Category Archives: Fungi

Taking Stock

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As year end approaches Bill and I will compile an annual report of our  progress toward restoring Timberhill.  The report will list new species collected in 2011, changes we have observed, and  advancement toward our restoration goals.  In order to make the best use of our time in the coming year we have to prioritize. In 2012 restoring the wetland and fen on the east and west sides of West Creek will continue to be the highest priority.  It is also our greatest challenge.   This site includes spring fed bottom wetlands and a hillside fen. We have enough experience restoring overstocked savanna to know how to proceed and what to expect.  But restoring wetland is beyond our expertise.  We have no idea what to expect. So we’re learning through trial and error and using instinct to guide us.

When we purchased the West Creek unit in 2004 the creek bottom, wetland, and fen were overgrown with honey locust and invaded by multiflora rose. The hillside above the pioneer spring was a dense stand of Eastern red cedar.  Furthermore, erosion from uphill cornfields had cut a deep ravine that bisected the West Creek unit. At the bottom of the erosional run was a small stand of prairie cord grass and sedge.  In 2011  the erosional run continued to decrease as the cover of  prairie cord grass and sedge increased.

Timberhill aerial with blue line indicating creek

In 2004 we introduced annual prescribed burns to control invasive plants and tall shrubs,  stimulate return of native plants, and restore the natural hydrology.    Other than girdling and removal of honey locusts we did no further clearing for three years, giving our  annual dormant season burns time to control some of the invasives.  In winter, 2007, we thinned the remaining trees except the elms which we left for morel habitat.  (They will die of their own accord and produce morel mushrooms as they die.) In August, 2007,  we burned the downed Eastern red cedars on the hillside above the pioneer spring.  Burning them while the surrounding plants were still green made the fire easy to control.  Not only have remnant populations of  native forbs, sedges and  warm season  grasses increased  on that hillside, but the contours have softened.  What had been a sharp drop to the creek has become a gentle slope.  Most interesting have been the changes around the pioneer spring.  The land between the spring and the creek is now dotted with seeps.

 

Seep that has developed below the pioneer spring. Note water dripping on right side.

On the east side of the creek we have made some progress, but it’s very slow.  The biggest problem is running fire through this area.  Only small sections at north and south end have burned.  In the north burned section Long-scaled tussock sedge, Carex haydenii, is out competing the other plants and slowly moving through the brush to the north fence line.  Fire has also stimulated clumps of Wood reed, Cinna arundinacea,  under the shingle oaks at the south end.  But the center portion is still a tangle of dead elms, invasive vines and multiflora rose.

 

We've made little progress in this center portion of the east side.

The most interesting new species we found this year was an Albatrellus, a polypore mushroom.  Polypores are usually found growing on wood, but this species was terrestrial, fruiting from the ground in the West 40 woodland,   It is also mycorrhizal, having a symbiotic association with trees.  A search of   the Iowa State University herbarium fungi database lists only two Albatrellus records:  1927 collection in a Webster County woodland and a 1936 Johnson County collection.   The specimens I collected were too immature to key.  Hopefully, this interesting mushroom will fruit again next year when I will know enough to let it mature before collecting.

Albatrellus mushroom

A Timberhill Tour: The Southeast Woodland

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The Southeast Woodland comprises approximately 20  acres in the southeast corner of Timberhill.  It borders a ridgetop meadow in the center of the property. From there the sharply dissected ridges drop steeply to Brush Creek, our east boundary.  Timber stand improvement, i.e., removing the midstory weed trees and thinning the pole timber was completed there in 1998.  Since this unit contained lot of red oak which species is highly susceptible to oak wilt we anticipated higher than normal mortality and left sixty trees per acre, more than in other units.

SE Woodland before prescribed burns

We didn’t burn this unit until 2000 because there was no firebreak.  Then we found an old trail just inside the south property line. It was a mess.  Several large trees blocked the trail.  Between that and the heavy brush it took a friend with a Bobcat, Bill with a clearing saw and chain saw to cut our way to down to Brush Creek. Then we recruited volunteers for the first prescribed burn in 2001.  This unit has been burned every year since.

SE Woodland after 10 prescribed burns

Recovery of the understory plants has been inconsistent.  After three prescribed burns yellow ladyslipper orchids appeared clinging to the side of seepy bluff overlooking the ravine at the north end. Pockets of other conservative plants such as false hellebore are scattered through the rest of the woodland, but much of the understory is still in early stages of recovery.    The canopy is denser here than in the East Savanna and ambient light is less than 10% of full sunlight.  That may be why it is taking so long.

False hellebore, Veratrum woodii

But  ectomycorrhizal fungi that have fruited here since we began managing this woodland have compensated for the lack of floristic quality.  (Ectomycorrhizal fungi have a symbiotic association with the roots of a vascular plant.  Mushrooms collected in the SE Woodland have all been associated with white oaks. ) After the first prescribed burn the woodland north of the trail/firebreak was filled with deadly destroying angel mushrooms.  After three burns these fungi were replaced by various species of brittlecap, milky cap and Amanita fungi.    In 2007 we were thrilled with a heavy fruiting of king bolete, a choice edible.  We also had several nice fruitings of golden chanterelles, another choice edible. The SE Woodland mycoflora has become more interesting since then.  Each year a new bolete species has fruited here.  (The underside of Bolete mushroom caps have pores instead of gills. Bolete spores are released from inside these pores.)  Several have been species new to Iowa records. The latest was Leccinum subglabripes, with bright yellow pores and stalk that stains red.

Leccinum subglabripes

A diverse population of fungi is essential to oak savanna quality.   In a woodland it is the fungi that bind all the other organisms together.  Mycelium, the threadlike vegetative structure of fungi, links plants together and regulates the flow of nutrients and water. Each species delivers specific benefits to its host plant.  The more diverse the ectomycorrhizal fungi in a woodland, the healthier the woodland.

Surprising morels

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Cluster of yellow morels in Hickory Grove

Our neighbor, Doyle, introduced Bill and me to the annual spring rite of hunting for morels.  He has been harvesting these delectable fungi since childhood and is a true expert.  Our first year at the farm we followed Doyle through the riparian woodland along Brush Creek. Instead of looking down at the ground, he looked up at the leaves of silver maple trees. They were just large enough that one could make out their distinct shape. Satisfied that the maple leaves indicated it was time, he walked slowly around the base of a silver maple looking for the first morels of the season.  Pushing aside the leaves with a stick he showed us the clusters of small gray morels. Thanks to Doyle,  Bill and I eventually learned to find these early morels and the later fruiting yellow ones ourselves.

In southern Iowa morels begin fruiting in mid to late April.  Depending on the weather the season lasts from two to four weeks.  Since they tend to fruit in the same locations each year we counted on harvesting them under the silver maple, elm and hackberry trees along Brush Creek every year.  However, one cold wet spring we couldn’t find a single specimen and had to search for them elsewhere.

That was the  year we learned that morels can be a delicious side benefit of timber stand improvement and annual prescribed fire. Our West 40 unit was heavily overstocked with elm and Eastern red cedar when we purchased it in 2001. After thinning and annual prescribed burns I was not surprised to find abundant fruiting of morels around some of the elm stumps.  Morels are often associated with elms for three years after the trees die. Some stumps produced over fifty morels the first year.   What has surprised me is that morels have continued to fruit in the West 40 every year since.  Our most reliable site is a prairie remnant where the earliest morels of the season fruit among the hoary puccoon and wood betony.  They aren’t as plentiful as they were seven years ago, but we usually harvest what Doyle calls, “a good mess”.

2011 was a particularly sparse morel season in south central Iowa.  Morel hunters complained that there was no fruiting in any of their usual spots.  They complained that morels could only be found in sites where they had never fruited before.  That was certainly true at Timberhill.  This year the most abundant fruiting was in the Hickory Grove where we’ve never found any morels. The only trees in this woodland are shagbark hickory and young oak sprouts yet we harvested five pounds of morels there this season. Even before thinning there were no elms in this woodland.   Heavy fruiting of black morels is common one  year after forest fires in the western states and one wonders if prescribed fire at Timberhill also stimulates fruiting of grey and yellow morels  in Iowa.

 

Late successional ECM fungi at Timberhill

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Before we began restoring Timberhill in 1993 the only bolete mushroom species  I found on the property was Tylopilus felleus, the Bitter bolete.  Boletes are a large group of  ectomycorrhizal (ECM) fungi with a spongy surface of pores instead of gills on the underside of the cap  and are usually found growing in soil.  Of the  many genera in this group  species of Boletus, Leccinum, Gastroboletus, Phylloporus, Strobilomyces, and Tylopilus are collected here each year.

As our oak savanna restoration proceeded I began documenting the succession of ECM fungi that accompanied the increasing floristic diversity. I learned that ECM succession culminates in highly conservative boletes.    I also found that there is a succession of boletes from the early successional less conservative species such as B. campestris and B. bicolor to the highly conservative species. Late successional species  such as Boletus dupainii fruit only in sites with the most conservative forbs such as Agalinis gattingeri.

 

Boletus dupainii

A good example is the SE Woodland.  The first prescribed burn there after thinning of the overstocked timber was in early spring, 2001.   It has been burned every year since.  In October, 2001, the woodland floor was covered with a heavy fruiting of the deadly Amanita virosa.  In the succeeding years the A. virosa declined and was replaced by various species  of ECM fungi.  In 2006 the boletes began to  fruit  on the woodland floor.  Boletus submentosus and B. spadiceus were followed by  B. griseus, B. edulis, B. inedulis, B. dupainii, and Gastroboletus turbinatus in 2007.  In 2008 I collected  Phylloporus rhodoxanthus a small reddish brown capped mushroom with bright yellow gills (this is one of a few gilled boletes) there. Leccinum subglabripes (2009) is the newest resident.

Leccinum subglabripes

New bolete species have fruited at Timberhill each year since 2002.  In 2010 it was Boletus rhodosanguineus previously recorded only in Ohio and western New York state.  It fruited in  clumps of little blue stem  near a white oak  in the east savanna.  (B. dupainii has fruited nearby for several years.)

Boletus rhodosanguineus in a clump of little blue stem

I wish I knew how to account for this succession.  Little information is available.   A study (L. Tedersoo et al. “Diversity and community structure of ectomycorrhizal fungi in a wooded meadow.” Mycological Research 110 (2006), 734-748.)  of the diversity and community structure of ECM fungi in managed and forested parts of a wooded meadow in Estonia  found that boletes fruit predominantly in the open managed meadows.  A University of Minnesota study (I.A. Dickie at al. “Ectomycorrhizal fungal communities of oak savanna are distinct from forest communities”. Mycologia, 101 (4), 2009, 473-483)   whether ECM fungal communities of oak savanna are distinct from forest communities, collected  B. nobilissimus (similar to B. edulis commonly found at Timberhill) in all three savanna plots but none in the forested plots.  No other bolete found at Timberhill was found in the Minnesota managed oak savanna plots.  The difference in major ECM hosts, Quercus macrocarpa, Q. ellipsoidalis and Corylus americana in Minnesota may account for the difference.  White oak, Quercus alba, the primary ECM host at Timberhill is not listed as an ECM host in the Minnesota  study.

Hydrology is also a likely factor.  There is little erosion at Timberhill.  Most of the precipitation is absorbed into the soil  providing a constant source of  water to plants and fungi.  But I would love to know if our annual burn regimen has anything to do with it.  Any suggestions would be most welcome. 

Components of a Fully Functioning Oak Savanna: Ectomycorrhizal Fungi #2

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Ectomycorrhizal (ECM) fungi, fungi that form a symbiotic relationship with trees and some plants perform many vital functions in an oak savanna.  They capture and supply vital nutrients, particularly nitrogen and phosphorus to their host plant, protect their host against pathogens and toxic substances and are a buffer against moisture stress.  ECM fungi secrete enzymes and acids that decompose organic matter. Each species exudes a  unique mix of enzymes and acids thus delivering specific nutritional benefits. In fact more than one ECM species may be associated with the same tree, even the same root tip. Therefore, a diverse population of fungi is very important to plant nutrition.

In my last blog I introduced the ECM fungi that fruit in early summer, usually by June 15.  Here in southern Iowa that season may last only two weeks or, if conditions are favorable,  may extend into July and early August .   Once  the early fruiting species of Russula, Lactarius and Amanita are established a succession of ECM species appears throughout the growing season.  Some of the later fruiting ECM fungi are species that don’t look like the typical mushroom. These include mushrooms in the genera Thelephora (Fiber fans and vases), Clavariadelphus (Earth clubs) and Ramaria (Corals).  Three species  commonly found at Timberhill are Thelephora palmata, Ramaria aurea, and Clavariadelphus americanus.

Solitary or scattered around white oaks fan-shaped   Thelephora palmata consists of  numerous purple-brown branches arising from a short (5/8″) common stem.  The spatula shaped branches terminate in whitish finely  fringed tips.  Commonly called Stinking Earthfan the tough leathery flesh has a strongly disagreeable odor. The entire fruiting body is 1.5 – 4″ tall and 1.5-2-5″ wide. It is usually associated with conifers but at Timberhill it is abundant under white oaks.  I have collected it as early as July 4 and as late as October 5.

Ramaria aurea, Golden coral

At Timberhill Golden coral fungus, Ramaria aurea is the most abundant of several coralloid fungi. Ramaria aurea, actually constitutes a collective species – a collection of  closely related species which are difficult to distinguish.  Resembling a yellow cauliflower the many branched mass of short often fused stalks arises from a white, bulbous base.  It is not unusual to find them growing in clusters among the sedges and forbs in late August and September.

Clavariadelphus americanus

Pestel shaped with wrinkled and channeled tips Clavairadelphus americanus (a similar species  C. pistillaris is associated with conifers) is variable in form and size.  Note the depressed tip of the  older specimen on the left  whereas the younger specimens have rounded tips.   Also note the white encrusted base.  Although this variety may fruit singly,  at Timberhill I usually find it  growing in clusters.

Little is known about the conditions that contribute to high ECM diversity in a woodland.  However, I have read  that mycorrhizas develop best in sites with over 25% full daylight, where nitrogen and phosphorus are somewhat deficient and where plant roots contain abundant soluble carbohydrates.  We know that thinning the Timberhill woodlands has provided adequate sunlight (canopy is now reduced to 50%) for ECM fungal diversity and the many vigorous oak trees supply the necessary soluble carbohydrates,  but we don’t understand the role of annual fire.   Annual fire releases nitrogen and phosphorus into the soil, increasing it’s concentration.    There is no deficiency of nitrogen or phosphorus,  yet Timberhill supports an abundant, highly diverse population of ECM fungi. It’s a conundrum.