Mycorrhizal patterns in depth

Franklin DiggsSUNY ESF

Review• Mycorrhiza are

symbiotic relationships between plant roots and soil inhabiting fungi

• Plants pass photosynthate to the fungi in return for mineral nutrients, particularly nitrogen and phosphorous

• Formed by most land plants

http://www.keywordpictures.com/keyword/mykorrhiza/

Forests as networks

http://greenlighte.files.wordpress.com/2011/07/alberton-o-kuypert-2009.jpg

Martin Dodge, 2007)

Classification

http://eagle-rock.org/images/thumb/Coupe_mycorhizes.jpg/400px-Coupe_mycorhizes.jpg

http://bioweb.uwlax.edu/bio203/2011/bielmeie_luke/Phylogeny.htm

sporocarp

mantleHartig Net vesicle

Why are we interested in depth?Niche partitioning

Nutrient cycling

Studies in monocultures of dual infection hosts have shown guild wide niche partitioning (Neville et al. 2002)

Arbuscular mycorrhizae are thought to be responsible for phosphate mining, and may be a chief component of phosphorous additions to older plant communities (Smith and Read 2008)

Objectives• Compare percent root length colonized

in each guild along depth and the ratio of the two

• Compare the root length of each guild along depth and the ratio of the two \

Hypotheses• Percent root length colonized will be less in

the deeper soils than in the shallow in both guilds, the AM/EM ratio will increase with depth

• Colonized root length will be less in the deep soil, but the AM/EM ratio will increase with depth

Field methods

• Roots were collected by the shoestring crew in fall 2010

• Shallow soils were collected using 10cm soil cores• A 20cm power core was used to collect deep soils• Soils were separated into horizons based on visual

inspection

MethodsRoot length is estimated using grid intersection

Ectomycorrhizal colonization is estimated by using the proportion of those intersections which crossed ectomycorrhizal root tips compared to colonized root

To estimate Arbuscular mycorrhizal percentage <1mm diameter roots are cut into 2mm section and stained, slides are prepared and examined at 400x magnification and the presence or absence of arbuscular mycorrhizal features is noted

Methods

http://mycorrhizas.info/method.html

Results

C5 shallow C5 Deep C7 Shallow C7 Deep0

2

4

6

8

10

12

14

Am Length EM Length Non mycorrhizal length

roo

t le

ngth

cm

/cm

^2

soil

Root length per area of soil by mycorrhizal guild

Results• Greater colonization in shallow soils regardless of

guild (p<0.001)• Greater root length in shallow soils regardless of

guild (p=0.016) • No change in the ratio of percent colonization

between guilds across depth (p=0.46)• Change in the ratio of root length between guilds

across depth in one stand

Future workPost treatment mycorrhizal measurements

-Decrease in mycorrhiza tion

in response to fertilization

Use molecular methods to determine variation in mycorrhizal diversity across depth

Development of new AM primers may lead to a unified methodology for sampling mycorrhiza of both guilds

Acknowledgements Ruth YanaiThomas Horton Tim Fahey

2010 Shoestring crewMatt VadeboncoeurApril DonerKikang Bae

MELNHE project and the Shoestring crewMcIntire-Stennis FundBartlettt experimental forest

Works cited• Brundett, M., N. Bougher, B. Dell, T. Grove, and N. Malajczuk. 1996. Working

with Mycorrhizas in Forestry and Agriculture. Australian Centre for International Agricultural Research.

• Dickie, I. A., B. Xu, and R. T. Koide. 2002. Vertical niche differentiation of ectomycorrhizal hyphae in soil as shown by T-RFLP analysis. New Phytologist 156:527–535. doi: 10.1046/j.1469-8137.2002.00535.x.

• Neville, J., J. . Tessier, I. Morrison, J. Scarratt, B. Canning, and J. . Klironomos. 2002. Soil depth distribution of ecto- and arbuscular mycorrhizal fungi associated with Populus tremuloides within a 3-year-old boreal forest clear-cut. Applied Soil Ecology 19:209–216. doi: 10.1016/S0929-1393(01)00193-7.

• Smith, S. E., and D. J. Read. 2008. Mycorrhizal Symbiosis, Third Edition, 3rd edition. Academic Press.