DOI: 10.5061/dryad.z612jm695
title: Equilibrium in plant functional trait responses to warming is stronger under higher climate variability during the Holocene

description: Aim.The functional trait composition of plant communities is thought to be
 largely determined by climate, but relationships between contemporary
 trait distributions and climate are often weak. Spatial mismatches between
 trait and climatic conditions are commonly thought to arise from
 disequilibrium responses to past environmental changes. We here
 investigated whether current trait-climate disequilibrium were likely to
 emerge during plant functional responses to Holocene climate warming.
 Location.North America Time period.14-0Kya Major taxa studied. Terrestrial
 plants Methods. We joined global trait data with paleoecological
 time-series and climate simulations on 425 sites. We estimated plant
 community functional composition for three leaf traits involved in
 resource use. We then quantified disequilibrium in plant trait temporal
 responses to climate change during two contrasted periods : a period of
 high climate variability (14-7 Kya), and a period low climate variability
 (7-0 Kya). Results. Functional trait composition showed consistent
 deviation from climatic equilibrium during both periods. The temporal
 dynamics of trait composition tends to be positively correlated to climate
 equilibrium expectations during Holocene climate warming (14-7 Kya), but
 not during a following period of low climate variability (7-0 Kya). Main
 conclusions.Long-term functional responses of plants to climate change
 showed mixed evidence for both equilibrium and disequilibrium responses.
 Temporal trait dynamics were closer to spatial dynamics expectations under
 high climate variability, indicating that relevance of space-for-time
 substitution might be partially dependent on climate variability. Our
 results further suggest that current mismatches between trait and climatic
 conditions may arise due to a divergence of factors influencing trait
 dynamics during low climate variability periods. These findings provide a
 counterpoint to the common assumption that contemporary trait-climate
 mismatches result from lagged responses to past climate warming. Our study
 also demonstrates the need for a deeper investigation of the potential
 influence of non-climatic factors on functional plant community dynamics.
description: A .Rdata file containing all the paleo
 community, climate informations at each site/trait/time/period used in the
 study. Along with the community response diagram statistics for each
 site/period. Please contact Pierre Gauzere if more informations are
 needed.
description: <pre id="rstudio_console_output" tabindex="0">
 "site" : site code "time" : time slot (500 year)
 "trait_name" : functional trait (SLA, LDMC LA)
 "average_trait_value" : mean community trait value based on
 species average "sd_trait_value" : community trait standard
 deviation based on species average "average_trait_value_distrib"
 : mean community/time trait value based on all TRY-TTT values
 "sd_trait_value_distrib" : community/time trait standard
 deviation based on all TRY-TTT values "SiteName" : site name
 full "Altitude" : site altitude "Longitude" : site
 Longitude (WGS84) "Latitude" : site Latitude (WGS84)
 "ClimTmax.ave" : average site/time maximum annual temperature
 within 50km buffer "ClimPrec.ave" : average site/time annual
 precipitation within 50km buffer "ClimTmax.sd" : standard
 deviation site/time maximum annual temperature within 50km buffer
 "ClimPrec.sd" : standard deviation site/time annual
 precipitation within 50km buffer
 "average_trait_value_distrib_loess" : smoothed mean
 community/time trait value based on all TRY-TTT values
 "average_trait_value_distrib_loess_SE" : standard error of
 smoothed mean community trait value based on all TRY-TTT values
 "ClimTmax.ave_loess" : smoothed average site/time maximum annual
 temperature within 50km buffer "ClimTmax.ave_loess_se" :
 standard error smoothed average site/time maximum annual temperature
 "ClimPrec.ave_loess" : smoothed average site/time maximum annual
 precipitation "ClimPrec.ave_loess_se" : standard error smoothed
 average site/time annual precipitation "t0" : time from 0 BP
 "period" : period based on t0 "period2" : period based
 on the 14Ka separation (the one used in the study) "time2" :
 inverse time "crossings.mean" : mean state number (CRD
 statistic) "crossings.max" : maximum state number (CRD statistic
 max state number) "trait.change" : absolute trait change during
 the timeseries (CRD statistic) "env.change" : absolute maximum
 temperature change during the timeseries (CRD statistic)
 "deviation.base" : climate deviation based on baseline value
 (CRD statistic) "mean.absolute.deviation" : mean value of
 aboslute deviations (CRD statistic absolute deviation)
 "absolute.mean.deviation" : absolute value of mean deviation
 (CRD statistic) "deviation.change" : total deviation change
 during the timeseries (CRD statistic) "deviation.change.1Ky" :
 deviation change per 1Ky (CRD statistic) "num.points" : number
 of points (lenght of the time series) "num.points.not.na" : :
 number of points not NA (lenght of the time series)
 "lm.intercept" : intercept of the TTER ~ STER linear model (CRD
 statistic) "lm.slope" : slope of the TTER ~ STER linear model
 (CRD statistic) "lm.se" : standard deviation of the slope of the
 TTER ~ STER linear model (CRD statistic) "lm.pval" : p-value of
 the slope of the TTER ~ STER linear model (CRD statistic)
 "lm.r2" : r-squared of the TTER ~ STER linear model (CRD
 statistic) "lm.rho": rho of the TTER ~ STER linear model (CRD
 statistic response fit) "time.lag" : cross-correlation function
 fo asses time lag between TTER adn STER</pre>