Why need to understand how roots and mycorrhizas interface with the ecosystem:

1. Why need to understand how roots and mycorrhizas interface with the ecosystem: • Roots/mycorrhizas research exist a black hole and difficult to study because can’t see them expect in wet tropics where roots crawl out of the ground and into tree canopies • Plants obligate relationships with mycorrhizas to survive In less weathered (low nutrient availability ) and highly weathered soils (low nutrient availability, higher toxic chemicals), older growth stages and late successional stages • Roots/mycorrhizas allow plants to adapt to their changing soil environment during succession and when soil chemical is altered by human land-use activities • Fertilizing forests with a limiting nutrient like N may increase total NPP but reduce fine roots/mycorrhizas. Total NPP increase is not real, just shift allocation of C from below- to aboveground • Increasing (during C enrichment of atmosphere) or decreasing carbohydrate production by plants (herbivory) will change amount of mycorrhizas found on roots

2. Leached layers where nutrient availability is low Layers that are impermeable to easy root penetration so restrict roots to surface horizons http://www.hubbardbrook.org/research/gallery/soil/HB_115_Spodosol.jpg Typical view of the HIDDEN HALF – a black box in soil

3. Temperate climatic zones Pacific silver fir tip-over, Findley Lake, Washington Root tip-over, Kenai, Alaska This is when we typically see roots

4. Temperate climatic zones Temperate Conifer forests – roots located close to surface where most nutrients limiting tree growth foundRoot excavation for tracking disease in Washington (photo Bob Edmonds)

5. Temperate climatic zones Temperate Deciduous Forests have deeper soils and are more nutrient rich compared to Conifer Forests. Roots are growing to available nutrients Canada – Root excavation; Root growth is extensive – can be 30 meters from base of the tree

6. Tropical Forest Soil Temperate ConiferousForest Soil • Roots / mycorrhizas found more than 30 meters deep • Roots not just found in soils • Old soils • Soils low in Ca, K, N (except where N fixing trees used to shade coffee) How much soils weathered determines where find ROOTS/Mycorrhizas • Roots / mycorrhizas found mainly in the surface organic horizons/soil • Young soils • Soil nutrient availabilities decrease with land-uses (i.e. acid precipitation)

7. Tropical climates http://green.nationalgeographic.com/environment/photos/rainforests-tropical/rhinohornbilldipterocarp.html

8. Tropical climates Deep rooted in highly weathered soils Sparse palm trees spread across the savanna of Madagascar. Photograph by Maria Stenzel http://green.nationalgeographic.com/environment/photos/savannah/palmdottedsavannah.html Greater rheas graze in the tall savannah grass of Brazil's Pantanal. Photograph by Joel Sartore http://green.nationalgeographic.com/environment/photos/savannah/rheasgraze.html

9. Tropical climates http://travel.mongabay.com/indonesia/images/singapore5485.html OR roots do not remain in the soil http://travel.mongabay.com/malaysia/images/malaysia1016.html http://travel.mongabay.com/indonesia/images/singapore5456.html

10. Apogeous roots of Tabonuco climbing up a Sierra palm to acquire stem flow nutrients, Luquillo LTER, Puerto Rico Nodules of nitrogen fixing tree species (e.g. Inga spp.) Roots in streams Tropical climates

11. Tropics and Temperate have Root Grafting Root grafting between different species of plants and borrowing C, nutrients from other plants

12. Root rot disease transmitted through root grafts – western hemlock (photo Bob Edmonds) Roots pass pathogens, carbohydrates, nutrients to other trees in same forest

13. Tropics and Temperate have mycorrhizal associations

14. Between 60,000 and 1.2 million ectomycorrhizas were found in one square metre of forest and 95% of the root tips examined had formed an ectomycorrhizal partnership. http://www.nifg.org.uk/ecto.htm

15. This is the mycorrhizal fungus Laccaria laccata on ponderosa pine. Note the bifuricate shape of the mycorrhizas. You can see the fungal sheath (white area), hyphae, and hyphal strands (if you have 400x vision!).Thank you Jim Trappe for the slide! http://www.cof.orst.edu/cof/teach/for442/cnotes/sec3/myco.htm

16. *Cartoon from Masters Thesis UAF

17. The fungus gains carbon  and other essential organic substances from the tree and in return helps trees take up water, mineral salts and metabolites, fight off parasites, predators such as nematodes and soil pathogens. Indeed, most forest trees are highly dependant on their fungal partners and in areas of poor soil, could possibly not even exist without them. Thus in forest management, if we do not manage for the mycorrhizal fungi, we could be damaging the trees. http://www.nifg.org.uk/ecto.htm

18. Monotropa uniflora (Canada) is a myco-heterotrophic plant lacking chlorophyll that is entirely dependant on ECM fungi linked to nearby trees. http://mycorrhizas.info/index.html

19. Root – mycorrhizal fungal mats accessing nutrients for plants

20. Tabonuco root mat (> 40 cm deep) on the surface of forest floor, Luquillo LTER, Puerto Rico

21. Water Availability Nutrient Availability Regulation point What controls how much roots and mycorrhizas are produced and supported by plants? Root Area Leaf Area

22. 10 year old Site Class II [HIGH SITE QUALITY] Douglas-fir, Washington (note person in photo) Tree height 10 year old Site Class IV [LOW SITE QUALITY] Douglas-fir, Washington (note person in photo) Person Person Which stand has more fine roots, mycorrhizas??

23. Douglas-fir(% of Total Annual Production) Control: 30% total NPP in fine roots Fertilized: 18% total NPP in fine roots

24. The Links between Plants (Belowground) & Soils Plants Litterfall Uptake Dissolved OM (eg, P, Si, Al) Decomposition Uptake Detritus Mineralization Mineralization Other crystalline & non-cryst Al-Silicate PO4-3 exch sites SOIL Imogolite paracrystalline Al-SilicatePO4-3 exch sites/complex Organic exch sites /complex Solution

25. PNW Pacific Silver fir Example Oi Oe Oa E Bhs

26. Root appearance when not affected by high aluminum levels and properly functioning roots

27. Roots dying from aluminum toxicity and no longer able to take up nutrients

28. Image of roots taken in spruce forests in Germany where trees were dying from acid rain

29. 10 parts Ca and 50 parts Al = 0.2 ratio Abies amabilis, WA Ca/Al ratio -< 0.2 critical, mortality Deeper into the soil 10 Ca, 1 Al 10 Ca, 11 Al 10 Ca, 50 Al 10 Ca, 100 Al SOIL Fine roots < 1mm diam

30. Aluminum in Roots by HorizonMRT = mean residence time (yrs) of decaying rootsWhat does it mean to have a long MRT?? Deeper into the soil

31. How do you benefit from being an Al accumulator?? Al accumulator- foliage 500-1,120; fine roots 1320 ppm Not Al accumulator - foliage 110-260; fine roots 730 ppm

32. Wet Nitrate Deposition (kg/ha) 1995-1998NADP/NTN Monitoring Data

33. Spruce dominated stands with co-associates fir, birch, maple New England Example SPODOSOL http://www.hubbardbrook.org/research/gallery/soil/HB_115_Spodosol.jpg

34. ANPP -Tree Species compared to Controls(significant only) After 6 years treatment

35. Alaska succession No or Facultative mycorrhizal Obligate mycorrhizal Courtesy of John P. Bryant

36. Alaska Succession Courtesy of Keith Van Cleve Courtesy of Keith Van Cleve

37. Moose (Alces alces) and Snowshoe hare (Lepus americanus) excluded from exclosures Courtesy of John P. Bryant

38. Willow and balsam poplar growing outside exclosures had ectomycorrhizal infection reduced by ~ 16% compared to plants protected from browsing for the previous 4 winters Why care?? Moose and snowshoe hare browsing reduces the supply of soluble carbohydrate available to ectomycorrhizae Repercussions?? Altering successional pathways by reducing ectomycorrhizal infection of willow and balsam poplar fine roots and reduce their ability to compete for nutrients with alder –also mycorrhizal but rarely browsed by snowshoe hare and moose

39. Mycorrhizal dynamics under elevated CO2 and nitrogen fertilization in a warm temperate forest Maria O. Garcia & Tatevik Ovasapyan & Mary Greas & Kathleen K. Treseder Plant Soil (2008) 303:301–310, http://face.env.duke.edu/PDF/ps00-08.pdf “In particular, we hypothesized that mycorrhizal fungi and … would become more prevalent under elevated CO2 ... .. Overall, we observed a 14% increase in ectomycorrhizal (ECM) root colonization under CO2 enrichment, which implies that elevated CO2 results in greater C investments in these fungi.” DOI 10.1007/s11104-007-9509-9 Received: 16 August 2007 / Accepted: 29 November 2007 / Published online: 15 December 2007 # Springer Science + Business Media B.V. 2007

40. Subtropical Forest Puerto Rico Example

41. 6 Hurricanes during ~ 10 yr study:Sept 1989 – Hugo;early-mid Sept 1995 – Luis & Marilyn;Jul 1996 – Bertha;Sept 1996 -Hortense;Sept 1998 - Georges Weather events keeps forests early successional Hurricane Georges hits Puerto Rico on September 21, 1998. Image by Dennis Chesters, Marit Jentoft-Nilsen, Craig Mayhew, and Hal Pierce, Laboratory for Atmospheres, NASA Goddard Space Flight Center from data derived from NOAA GOES-8 satellite. Image from "http://rsd.gsfc.nasa.gov/rsd/images/Georges.html".

42. Foliage decay < 6 months so pulse of nutrients available; however, foliage area takes several years to re-establish Hurricane Hugo

43. So why doesn’t the loss of foliage cause loss of mycorrhizas and fine roots???

44. Drought 1994 Drought 1997 H. Hortense H. Bertha Drought 1996 H. Luis & Marilyn Wood addition Root growth increased with wood addition Wood removal

45. Some Benefits of Mycorrhizas • Allow plant establishment on nutrient poor soils (mining reclamation, revegetation projects) • Increase plant size in short time period (forestry) • Reduce fertilizer requirements • Cut down production costs • Decrease fertilizer contamination of the environment

46. Old growth Douglas-fir forests, Northern Spotted owl (NSO), Flying Squirrel feed on the mushrooms (mycorrhizas) that form specifically on Old Growth tree roots and preyed upon by NSO. Take one link out, ecosystem may not be as resilient Photo courtesy Jerry Franklin

47. Native plant roots: what goes on below the surface http://www.laspilitas.com/advanced/advroots.htm

48. “Mycorrhizal fungi allow the plant to withstand more stress Healthy soil smell good! Encourage the good organisms in the soil. Build a native garden right and the microorganisms are stable and happy. Along with the mycorrhizas are associated soil bacteria that are nearly as important. Encourage the good ones (that live in the sweet smelling garden or forest soil good gardeners know) and discourage the bad ones (that live in the soil that has no smell or smells like musty newspapers, sauerkraut, or has a sharp acrid smell ). Smelling soil is as old as farming and has been a very reliable technique. That's very unscientific but it has been consistently right.” http://www.laspilitas.com/advanced/advroots.htm

49. Why need to understand how roots and mycorrhizas interface with the ecosystem: • Roots/mycorrhizas research exist a black hole and difficult to study because can’t see them expect in wet tropics where roots crawl out of the ground and into tree canopies • Plants obligate relationships with mycorrhizas to survive In less weathered (low nutrient availability ) and highly weathered soils (low nutrient availability, higher toxic chemicals), older growth stages and late successional stages • Roots/mycorrhizas allow plants to adapt to their changing soil environment during succession and when soil chemical is altered by human land-use activities • Fertilizing forests with a limiting nutrient like N may increase total NPP but reduce fine roots/mycorrhizas. Total NPP increase is not real, just shift allocation of C from below- to aboveground • Increasing (during C enrichment of atmosphere) or decreasing carbohydrate production by plants (herbivory) will change amount of mycorrhizas found on roots