DOI: 10.5061/dryad.0g648
title: Data from: Aboveground biomass is driven by mass-ratio effects and stand structural attributes in a temperate deciduous forest

description: 1.Forest ecosystems are critical for the global regulation of carbon (C),
 a substantial portion of which is stored in aboveground biomass (AGB).
 While it is well understood that taxonomic and functional composition,
 stand structure, and environmental gradients influence spatial variation
 in AGB, the relative strengths of these drivers at landscape-scales has
 not been investigated in temperate forests. Furthermore, when biodiversity
 enhances C storage, it is unclear whether it is through mass-ratio effects
 (i.e., the dominant trait in communities regulates AGB) or through niche
 complementarity (i.e., increased AGB due to interspecific resource
 partitioning). 2.To address these mechanisms, we analyzed data from a
 census of 28,262 adult trees sampled across 900 ha of temperate deciduous
 forest in southwestern Pennsylvania. We used data on four key plant
 functional traits to determine if (1) there is a positive relationship
 between species diversity and AGB and (2) whether this is due to
 mass-ratio effects or niche complementarity. We also sought to (3)
 identify the physical stand structural attributes and topographic
 variables that influence AGB across this landscape. 3.We found AGB was
 positively related to species richness and negatively related to species
 evenness, albeit weakly, while functional diversity indices had neutral
 effects. AGB was enhanced in communities dominated by traits related to
 greater maximum tree height, deeper minimum rooting depths and larger
 seeds. Most importantly, areas with high AGB were dominated by Acer
 saccharum and Liriodendron tulipifera. Overall, these results support
 mass-ratio effects, with little evidence for niche complementarity.
 4.Synthesis: Stand structure, topography, and species and functional
 composition, but not taxonomic or functional diversity, were found to be
 key drivers of AGB at landscape-scales (&lt;900 ha) in this temperate
 deciduous forest. Our findings suggest that simultaneously managing for
 both high diversity and for aboveground C storage may prove challenging in
 some forest systems. Our results further indicate that the impact of tree
 biodiversity loss on aboveground C stocks will depend greatly on the
 identity of the species that are lost.
description: Data_DryadMaster data set for the paper entitled "Aboveground biomass is driven by mass-ratio effects and stand structural attributes in a temperate deciduous forest." This data set contains all the block (9 plots) information in which analyses were run. Each block has UTM coordinates for their location at Powdermill Nature Reserve (PNR) and all the dependent and independent variables used in the analyses. Abbreviated headlines are as follows: "Block_ID" = Block; "UTM_E" = Easting coordinate for block; " UTM_N" = Northing coordinate for block; "Total.biomass_Mg.ha"= Total biomass in mega-grams of all species for each block on a per hectare basis; "Biomass.ACRU_Mg.ha"= Total biomass in mega-grams of Acer rubrum for each block on a per hectare basis; "Biomass.LITU_Mg.ha"= Total biomass in mega-grams of Liriodendron tulipifera for each block on a per hectare basis; "Biomass.ACSA_Mg.ha"= Total biomass in mega-grams of Acer saccharum for each block on a per hectare basis; "Biomass.QURU_Mg.ha"= Total biomass in mega-grams of Quercus rubra for each block on a per hectare basis; "DBH.max"= Maximum DBH per block; "DBH.stdev" = standard deviation of DBH per block; "Elevation_m" = Elevation above sea level in meters for each block; "Aspect_deg" = Aspect direction in degrees for each block; Aspect.dir" = Aspect direction in degrees organized into four categories (NE, NW, SE, and SW); "Slope_deg" = Slope in degrees for each block; "Convexity" =average elevations of the eight adjacent blocks minus the central block's elevation; "Richness" = species richness (counts); "Evenness" = species evenness; "NMS1" = first axis from non-metric multidimensional scaling; "FRic" = Functional richness; "FEve" = Functional evenness; "FDiv" = Functional divergence; "FDis" = Functional diversity; "RaoQ" = Rao’s Quadratic entropy index; "CWM.max.height" = Community weighted mean of maximum tree height; "CWM.min.root.depth" = Community weighted mean of minimum rooting depth; "CWM.seed.count" = Community weighted mean of seed weight; "CWM.wood.density" = Community weighted mean of wood density.