Changes of arthropod diversity across an altitudinal ecoregional zonation in Northwestern Argentina

Abstract

This study examined arthropod community patterns over an altitudinal ecoregional zonation that extended through three ecoregions (Yungas, Monte de Sierras y Bolsones, and Puna) and two ecotones (Yungas-Monte and Prepuna) of Northwestern Argentina (altitudinal range of 2,500 m), and evaluated the abiotic and biotic factors and the geographical distance that could influence them. Pitfall trap and suction samples were taken seasonally in 15 sampling sites (1,500–4,000 m a.s.l) during one year. In addition to climatic variables, several soil and vegetation variables were measured in the field. Values obtained for species richness between ecoregions and ecotones and by sampling sites were compared statistically and by interpolation–extrapolation analysis based on individuals at the same sample coverage level. Effects of predictor variables and the similarity of arthropods were shown using non-metric multidimensional scaling, and the resulting groups were evaluated using a multi-response permutation procedure. Polynomial regression was used to evaluate the relationship between altitude with total species richness and those of hyperdiverse/abundant higher taxa and the latter taxa with each predictor variable. The species richness pattern displayed a decrease in species diversity as the elevation increased at the bottom wet part (Yungas) of our altitudinal zonation until the Monte, and a unimodal pattern of diversity in the top dry part (Monte, Puna). Each ecoregion and ecotonal zone evidenced a particular species richness and assemblage of arthropods, but the latter ones displayed a high percentage of species shared with the adjacent ecoregions. The arthropod elevational pattern and the changes of the assemblages were explained by the environmental gradient (especially the climate) in addition to a geographic gradient (the distance of decay of similarity), demonstrating that the species turnover is important to explain the beta diversity along the elevational gradient. This suggests that patterns of diversity and distribution of arthropods are regulated by the dissimilarity of ecoregional environments that establish a wide range of geographic and environmental barriers, coupled with a limitation of species dispersal. Therefore, the arthropods of higher taxa respond differently to the altitudinal ecoregional zonation.

Native bees of high Andes of Central Chile (Hymenoptera: Apoidea): biodiversity, phenology and the description of a new species ofXeromelissaCockerell (Hymenoptera: Colletidae: Xeromelissinae)

“…Mountain and plateau systems cover approximately 22% of Earth's land surface distributed in all climatic zones (Manuelli, Hofer & Springgay, 2019), often harboring a high biodiversity (Hoorn et al, 2013) and comprising different ecoregions, such as montane grasslands, scrublands, and tundra (Öztürk et al, 2015;WWF, 2019). Furthermore, each of these have communities with an assemblage of species with crucial contributions to global diversity (Paknia & Pfeiffer, 2011;González-Reyes, Corronca & Rodriguez-Artigas, 2017). Ecological regions adjacent to high-altitude ecosystems may also share high proportions of species in common, and could also act as filters for the distribution and/or exchange of other species (González-Reyes, Corronca & Rodriguez-Artigas, 2017).…”

“…Furthermore, each of these have communities with an assemblage of species with crucial contributions to global diversity (Paknia & Pfeiffer, 2011;González-Reyes, Corronca & Rodriguez-Artigas, 2017). Ecological regions adjacent to high-altitude ecosystems may also share high proportions of species in common, and could also act as filters for the distribution and/or exchange of other species (González-Reyes, Corronca & Rodriguez-Artigas, 2017). This means they could limit the distribution of certain species, and at the same time, support a higher diversity of shared generalist species.…”

Beta diversity and specialization in plant–pollinator networks along an elevational gradient

“…Only a few available studies assess the variation in these two components of diversity along elevational gradients. They indicate that changes in species composition are primarily caused by the replacement component, because many pollinator insects tend to appear at particular elevations rather than persisting across the entire gradient (Bishop, Robertson, Rensburg, & Parr, ; da Silva, Lobo, Hensen, Vaz‐de‐Mello, & Hernández, ; González‐Reyes, Corronca, & Rodriguez‐Artigas, ; Nunes, Braga, Figueira, Siqueira Neves, & Fernandes, ; Perillo, Siqueira Neves, Antonini, & Martins, ). However, the generality of this pattern is sometimes challenged by strong context‐dependency (da Silva et al, ; González‐Reyes et al, ).…”

“…However, the generality of this pattern is sometimes challenged by strong context-dependency (da Silva et al, 2018;González-Reyes et al, 2017).…”

Analysis of tropical and temperate elevational gradients in arthropod abundance

“…However, all but two of the studies included in our analyses sampled at least one site within the lowest 400m of the elevational gradient for that region. The only exceptions were the elevational gradients in western Himalayas sampled by Ghosh-Harihar (2013) and northwestern Argentina sampled by González-Reyes et al (2017), where the lowest elevations sampled were 1350m and 1586m respectively, whereas in both regions the elevational gradient extends to below 400m. Across four North American gradients, the lowest elevation sampled is over 1400m, but the lowest elevation in the region is at about 1000m.…”