Finally, snow. Enough to shovel.
But nature’s first attempt to dump a lasting white calling card on Toronto Friday might be too little, too late for local critters, bugs and plants that have evolved to tolerate frigid, snowy Canadian winters — not tennis-playing temperatures in December and January, which put their survival at risk.
“We don’t need statistics to tell us something odd is happening,” says Ryan Ness, manager of water resources at the Toronto and Region Conservation Authority.
His evidence, besides not needing boots until now? Ponds and streams usually covered weeks ago with solid ice — which protects resting fish with a stable environment buffered from very cold air and calorie-burning turbulence — are open water.
Odd, too, are the extreme freeze-and-thaw cycles of the past few two months. For this weekend, for example, forecasters were predicting thermometers would plunge into bitter below-zero range, then rocket back up to 5, with rain, on Tuesday.
Environmental experts say temperature swings stress out animals, invertebrates and plants used to one long winter freeze with a gradual warm, rainy melt into spring.
From wood frogs and salamanders to swallowtail butterflies and seed-bearing trees, species can die (lack of a snowy insulating layer means greater exposure to cold temperatures for meadow voles, for instance) or produce stunted offspring.
Trees, in particular, can be affected. While mild weather mitigates damage like broken branches from heavy ice, temperature swings can stunt reproduction at a time when provincial tree canopies, already considered too sparse, are being beefed up with millions of plantings.
“It’s funny, a lot of people will say, ‘Ha, this is great, it’s six degrees out today and I only have to wear a light coat,’ ” says forester Rob Keen, CEO of Trees Ontario, which helps to create and restore forests through seed collections when trees flower in spring.
“What we’ve seen in the last several years with the milder springs are the trees start to put flowers on earlier. Then we’ve seen frosts come in, killing the flowers and therefore, killing the seed production. It’s really detrimental to our restoration efforts.”
Okay, we’ve gotten this far without mentioning climate change — but hold that thought.
Periodic stretches of unusual weather are “quite within the tolerance” of creatures that have adapted to habitat changes over the eons, says Ralph Toninger, manager of habitat restoration at Toronto and Region Conservation Authority.
“It would really take something like successive years of warm weather, like if we had four straight winters of warm weather like this, before you’d really start to see an impact on trees and native wild life,” Toninger explains.
That brings us back to climate change. Is this Year One of a hotter, more disturbing pattern or simply a one-off occurrence?
Bill Parker, a research scientist with the Ministry of Natural Resources Ontario Forest Research Institute in Sault Ste. Marie and a climate change specialist, thinks the GTA is just one of many areas that may be starting a gradual warming.
“This is obviously an abnormally warm winter so far and I would say that this type of weather is consistent with what is projected to occur in the future under climate change,” he says.
“This will become more and more common, it’s believed.”
Until Friday, the GTA winter has been balmy experience. No snow crunching underfoot, no icy pellets sparkling in trees or prolonged freezes to magically transform ponds into skating rinks. Even Friday’s “storm” mellowed out when it hit, spitting out a few greasy centimetres of wet snow during the morning rush hours.
Without a substantial blanket of snow and ice, some types of fish are at risk for starvation, and their breeding areas can be damaged..
“When you don’t get a lot of snow buildup, what you don’t get in spring is the big rush of water that flushes out all the accumulated sediment and cleans up gravel in areas where fish spawn,” Ness says.
“It’s a pattern that fish are used to. Some fish spawn at that time of year (when water levels are high) so they go to where they need to go to spawn.
“Now, because a lot of precipitation falls as rain instead of snow, it runs off into water courses and increases flow almost all winter. So you get periodic small flows instead of one big one in spring.”
Christine Tu, a rivers and streams specialist at of the Toronto and Region Conservation Authority, says solid ice cover provides a low-turbulence environment for fish in medium-sized streams during winter months, when their metabolism decreases because food sources are scarce. Fish tend to group in deep pool areas of streams, feeding and moving very little, but without ice, there can be turbulence forcing the fish to move, Tu explains.
Another problem in this scenario is frazil ice, which is columns of swirling ice crystals that can reach down into a creek channel. Frazil ice can nudge fish from their quiet refuge pool, which makes them expend energy.
“You’ve got this double-edge sword,” Tu says, “not enough food and higher metabolism from movement they’re not used to and essentially, you have a starvation condition.”
(Fish can also die from a lack of oxygen. That’s usually in ponds where ice cover doesn’t break soon enough and fish have depleted the oxygen supply.)
Though the absence of snow can be a bountiful time for animals like deer which can forage freely, Toninger says it can also adversely affect a hunter-prey relationship.
Voles, for example, live under a thick snow covering to stay warm. Without it, the small rodents are exposed directly to cold air temperatures as they hunker down in forests.
“Even though it’s been a warmer winter, voles will find it more difficult (because) even if it’s -5, they’ll feel that full -5,” the biologist says.
Another vole domino: local great horned owls hunt voles by sound as they tunnel through the snow at ground level. The little guys are harder to pinpoint on bare earth, which also affects the visiting Arctic snowy owl.
Toninger says snowy owls, which have been spotted in Tommy Thompson Park along the Leslie Street Spit, come south now and then, probably prompted not by weather patterns but by a low lemming count up north.
And insects? Some in this area are highly cold-tolerant, but it’s unknown what repeated freeze-thaw cycles might have on their survival rates and the fitness of offspring, says Brent Sinclair, an assistant professor in the University of Waterloo’s department of biology.
The warmer weather seems to have tricked at least one bird that should be nibbling on juicy tropical treats right now instead of hanging around Toronto. Toninger says a palm warbler was spotted during a Christmas bird count he was on. It should have flown south in September but likely figured there was enough food and warmth here to last until spring.
“For a lot of wildlife, in an area like this, there’s a risk-reward,” Toninger says. “If there’s enough food to keep the fires going, they can forage at -35.”
Should there be a quick deep freeze and the warbler decides to fly south, what happens when it burns up precious calories as the temperature plummets?
“It probably made a bad decision and probably will not make it,” he says, noting it would likely freeze to death trying to fly across Lake Ontario.
Original Article
Source: Star
But nature’s first attempt to dump a lasting white calling card on Toronto Friday might be too little, too late for local critters, bugs and plants that have evolved to tolerate frigid, snowy Canadian winters — not tennis-playing temperatures in December and January, which put their survival at risk.
“We don’t need statistics to tell us something odd is happening,” says Ryan Ness, manager of water resources at the Toronto and Region Conservation Authority.
His evidence, besides not needing boots until now? Ponds and streams usually covered weeks ago with solid ice — which protects resting fish with a stable environment buffered from very cold air and calorie-burning turbulence — are open water.
Odd, too, are the extreme freeze-and-thaw cycles of the past few two months. For this weekend, for example, forecasters were predicting thermometers would plunge into bitter below-zero range, then rocket back up to 5, with rain, on Tuesday.
Environmental experts say temperature swings stress out animals, invertebrates and plants used to one long winter freeze with a gradual warm, rainy melt into spring.
From wood frogs and salamanders to swallowtail butterflies and seed-bearing trees, species can die (lack of a snowy insulating layer means greater exposure to cold temperatures for meadow voles, for instance) or produce stunted offspring.
Trees, in particular, can be affected. While mild weather mitigates damage like broken branches from heavy ice, temperature swings can stunt reproduction at a time when provincial tree canopies, already considered too sparse, are being beefed up with millions of plantings.
“It’s funny, a lot of people will say, ‘Ha, this is great, it’s six degrees out today and I only have to wear a light coat,’ ” says forester Rob Keen, CEO of Trees Ontario, which helps to create and restore forests through seed collections when trees flower in spring.
“What we’ve seen in the last several years with the milder springs are the trees start to put flowers on earlier. Then we’ve seen frosts come in, killing the flowers and therefore, killing the seed production. It’s really detrimental to our restoration efforts.”
Okay, we’ve gotten this far without mentioning climate change — but hold that thought.
Periodic stretches of unusual weather are “quite within the tolerance” of creatures that have adapted to habitat changes over the eons, says Ralph Toninger, manager of habitat restoration at Toronto and Region Conservation Authority.
“It would really take something like successive years of warm weather, like if we had four straight winters of warm weather like this, before you’d really start to see an impact on trees and native wild life,” Toninger explains.
That brings us back to climate change. Is this Year One of a hotter, more disturbing pattern or simply a one-off occurrence?
Bill Parker, a research scientist with the Ministry of Natural Resources Ontario Forest Research Institute in Sault Ste. Marie and a climate change specialist, thinks the GTA is just one of many areas that may be starting a gradual warming.
“This is obviously an abnormally warm winter so far and I would say that this type of weather is consistent with what is projected to occur in the future under climate change,” he says.
“This will become more and more common, it’s believed.”
Until Friday, the GTA winter has been balmy experience. No snow crunching underfoot, no icy pellets sparkling in trees or prolonged freezes to magically transform ponds into skating rinks. Even Friday’s “storm” mellowed out when it hit, spitting out a few greasy centimetres of wet snow during the morning rush hours.
Without a substantial blanket of snow and ice, some types of fish are at risk for starvation, and their breeding areas can be damaged..
“When you don’t get a lot of snow buildup, what you don’t get in spring is the big rush of water that flushes out all the accumulated sediment and cleans up gravel in areas where fish spawn,” Ness says.
“It’s a pattern that fish are used to. Some fish spawn at that time of year (when water levels are high) so they go to where they need to go to spawn.
“Now, because a lot of precipitation falls as rain instead of snow, it runs off into water courses and increases flow almost all winter. So you get periodic small flows instead of one big one in spring.”
Christine Tu, a rivers and streams specialist at of the Toronto and Region Conservation Authority, says solid ice cover provides a low-turbulence environment for fish in medium-sized streams during winter months, when their metabolism decreases because food sources are scarce. Fish tend to group in deep pool areas of streams, feeding and moving very little, but without ice, there can be turbulence forcing the fish to move, Tu explains.
Another problem in this scenario is frazil ice, which is columns of swirling ice crystals that can reach down into a creek channel. Frazil ice can nudge fish from their quiet refuge pool, which makes them expend energy.
“You’ve got this double-edge sword,” Tu says, “not enough food and higher metabolism from movement they’re not used to and essentially, you have a starvation condition.”
(Fish can also die from a lack of oxygen. That’s usually in ponds where ice cover doesn’t break soon enough and fish have depleted the oxygen supply.)
Though the absence of snow can be a bountiful time for animals like deer which can forage freely, Toninger says it can also adversely affect a hunter-prey relationship.
Voles, for example, live under a thick snow covering to stay warm. Without it, the small rodents are exposed directly to cold air temperatures as they hunker down in forests.
“Even though it’s been a warmer winter, voles will find it more difficult (because) even if it’s -5, they’ll feel that full -5,” the biologist says.
Another vole domino: local great horned owls hunt voles by sound as they tunnel through the snow at ground level. The little guys are harder to pinpoint on bare earth, which also affects the visiting Arctic snowy owl.
Toninger says snowy owls, which have been spotted in Tommy Thompson Park along the Leslie Street Spit, come south now and then, probably prompted not by weather patterns but by a low lemming count up north.
And insects? Some in this area are highly cold-tolerant, but it’s unknown what repeated freeze-thaw cycles might have on their survival rates and the fitness of offspring, says Brent Sinclair, an assistant professor in the University of Waterloo’s department of biology.
The warmer weather seems to have tricked at least one bird that should be nibbling on juicy tropical treats right now instead of hanging around Toronto. Toninger says a palm warbler was spotted during a Christmas bird count he was on. It should have flown south in September but likely figured there was enough food and warmth here to last until spring.
“For a lot of wildlife, in an area like this, there’s a risk-reward,” Toninger says. “If there’s enough food to keep the fires going, they can forage at -35.”
Should there be a quick deep freeze and the warbler decides to fly south, what happens when it burns up precious calories as the temperature plummets?
“It probably made a bad decision and probably will not make it,” he says, noting it would likely freeze to death trying to fly across Lake Ontario.
Original Article
Source: Star
No comments:
Post a Comment