DOI: 10.5061/dryad.15dv41nzf
title: Mycorrhizal colonization and root diameter of native and invasive plants of eastern North America

description: Arbuscular mycorrhizal colonization (total and arbuscules) were measured
 in roots of 10 species of eastern North American woody plants. Five were
 non-native invasive and 5 were native species. Roots were collected from
 ingrowth cores over three harvests during a single season, from a common
 garden. Diameter was estimated from published root density and specific
 root length values for each species.
description: Arbuscular mycorrhizal colonization (total and arbuscules) were
 measured in roots of 10 species of eastern North American woody plants.
 Five were non-native invasive and 5 were native species. Roots were
 collected from ingrowth cores over three harvests during a single season,
 from a common garden. Diameter was estimated from existing data on root
 density and specific root length. The aim of the study was to investigate
 the relationship between species nativity and mycorrhizal colonization,
 and to correlate mycorrhizal colonization with plant traits.
description: We measured AMF colonization in archived roots that were
 originally collected by Jo et al. (2017) for root productivity and
 chemistry measurements. Root samples were obtained from harvests of
 point-in-space ingrowth cores (Milchunas et al., 2005) installed in
 September 2013 and harvested in late May, late July, late September and
 late November of 2014. Ingrowth cores made of 1x1 cm plastic mesh (4 cm
 diameter) were installed at a depth of 0-10 cm and filled with root-free
 soil from the site. Each plot contained 9-12 cores from which fine roots
 (including first to third order) were pooled to obtain one representative
 sample per plot at each harvest date. Collected roots were cleaned using
 deionized water and dried at 65 °C for &gt;2 days. We used roots from
 the May, July and September 2014 harvest dates for AMF scoring, which
 spanned the majority of the growing season. Dried fine roots were
 rehydrated in water, and cleared and stained using the ink and vinegar
 method (Vierheilig and Piché, 1998). Total AMF colonization was quantified
 using the magnified line intersect method (McGonigle et al., 1990) at 400x
 magnification. Colonization by arbuscules, the primary sites of resource
 exchange for the symbiosis, were also scored. In some cases, root material
 from a sample was consumed in previous measurements of root chemistry
 conducted by Jo et al. (2017) or roots were too difficult to sufficiently
 clear for visual inspection, reducing the sample size for some species.
 Each species was represented by 3 to 9 replicates (median = 8.5) in the
 final dataset, for a total sample size of 69 observations. Specific root
 length (SRL, m g-1) and root tissue density (RTD, g cm-3) from Jo et al.
 (2015) were used to calculate average root diameter for the same species
 (mm). The following plant species were included: <em>Celastrus
 orbiculatus </em>Thunb.<em>, Celastrus scandens L., Frangula
 alnus </em>Mill.<em>, Frangula caroliniana </em>(Walter)
 A. Gray<em>, Lonicera canadensis </em>W. Bartram ex
 Marshall<em>, Lonicera sempervirens L., Lonicera
 villosa</em> (Michx.) Schult., <em>Lonicera
 fragrantissima Lindl.</em> & Paxton, <em>Lonicera
 japonica Thunb</em>., <em>Lonicera morrowii</em> A.
 Gray. Jo, I., J. D. Fridley, and D. A. Frank. 2017.
 Invasive plants accelerate nitrogen cycling: evidence from experimental
 woody monocultures. Journal of Ecology 105, 1105-1110.
 Jo, I., J. D. Fridley, and D. A. Frank. 2015. Linking above- and
 belowground resource use strategies for native and invasive species of
 temperate deciduous forests. Biological Invasions 17: 1545-1554.
 McGonigle, T. P., M. H. Miller, D. G. Evans, G .L. Fairchild, and
 J. A. Swan. 1990. A new method which gives an objective measure of
 colonization of roots by vesicular-arbuscular mycorrhizal fungi. New
 Phytologist 115: 495-501. Milchunas, D. G., A. R.
 Mosier, J. A. Morgan, D. R. LeCain, J. Y. King, and J. A. Nelson. 2005.
 Root production and tissue quality in a shortgrass steppe exposed to
 elevated CO2: using a new ingrowth method. Plant and Soil 268:
 111–122. Vierheilig, H, and Y. Piché. 1998. A modified
 procedure for staining arbuscular mycorrhizal fungi in roots. Journal of
 Plant Nutrition and Soil Science 161: 601–602.