DOI: 10.7280/d1j971
title: Data from: The functional effects of a dominant consumer are altered following the loss of a dominant producer

description: Human impacts on ecosystems are resulting in unprecedented rates of
 biodiversity loss worldwide. The loss of species results in the loss of
 the multiple roles that each species plays or functions (i.e., “ecosystem
 multifunctionality”) that it provides. A more comprehensive understanding
 of the effects of species on ecosystem multifunctionality is necessary for
 assessing the ecological impacts of species loss. We studied the effects
 of two dominant intertidal species, a primary producer (the seaweed
 Neorhodomela oregona) and a consumer (the shellfish Mytilus trossulus), on
 twelve ecosystem functions in a coastal ecosystem, both in undisturbed
 tide pools and following the removal of the dominant producer. We modified
 analytical methods used in biodiversity-multifunctionality studies to
 investigate the potential effects of individual dominant species on
 ecosystem function. The effects of the two dominant species from different
 trophic levels tended to differ in directionality (+/-) consistently (92%
 of the time) across the twelve individual functions considered. Using
 averaging and multiple threshold approaches, we found that the dominant
 consumer – but not the dominant producer – was associated with ecosystem
 multifunctionality. Additionally, the relationship between abundance and
 multifunctionality differed depending on whether the dominant producer was
 present, with a negative relationship between the dominant consumer and
 ecosystem function with the dominant producer present compared to a
 non-significant, positive trend where the producer had been removed. Our
 findings suggest that interactions among dominant species can drive
 ecosystem function. The results of this study highlight the utility of
 methods previously used in biodiversity-focused research for studying
 functional contributions of individual species, as well as the importance
 of species abundance and identity in driving ecosystem multifunctionality,
 in the context of species loss.
description: This dataset contains the raw data from a
 removal experiment, which includes the physical characteristics of the
 tide pools (water depth, volume, surface area, etc.) and details about the
 removal manipulation (e. g., mass of removed algae). It also includes the
 data from seven sets of community biodiversity surveys, in which the
 surface area of all non-mobile species were measured (recorded in
 measurements of “squares”, each of which is equal to
 100cm<sup>2</sup>) and the number of individuals of mobile
 species were counted in each tide pool. Additionally, the data collected
 during two sets (before and after removal) of light/dark productivity
 trials, in which the tide pools were incubated under opaque tarps for a
 period of time to assess photosynthetic activity and respiration, are
 included. Initial measurements were collected prior to incubation, “dark”
 measurements were collected immediately following the incubation, and
 recovery measurements were taken approximately 30 minutes after the end of
 the incubation. All measurements taken during the trials (light, salinity,
 dissolved oxygen, temperature, and pH) are included. Finally, the data
 collected across four water samplings were included. Each water sampling
 consisted of a series of measurements (light, salinity, dissolved oxygen,
 temperature, and pH) and samples collected (for analysis to determine pH
 and nutrient concentration) across all ten experimental tide pools, across
 three time points, over the course of ~3 hours. Two of the four water
 samplings were conducted prior to the algae removal manipulation (day and
 night) and two were conducted following algal removal (day and
 night).
description: Microsoft Excel