Spatiotemporal dynamics of the ant community in a dry forest differ by vertical strata but not by successional stage

Abstract

Ants are diverse and ecologically important organisms in tropical forests, where their spatiotemporal distribution can be highly complex. This complexity arises mainly from marked differences in microclimatic conditions and resource availability through space and time that is even more evident in highly seasonal environments, such as tropical dry forests. However, it is unclear how seasonality interacts with other factors that might shape temporal variation of ant composition (β-diversity), like vertical strata and habitat disturbance. Our goal was to examine the potential influence of vertical stratification and the successional stage on the spatiotemporal variation of a tropical dry forest's ant species composition. We assessed whether species turnover or nestedness was the main component determining the spatiotemporal β-diversity of ant communities across the canopy and litter strata. We sampled canopy and litter ants in ten plots, half in the early and half on the late stage of secondary succession at four times, twice in wet and twice in dry season. A high species turnover defined the spatiotemporal β-diversity of canopy and litter ant communities across years and seasons in our focal dry forests. Importantly, the temporal ant species composition was much more stable in the canopy than in the litter. Moreover, we found that the ant community's temporal dynamics was consistently high across successional stages, not differing in the temporal β-diversity between early and late succession. Our results provide valuable insights into the potential underlying causes of community assembly and spatiotemporal dynamics in seasonal habitats, like the highly threatened and diverse tropical dry forests.

Trophic ecology of the arboreal and ground ant communities in forests and savannas of central Brazil

“…As also observed in previous studies (Brühl et al, 1998;Yanoviak & Kaspari, 2000;Campos et al, 2008 Neves et al, 2021), we detected marked differences in taxonomic composition between the arboreal and ground-dwelling faunas (see also Fig. S1).…”

Spatiotemporal Distribution of Herbivorous Insects Along Always-Green Mountaintop Forest Islands

“…In fact, all three herbivorous insect guilds, regardless of the strata, showed high temporal β-diversity, corroborating that we do have a highly variable system over space and time. However, fluid-feeding and leaf-chewing insects presented a greater temporal β-diversity for the canopy, which is the opposite of the pattern found for ants in a tropical dry-forest (Neves et al, 2021). The temporal β-diversity of both fluid-feeding and chewing insects being higher in the canopy than in the understory may be linked to the different effects of seasonality on specific microhabitats of these two strata.…”

“…We assessed the spatial and temporal variations of the herbivorous species composition (β-diversity) using the Sørensen dissimilarity index in a multiple-spatial and time approach (see Baselga, 2010;Neves et al, 2021). So, we decomposed total spatial and temporal β-diversity among the forest islands (using the Sørensen and Simpson index of similarity), which we partitioned into turnover and nestedness-related components using the "beta.multi" function in the "betapart" R package (Baselga and Orme, 2012).…”

“…The function 'beta-multi' includes the functions to compute multiplesite dissimilarities β SOR , β SIM and β NES , called beta.SOR(x), beta.SIM(x), and beta.NES(x), respectively, where x is a data frame in which sites are rows and species are columns. We used the results of this calculation to determine whether species substitution or species loss/gain influenced the general spatial pattern of temporal β-diversity (Baselga, 2010;Neves et al, 2021).…”

“…Unlike oceanic islands, which are surrounded by a matrix that is a barrier to most terrestrial fauna, forest islands have more permeable matrices that harbor an important percentage of fauna (Cook et al, 2004;Driscoll, 2005;Yekwayo et al, 2016) and provide additional resources to species (Öckinger et al, 2012). In such systems, that occur immersed in grassland-dominated ecosystems on tropical mountaintops (Streher et al, 2017), vagile organisms like wasps, bees, dung beetles and fruit-feeding butterflies can seek different resources (da Silva et al, 2019;Perillo et al, 2020;Silva et al, 2020), where habitat diversity and configuration of the landscape may elicit different responses among them (Neves et al, 2021). Although the distribution of host plants at a given scale represents food resource availability and physical structure for herbivorous insects to find shelter and breeding sites (Lewinsohn and Roslin, 2008), evidence of this relationship in forests patches at landscape scales and its effects on herbivorous insect communities is still poorly documented (Rossetti et al, 2019).…”