DOI: 10.5061/dryad.ffbg79cv3
title: Stand-level variation drives canopy water storage by non-vascular epiphytes across a temperate-boreal ecotone

description: Epiphytes, including bryophytes and lichens, can significantly change the
 water interception and storage capacities of forest canopies. However,
 despite some understanding of this role, empirical evaluations of canopy
 and bole community water storage capacity by epiphytes are still quite
 limited. Epiphyte communities are shaped by both microclimate and host
 plant identity, and so the canopy and bole community storage capacity
 might also be expected to vary across similar spatial scales. We estimated
 canopy and bole community cover and biomass of bryophytes and lichens from
 ground-based surveys across a temperate-boreal ecotone in continental
 North America (Minnesota). Multiple forest types were studied at each
 site, to separate stand level and latitudinal effects. Biomass was
 converted into potential canopy and bole community storage on the basis of
 water-holding capacity measurements of dominant taxa. Bole biomass and
 potential water storage was a much larger contributor than outer canopy.
 Biomass and water storage capacity varied greatly, ranging from 9 to
 &gt;900kg ha–1 and 0.003 to 0.38 mm, respectively. These values
 are lower than most reported results for temperate forests, which have
 emphasized coastal and old-growth forests. Variation was greatest within
 sites and appeared to reflect the strong effects of host tree identity on
 epiphyte communities, with conifer-dominated plots hosting more
 lichen-dominated epiphyte communities with lower potential water storage
 capacity. These results point to the challenges of estimating and
 incorporating epiphyte contributions to canopy hydrology from stand
 metrics. Further work is also needed to improve estimates of canopy
 epiphytes, including crustose lichens.
description: FILE NAME: LitterMass_UMN.csv DESCRIPTION:
 This spreadsheet is used to keep track of which canopy/twig litter samples
 have been processed, and collect data on the mass of epiphytes
 collected. Description of each column:
 Debris Type: The type of litter being processed. Options are:
 "foliose" (foliose lichen growth form), "fruticose"
 (fruticose lichen growth form), "moss" (any moss removed from
 branches), "litter" (the twigs themselves, that are being
 cleaned) Plot: The name we assigned to the plot,
 consisting of (site acronym)_(dominant tree acronym)_(replicate if
 reapeating the same site+dominant tree combination).
 Site: (site acronym) from the plot name. This is the name of the
 site/are in which the plot is located, including State Parks, State
 Forests, Research Stations, Wildlife Management Areas, Recreation Areas,
 County lands, other parks, etc. ForestType: (dominant
 tree acronym) from the plot name. This is a 4 letter acronym for the latin
 name of the dominant canopy tree species. It contains the first two
 letters of the genus and first two letters of the species.
 Plot Replicate: from the plot name. This is the replicate number
 of the plot if there are multiple plots in the same forest type at the
 same site. Microplot: The microplot from which the
 litter was collected. Format is cardinal direction + distance (m) from
 plot center. (i.e. N22 is located 22m N of plot center.)
 Mass: The total mass of each debris type (in grams) isolated from
 the litter. FILE NAME: BoleCover_UMN.csv
 Description of each column: Plot: Plot name,
 comprised of "locality"_"dominant tree species 4 letter
 acronym"_"replicate number". i.e. The plot CC_LALA_01 is
 from Cedar Creek, is dominated by Larix laricina (Tamarack), and is the
 first replicate of that forest type at that locality.
 Microplot: Microplot name, comprised of the cardinal direction of
 the transect upon which the microplot is located (N-north, S-south, etc.)
 and the distance from plot center in meters (6 - 6 meters, etc.). i.e.
 Microplot N6 is located along the north transect of the main plot, 6
 meters from plot center. DirectionHeight: The direction
 the quadrat was facing (N- north, and S-south) and the height at which the
 quadrat was attached to the tree (0 - at ground level, 1.5 - center of the
 quadrat at ~ breast height, or 1.5 meters). Direction:
 The direction the quadrat was facing (N- north, and S-south)
 Height: The height at which the quadrat was attached to the tree
 (0 - at ground level, 1.5 - center of the quadrat at ~ breast height, or
 1.5 meters) TreeSpecies: The 4 letter acronym for the
 species of tree the quadrat was attached to.(e.g. LALA = Larix laricina,
 PIST = Pinus strobus, etc.) DBHcm: The diameter at
 breast height of the sampled tree, in centimeters.
 SpeciesGroup: The functional group each epiphyte belongs to in
 this study. SpeciesType: Denotes whether each epiphyte
 is a lichen or bryophyte. PercentCover: The estimate of
 percent cover of each epiphyte in the quadrat. FILE
 NAME: Plot_Data_UMN.csv Description of each
 column: Plot: The name we assigned to the plot,
 consisting of (site acronym)_(dominant tree acronym)_(replicate if
 reapeating the same site+dominant tree combination).
 FieldName: The plot name assigned in the field. The FieldName
 sometimes differed from the Plot name in the 2018 field season, before we
 had settled on using dominant tree acronyms. For example, the oak savanna
 plots at Cedar Creek started out as “CC_OAK…” and later became “CC_QUMA…”
 (QUMA = Quercus macrocarpa, or bur oak).
 Microplot_Sample_Date: This is the date the microplot (ground,
 bole, and canopy) data was collected. This sometimes differed from the
 Community_Sample_Date in the 2018 field season, because we started
 surveying before we had developed our microplot protocols. Once these were
 established, we revisited the same sites and completed the microplot
 sampling. Latitude: Latitude of the center of the
 plot. Longitude: Longitude of the center of the plot.
 State: State in which the plot is located. County:
 County in which the plot is located. Site: This is the
 name of the site/are in which the plot is located, including State Parks,
 State Forests, Research Stations, Wildlife Management Areas, Recreation
 Areas, County lands, other parks, etc. Forest_Type:
 This is the forest type name associated with the NPC Code in which the
 plot is located. Dominant_Tree: This is the latin name
 for the dominant canopy tree species in the plot.
 Dominant_Acronym: This is a 4 letter acronym for the latin name
 of the dominant canopy tree species. It contains the first two letters of
 the genus and first two letters of the species.
 Plot_Replicate: This is the replicate number of the plot if there
 are multiple plots in the same forest type at the same site.
 NPC_Code: Native Plant Community class, type, and subtype. This
 is the DNR code for the Native Plant Community (NPC) given for the plot
 location. It was provided to us either by the DNR shapefile used in
 mapping, or by Erika Rowe at the DNR (for EMN sites only)Some of these
 contain subtypes that give a finer scale distinction of the flora at a
 site. "Native plant community classes are units of
 vegetation that generally have uniform soil texture, soil moisture, soil
 nutrients, topography, and disturbance regimes. For wooded vegetation,
 native plant community classes were developed by emphasizing understory
 vegetation more than canopy trees, under the hypothesis that in much of
 Minnesota understory plants are often more strongly tied to local habitat
 conditions (such as levels of nutrients and moisture) than are canopy
 trees. " "Native plant community types are
 defined by dominant canopy trees, variation in substrate, or fine-scale
 differences in environmental factors such as moisture or nutrients. Type
 distinctions were also made to describe geographic patterns within a
 class." "Native plant community subtypes are
 based on finer distinctions in canopy composition, substrates, or other
 environmental factors. In some instances, subtypes represent apparent
 trends within a type for which more study and collection of data are
 needed. In other instances subtypes are well-documented, fine-scale units
 of vegetation that are useful for work such as rare plant habitat
 surveys." NPC1: Native Plant Community class only.
 This is a simplified version of the available NPC with all type and
 subtype letters/numbers removed. NPC2: This is an even
 more simplified version of the NPC which only contains the system code
 (i.e. MH = Mesic Hardwood, WF = Wet Forest, FD = Fire Dependent Woodland,
 etc.) All system codes are listed in the DNR field guides.
 Ecological_Section: The DNR ecological section in which the plot
 is located. "Sections are units within Provinces that are defined by
 origin of glacial deposits, regional elevation, distribution of plants,
 and regional climate. Minnesota has 10 sections."
 MN DNR Abbreviations are as follows: MIM -
 Minnesota & NE Iowa Morainal MDL - N. Minnesota
 Drift & Lake Plains NSU - Nrthern Superior
 Uplands Physiography: Denotes whether the plot was
 located in an upland, lowland, or riparian area.
 Elevation_m: Elevation at the center of the plot in meters, as
 determined in the field using a GPS. BasalArea_m2ha:
 Total basal area of the plot in square meters per hectare.
 BasalArea_PercentConifers: Percentage of the total basal area
 composed of coniferous trees.
 BasalArea_PercentHardwoods: Percentage of the total basal area
 composed of hardwood trees. *BASAL AREA CALCULATIONS* Basal area is
 measured at 5 points throughout each plot (center, N, S, E, W boundaries).
 Stand basal area is calculated from these 5 numbers directly on the
 datasheet. See annotated plot datasheet for detailed calculation
 instructions (LCCMR &gt; METHODS &gt; Field &gt; Datasheets
 &gt; LCCMR_PlotDatasheet) Plot Location:Written
 description of the plot location, with additional notes on how to navigate
 to the plot. Plot Notes:Notes taken in the field
 regarding plant communities, topography, etc. about the plot. This is
 transcribed from section 8 "Notes" on the plot
 datasheet. FILE NAME: FunctionalGroups.csv
 DESCRIPTION: This spreadsheet is used to asign biomass and
 water-holding capacity values to each growth form or functional group of
 lichen and bryophyte. Description of each
 column: SpeciesGroup: Name of functional group, usually
 a growth form. These correspond to the categories used in Bole Cover
 surveys Type: Whether the functional group is a Lichen
 or Bryophyte N replicates: Number of replicates used in
 generating mean STM or WHC values STM: Specific thallus
 mass calculated as (Dry mass of specimen) / (Wet area of specimen), in g
 cm-2 WHCBlot: Water-holding capacity measured as
 described in the Hembre et al. 2021, the mass of H2O contained internally
 in a specimen following gentle hydration, shaking and blotting (to remove
 external water), in g H2O cm-2