Isolation drives species gains and losses of insect metacommunities over time in a mountaintop forest archipelago
Data files
Sep 06, 2023 version files 54.81 KB
Abstract
Aim: We evaluated the effects of forest island size, isolation, and area in the landscape driving temporal changes of insect biodiversity in a mountaintop forest archipelago. We tested the following hypotheses: (i) changes in insect species composition is higher and dominated by species gains through time in smaller but less isolated forest islands; (ii) larger amounts of forest in the landscape result in higher gains of more vagile species over time, regardless of their size and isolation; (iii) heterogenization processes will prevail in less vagile groups, while homogenization processes will dominate in highly vagile groups due to differences in dispersal capability.
Location: Espinhaço Range Biosphere Reserve, Brazil.
Taxon: Insects.
Methods: We used ants, dung beetles, bees, wasps, and butterflies as study models to represent a gradient of low-to-high dispersal capability. We evaluated the colonization- and extirpation-resultant components of temporal β-diversity using area- and isolation-related variables as predictors.
Results: We found distinct colonization- and extirpation-resultant homogenization and heterogenization processes acting according to each insect group, likely due to different dispersal capabilities. Ants were dominated by species losses, with widespread and rare species being lost. Butterflies gained species, represented mainly by widespread species, leading to an increased colonization-resultant homogenization. Distance to neighboring forest islands was the underlying predictor affecting the temporal β-diversity of insect groups and on species gains and losses but differed according to the survey period. Effects of the forest amount in the landscape increased the temporal β-diversity of bees and butterflies but decreased that of ants, dung beetles, and wasps.
Main Conclusions: We recommend conserving the forest amount in the landscape and keeping forest connectivity among forest islands since the temporal dynamics of local colonization and extirpation can depend on the organisms’ dispersal capability. Fragmentation and habitat loss-related hypotheses will benefit from incorporating colonization-extirpation processes into their predictions.
README: Title of Dataset: Insect_Capoes_PELD-CRSC
This dataset contains occurrence data for five groups of insect species (S=277 species; ants, bees, butterflies, dung beetles, and wasps in columns titled as "Species") in natural forest islands (capes de mata, coded C01 to C14 in lines titled as "Group") in Serra do Cipó, Minas Gerais, Brazil. These forest islands are common on mountaintops of at least 1200 m a.s.l. and have a floristic composition similar to the semi-deciduous forests associated with the Atlantic Forest domain. We sampled the insects in 14 forest islands, which differed in size, distances from each other, and distances from a continuous forest (i.e., possible species source). In the central region of each forest island, we installed a 20-50 m plot, where specific traps were installed for each insect group. We sampled insects during the summers (January or February, middle of the rainy season) of 2014, 2015, 2018, and 2020, coded as "Year". In 2014 and 2015, we were unable to sample butterflies in three forest islands. Between 2014 and 2020, we sampled 377 insect species: 114 ants, 55 dung beetles, 35 bees, 131 wasps, and 42 butterflies (Table S2). Pooled insect species richness per forest island ranged between 71–126 species (average ± sd: 103.1 ± 13.8 species), with 33–46 species of ants (39.8 ± 3.8), 13–22 species of dung beetles (16.4 ± 2.9), 1–15 species of bees (5.1 ± 3.9), 16–49 species of wasps (33.6 ± 9.0), and 1–16 species of butterflies (8.3 ± 4.8).
Description of the Data and file structure
This .csv type dataset provides the identity and occurrence of 377 species of each insect group (ants, bees, butterflies, dung beetles, and wasps) sampled on the 14 forest islands (C01 to C14) per sampling period (2014, 2015, 2018, and 2020). We sampled the insects in 14 forest islands, which differed in size, distances from each other, and distances from a continuous forest (i.e., possible species source) (Table S1, Figure S1). In the central region of each forest island, we installed a 20 × 50 m plot, where specific traps were installed for each insect group (see Appendix S1 for detailed information). We sampled insects during the summers (January or February, middle of the rainy season) of 2014, 2015, 2018, and 2020. In 2014 and 2015, we were unable to sample butterflies in three forest islands. Thus, only comparisons between 2018 and 2020 were based on 14 forest islands for butterflies; all comparisons with 2014 or 2015 were based on 11 forest islands.