The Verdict - Buckthorn Disease is Oat Crown Rust

I received a number of responses and all led me to Oat Crown Rust as the disease that has affected our buckthorn bushes. Some bushes are so badly hit now that they appear to be dying, or at least severely weakened.

Thanks to Drs. Andre, Bernard and Richard.

Richard Wilson,  Forest Program Pathologist with the Ontario Ministry of Natural Resources provided the following response.

 I am pretty sure what you are seeing is Oat Crown Rust, and buckthorn is the alternate host for this disease. This is a tentative identification for now and I will send you positive ID once our lab can confirm this.

The causal agent of this disease is Puccinia coronata, a serious disease on oats and as you have seen, can be very damaging to buckthorn too.  I have include a few websites here for your information.

http://ipm.illinois.edu/diseases/series100/rpd109/

http://www.apsnet.org/publications/imageresources/Pages/Volume87-8-1-3.aspx

http://www.omafra.gov.on.ca/english/crops/facts/ontweeds/european_buckthorn.htm



I now see the rust affecting buckthorn quite widely for many kilometres all around.

Buckthorn Blight

As mentioned in previous posts, our woodlot is infested from corner to corner by the two common invasive species of Buckthorn. These are the Common buckthorn [Rhamnus cathartica] and the Glossy buckthorn [Frangula alnus]. Both have also been referred to as European buckthorn in different sources, so I have decided to avoid that name altogether.

In the last week I have found a disease on both species of buckthorn that in some cases has completely defoliated the bush. The disease is quite widespread but still only infecting selective trees. It looks like a bright orange mould as pictured here.

I wonder what that is?

Black Bear sighting

This afternoon I spotted a small black bear [Ursus americanus] browsing and foraging along our road about 150 metres ~ 500 feet) away. It was about a head taller than our neighbour's full grown St. Bernard dogs. At first I wondered who's black dog that was, until I saw the thick legs and paws that immediately gave away its identity.

The Return of the Ant

After a much colder and snowier winter it seems that it took longer for the ant population to resurface. In the past we have experienced what likely is a carpenter ant. We have been diligently trying to get rid of it with varied levels of success. 

This year however we have found a very different ant. It had a black abdomen, a red torso and a larger black head. It has very aggressive mandibles. Based on some very basic research it most closely resembles Myrmica incompleta (lets call it MI). This species can be viewed at: http://www.insectsofalberta.com/myrmica-incompleta.htm

Last summer, I had observed ant wars between the carpenter ant and the Myrmica incompleta so the two species are evidently not compatible. Could it be that MI is now keeping the Carpenter ant away, a blessing in disguise.

  

The Snow Bunting is a Regular Winter Visitor to the open fields

Every winter we see the odd flock of snowbirds -- as we might call them -- fluttering across the snow covered farmer's fields out here in the country. They are actually snow buntings [Plectrophenax nivalis ]. Shown here is a flock that is just about to take flight after feeding for mere moments on some corn that was put out on the snow for the wild turkeys.

The Dogbane Beetle

Our third unusual and interesting bug for this week -- so far is this very attractive Dogbane Beetle [Chrysochus auratus] sitting still on our green bin (food compost recycling bin).

Stump Stabber

So whats with all the weird bugs. Over the last week I have found 5 unusual and very interesting insects. Today I also found a Stump Stabber [Megahyssa spp.] which appears like a wasp with a very long tail as shown in the photo.

This insect preys on eggs of a horntail -- another wasp that lays eggs in the wood of trees. It apparently 'sounds' the wood looking for horntail eggs to lay its eggs in.  This is likely the [Megarhyssa macrurus] as shown on Wikipedia.

Dog Day Cicada

Today was one of those hot dog days of summer when you can hear the high pitched buzz of the "heat bug" as we used to call it as kids. In my 60 years I have never seen a cicada until today. While climbing the TV tower to do some work, I found this green Cicada on the roof next to the stabilizing bar of the tower. And there was also quite a buzz in the trees above.

According to Bugs of Ontario, by John Acorn, ISBN 1-55105-287-3, this is the Dog Day Cicada [Tibicen canicularis.]

Bear Tracks

Sunday, while clearing some trail we came across this bear track of a fairly young bear. Relatives say that they have seen a small 300 lb or so bear near here. There is only one species of bear here which is the black bear.

A small white moth in the woods

Walking through the woods one occasionally stirs up a small white moth like the one pictured here. I have identified this one as Pale Beauty (Campaea perlata). A nearly all white moth with black beads for eyes. It is quite an evaisive moth and quite hard to capture. This moth was found dead on the forest floor and stood out quite strikingly agains the dark background.

Oak Trees are tolerant to Juglone toxin (Butternut and Black Walnut)

This woodlot is entirely forested but for a few open clearings. Clearings can always be found about the dead butternut stands, which one can assume were created by the juglone toxin produced by the butternut trees when still living. I am looking for sites to plant the red oaks that have germinated. Red oaks are partially shade tolerant so clearings are ideal for planting. The question then is if the oaks are tolerant to the juglone toxin which apparently they are. According to http://pubs.cas.psu.edu/FreePubs/pdfs/xj0039.pdf the following list of trees are resistant to juglone toxin. So far 60 acorns have germinated and to date I have planted 52 in various clearings.
  

Most maples except silver maple (Acer spp)

Eastern Red Cedar (Juniperus virginiana)

Serviceberry, Shadblow (Amelanchier)

Yellow Poplar (Liriodendron tulipifera)

River Birch (Betula nigra)

Hickory (Carya spp)

Virginia Pine (Pinus virginiana)

Black Cherry (Prunus serotina)

Flowering Dogwood (Cornus florida)

Oak species (Quercus spp)

Dogwood (Cornus alternifolia)

Staghorn Sumac (Rhus typhina)

Hawthorne (Crataegus spp)

Black Locust (Robinia pseudoacacia)

American Beech (Fagus grandifolia)

Arborvitae or Eastern White Cedar (Thuja occidentalis)

White Ash (Fraxinus americana)

Canada Hemlock (Tsuga Canadensis)

Honeylocust (Gleditsia triacanthos)

American Elm (Ulmus americana)

Carolina Silverbell (Halesia caroliniana)

Blackhaw Viburnum (Viburnum prunifolium)

Further Acorn Tests and Acorn Gemination

The collection of acorns that were described in earlier posts, were bagged into ziplock bags and stored over winter in the fridge to be "stratified" as they call it. By now all the weevil worms would have emerged and some were still found in the bottom of the fridge. They chewed their way through the plastic bags. The surviving acorns were again float tested and only 130 finally survived. These were then placed on a layer of earth and covered by wet newspapers. in about a week the acorns started to produce a tap root as pictured here.

Sorting Acorns by Floating and Sinking

It turns out that floating acorns is a very quick way of selecting the good from the bad. The bad acorns float and the good acorns sink. In fact after floating them I found that the majority of the remaining acorns very unfortunately floated and failed the float/sink test. So how effective is this test anyway? I decided to dissect a number of good and bad acorns to see really how effective this test is. Results are shown in the following photos.

Floaters

Evidently all the floaters were bad. 

 

Sinkers 

The sinkers were evidently in generally very good condition. However a number of the sinkers still had larvae exit holes so this test is not 100%.

At some point the larvae should stop emerging so at that point we should be able to determine that all remaining acorns are clean. I can't store the nuts in a plastic bag if there are any larvae remaining.

The number of remaining acorns was sufficiently low to count them and 370 acorns are left. That is a loss of  71% of the nuts or a survival rate of 29% and I don't think it is over yet and more losses are expected.

Acorn Update

Red oak acorns need to be stored in a cool place for a month or so before planting. so I stored the acorns in a plastic bag in the beer fridge cooler.

Larva found of  Acorn Weevil

Much to my dismay, I found many larvae at the bottom of the fridge which tweaked my curiousity. It turns out that even though the acorns were selected many were still contaminated by eggs and the emerging larvae of the Acorn Weevil [Curculio glandium.] Apparently the larvae fall to the bottom of the bag and then chew their way through the plastic thus ending up at the bottom of the fridge. In nature they fall to the ground and then bury into the earth. I found that many of the acorns had the typical exit holes. So I will have to sort the good from the bad acorns one more time.   

A Friendly Thrush

Last week while clearing some trail and making lots of chainsaw noise I was surprised to see this thrush hopping around nearby among the leaves gleaning the forest floor for bugs and seeds. It seemed quite unperturbed by my ruckus, which for a thrush should be quite unusual. I am having a challenge trying to identify if this is a hermit thrush, or wood thrush which are the more common thrushes in the area. Anybody know? I am even thinking it might be a grey cheeked thrush. 

Not enough spots for a Wood Thrush

A Gift of Acorns

Bert, a colleague in the Ontario Woodlot Association offered me a large quantity of red oak acorns. While there are many Burr Oaks, I have no red oaks on this property and welcome the idea of adding some more diversity on the woodlot. I have very large areas of concentrated ash trees and fearfully anticipate that the emerald ash borer will devastate those areas so diversity should pay off. Bert advised me that the acorns had already been floated and the floaters have been removed so the thought was that what remains are pretty well in good condition. To get an estimate of the number of acorns, I weighed 100 acorns and then weighed the whole box and by extrapolation calculated an estimate of 1270 acorns after taking out the weight of the box.

Tent Catepillars in our Burr Oak by the House

Red Maple Saplings are hit hard by White-tailed Deer

During my childhood, the red maple [Acer rubrum] was a common tree in the clay based swampy woods that was part of my playground near my home in the Montreal suburbs; and thus I have some memorable attachment to the species. It also has a very lovely display of fall colour. For that reason I was happy to see one red maple sapling west of the house and it has been attempting for the longest time to grow, but every fall and winter it would get the top nipped off by white-tailed deer (Odocoileus virginianus). This is somewhat frustrating since there are so few red maples around. Cutting the top or leader of this tree doesn't kill it but severely stunts its growth. It then has to start over again to find a new leader. The only good thing is that in the mean time it keeps building up its root system in anticipation for a chance to shoot out. Once the tree is about 6 feet tall the leader is harder to reach and it should be safe from deer browsing.

To add to the diversity of this woodlot, in May I bought and planted several dozen young red maples from the Ferguson Forest Centre Nursery in Kemptville, Ontario. Thinking that the deer would have ample supply and variety of greenery for food at this time of year, I didn't bother taking any preventive measures yet to protect these saplings from the deer. Alas on my recent inspection of the new arrivals I was much dismayed to find that at least half of the new saplings have already been munched on and topped by deer as seen in this photo. The satchel is placed in the background to provide contrast.



The deer must really favour and be able to sniff out the red maple since many of them were obscured among other greenery. It was quite surprising how they singled out this particular plant. This is discouraging for the success of red maples in the area since all sapling are threatened this way. Instead other much more successful plants and often undesirable invasives like buckthorn just merrily grow and carpet the area untouched by deer. The deer in this case is its own worst enemy in this mix leaving an undesirable landscape for them as well as me.

I immediately started to protect the trees, and cut strips of Bounce fabric softener sheets which deer don't like and attache them to the top branch, or leader, of what remains of all the new saplings.

For preferred deer foods: http://www.michigan.gov/dnr/0,4570,7-153-10370_12148-61306--,00.html

Balsam Fir

As a youth I was always intrigued by the Balsam Fir Tree [Abies balsamea]. The bark of this tree typically produces blisters containing an oily gum. Back in the 60's we often had to entertain ourselves through bouts of boredom as there was very little in the way of electronic gadgets then. So as kids one of the activities we did was break a small twig, poke one end of it into the gum blister and then place the twig in the water of a stream or ditch. The twig would then be propelled by the change in surface tension on the water which was sort of entertaining and even mystifying. This was admittedly only a brief diversion, since we with short attention spans then probably had to run off and pursue imaginary forest spirits, or play hide-and-go-seek or something.

Our woodlot has a very limited diversity of trees dominated probably by white spruce which was planted in the abandoned fields and white cedar and ash which naturally regenerated everywhere else it seems. To add to the mix I was advised by a colleague woodlot owner that his property is over run by Balsam Fir so I offered to relieve him of some of the seedlings. I since planted 95 Balsam firs from that event.

This spring I have also ordered and planted Balsam firs, Eastern Hemlocks and Red Maples bought from the Ferguson Forest Centre. All three species are virtually nonexistent here.

There is an excellent website that gives pretty detailed information on tree species of Norther Ontario which is: http://www.rook.org/earl/bwca/nature/trees/abiesbal.html

Some of these northern species are also common here and I cut and pasted a portion of the data on Balsam firs below.

• Soils mostly acid, though tolerating a wide range of soil acidity, on textures from heavy clay to rocky soils, underlain by a variety of materials, including gneiss, schist, slate, sandstone, and limestone. Most common on cool, medium to wet sites with soil pH of 5.1-6.0.
• Late successional or climax species. Replaced after fire by pioneering hardwoods and conifers, such as Aspen (Populus tremuloides), Paper Birch (Betula papyrifera), Balsam Poplar (Populus balsamifera), Jack Pine (Pinus banksiana), and Black Spruce (Picea mariana), it is generally absent for the first few postfire decades.
• Shade tolerant with less demanding seedbed requirements than many associates, it readily establishes under a canopy of hardwoods and conifers. Usually common in understory beneath pines, aspen, and paper birch. In the continued absence of fire, may assume dominance as the canopy of the pioneering trees begins to die off.
• Subject to windthrow, especially on shallow wet soils.

Buckthorn Succession - Something New

While attempting to find suitable locations for tree planting, I thought I would plant some shade-tolerate trees like hemlock and balsam fir in areas that are completely overtaken by Glossy buckthorn [Rhamnus Frangula] with the hopes that the trees would in time shade out and out compete the buckthorn. Much to my surprise and delight I already found Eastern white cedars [Thuja occidentalis] growing among the buckthorn as seen in this photo. This cedar is also known to be shade tolerant and appears to be doing well even in the heavy shade of the buckthorn. This is so encouraging. The losing battle with buckthorn can be exasperating at times.