DOI: 10.5061/dryad.h0832
title: Data from: The underappreciated role of life history in mediating the functional consequences of biodiversity change

description: Biodiversity is changing on both global and local scales, motivating
 research to understand the consequences of these changes for how
 communities and ecosystems function. Here, we explore the role of life
 history strategies in mediating biodiversity and ecosystem functioning. In
 particular, we evaluate how the composition, biomass (% cover), and
 richness of perennial (persistence ≥ 1 year) and ephemeral (persistence
 &lt; 1 year) species change along a gradient of increasing seaweed
 species richness on a rocky shoreline. We show that the majority of
 biomass is comprised of perennial species, especially where overall
 richness is low, whereas the majority of species are ephemeral, especially
 where overall richness is high. We then present and discuss the results of
 an 18-month field manipulation quantifying the factorial effects of tidal
 elevation, wave exposure, herbivore removals, thermal and desiccation
 stress amelioration, and nutrient additions on perennial vs. ephemeral
 species. In particular, the diversity of ephemeral species was strongly
 affected, relative to perennial species, by tidal elevation, wave
 exposure, and herbivory; herbivores reduced diversity of ephemeral species
 relative to perennials. Relative to perennial cover, ephemeral cover was
 greater higher on the shore, in more wave-exposed habitats, and where
 herbivores were removed, plots were unscreened, and/or nutrients were
 added. Thus, perennials and ephemerals responded differently to
 environmental context and experimental manipulation. We compared nitrate
 uptake and photosynthesis rates of ephemeral and perennial species and
 found that maximum nitrate uptake and photosynthesis rates of ephemerals
 were twice as high as those of perennials. These results highlight the
 disproportionate roles that ephemeral species play in mediating
 ecosystem-level processes. In combination with our comparisons of the
 diversity and cover of perennial and ephemeral species along a
 biodiversity gradient, these results demonstrate the utility of
 incorporating life history traits into our efforts to understand the
 functional consequences of biodiversity change.
description: Cover of all species
 during initial surveysData are cover of
 macroalgae recorded during initial surveys of 159 plots during March of
 2007 in the Bodega Marine Reserve, Sonoma County,
 California.Bracken_OIK-03884-R1_Cover.txtAverage cover of all species along a gradient in species richnessSummary data from initial surveys highlighting cover of all species along a gradient in species richness.Bracken_OIK-03884-R1_Richness.txtDifferences in perennial vs. ephemeral coverData are differences between the cover of perennial and ephemeral species in each plot over six censuses spanning 18 months. Values &gt; 0 indicate higher perennial cover, whereas values &lt; 0 indicate higher ephemeral cover. Environmental factors included wave exposure (exposed, protected) and tidal elevation (higher, lower), and experimental manipulations included screens (absent [0], present [1]), herbivores (removal, ambient), and nutrients (none, addition).Bracken_OIK-03884-R1_PvE_Cover_Census.txtDifferences in perennial vs. ephemeral richnessData are differences between the number of perennial and ephemeral species in each plot over six censuses spanning 18 months. Values &gt; 0 indicate higher perennial richness, whereas values &lt; 0 indicate higher ephemeral richness. Environmental factors included wave exposure (exposed, protected) and tidal elevation (higher, lower), and experimental manipulations included screens (absent [0], present [1]), herbivores (removal, ambient), and nutrients (none, addition).Bracken_OIK-03884-R1_PvE_Richness_Census.txt