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High Park

High Park

In recognition of the International Day of Forests, we're somewhat ironically featuring an image of a controlled burn in High Park (Toronto). Ironic, because High Park is managed to maintain its rare black oak savanna plant community. Savannas aren't considered forests in the literal sense, but instead defined as grasslands with significant woody plant components. Still, since savannas are in-between open grasslands and closed-canopy forests, I think using a savanna image can be forgiven. Today's photograph is courtesy of swampr0se@Flickr, and made on March 21 two years ago. Thank you for contributing, swampr0se.

I admire the willingness of the City of Toronto to permit and continue with prescribed burns in an urban area (article with additional photographs). We'd love to do something similar with our Garry Oak Meadow and Woodland Garden for long-term management, but our proposals have not been successful to-date.

When nature is no longer permitted to take its course, mimicking natural cyclical events such as fire is often necessary to maintain a semblance of the pre-existing plant community. Over the long-term, though, these practices require periodic re-assessments due to the complications of climate change or other factors (re: climate change, see: Holmes, KR et al. 2013. Biodiversity Indicators Show Climate Change Will Alter Vegetation in Parks and Protected Areas. Diversity. 5(2):352-373. doi:10.3390/d5020352 ). In brief, parks and protected areas boundaries are typically static. If established specifically for particular plant and/or animal communities (cf. parks established for geological features), the shift in vegetation due to climate change may no longer support the plants or animals that were the reason for the establishment of the protected area. Another complicating factor is when natural successional processes occur in parks and protected areas and threaten populations of rare species.

I know few specific details, but one local controversy is alluded to by Dr. Hans Roemer at the end of this interview with him about British Columbia's Ecological Reserves: A Conversation with Hans Roemer. Mt. Tzuhalem Ecological Reserve, where the interview took place, would likely be blanketed with Douglas-fir forest without a history of human intervention. However, (I speculate) due to a combination of human-induced fires by First Nations and later logging of established Douglas-firs, a Garry oak savanna plant community was successfully established in the area (and was, I think, one of the primary reasons for establishing the ecological reserve, as it contains a number of rare species including the endangered Balsamorhiza deltoidea). A suppressed fire regime (preventing both natural and human-induced fires) and successional processes have led to a relatively rapid incursion of Douglas-fir trees into the savanna areas, potentially threatening the rare species associated with the savanna.

To give a bit of context to the following comments, British Columbia's Ecological Reserves were established with the most restrictive protections of any protected area type, with some permitting research as the only allowable human activity. As Hans notes, management for rare species can sometimes conflict with other conservation goals (e.g., "hands-off and allowing nature to take its course"). He states: "No objections arose against 20 years of broom management in the Mount Tzouhalem ER but some [native] Douglas fir in-growth has been managed or started to be managed or stopped in this same ER and everybody is horrified. There is also an issue of what kind of Ecological Reserve (ER) it is. If this is a representative ER, then it could be left alone and there are no objections to going through successional changes. But it could be another ER where we have so many rare plants that you don't want these successional changes. Basically trying to arrest successional change is almost a futile attempt, but there are instances where it can be slowed down. The attempt to slow down Douglas fir in-growth met with very major objections."

Needless to say, unanswered questions remain as to how to address these situations. Is management appropriate or not? If so, does one manage to preserve components (e.g., for populations of rare species) or allow natural processes to take place? What will be the long-term effects of climate change on park and protected areas borders, particularly in instances where no or little buffer / transitional zones exist to provide corridors for biodiversity to shift with the accompanying vegetation changes (e.g., Riding Mountain National Park)? Many vexing questions.

For more on the International Day of Forests, see FAO's page on International Day of Forests, CITES International Day of Forests and the United Nations Economic Commission for Europe Forests for Fashion event.

6 Comments

What a striking photograph and thought-provoking write up! Many thanks, Daniel.

We used to burn savannah type forests in Florida in the winter time to get rid of trashy species that would turn the whole thing into a woodland that could not support semi wild cattle and pigs . Burning kept out the weedy species such as Sapium japonicum and Camphora cinnamonum that could easily take over and eliminate native species . Plus by burning the lush new growth of many herbaceous plants provided good forage for the semi wild farm animals. It was a win win situation for all concerned . Too much time is now spent not allowing this type of thing to happen with regularity which causes big problems.

Thank you for the photo, and for laying out the dilemma of conflicting nature values, when everyone has the goal of "conservation". Mankind has never been the best arbiter of which natural elements are most important, but Nature is almost as brutal as we are!

Thanks Daniel. Botany Photo of the Day is a special part of my day, and today it resonanted deeply. Vexing questions, indeed. Our local Natural Area sporadically "suffers" from unintentional fires set by partying individuals, but the changes in vegetation are generally not the "catastrophe" that most people see shortly after.

Burning is a very controversial problem here in the Missouri (USA) Ozarks where I live. "Controlled" burns are the right of the property owner. Problem? Burning to clear thatch from the hay fields is a good idea; the problem occurs due to the weather conditions that make for an "ideal" burn. Wind to move the fire quickly across the fields helps keep the fires from burning too hot- the heat damages the grass roots. The wind also moves the fire right on into the wooded areas the normally surround the hay fields.

The poor quality wooded areas in this region are a result of several factors: uncontrolled burning - "it controls the ticks"; long horned oak beetles - these invasive pests spread quickly because the burning kills the cedar trees and other fire sensitive species; and the horrible, horrible ice storm of 2007 - the breaking branches and trees falling sounded like a battlefield with cannon and rifle fire.

My take on this? The fires have damaged my tree inventory to the point of the trees having no financial value for timber; the area is dangerous in the extreme - a high wind last month pushed over large trees that looked mostly ok - but gave new meaning to the term "widow maker".

Burning has long, long term consequence to a natural area; I understand the "push back" from concerned citizens. I think the jury is still out on whether it works or not; man vs nature is a debate for the ages.

Thank you Daniel for bringing up this paradox. Our ecosystems are truly complex and finding a quick fix for such issues is not an option. Thorough observation, reflection, coherence and joint agreements with all stakeholders are a must. With our actions and climate change impacting in such an intense and vast array it's hard not to be discouraged at the cluelessness of a lot of our public policy makers. Thanks for disseminate this critical information.

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