Compositional changes in bee and wasp communities along Neotropical mountain altitudinal gradient

Abstract

Climate conditions tend to differ along an altitudinal gradient, resulting in some species groups’ patterns of lower species richness with increasing altitude. While this pattern is well understood for tropical mountains, studies investigating possible determinants of variation in beta-diversity at its different altitudes are scarce. We sampled bee and wasp communities (Hymenoptera: Aculeata) along an altitudinal gradient (1,000–2,000 m.a.s.l.) in a tropical mountainous region of Brazil. Trap nests and Moericke traps were established at six sampling points, with 200 m difference in altitude between each point. We obtained average climate data (1970–2000) from Worldclim v2 for altitudes at each sampling site. Nest traps captured 17 bee and wasp species from six families, and Moericke traps captured 124 morphospecies from 13 families. We found a negative correlation between altitude and species richness and abundance. Temperature, precipitation, water vapor pressure, and wind speed influenced species richness and abundance, and were correlated with altitude. β-diversity was primarily determined by species turnover as opposed to nestedness, and Aculeate community similarity was higher for more similar altitudinal ranges. Moericke traps seem to be more efficient for altitudinal surveys compared to nest traps. We found high occurrence of singleton and doubleton species at all altitudes, highlighting the need for long-term studies to efficiently assess hymenopteran diversity in these environments.

Climate and food resources shape species richness and trophic interactions of cavity‐nesting Hymenoptera

“…We found a highly diverse stem-nesting insect fauna with 81 host and 49 antagonist species, in comparison to other trap-nest studies from the tropics where five to eight bee and seven to fifteen wasp species were reported (Klein, Steffan-Dewenter, & Tscharntke, 2006;Perillo, Neves, Antonini, & Martins, 2017;Stangler, Hanson, & Steffan-Dewenter, 2015;Tylianakis, Tscharntke, & Lewis, 2007).…”

“…One reason for the higher diversity may be the broader climatic amplitude and the coverage of different habitat types in our study. With the exception of Perillo et al (), other studies did not include a significant elevational gradient in their study region. A second reason for the high diversity may be the close proximity to the origin of bees, which goes back to the xeric interior of Gondwana (todays Africa and South America), providing a long time to diverge to current diversity levels (Danforth et al, ; Hedtke et al, ; Michener, ).…”

“…We found a humped‐shaped decline of both caterpillar‐hunting and spider‐hunting wasp species richness, with a peak in species richness at intermediate elevations. Depending on the taxonomic group of wasps, other studies either found a distinct decline of species richness or a mid‐elevation increase in diversity as was demonstrated for wasps, but ultimately a decline in species richness at highest elevations (Kumar, Longino, Colwell, & O'Donnell, ; Perillo et al, ). The humped‐shaped species richness pattern of wasp taxa at Mt.…”

“…As we were able to separate the effects of temperature from those of resource availability and top‐down control, our results suggest that ecological mechanisms such as temperature‐mediated resource exploitation or evolutionary processes such as faster speciation or lower extinctions rates are the underlying temperature‐mediated causes of diversity patterns (Buckley et al, ; Classen et al, ). We are aware that temperature is not independent of elevation and thus co‐varying environmental factors, such as precipitation, atmospheric pressure, solar radiation and land area might also influence species richness (Perillo et al, ). However, both ecological theory and empirical findings underscore the importance of temperature for the origination and maintenance of diversity gradients, while only very limited evidence exists for a role of the other mentioned environmental factors changing with elevation (Peters et al, , ).…”

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, ).…”