DOI: 10.5061/dryad.91nd2
title: Data from: Nutrient foraging behaviour of four co-occuring perennial grassland plant species alone does not predict behaviour with neighbours

description: The spatial arrangement of nutrients and neighbours in soil influences
 plant growth and reproduction. Plants often respond to such stimuli
 through plasticity in root proliferation (root mass per soil volume), or
 the breadth of their root system. Here, we asked how plants adjust
 nutrient foraging strategies when grown alone or with neighbours. We asked
 (i) Does root proliferation into nutrient-rich patches when plants are
 grown alone predict root proliferation when plants are grown with
 neighbours? (ii) What factors (nutrients or neighbours) best predict the
 probability of root placement at different soil locations? (iii) How does
 the spatial distribution of nutrients alter the degree to which neighbours
 suppress plant growth? To answer these questions, we grew four grassland
 species either as individual plants or in competition, in patchy or
 patch-free soil, in a factorial design. We used genomic DNA to identify
 the spatial distribution of roots of each species when plants were grown
 in mixtures. The root foraging behaviour of individuals grown alone did
 not consistently predict behaviour in mixture. Specifically, (i) the
 behaviour of individually grown plants predicted behaviour of competing
 plants inside patches, but not in background soil. We observed
 over-proliferation of roots in background soil relative to what was
 expected from plants grown alone. (ii) Neighbours were consistently the
 most important variable for predicting the placement of roots in soil and
 caused either an increase in root system breadth, or no change relative to
 alone. (iii) If a species experienced growth suppression when grown in
 competition, individuals experienced this more severely in patchy soil
 compared to patch-free soil. Synthesis. Game theoretic models have
 predicted that under interspecific competition, over-proliferation of
 roots in the presence of neighbours might occur for some species but not
 others. Our data are consistent with these predictions but more work is
 needed. Nutrient foraging studies have primarily focused on plants grown
 alone or assumed that plants do not respond separately to neighbours and
 nutrients. Our data call these practices into question and contribute to a
 growing understanding that plants integrate information about both
 nutrients and neighbours when placing roots in soil.
description: Root biomass
 aloneThis is the root biomass
 data recorded in patches and background soil for each species grown alone.
 Methodological details are given in the manuscript.Root biomass with
 neighboursThis is the root biomass
 data recorded in patches and background soil for all four species combined
 when grown with neighbours. It was not possible to seperate the biomass of
 each species individually. Methodological details are given in the
 manuscript.Root Presence with
 neighboursThis is the root
 presence/absence data recorded in patches and background soil for each of
 the four species when grown with neighbours. Molecular techniques were
 used to identify the presence of each species individually. Methodological
 details are given in the manuscript.