffles environments. Sampling was carried out 118 days after installation of the experiment. From the data of species richness and abundance sampled uni and multivariate statiscal analysis were made, being as Normality Analysis Shapiro-Wilk, Analysis Non-parametric Mann-Whitney and Correspondence Analysis Detrended. We found 10 species of macroalgae, with 40% belonging to the Chlorophyta division, 20% to the division Cyanophyta, Rhodophyta division to 30% and 10% to Ochrophyta division. Among them, only two were sampled exclusively on samplers and four out of samplers. Comparing the mean richnnes found in the applied treatments, we observed greater number of species in riffles environments compared to pools environments and greater abundance in the most complex substrates in relation to less complex. The non- parametric Mann-Whitney test showed that there was significant difference between pools and riffles environments for both richness data (U = 70, p = 0.0024), and for abundance (U = 76.5, p = 0, 0052). Riffles environments which present greater richness and abundance with respect to backwater environments, emphasizing the importance of the current in obtaining nutrients and light attenuation. However, there was no significant difference between smooth and rough substrate for both richness (U = 157, p = 0.887) and abundance (U = 132.5 p = 0.3311). The Correspondence Analysis Detrended (DCA) did not present any standard entres composition of the sampled points, presenting an explicability of 80.54% in total. Although it was not possible to test the effects of interaction between the mesohabitat and substrate complexity, the result obtained in this study supports further research.
Abstract
Descrição
Trabalho de Conclusão de Curso apresentado ao Instituto Latino-Americano de Ciências da Vida e da Natureza da
Universidade Federal da Integração Latino-Americana, como requisito parcial à obtenção do título de Bacharel em Ciências
Biológicas – Ecologia e Biodiversidade. Orientador: Prof. Dr. Cleto Kaveski Peres. Co-orientador: Cristian Antonio Rojas.
Palavras-chave
Heterogeneidade ambiental, Biodiversidade, Riacho
Citação
GUIMARÃES, Jannie Francianne. Efeitos da interação entre complexidade do substrato e mesohabitat na colonização de macroalgas lóticas. 41 p. Trabalho de Conclusão de Curso (Graduação em Ciências Biológicas - Ecologia e Biodiversidade) - Universidade Federal da Integração Latino-Americana (UNILA), Foz do Iguaçu, PR, 2015.