DOI: 10.5061/dryad.gf1vhhmrb
title: Does ant-plant mutualism have spillover effects on the non-partner ant community?

description: Mutualism benefits partner species and theory predicts these partnerships
 can affect the abundance, diversity, and composition of partner and
 non-partner species. We used 16 years of monitoring data to determine the
 ant partner species of tree cholla cacti (Cylindriopuntia imbricata),
 which reward ants with extrafloral nectar in exchange for anti-herbivore
 defense. This long-term data revealed one dominant ant partner (Liometopum
 apiculatum) and two less common partners (Crematogaster
 opuntiae and Forelius pruinosus. We then used short-term
 characterization of the terrestrial ant community via pitfall
 trapping to sample partner and non-partner ant species across ten plots of
 varying cactus density. We found that the dominant ant partner tended a
 higher proportion cacti in plots of higher cactus density, and
 was also found at higher occurrence within the pitfall traps in higher
 density plots, suggesting strong positive feedbacks that promote ant
 partner occurrence where plant partners are available. Despite
 the strong association and increased partner occurrence, ant
 community-wide effects from this mutualism appear limited. Of the
 common ant species, the occurrence of a single non-partner ant species was
 negatively associated with cactus density and with the increased
 presence of L. apiculatum. Additionally, the composition and diversity of
 the ant community in our plots were insensitive to cactus density
 variation, indicating that positive effects of the mutualism on the
 dominant ant partner did not have cascading impacts on the ant community.
 This study provides novel evidence that exclusive mutualisms, even those
 with strong positive feedbacks, may be limited in the scope of their
 community-level effects.
description: Ant_community_data.csv  Results of ant
 species counts from pitfall trapping. Data fields are as follows: ID -
 unique identifier; Plot - the plot (1-10) in which the pitfalls were
 placed; Station - pitfall ID; StatID - unique plot and station ID;
 Latitude - latitudinal coordinates; Longitude - Longitudinal coordinates;
 Misc - non-ant species that were captured in the pitfall trap;
 Camponotus_sp1:Temnothorax_sp1 - number of ants of each species found in
 each pitfall trap Ground_cover.csv 
 Results of ground cover surveys of eight quadrats within each
 plot. Data fields are as follows: Plot - the plot (1-10); Quadrant -
 sampling quadrant (1-8); ID - unique identifier of plot and quadrant; Bare
 Ground: Other - the percentage of total cover for each of the ground cover
 types; Cactus details - description of whether the cactus is Cholla or
 prickly pear; Other details - description of what the other category
 contains
 Additional_plots_cactus_data_2013.csv
 Results of cactus
 surveys in the additional plots (9 and 10) in 2013. The data fields follow
 that of Miller 2020 (https://doi.org/10.6073/pasta/dd06df3f950afe4a4642306182237d13). These are: Plot - ten 30m x 30m plots (1-10; Tag_ID - Unique identifier for individuals - Tag_ID's are reused between plots, so the unique individual ID is given by the Plot-TagID combination; Year_t - Calendar year at the start of the transition year (late May or early June); Height_t - Height in year t; Width_t - Maximum width in year t; Perp_t - Width perpendicular to the maximum in year t; NS_t -  Number of new vegetative segments initiated in year t; GoodBuds_t - Number of viable (very likely to flower) flowerbuds in year t; ABFlowerbuds_t - Aborted flowerbuds in year t; Antsp_t - If ants are present, this field gives their species identity - There are four common ant species in this system: <em>Crematogaster opuntiae</em> ('crem'), <em>Liometopum apiculatum</em> ('liom'), <em>Forelius pruinosa </em>('fore'). Occasionally other ant species are observed and these are indicated by 'other'. Vacant plants are denoted 'vacant'.