Do soil communities differ between native and invasive grasses on sand ?

Matthew L. Reid & Sarah M. Emery MIPN Invasive Symposium December 10, 2015 Exotic

www.inps.gov

www.iextension.entm.purdue.edu Plant Host-Parasite Plant-Plant Interactions Competition

Plant-Herbivore Interactions Plant-Mutualist Interactions Plant Host-Parasite Plant-Plant Interactions Competition

Plant-Herbivore Interactions Plant-Mutualist Interactions Plant Host-Parasite Plant-Plant Interactions Competition

Plant-Herbivore Interactions Plant-Mutualist Interactions

Plant-Soil Feedbacks Plant Host-Parasite Plant-Plant Interactions Competition

Plant-Herbivore Interactions Plant-Mutualist Interactions

Mutualists Competitors

Herbivores Parasites Invasive Plants & Soil Interactions

• Enemy Release – Root herbivores & parasites • Reduced Dependence on Native Mutualists – But may utilize native mutualists to their advantage

Belowground Interactions

Arbuscular mycorrhizal fungi

http://mycorrhizas.info/vam.html www.ipm.iastate.edu Functional Groups

www.wageningenur.nl www. plpnemweb2.ucdavis.edu/nemaplex

Plant-parasite Predator Bacteria-feeder Fungal-feeder

www.und.edu www.urbanext.illinois.edu Enemy Release

www.wageningenur.nl

Invasive Plants Fewer plant-parasites Plant-parasite Arbuscular Mycorrhizal Fungi

• Nutrient uptake • Bioprotection Reduced Mycorrhizal Dependence

Invasive Plants Lower AMF abundance (root colonization, spores) Study System

Aquatic-terrestrial interface

www.earthobservatory.nasa.gov

Extent 275,000 acres of dunes in MI Dune Grasses

Ammophila breviligulata Leymus arenarius

Native Exotic Leymus arenarius

• Biomass • Height • Leaf length & width • Flower production • Seed mass

Primary Succession

Ammophila colonizes & stabilizes dune

Ammophila dieback

Colonization by later Emery. 2010. Nature Education Knowledge. successional species Primary Succession

Ammophila colonizes & stabilizes dune

Ammophila dieback

Colonization by later Emery. 2010. Nature Education Knowledge. successional species Research Questions

1. Is invasion by Leymus associated with different soil communities?

2. Can invasion by Leymus be facilitated by belowground interactions with arbuscular mycorrhizal fungi and nematodes? Research Questions

1. Is invasion by Leymus associated with different soil communities? – Field survey 2. Can invasion by Leymus be facilitated by belowground interactions with arbuscular mycorrhizal fungi and nematodes? – Greenhouse experiment Research Questions

1. Is invasion by Leymus associated with different soil communities? – Field survey 2. Can invasion by Leymus be facilitated by belowground interactions with arbuscular mycorrhizal fungi and nematodes? – Greenhouse experiment Hypotheses

1. Reduced mycorrhizal dependence – Leymus will have a weaker association with AMF. 2. Enemy release – Leymus soil will harbor fewer plant-parasitic nematodes. 2014 Field Survey Field Survey Methods

1m2 20 m

• Vegetation survey • 10 composite soil cores – Nematodes and roots for AMF • Collect tiller for nutrient analyses

Field Survey Methods

• AMF staining via vinegar-ink • Nematode extraction via sugar flotation • Functional group ID • Analyses – Mixed model ANOVA • Fixed effect: Native (Ammophila)/Exotic (Leymus) • Random effect: Site, Site*Species • Response – AMF: Root colonization • Response – Nematodes: Abundance per functional group

Results – Root Colonization

• Site and 40 site*species

interaction 30 p = 0.330 non-significant • No difference 20 in levels of root 10

colonization ColonizationRoot %

0 Ammophila Leymus Results – Total Nematodes

• Site and 100

site*species p = 0.5864 80 interaction non-

significant 60 • No difference in total nematode 40

abundance 20 Nematodes/100mL sand Nematodes/100mL 0 Ammophila Leymus Results – Plant Parasites

• Site and

60 site*species interaction non- 50 p = 0.559 significant 40

• No difference in 30 abundance of plant-parasites 20

Nematodes/100mL sand Nematodes/100mL 10

0 Ammophila Leymus Results – Predators

• Site and 20 site*species p = 0.415 interaction non- 15 significant

• No difference in 10 abundance of

predators 5 Nematodes/100mL sand Nematodes/100mL

0 Ammophila Leymus Results – Bacteria-Feeders

• Site and site*species 30 p = 0.066

interaction non- sand

significant 20 • Marginal difference in 10

abundance Nematodes/100mL 0 Ammophila Leymus Field Survey Results

• No evidence supporting reduced mycorrhizal dependence • No evidence supporting release from plant- parasitic nematodes • Trend of increased abundance for bacterial- feeding nematodes – Litter quality or quantity? – Root exudates? – Root turnover? Field Survey Results

• Plant Tissue Properties

Site Species % Nitrogen % Phosphorus Green Point Dunes Leymus 0.90% 0.13% Green Point Dunes Ammophila 1.13% 0.12% Ludington State Park Leymus 0.92% 0.08% Ludington State Park Ammophila 1.14% 0.11% Meinert Park Leymus 1.66% 0.10% Meinert Park Ammophila 1.52% 0.08% Field Survey Results

• Soil Properties

Site Species Organic Matter Total Nitrogen Green Point Dunes Leymus 0.52% 0.009% Green Point Dunes Ammophila 0.67% 0.009% Ludington State Park Leymus 0.28% 0.013% Ludington State Park Ammophila 0.34% 0.009% Meinert Park Leymus 0.12% 0.015% Meinert Park Ammophila 0.17% 0.008% Nematode Community Composition

Dorylaimoides sp. Acrobeles sp.

Trophurus sp. 2015 Field Survey Research Questions

1. Is invasion by Leymus associated with different soil communities? – Field survey 2. Can invasion by Leymus be facilitated by belowground interactions with arbuscular mycorrhizal fungi and nematodes? – Greenhouse experiment Hypotheses

1. Leymus will be less susceptible to plant- parasitic nematodes (PPN). 2. Leymus will be less dependent on arbuscular mycorrhizal fungi (AMF). 3. Leymus will have altered interactions with AMF and PPN in combination. Methods

• Treatments: – Native Ammophila AMF – Invasive Leymus -AMF +AMF

-PPN -PPN PPN -AMF +AMF +PPN +PPN AMF = Rhizophagus intraradices

• Obtained from INVAM at West Virginia University PPN = Pratylenchus penetrans

• Migratory endoparasite

www.nematode.unl.edu Methods

• Replication: 10 per treatment combination • Data Analyses: 3-way ANOVA

Methods

• Response variables of interest – Root colonization – Nematode abundance – Biomass • Root, shoot, total – Other traits • Root architecture, shoot characteristics Direct effect of AMF

p = 0.904 Direct effect of AMF

• AMF – (P = 0.015) • AMF*Species – (P = 0.444) – Leymus 30% increase – Ammophila 41% increase Direct effect of PPN

• PPN – (P < 0.001) • PPN*Species – (P = 0.089) – Leymus 50% decrease – Ammophila 63% decrease AMF enhance growth in the presence of plant-parasitic nematodes Hypotheses

1. Leymus will be less susceptible to plant- parasitic nematodes (PPN). – Some support 2. Leymus will be less dependent on arbuscular mycorrhizal fungi (AMF). – Not supported 3. Leymus will have altered interactions with AMF and PPN in combination. – Supported Implications

• Potential competitive displacement

• Altered successional trajectories?

• Management – Clearcast herbicide, seed head clipping Acknowledgments

Katie Arstingstall Brad Gottshall Andrea Howes Erin Kinnetz Land Managers Michigan DNR Grant Traverse Regional Land Conservancy Muskegon County Parks

Questions?