Diversity and abundance of insects along an elevational gradient on the tropical Andes

Monday, November 14, 2022

8:36 AM – 8:48 AM PT

Location: Vancouver Convention Centre, Meeting Room 306

Presenting Author(s)

Cesar Cabra-Arias

Msc.
The University of British Columbia
Vancouver, British Columbia, Canada

Co-Author(s)

Luis Camacho

Student
Universitat Autònoma de Barcelona
KT

Karina Torres

The University of British Columbia
Quito, Pichincha, Ecuador
LA

Leticia Aviles

The University of British Columbia
Vancouver, British Columbia, Canada

The abundance and diversity of insects and other arthropods are expected to decline as temperature and productivity decline with elevation, but may also reflect differences in the structural complexity of the vegetation. Researchers have also found that certain insect groups and their appearance are differentially sensitive to changes in temperature, precipitation, and other variables. We conducted research on the tropical Andes to address the question of how insect diversity, abundance, and community composition change with elevation, microhabitat type, forest strata, and between diurnal and nocturnal communities. For this purpose, we sampled insects with three different collecting methodologies and identical sampling effort across eight localities distributed from 0 to 4000 m.a.s.l. on the Ecuadorian Andes. At each locality, we sampled insects at four forest edge and four forest interior areas, three forest strata, and differentiated with one of our methods between day and night samples. We deployed malaise traps in the canopy and the understory of the forest, used Winkler extractors to sample ground dwelling arthropods, and carried out beating collections at three different strata within the forest. We simultaneously recorded temperature, relative humidity, precipitation, and light intensity at each of the sites. Our partial results reveal that there is variability for most of the insect groups across the gradient, with a diversity and abundance peak at mid-elevations. There was, however, an unexpected increase in the abundance of certain groups at the higher elevations. Dipterans and predatory beetles had greater representation at night than in diurnal communities.