DOI: 10.5061/dryad.n5tb2rbw8
title: Data from: Closely related parasitic plants have similar host requirements and related effects on hosts

description: The performance of root hemiparasites depends strongly on host species
 identity, but it remains unknown whether there exist general patterns in
 the quality of species as hosts for hemiparasites and in their sensitivity
 to parasitism. In a comparative approach, the model root-hemiparasites
 Rhinanthus minor and R. alectorolophus were grown with 25 host species
 (grasses, forbs and legumes) at two nutrient levels. Hosts grown without
 parasites served as a control. Host species identity strongly influenced
 parasite biomass and other traits and both parasites grew better with
 legumes and grasses than with forbs. The biomass of R. alectorolophus was
 much higher than that of R. minor with all host plants and R.
 alectorolophus responded much more strongly to higher nutrient
 availability than R. minor. The performance of the two species of
 Rhinanthus with individual hosts was strongly correlated, and it was also
 correlated with that of R. alectorolophus and the related Odontites
 vulgaris in previous experiments with many of the same hosts, but only
 weakly with that of the less closely related Melampyrum arvense. The
 negative effect of R. minor on host biomass was less strong than that of
 R. alectorolophus, but stronger relative to its own biomass, suggesting
 that it is more parasitic. The impact of the two parasites on individual
 hosts did not depend on nutrient level and was correlated. Several legumes
 and grasses were tolerant of parasitism. While R. minor slightly reduced
 mean overall productivity, R. alectorolophus increased it with several
 species, indicating that the loss of host biomass was more than
 compensated by that of the parasite. The results show that closely related
 parasites have similar host requirements and correlated negative effects
 on individuals hosts, but that there are also specific interactions
 between pairs of parasitic plants and their hosts.
description: In a comparative approach, the model root-hemiparasites
 <i>Rhinanthus minor</i> and <i>R.
 alectorolophus</i> were grown with 25 host species (grasses, forbs
 and legumes) at two nutrient levels. Hosts grown without parasites served
 as a control. The performance of the two species of
 <i>Rhinanthus</i> with individual hosts was also related to
 that of <i>R. alectorolophus</i> and the related
 <i>Odontites vulgaris</i> and <em>Melampyrum
 arvense</em> in previous experiments with many of the same
 hosts.
description: <b>Explanation of variables in "Data Experiment"
 (Experiment with 2 parasites x 25 Hosts x 2 nutrient
 levels)</b> Parasite: No parasite / Rhinanthus
 minor / Rhinanthus alectorolophus Host: Host
 species Nutrients: Low or high nutrient level
 FunctGroup: Functional group of host (Grass, forb,
 legume) HNutrientStatus: Nutrient status of host
 habitat PMass: Mass of parasite (mg)
 LogPMass: Log10 of parasite mass
 LeafLength4Weeks: Length of longest leaf of parasite after 4
 weeks of growth (mm) Host mass: Mass of host
 (mg) LogHostMass: Log10 of host mass
 TotalMass: Total mass per pot (parasite + host) (mg)
 LogTotalMass: Log10 of total mass per pot
 DaysToFlowering: Days until parasite flowered
 InfloLength: Sum of length of all inflorescences (mm)
 LogInfloLength: Log10 of inflorescence length
 LengthLongestLeaf: Length of longest leaf of parasite at
 harvest Height: Height of parasite (mm)
 LogHeight: Log10 of height HostSeedMass: Mean
 seed mass of host (mg) LogHostMassNoP: Mean log10 of
 biomass of host grown without a parasite
 HostInitialMass: Host mass at time of parasite transplanting
 (mg) LogHostInitialMass: Log10 initial host
 mass LogHostSeedMass: Log10 of mean host seed
 mass RGR: Relative growth rate of host
 Survived: Whether the parasite survived or not
   <b>Explanation of variables in
 "Data Comparison" (Data on performance of parasites with the
 same hosts in various experiments)</b> Host: Host
 species LogBiomMinor: Log10 biomass of Rhinanthus minor
 in current experiment LogBiomAlec: Log10 biomass of
 Rhinanthus alectorolophus in current experiment
 LogBiomMelam: Log10 biomass of Melampyrum arvense in study of
 Matthies (2017) LogBiomS&M: Log10 biomass of
 Rhinanthus alectorolophus in study of Sandner & Matthies
 (2018) LogBiomOdontites: Log10 biomass of Odontites
 vulgaris in study of Geppert (2012)