Assembleia de nematodas como modelo para a hipótese da heterogeneidade ambiental: estudo de caso na margem continental do Atlântico Sul
Data
2021-02-23
Autores
Nascimento, Yago Ferreira 
Santos, Larissa Gomes Salomão dos
Orientadores
Gallucci, Fabiane
Tipo
Trabalho de conclusão de curso
Título da Revista
ISSN da Revista
Título de Volume
Resumo
A hipótese da heterogeneidade ambiental, desenvolvida inicialmente por MacArthur
& MacArthur (1961) estabelece que naqueles ambientes onde o grau de heterogeneidade é maior, há maior oferta de recursos, permitindo a coexistência de um maior número de espécies. Esta relação da heterogeneidade ambiental e a diversidade de espécies já foi testada para vários organismos, sendo que na maioria dos casos tiveram relação positiva. Enquanto a contribuição
de diferentes fatores ambientais tem recebido considerável atenção no entendimento da estruturação das comunidades bentônicas ao longo de gradientes em sedimentos das margens continentais oceânicas, o papel da heterogeneidade ambiental, em particular sua relação com a diversidade, tem sido menos explorado. Este estudo teve por objetivo testar a hipótese da heterogeneidade ambiental utilizando a assembleia de nematódeos como modelo, visto sua alta representatividade numérica e grande riqueza de gêneros em sedimentos marinhos, considerando as variações ambientais e biológicas ao longo de gradientes batimétricos e latitudinais em parte da margem continental do Atlântico Sul. Foi testada a hipótese de que a variação biológica aumentaria de acordo com o aumento da variação ambiental. No gradiente latitudinal a variação biológica aumentou de acordo com a profundidade; já a variação ambiental não apresentou um padrão no que diz respeito a batimetria. Quando avaliado o gradiente batimétrico, não foi possível constatar uma variação relevante entre os transectos tanto na variação biológica quanto na ambiental. A regressão linear feita com ambos os gradientes deixou claro, confirmando a hipótese, de que existe uma relação positiva entre a heterogeneidade ambiental e a diversidade de espécies.
The hypothesis of environmental heterogeneity, initially developed by MacArthur & MacArthur (1961) establishes that in environments where the heterogeneity is higher there is greater resources availability, thus making possible the coexistence of a larger number of species. This relation between environmental heterogeneity and species diversity was tested for various organisms, where in most cases it was positive. While the contribution of different environmental factors has received considerable attention on the understanding of benthic communities along gradients in sediments from oceanic continental margins, the effect of environmental heterogeneity, in particular its relation with diversity, has been explored less. This study had as objective testing the hypothesis of environmental heterogeneity using the nematode assembly as model, because of it's high numerical representativity and large gender richness in marine sediments, considering the environmental and biological variations along with latitudinal and bathymetric gradients in part of the South Atlantic continental margin. The hypothesis that the biological variation would grow according to the growth of the environmental variation was tested. The biological variation in the latitudinal gradient grew according to the depth, but the environmental variation did not present any pattern in regards to bathymetry. When the bathymetric gradient was evaluated, it wasn't possible to verify a relevant variation between the transects both in the biological and environmental variation. The linear regression made with both gradients made clear, confirming the hypothesis that there is a positive relation between the environmental heterogeneity and the diversity of species.
The hypothesis of environmental heterogeneity, initially developed by MacArthur & MacArthur (1961) establishes that in environments where the heterogeneity is higher there is greater resources availability, thus making possible the coexistence of a larger number of species. This relation between environmental heterogeneity and species diversity was tested for various organisms, where in most cases it was positive. While the contribution of different environmental factors has received considerable attention on the understanding of benthic communities along gradients in sediments from oceanic continental margins, the effect of environmental heterogeneity, in particular its relation with diversity, has been explored less. This study had as objective testing the hypothesis of environmental heterogeneity using the nematode assembly as model, because of it's high numerical representativity and large gender richness in marine sediments, considering the environmental and biological variations along with latitudinal and bathymetric gradients in part of the South Atlantic continental margin. The hypothesis that the biological variation would grow according to the growth of the environmental variation was tested. The biological variation in the latitudinal gradient grew according to the depth, but the environmental variation did not present any pattern in regards to bathymetry. When the bathymetric gradient was evaluated, it wasn't possible to verify a relevant variation between the transects both in the biological and environmental variation. The linear regression made with both gradients made clear, confirming the hypothesis that there is a positive relation between the environmental heterogeneity and the diversity of species.
Descrição
Citação
SANTOS, Larissa Gomes Salomão dos; NASCIMENTO, Yago Ferreira. Assembleia de nematodas como modelo para a hipótese da heterogeneidade ambiental: estudo de caso na margem continental do Atlântico Sul. 2021. 27f. Trabalho de conclusão de curso de graduação (Bacharelado Interdisciplinar em Ciência e Tecnologia do Mar) - Instituto do Mar, Universidade Federal de São Paulo, Santos, 2021.