Competition increases risk of species extinction during extreme warming
Data files
Dec 05, 2023 version files 61.94 KB
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data_density_detail.csv
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data_density_detail.xlsx
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data_density_mean.csv
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data_density_trial.csv
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data_richness.csv
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data_Te_De.csv
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R_code.txt
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README.md
Abstract
Temperature and interspecific competition are fundamental drivers of community structure in natural systems and can interact to affect many measures of species performance. However, we know surprisingly little about the extent to which competition affects extinction temperatures during extreme warming. This information is important for evaluating future threats to species from extreme high-temperature events and heat waves, which are rising in frequency and severity around the world. Using experimental freshwater communities of rotifers and ciliates, this study shows that interspecific competition can lower the threshold temperature at which local extinction occurs, reducing time to extinction during periods of sustained warming by as much as two weeks. Competitors may lower extinction temperatures by altering biochemical characteristics of the natural environment that affect temperature tolerance (e.g., levels of dissolved oxygen, nutrients, and metabolic wastes) or by accelerating population decline through traditional effects of resource depletion on life history parameters that affect population growth rates. The results suggest changes in community structure in space and time could drive variability in the upper thermal limits.
README: COMPETITION INCREASES RISK OF SPECIES EXTINCTION DURING EXTREME WARMING
Author: Paul Bendiks Walberg (paul.walberg@rutgers.edu)
Summary: We know surprisingly little about whether competition affects extinction temperature during periods of extreme warming. Using experimental freshwater communities of rotifers and ciliates, this study showed that interspecific competition can lower the temperature at which local extinction occurs, reducing time to extinction during periods of sustained warming by as much as two weeks. The results suggest changes in community structure in space and time could drive variability in the upper thermal limits.
DATA FILES:
data_density_detail.csv (also data_density_detail.xls)
This file, presented in both .csv and .xlsx format, includes the complete density time series for the three test species. Data are presented in Fig. 1.
species = test species (euplotes, coleps, rotaria)
factor = temperature factor (increasing, constant)
temp = temperature (degrees C)
day = corresponding day
p1-p6 = density (#/ml) of polyculture replicates 1-6
m1-m6 = density (#/ml) of monoculture replicates 1-6
data_density_mean.csv
This file includes mean density for the three test species. Data are analyzed in the ANOVA AND POST HOC TUKEY TEST ON DENSITY (see file ‘R_code.txt’). Results are presented in Supplementary material, Table S1(a-b).
rep = replicate #
spec = species factor (euplotes, coleps, rotaria)
temp = temperature factor (incr = increasing, cons = constant)
comp = composition factor (poly = polyculture, mono = monoculture)
density = mean density (#/ml) across time series
data_Te_De.csv
This file includes temperature of extinction (Te) and days to extinction (De) data for the three test species. Data are presented in Fig. 2 and analyzed in the ANOVA AND POST HOC TUKEY TEST ON TEMPERATURE OF EXTINCTION (see file ‘R_code.txt’). Results are presented in Supplementary material, Table S2(a-c).
rep = replicate #
spec = species factor (euplotes, coleps, rotaria)
comp = composition factor (poly = polyculture, mono = monoculture)
Te = temperature of extinction (°C)
De = days to extinction
data_density_trial.csv
This file includes density data for all 10 species in monoculture and polyculture from trial experiments. Data are presented in Supplementary material, Fig S1, and analyzed in the ANOVA ON DENSITY IN TRIAL EXPERIMENTS (see file ‘R-code.txt’). Results are presented in presented in Supplementary material, Table S3(a-b).
rep = replicate #
spec = species factor (names of each of 10 study species)
comp = composition factor (polyculture, monoculture)
density = density (#/ml) at 26.0C
data_richness.csv
This file includes species richness in increasing-polyculture communities at each temperature. Data are presented in Fig. 3.
temp = temperature
p1-p6 = species richness in replicates 1-6 of increasing polyculture communities
R_code.txt
This file includes all code used to analyze density, Te and richness data in R (version 4.2.2). The code requires downloading and installing the ‘CAR’ (version 3.1-2) and ‘dplyr’ (version 1.1.2) packages.
Methods
Please see methods section in corresponding paper.
Usage notes
All files are in .txt or .csv format.