DOI: 10.5061/dryad.sxksn038c
title: Isolation drives species gains and losses of insect metacommunities over time in a mountaintop forest archipelago

description: 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.
description: # 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.