Scientists say the province's average temperatures and precipitation levels are projected to continue rising over the next 50 to 100 years, and extreme weather events such as heavy rainfall or very dry years are likely to become more frequent as well.
Experts say ongoing research indicates the most dramatic change projected for Alberta will be expansion of grasslands at the expense of other ecosystems, with the boreal forest, and its inhabitants, projected to suffer the greatest loss.
Some wildlife, they say, will fare much better than others, noting coyotes are likely to adapt to climate change, but pikas that live high in the mountains of Alberta may have a tougher go.
“Things are going to change and resistance is futile,” said wildlife biologist Chris Shank, who is co-author of a report on Understanding and Respecting the Effects of Climate Change on Alberta's Biodiversity, during a recent presentation for the Bow Valley Naturalists.
“We have to accept that the landscape is going to look different to our grandchildren and great grandchildren.”
Research indicates the provincial mean annual temperature has increased by 1.4 C over the past 100 years, with much of that increase occurring since the 1970s from increases in winter and spring temperatures.
The trend is projected to continue over the next 100 years, even if greenhouse gas emissions stabilize. Alberta's mean annual temperature could increase by at least 2 C by the end of the century, possibly be as much as 4-6 C higher, according to projections.
In addition to warming temperatures in Alberta, there's expected to be an overall increase in provincial annual precipitation, by about 10 per cent on average. However, precipitation is more difficult for scientists to predict than temperatures.
Shank said predictions are based on an average of 19 global climate models and on the assumption greenhouse gas emissions will continue to increase.
“These are assumptions, but the trend is clearly there. It's warming up,” said Shank, who, prior to 2006, was the provincial biodiversity specialist for Alberta Fish and Wildlife.
“Even though there may be an increase in precipitation, it's going to fall in a smaller number of intense events, with all the ramifications that we're all aware of.”
Guy Greenway, a senior planner with the Miistakis Institute, worked with Shank on the Biodiversity Management and Climate Change Adaptation Project, which focused on developing knowledge and tools to support the management of Alberta's biodiversity in a changing climate.
Greenway, who works in the fields of conservation planning, conservation communication and private land conservation, said a changing climate will have significant implications for species that rely on Alberta's natural systems – both human and wild.
He said he's hopeful the varying levels of governments will adopt the so-called precautionary principle when dealing with the implications of climate change.
“Our message is the precautionary principle. The language we use is around risk management and costing. We found the precautionary principle would resonate when it's put into that context. What's the cost of inaction?” said Greenway.
“But putting it in terms of risk management and costing, which, for a lot of people, including me, is hard, and one danger of that is starting to turn this conversation purely into an economic conversation.”
Projections for Alberta's major ecosystems indicate changes size and distribution under different climate change scenarios, in particular an expansion of grasslands and a decline of the boreal forest.
Under one model, grasslands were predicted to expand northward into parkland this century, while under a hotter model, the predicated expansion of grasslands was more rapid until, by the end of the century, the ecosystem covered most of the province.
A hotter climate model projects boreal forest will disappear completely by the end of the century, except for a remnant area at higher elevations in areas such as the Caribou Mountains, Birch Mountains and Swan Hills area.
“In order to turn into grasslands, the forest basically has to be destroyed by either forestry, or bugs, or wildfire,” said Shank. “It might not be quite that fast, but the trend is clear – the boreal forest is in trouble in Alberta over the long-term.”
Researchers have also been looking at what Alberta's changing ecosystems will mean for species, and for the first time, assessed the relative vulnerability of 173 species of amphibians, birds, insects, mammals and plants to climate change over the next 40 years.
As part of an assessment, the Ord's kangaroo rat, an endangered species in this province, was ranked number one, while the American pika, found high in the mountains of Alberta, ranked second.
The assessment showed reptiles and grassland amphibians were among the species most at risk to a changing climate, noting the Great Plains toad is highly vulnerable, in part because of its reliance on ephemeral wetlands for breeding.
In general, wide-ranging and common species like coyotes were ranked lower in terms of their vulnerability, while birds typically were considered as less vulnerable because of their ability to fly to new areas.
The harlequin duck, however, was ranked as moderately vulnerable. Although the colourful sea duck can fly to areas where the habitat and climate are suitable, the preference of this species is for cool mountain streams.
Species at risk scored a greater vulnerability, too, mainly because of their restricted ranges and already small populations.
For example, burrowing owls, an endangered species which nests in burrows in the flat, treeless grasslands, are fairly vulnerable to climate change, in part because of the effects of extreme weather, including heavy rainfalls and storms.
The long-term survival of the burrowing owl is considered uncertain considering the expected increase in extreme heavy rainfall events within its breeding range as climate change progresses.
Shank said not all of Alberta's species will experience climate change to the same degree, and not all will be able to adapt equally well.
He said the challenge is to better understand which species may be most affected by climate change, either negatively or positively.
“Something like the coyote is going to do really well under climate change,” said Shank. “Something like the Great Plains toad is likely to be in a bit of trouble in the future.”
The future of birds has also been looked at.
By the end of the century, most of Alberta's boreal songbirds are projected to decline in numbers, and expected to shift their distribution northward and into areas of higher elevations.
Bay-breasted and Tennessee warblers were projected to shift almost entirely out of the province, while birds such as Ovenbird and Canada warbler were generally projected to adapt to a smaller range in the central part of the province and into highland regions.
“The Tennessee warbler currently has its highest density around the tar sands, but the expectation is by the end of the century it's essentially gone from Alberta,” said Shank.
“It's not like they're going to go extinct, but they are going to move up into the Northwest Territories. Is that so bad? I don't know.”
Mountain species such as Varied thrush and Townsend's warbler were generally projected to higher elevations, while grassland species like Savannah sparrow and Clay-coloured sparrow would likely expand into the current boreal region.
“Different species are going to respond differently to climate change,” said Shank.
Shank said more than 1,540 plant species have been looked at.
“A quarter of them are going to lose almost all their range in Alberta, but a third of them are going to more than double, so there's going to be some winners, there's going to be some losers,” he said.
“A lot of the province is going to show an increase in the number of plant species, but the big losers are going to be in the mountains. We could lose many as 200 plant species in the mountains.”
Research has also been done on the potential effects of climate change on invasive plants coming into Alberta including several wide-ranging species that aren't here yet.
Shank said Giant Knotweed, Salt Cedar, and Alkali Swainsonpea have been identified as three high-risk invasive plants for Alberta under future climate conditions.
“Those three species are a major concern, and highlight several areas in southern Alberta at greatest risk of new invasions, and several areas in southwestern Alberta are most at risk from invasion of these species,” he said.
There are also a series of field experiments, including on rare plants such as the northern blazing star, by way of a controversial conservation tool called ‘assisted migration.'
The plants were dug up from their natural environment, mostly found in the northern part of the parkland area, and moved to various areas of the province both south and north of the plant's current range.
The research, done in conjunction with the University of Alberta, looked at several factors, including looking at survival, height and florets, as well as seed establishment and emergence, among many other things.
“The fitness was much higher in the northern site, which indicates maybe the current distribution of northern blazing star is already out of step with climate change. It indicates, in the future, they're going to be in real trouble,” said Shank.
“Birds can fly easily, but many plants can only disperse a few metres a year, and not be able to keep up with climate change. One way is to possibly move them to new locations, but that's very controversial because we're basically introducing a new species.”
Shank said it is vitally important to continue to monitor Alberta's species.
“One of the most important things we can do to help species respond to climate change is make sure that we do not wipe them out another way first,” he said.
Wednesday, Mar 16, 2016 03:28 pm
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