Patrones biogeográficos de equinodermos en la costa del Océano Pacífico sureste : el rol de la variación ambiental
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Fecha
2020
Profesor/a Guía
Facultad/escuela
Idioma
es
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Universidad Andrés Bello
Nombre de Curso
Licencia CC
Licencia CC
Resumen
La biogeografía es una disciplina integradora que nos ayuda a
comprender los procesos históricos y contemporáneos que pueden explicar
los patrones de distribución, abundancia y diversidad de especies. Los
equinodermos (estrellas, erizos y pepinos de mar, entre otros) a pesar de ser
animales comunes en el litoral del Pacífico, no se conoce su biodiversidad y
patrones biogeográficos a lo largo de Perú y Chile, y si estos están asociados
a la variación ambiental. Estos han sido poco estudiados en ambos países,
principalmente porque aún existen algunos problemas con la identificación de
muchas especies. Además, su distribución y riqueza solo se conocen
parcialmente. En los estudios biogeográficos, los equinodermos prácticamente
no se han incluido como modelos de estudio a pesar de su gran diversidad
local. El objetivo general de este estudio es establecer los patrones
biogeográficos de los equinodermos (distribución y riqueza) y determinar su
relación con la variación ambiental a lo largo de la costa continental del Océano
Pacífico Sureste, para ello se utilizaron colecciones preexistentes,
principalmente de especímenes de la costa continental. Con los datos
obtenidos (1) se realizó una matriz de presencia y ausencia de cada especie,
(2) análisis de agrupamiento jerárquico utilizando el algoritmo UPGMA con el
índice de similitud de Jaccard para buscar unidades biogeográficas, (3) red de
similitud faunística, (4) diversidad beta, (5) modelos Autorregresivos
Espaciales (SAR) para evaluar la asociación de la diversidad con las variables
ambientales. La mayoría de los equinodermos del PSE tienen una amplia
distribución y habitan en varias ecorregiones y provincias. Existe una clina de
similitud faunística entre las ecorregiones y a su vez una completa
desconexión entre las especies de los extremos. Este patrón produce un
aumento de especies hacia altas latitudes debido a la sobreposición de rangos
de distribución que genera un gradiente de recambio de especies a lo largo de
la costa del PSE. Este aumento de la diversidad de equinodermos hacia el polo sur está
correlacionado inversamente con la temperatura superficial del mar. El
aumento de especie hacia el polo podría ser un epifenómeno asociado a que
muchas de las especies tienes amplia distribución en el océano Austral. Este
estudio agregará nueva información biológica crítica para este grupo, que
quizás podrá contribuir a definir categorías de conservación para ellos.
Biogeography is an integrative discipline that helps us to understand the historical and contemporary processes that can explain patterns of distribution, abundance and diversity of the species. Despite being common animals in the Pacific coast, the biodiversity and biogeographic patterns of echinoderms (sea stars, sea urchins, sea cucumbers, among others) along Peru and Chile are not yet known, and whether these are associated with environmental variation. In both countries, echinoderms have been scarcely studied, and this is mainly due to problems in the identification of several species. In addition, the distribution and richness of echinoderms in these areas are only partially known. In regard to biogeographic studies, echinoderms have practically not been included as study model, regardless of their great local diversity. The general objective of this study is to establish the biogeographic patterns (distribution and richness) of echinoderms and determine their relationship with environmental variation along the continental shelf of the Southeastern Pacific Ocean. Echinoderms from the continental shelf deposited in collections were used and the following procedures were developed: (1) a presence/absence matrix of each species, (2) a hierarchical clustering analysis using UPGMA algorithm with Jaccard similarity index to find biogeographic units, (3) a network of faunistic similarity, (4) beta similarity, (5) Spatial AutoRegression (SAR) models to evaluate the association between diversity and environmental variables. Most echinoderms in the SEP have a wide distribution and inhabit several regions and provinces. There is a gradient of faunistic similarity among regions and a full disconnection of the species between edges. This pattern causes an increase of species towards high latitudes due to the overlap of distribution ranges, which originates a gradient of species replacement along the SEP coast. This increase of echinoderms towards the south pole is inversely correlated with the sea surface temperature. The increase of species towards the pole could be an epiphenomenon associated to the fact that several species have a wide distribution in the Southern Ocean. This study will incorporate new key biological information of this group of invertebrates that could contribute to define conservation categories.
Biogeography is an integrative discipline that helps us to understand the historical and contemporary processes that can explain patterns of distribution, abundance and diversity of the species. Despite being common animals in the Pacific coast, the biodiversity and biogeographic patterns of echinoderms (sea stars, sea urchins, sea cucumbers, among others) along Peru and Chile are not yet known, and whether these are associated with environmental variation. In both countries, echinoderms have been scarcely studied, and this is mainly due to problems in the identification of several species. In addition, the distribution and richness of echinoderms in these areas are only partially known. In regard to biogeographic studies, echinoderms have practically not been included as study model, regardless of their great local diversity. The general objective of this study is to establish the biogeographic patterns (distribution and richness) of echinoderms and determine their relationship with environmental variation along the continental shelf of the Southeastern Pacific Ocean. Echinoderms from the continental shelf deposited in collections were used and the following procedures were developed: (1) a presence/absence matrix of each species, (2) a hierarchical clustering analysis using UPGMA algorithm with Jaccard similarity index to find biogeographic units, (3) a network of faunistic similarity, (4) beta similarity, (5) Spatial AutoRegression (SAR) models to evaluate the association between diversity and environmental variables. Most echinoderms in the SEP have a wide distribution and inhabit several regions and provinces. There is a gradient of faunistic similarity among regions and a full disconnection of the species between edges. This pattern causes an increase of species towards high latitudes due to the overlap of distribution ranges, which originates a gradient of species replacement along the SEP coast. This increase of echinoderms towards the south pole is inversely correlated with the sea surface temperature. The increase of species towards the pole could be an epiphenomenon associated to the fact that several species have a wide distribution in the Southern Ocean. This study will incorporate new key biological information of this group of invertebrates that could contribute to define conservation categories.
Notas
Tesis (Licenciado en Biología)
Palabras clave
Equinodermos, Variación (Biología), Biogeografía, Océano Pacífico