DOI: 10.5061/dryad.kwh70rzd4
title: Data from: Canopy facilitation outweighs elemental allelopathy in a metalliferous system during an exceptionally dry year

description: The Elemental Allelopathy hypothesis states that the metal-rich litter of
 hyper-accumulating species may have a detrimental impact on neighbouring
 plants giving a competitive advantage to hyper-accumulators. Here, we aim
 to specify the conditions of application of this hypothesis in realistic
 field conditions, and its relative importance compared to other positive
 effects found in metalliferous systems. We disentangled the
 litter-induced elemental allelopathy and canopy effects of two
 metallophyte species (Arenaria multicaulis and Hutchinsia alpina) with
 different levels of leaf Zn and Cd accumulation on two ecotypes of
 Agrostis capillaris with different levels of metal tolerance. The
 experiment was conducted in two habitats with contrasting pollution levels
 in a former mining valley in the Pyrenees (France). The
 metallophyte species that accumulates more metals (Hutchinsia alpina)
 showed a strong elemental allelopathy effect on the target with lower
 metal tolerance in the habitat with lower pollution level, while the
 metallophyte species that accumulates less metals (Arenaria multicaulis)
 had no litter effect. Both metallophyte species had positive canopy
 effects likely due to the improvement of micro-climatic conditions. The
 drought that occurred during the experiment may have influenced these
 canopy effects, increasing their importance during the course of the
 study. For Hutchinsia alpina the positive canopy effects were
 stronger than the negative litter effects, resulting in overall positive
 effects on both target ecotypes. Synthesis. Our results brought a better
 understanding of the occurrence of elemental allelopathy in metallophyte
 communities and its relative importance as compared to micro-climatic
 facilitation in a global warming context.
description: # Title of Dataset: --- Dataset of final survival data, Plant-Plant
 Interactions (Imp and RII), metal concentration in soils, metal
 concentration in leaves, litter decomposition rates and traits values of
 both metallophyte species in our study ## Description of the Data and file
 structure ``` Final survival ``` Final binary survival data of all targets
 individuals (surv, 1= alive, 0= dead, NA=missing values due to disturbance
 of the plant individuals). "Block" column designate the number
 of the block. "Habitat" column designate the habitat at stake.
 "Metallophyte species" column designate the plant species at
 stake. "Neighbouring modality" column designate the neighbouring
 treatment in which the target grows. "Agrostis ecotype" column
 designate the level of tolerance to metals of targets. ``` Imp ```
 Different Imp values calculated with final survival rates.
 "Block" column designate the number of the block.
 "Habitat" column designate the habitat at stake.
 "Metallophyte species" column designate the plant species at
 stake. "Imp type" column designate the type of index at stake.
 "Agrostis ecotype" column designate the level of tolerance to
 metals of targets. ``` RII ``` Different RII values calculated with final
 survival rates. "Block" column designate the number of the
 block. "Habitat" column designate the habitat at stake.
 "Metallophyte species" column designate the plant species at
 stake. "RII type" column designate the type of index at stake.
 "Agrostis ecotype" column designate the level of tolerance to
 metals of targets. ``` Metal concentration in soils ``` Metal
 concentration values (C, in mg/kg) in the soils under both metallophyte
 species. "Block" column designate the number of the block.
 "Habitat" column designate the habitat at stake.
 "Metallophyte species" column designate the plant species at
 stake. "Metal" column designate the type of metal at stake. ```
 Metal concentration in leaves ``` Metal concentration values (C, in mg/kg)
 in the leaves of both metallophyte species."Block" column
 designate the number of the block. "Metallophyte species" column
 designate the plant species at stake. "Metal" column designate
 the type of metal at stake. ``` Litter decomposition rates ``` Differents
 decomposition rates (dec, %) for the litter of both metallophyte species.
 "Block" column designate the number of the block.
 "Habitat" column designate the habitat at stake.
 "Metallophyte species" column designate the plant species at
 stake. ``` Plant traits ``` Differents traits values for both metallophyte
 species. "Metallophyte species" column designate the plant
 species at stake. "Trait" column designate the type of trait
 (SLA= Specific Leaf Area in cm²/g, LDMC= Leaf Dry Matter Content in %).