Prescribed Burns Rejuvenate Native Grasslands

This black oak savannah is near Windsor, ON.

by Helen Mason

For more than a decade I lived on a small farm at the extreme eastern end of the Oak Ridge Moraine. When pioneers first arrived in southern Ontario, this area was covered with tall grass prairies and oak savannah. The sandy loam soils were ideal for farming. By the time Catharine Parr Traill and her family arrived in 1832, the area where I lived already included settled farms. Much of the grassland had been cultivated.

Much of the former prairie is now farmland and pastureland.

In an effort to rejuvenate some of the original flora and fauna, the Nature Conservancy of Canada and Alderville First Nation plan prescribed burns around the end of April each spring. Exact timing depends on weather. Too much wind can make it hard to control fires.

Controlled burns play an important role in tall grass prairies and black oak savannahs, especially ones that have introduced European grass species. They allow native plant species to grow again.

This prescribed burn is in the Cypress Hills, SK.

Many native species disappeared because they are warm-season species that start to grow later than the European species brought by early farmers. European agricultural species tend to be cool-season species that start earlier in the season. They also have a longer growing season. As a result, they out-compete the warmer season native species.

A fire in early spring helps tall grass prairies and oak savannahs in several ways. It increases the percentage of oak in hardwood stands because oak is more fire-tolerant than maple and beech.

Indigo buntings inhabit weedy fields.

It burns the introduced grass species, which may have already started their spring growth, and slows the growth of woody vegetation. The native prairie grasses, which are deep-rooted and start a little later, are not harmed by such a fire. In fact, burns clear vegetation right to soil level. This allows plenty of sunlight for sun-dependent plants.

 

After a burn, the blackened soil quickly absorbs heat from the sun. The warmed earth encourages seed germination. Charred vegetation provides a handy fertilizer for the new growth. The new grass growth provides nesting material and sites for grassland species.

The savannah provides habitat for the endangered Eastern hognose snake.

Bioblitzing: A New Outdoor Entertainment

by Jan Thornhill

A bit more than a month ago my friend Tony invited me to help with the fungi portion of the 2014 Ontario Bioblitz.

"Bioblitz?" I said. "What the heck is a Bioblitz?"

When documenting fungi for a Bioblitz, you document all fungi, like this
Rhytism americanum, a tar spot that attacks native maples. 

A Bioblitz, it turns out, is a pretty cool event. It's an intense 24-hour study of a specific area's flora and fauna during which professional biologists lead teams that document all the living things they can find. It's essentially an exercise that highlights biodiversity. Though ornithologists and entomologists worked through the night looking for owls and moths and other nocturnal critters, since I was working with the fungi team, led by Jean-Marc Moncalvo, Senior Curator of Mycology at the Royal Ontario Museum, and fungi don't move around a lot, we didn't have to forgo sleep and focussed on collecting samples when they were visible—during daylight hours.

A fresh specimen of Gloeoporus dichrous. During the Bioblitz,
we only found a dried up one from the previous fall.

Bioblitzes are a perfect introduction to citizen science, since the public is usually encouraged to help. This year's May 25 event was focussed on the Humber River Watershed. There were lots of activities, including guided walks with professional biologists, batbox-making workshops, and field-sketching workshops. But the main event was documenting species, and the main event was wonderfully successful. From the 24-hour period, a total of 1,563 species have been identified so far, including 109 arachnids, 121 birds, 27 fish, 500 insects, 100 non-insect invertebrates, 18 reptiles, 94 lichens, 21 mammals, 78 mosses, 450 plants, and 45 fungi.

That's a millimetre rule behind these fuzz-covered Lasiosphaeria ovina.

The fungi numbers were low—we only found about half the number of species documented on each of the first two Ontario Bioblitzes in 2012 and 2013, but we have an excuse: May 25 is never a prime fungi-finding time, on top of which there'd been almost no rain for two weeks.

The honey locusts growing in our Bioblitz fungi-hunting area were treacherous! 

Undeterred, Tony and I explored a scrubby woods not far from the McMichael Gallery parking lot. It was so dry that, at first glance, it looked as if we weren't going to find anything at all other than a few gnarly, desiccated, insect-ravaged tree-growing fungi from the previous fall (they still counted, though!). But once we got down on our hands and knees, (and wiped off the blood from being stabbed by the wicked thorns of honey locust trees), and started turning over fallen branches, we found a few interesting specimens. Admittedly most of these were tiny interesting specimens, but they included some exquisite, snow white, mini stemmed cups bejewelled with dew, and a quite beautiful parasitic rust fungus (featured in my fungi blog post, here), as well as a single, charismatic, and delectable, morel. 

We had to use a microscope to nail down the identity 
of these half-millimeter beauties, Lachnum subvirgineum.

It was fun. It's always fun looking for fungi. It's like a treasure hunt. So I was delighted to get an invitation to attend another Bioblitz. This one is at the Alderville First Nation Black Oak Savanna, located southeast of Rice Lake. The savanna is very special place, Canada's easternmost prairie habitat and one of the most endangered plant communities in Ontario, where the primary goal is to restore land that has previously been used for agriculture by planting and nurturing native tall-grass prairie species.  

Because there are a number of species at risk at the Alderville Black Oak Savanna site, this Bioblitz is not geared towards the public's participation in the same way that the much larger Ontario Bioblitz is, but if you'd like to visit the site you can book a tour by calling 905-352-1008. They also have programs and resources for schools, as well as an annual eco-friendly "Prairie Day," which, this year, is on Saturday, September 10. 

*You can read about a few interesting things we found during the Alderville Bioblitz on my Weird & Wonderful Wild Mushrooms blog.