Dissecting the assembly process of benthic communities from neotropical streams

• Autores: Juan David González Trujillo
• Directores de la Tesis: Sergi Sabater i Cortés (dir. tes.), Jhon Charles Donato Rondón (dir. tes.), Isabel Muñoz (codir. tes.)
• Lectura: En la Universitat de Girona ( España ) en 2020
• Idioma: español
• Tribunal Calificador de la Tesis: Stéphanie Gascón Garcia (presid.), Miguel Cañedo-Argüelles (secret.), Cayetano Gutiérrez Cánovas (voc.)
• Materias:
  • Ciencias de la vida
    • Biología de insectos (entomología)
      • Ecología de los insectos
  • Ciencias de la tierra y del espacio
    • Geografía
      • Biogeografía
    • Hidrología
      • Limnología
• Enlaces
  • Tesis en acceso abierto en: TDX
• Resumen

  •  The conservation and rehabilitation of ecosystem structure and functioning requires of a deep knowledge on the causes and consequences of its biodiversity. The assembly of Neotropical communities, particularly in riverine ecosystems, remains to be dissected.

     I used the metacommunity framework to dissect the relative influences of dispersal (in ecological and evolutionary timeframes), selection (driven by abiotic factors) and ecological drift on the assembly process of freshwater benthic communities.

     The study was carried out at 26-32 different stream segments within an area of about 40,000km2, in the Colombian Orinoco. The area encompasses an elevation gradient from 3400 to 300m a.s.l. and includes a heterogeneous assembly of ecoregions and landscapes.

     By using a pattern-matching approach, I provide evidences supporting that dispersal, selection and drift are directly involved in the assembly of freshwater benthic communities.

     My findings indicate that one or more events of dispersal limitation (i.e. allopatric isolation) in an evolutionary timeframe shaped distinct pools of taxa in the Orinoco basin. The extent of these pools partially matches the distribution of the ecoregions, suggesting that those events molding the riverscapes and the vegetation structure similarly affect the diversity and distribution of benthic species.

     Within each ecoregion, dispersal, selection and drift interact to constrain the structure and dynamics of communities and metacommunities among and within streams. Depending on the taxa belonging to each pool of species, the role of one of these processes may prevail over the others.

     These findings have implications for both basic and applied research in the disciplines of metacommunity and freshwater ecology as well as of conservation and biogeography.