DOI: 10.5061/dryad.g4f4qrfw5
title: Forest restoration treatments indirectly diversify pollination networks via floral- and temperature-mediated effects

description: In North American conifer forests a variety of federally initiated
 thinning programs are implemented to restore pre-European settlement
 forest structures, but these changes may impact ecosystem function via
 impacts on sensitive biotic communities. Across the wildland-urban
 interface of the Front Range region of Colorado, agencies associated with
 the ‘Collaborative Forest Landscape Restoration Program’ (CFLRP) have
 implemented thinning treatments across thousands of hectares of ponderosa
 pine forest; here we leverage these treatments as an experimental
 framework to examine thinning effects on a pollinator community. We
 measured variation in forest structure and sampled bee community
 assemblages using multiple methods (trapping and netting) to compare bee
 biodiversity and patterns of floral visitation by bees (bee-flower
 networks) between mechanically thinned stands that were 3–10 years
 post-treatment and non-thinned stands. Three key findings emerged: (1)
 Native bee abundance, richness, and diversity were 120, 53, and 37%
 greater, respectively, in thinned stands. Nestedness, richness, and
 abundance of bee-flower interactions were all substantially higher in
 thinned stands, and there was increased functional redundancy in bee
 assemblages after thinning. (2) Structural equation modelling indicated
 that variation in temperature and floral abundance were mediated by canopy
 openness and were correlated with bee richness and abundance, thereby
 indirectly driving variation in bee-flower interactions. (3) Four floral
 species (Penstemon virens, Cerastium arvense, Erysimum capitatum, and
 Geranium caespitosum) were identified as key connectors in bee-flower
 interaction networks, though these were not necessarily the most abundant
 flowering plants. Our analyses indicate that native bee α-diversity and
 bee-flower interactions positively responded to thinning treatments, and
 these effects were indirectly driven by canopy removal. We conclude that
 CFLRP treatments have conservation value for native bee communities.
 Further monitoring is warranted to evaluate the longevity of these
 effects.
description: The data presesnted here were collected using a combination of
 basic forestry survey in fixed-area plots and netting of bees to record
 bee-flower interactions.
description: # Colorado-Forest-Bees Data files associated with Forest restoration
 treatments indirectly diversify pollination networks via floral- and
 temperature-mediated effects. *** DATA FILES *** The following provides
 information for column designations in all data files included in this
 repository. *** Basal\_area.csv - Contains plot-level tree data ``` Site -
 plot designation Treatment - Control or Thinned Sample - sample number (10
 taken at each site) Trees - total number of trees counted using angle
 gauge Live - total number of live trees counted using angle gauge BAF -
 basal area factor (10) Live.PIPO - live Pinus ponderosa basal area, meters
 squared per hectare Dead.PIPO - dead Pinus ponderosa basal area, meters
 squared per hectare Live.PSME - live Pseudotsuga menziesii basal area,
 meters squared per hectare Dead.PSME - dead Pseudotsuga menziesii basal
 area, meters squared per hectare Live.PICO - live Pinus contorta basal
 area, meters squared per hectare Dead.PICO - dead Pinus contorta basal
 area, meters squared per hectare Live.JUSC - live Juniperus scopulorum
 basal area, meters squared per hectare Dead.JUSC - dead Juniperus
 scopulorum basal area, meters squared per hectare BA.all - basal area,
 meters squared per hectare, including dead and alive trees BA.live - basal
 area, meters squared per hectare, live trees only ``` ***
 BeeIdentification.csv - Contains all bee species ID's ``` Number -
 specimen number (all specimens are labeled and stored at Colorado State
 University or Utah State University. Date - date specimen was captured
 Site - plot designation SiteMonth - month captured and site number
 Treatment - thinned or control (non-thinned) Flower - flower species bee
 was captured on (if applicable) Flower_status - native or invasive floral
 species Method - capture method: Net, Blue vane, Pan trap Sex - female (F)
 or male (M) Genus - genus of identified bee Species - species of
 identified bee GenusSpecies - genus and species of identified bee Family -
 family of identified bee ``` *** CanopyOpenness.csv - Contains
 measurements for canopy openness ``` Site - plot designation Treatment -
 thinned or control (non-thinned) Photo - photo number Sky - measure of
 canopy openness calculated from photos with Gap Light Analyzer software.
 Measurement is given as 'percent canopy openness'(percent of
 overhead area not occupied by canopy cover). ``` *** CWD.csv - Course
 Woody Debris fuel load measurements ``` Treatment - thinned or control
 (non-thinned) Site - plot designation Transect - transect number
 Log_number - number of log within each site Diameter - diameter of log (in
 inches) Decay - rotten (R) or solid (S) ``` ***
 Dataset\_1\_floral\_abundances.csv - Contains data on floral abundances in
 thinned and non-thinned stands ``` Species - floral species Control -
 abundance of floral species 'x' in non-treated control stands
 Thinned - abundance of floral species 'x' in thinned stands ```
 *** Dataset\_2\_bee\_abundance.csv - Contains data on bee abundances in
 thinned and non-thinned stands ``` Family - bee family Genus - bee genus
 (Subgenera) species - species, and if appropriate, morphospecies and/or
 subgenus Treatment_control - abundance of bee species 'x' in
 non-treated control stands Treatment_thinned - abundance of bee species
 'x' in thinned stands ``` *** Flower\_Quadrats.csv - Contains
 plot-level data on floral density ``` Site - plot designation Treatment -
 thinned or control (non-thinned) Date - date measurements were taken Month
 - month measurements were taken Quadrat - quadrat number Species - floral
 species recorded Count - count of floral species recorded ``` ***
 GenusTraits.csv - Contains trait designations for bee taxa ``` Genus - bee
 genera Size - size of bee: small, mid, large (relative to Apis mellifera)
 Nest1 - nesting location above = above ground below = below ground klepto
 = kleptoparasitic behavior Nest2 - nesting strategy/construction excavate
 = excavate rent = rent klepto = kleptoparasitic behavior Sociality -
 sociality of bee genus multiple = varies between species within the genus
 solitary = solitary behavior social = social behavior klepto =
 kleptoparasitic behavior Lecty - diet breadth multiple = varies between
 species within the genus poly = polylectic (wide diet breadth) oligo =
 oligolectic (narrow diet breadth) klepto = kleptoparasitic behavior Season
 - phenology of bee species late = peak in August mid = peak in July early
 = peak in June ``` *** Ground\_Cover.csv - Contains plot-level transect
 data for ground cover ``` Site - plot designation Treatment - thinned or
 control (non-thinned) Transect - transect number (1-5); 25m transects
 Point - point number (1 - 20); sampled every 1m Cover_type - category of
 ground cover Bare = bare ground Litter = litter layer Rock = rock Shrub =
 shrub of flowering plant Tree = non-flowering shrubs and trees Wood = wood
 Grass = Grass Forb = Forb Moss = moss ``` *** SEMvars.csv - Combined data
 from all other spreadsheets used for construction of Structural Equation
 Models ``` Site - plot designation Treatment - thinned or control
 (non-thinned) Trees_ha - trees per hectare BA - tree basal area, meters
 squared per hectare QMD - quadratic mean diameter (the diameter of the
 tree of average basal area at a given site, in cm) Sky - canopy openness
 (%) floralab - floral abundance floralrich - floral species richness beeab
 - bee abundance beerich - bee species richness Shannon - Shannon diversity
 index Simpson - Simpson diversity index Bare - bare ground cover (%) Forb
 - forb cover (%) Grass - grass cover (%) Litter - litter cover (%) Rock -
 rock cover (%) Shrub - flowering shrub cover (%) Tree - tree cover (%)
 Wood - wood cover (%) Volume - CWD volume (MG/ha) MeanTemp - mean
 temperature (C) MaxTemp - maximum temperature (C) MinTemp - minimum
 temperature (C) interactionab - bee-flower interaction abundance
 interactionrich - bee-flower interaction richness ``` ***
 SiteInformation.csv - Contains plot-level metadata ``` NAME - plot
 designation SITE - site number TREATMENT - treatment: untreated, thinned
 PROJECT_NAME - CFLRP project name NATIONAL_FOREST - National forest (ARP =
 Arapahoe Roosevelt National Forest; PSI = Pike San Isabel National Forest)
 LATITUDE - latitude of site center (decimal degrees) LONGITUDE - longitude
 of site center (decimal degrees) RESIDUAL_BA - average BA within the CFLRP
 treatment area (total tree basal area in meters squared per hectare
 remaining at site following stem removal/thinning treatment; or, in the
 case of non-treated sites, total tree basal area in meters squared per
 hectare) YEAR_COMPLETED - year treatment (thinning) was completed
 TREATED_AREA_HA - size of treatment area (hectares) ELEVATION - elevation
 of site (feet) ASPECT - aspect of site SLOPE - slope of site ``` ***
 TempData - folder of .csv files containing temperature data recorded every
 30minutes for each site *** Tree\_Density.csv - Contains information on
 tree densities, summarized to plot-level ``` Site - plot designation
 Treatment - thinned or control (non-thinned stands) Total_Trees - count of
 trees within 0.1ha site Saplings - count of saplings within 0.1ha site
 Dead - count of dead trees within 0.1ha site ```