From the University of Arizona
Warming climate pushes plants up the mountain
Comparing plant communities today with a survey taken 50 years ago, University of Arizona-led research provides the first on-the-ground evidence for Southwestern plants being pushed to higher elevations by an increasingly warmer and drier climate
In a rare opportunity to directly compare plant communities in the same area now with a survey taken 50 years ago, a University of Arizona-led research team has provided the first on-the-ground evidence that Southwestern plants are being pushed to higher elevations by an increasingly warmer and drier climate.
The findings confirm that previous hypotheses are correct in their prediction that mountain communities in the Southwest will be strongly impacted by an increasingly warmer and drier climate, and that the area is already experiencing rapid vegetation change.
In a rare opportunity to obtian [sic] a “before – after” look, researchers studied current plant communities along the same transect already surveyed in 1963: the Catalina Highway, a road that winds all the way from low-lying desert to the top of Mount Lemmon, the tallest peak in the Santa Catalina Mountains northeast of Tucson.
“Our study provides the first on-the-ground proof of plants being forced significantly upslope due to climate warming in southern Arizona,” said Richard C. Brusca, a research scientist in the UA’s department of ecology and evolutionary biology who led the study together with Wendy Moore, an assistant professor in the UA’s department of entomology. “If climate continues to warm, as the climate models predict, the subalpine mixed conifer forests on the tops of the mountains – and the animals dependent upon them – could be pushed right off the top and disappear.”
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  IMAGE: Today, living alligator juniper first begin to make an appearance on upland slopes of the Catalina Mountains at around 5,000 feet elevation…
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The study, published in the journal Ecology and Evolution, was made possible by the existence of a dataset compiled 50 years ago by Robert H. Whittaker, often referred to as the “father of modern plant ecology,” and his colleague, William Niering, who catalogued the plants they encountered along the Catalina Highway.
Focusing on the 27 most abundantly catalogued plant species, Brusca and Moore discovered that three quarters of them have shifted their range significantly upslope, in some cases as much as a thousand feet, or now grow in a narrower elevation range compared to where Whittaker and Niering found them in 1963.
Specifically, Moore and her team found that the lowermost boundaries for 15 of the species studied have moved upslope; eight of those species now first appear more than 800 feet higher than where Whittaker and Niering first encountered them. Sixteen of the studied species are now restricted to a narrower band of elevation, the researchers noticed. As far as the plants’ upper elevation limits were concerned, the researchers observed a mixed trend: They found it to be higher for four species, lower for eight species and unchanged for 15.
For example, in 1963 Whittaker and Niering recorded alligator juniper as a component of upland desert and grassland communities in the Catalina Mountains, beginning at an elevation of just 3,500 feet. Today, one has to drive to the 5,000-foot elevation marker on the Catalina Highway to see the first live alligator juniper trees in upland habitats.
According to the authors, the main point emerging from the study is that plant communities on the mountain were different 50 years ago because plant species do not necessarily move toward higher elevations as a community. Rather, individual species shift their ranges independently, leading to a reshuffling of plant communities.
The scientists in this multidisciplinary group gathered the data during fieldwork in 2011, and included UA postdoctoral fellows and professors from several programs, including the UA departments of entomology and ecology and evolutionary biology, the Center for Insect Science and the Institute for the Environment, as well as botanists from the Arizona-Sonora Desert Museum.
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 IMAGE: …However, below 5,000 feet, hundreds of dead juniper attest to a former range much lower down on the mountain, reflecting cooler and wetter years of the past.
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Based on studies done by other scientists, including UA researchers, the researchers believe that a “thirstier” atmosphere might be a major driver behind the shifts in plant distribution, possibly even more so than lack of precipitation. As the atmosphere becomes warmer and drier, plants loose more water through their leave openings and become water-stressed.
According to the authors, the results are consistent with a trend scientists have established for the end of the Pleistocene, a period of repeated glaciations that ended about 12,000 years ago. By studying the distribution of plant seeds and parts preserved in ancient packrat middens, for example, paleo-ecologists have documented that as the climate warmed up, plant communities changed profoundly.
“In southern Arizona, some species moved north to the Colorado Plateau, others moved up mountain slopes, and others didn’t move at all,” said Moore, who has been collecting data on ground-dwelling arthropods, plants, leaf litter, weather, soil, and other ecological factors in the Santa Catalina Mountains for the Arizona Sky Island Arthropod Project based in her lab.
The Sky Islands encompass an “archipelago” of 65 isolated mountain ranges rising from the surrounding low-elevation desert and desert grassland in an area that constitutes the only major gap in the 4,500-mile long North American Cordillera, which runs from northern Alaska to southern Mexico. The Sky Islands, often referred to as the “Madrean Sky Islands,” span this gap in southeastern Arizona, southwestern New Mexico and northeastern Sonora, Mexico. They include the Santa Catalina Mountains, the Pinal Mountains and the Chiricahua Mountains.
Research publication: http://onlinelibrary.wiley.com/doi/10.1002/ece3.720/abstract
JimS! You owe me a new computer! Coffee and keyboards DO NOT MIX! “…pushed off the top”!!! ROTFLMAO!!! That quote from a peer reviewed paper is on the same level of intelligence as islands that tip over.
My guess is that CO2 fertilization is the cause – making the junipers more robust on the higher slopes, but less competitive with other plants that benefit even more from the added CO2 at lower elevations. Since added CO2 reduces moisture loss, it also reduces the heat lost through transpiration (i.e.., required to evaporate the water), making the plants more cold tolerant as well as more drought tolerant.
I suppose it has absolutely nothing to do with the fact that there were lakes and ponds in southern Arizona 75 years ago, and I don’t mean the cement pond variety. While you’re at it you might take [note] of those documented and surveyed deep cracks in the basins from ground water retreat. Those are well known changes.
I have no reason to be skeptical about plants moving up and down the sides of mountains due to changes in climate. I would expect they’ve been doing this since the beginning of plants.
There is nothing new here, but to alarmists out there its like manna from heaven.
I thought global warming meant more water vapour. I thought more co2 in the atmosphere made plants more drought resistant. Arrrrrggghhhh! Well, I’d better get back to some quick online learning I guess.
@Pamela Gray:
“JimS! You owe me a new computer! Coffee and keyboards DO NOT MIX! “…pushed off the top”!!! ROTFLMAO!!! That quote from a peer reviewed paper is on the same level of intelligence as islands that tip over.”
I chuckled some at that quite too. I guess it was put in there to attract the reader’s attention to read on. And I agree, it is on the same level as “islands that tip over,” and another one: “The solution to preventing our coastal cities from flooding due to climate change is simply dregging their harbours.”
Yawn…
Just another data point showing Climatology has the same predictive powers as Botany.
15 [of 27] of the species studied have moved upslope
Did any move downslope?
eight of those species now first appear more than 800 feet higher than where Whittaker and Niering first encountered them.
And what was the largest move downslope?
[16 of 27] of the studied species are now restricted to a narrower band of elevation,
That would be the 15 that moved their lower bounds higher, and 1 that moved its upper bound lower by more than the lower bound moved? It is not an independent statistic.
As far as the plants’ upper elevation limits were concerned, the researchers observed a mixed trend: They found it to be higher for four species, lower for eight species and unchanged for 15.
No statistically significant change.
Focusing on the 27 most abundantly catalogued plant species.
The 27 most abundant in 1963. Are these the most abundant today?
What about changes in abundance?
What about changes in “Land Use”. The term is not in the abstract.
I am not sure that I can follow their reasoning. They have a map of plant location along a highway that climbs a mountain. The map was created fifty years ago. They walk the highway, create a new map, and compare the two maps. The results of the comparison are:
“Focusing on the 27 most abundantly catalogued plant species, Brusca and Moore discovered that three quarters of them have shifted their range significantly upslope, in some cases as much as a thousand feet, or now grow in a narrower elevation range compared to where Whittaker and Niering found them in 1963.”
OK, but where are the plants? Are we really talking about a survey of plants near the road? Apparently, we are:
“In a rare opportunity to obtian [sic] a “before – after” look, researchers studied current plant communities along the same transect already surveyed in 1963: the Catalina Highway, a road that winds all the way from low-lying desert to the top of Mount Lemmon, the tallest peak in the Santa Catalina Mountains northeast of Tucson.”
For what reason did the researchers select this area along the road for their research? Because of the old map? That might be a good reason for creating a travelogue or musing on the contributions of the eminent scientist, Robert Whittaker, who created the original map, but why would anyone trained in science believe that the area is not simply peculiar and incapable of serving as the basis for scientific research?
The researchers conclude that a warming climate (might have) caused the change:
“Based on studies done by other scientists, including UA researchers, the researchers believe that a “thirstier” atmosphere might be a major driver behind the shifts in plant distribution, possibly even more so than lack of precipitation. As the atmosphere becomes warmer and drier, plants loose more water through their leave openings and become water-stressed.”
The next question that must be addressed is whether the climate in this area is warmer and drier. I do not see that they did empirical research on this matter. After that question, there comes the question whether any other change might explain the plant migration. I do not see that they did empirical research on this matter. Their imagination for empirical research seems to be wearing blinders. All they did is find a change in plant distribution at a questionable site that is consistent with their hypothesis of a warming climate. Unfortunately, it is also consistent with any of a thousand different explanations, the most obvious being that the road up the mountain is very popular. Why this sort of thing gets called science escapes me completely.
Seems the plants are adapting better than the alarmists.
Wasn’t there an equally lame ‘study’ done in Spain a couple of years back? Wasn’t the resolution in the handful of meters? Like, I mean, who cares?
@Chad Wozniak 9:55 am
My guess is that CO2 fertilization is the cause – making the junipers more robust on the higher slopes, but less competitive with other plants that benefit even more from the added CO2 at lower elevations.
Competitive pressures. Very astute. Seeing the changes in the distributions of plants would be essential, but was that data collected in 1963, or was it just the collection of the outlier lowest and highest occurance?
I don’t know about the Santa Catalina Mountains but here is Europe and Greenland according to Dr. Michael Mann.
Simply reverse the first two letters of altitude and you have latitude. Going up the side of a mountain is similar to going toward the poles. Von Humboldt recognized this in the mid-nineteenth century with his climate zones going up the mountainsides in South America.
I published a chapter in the book “Climate Since 1500 AD.” edited by Bradley and Jones. It led to my only CRU leaked email reference by Jones who said I was doing good work then and he couldn’t understand why or where I went wrong. Although I only referenced the article in my chapter, a part of my research involved assessing the movement of the tree line in central Canada by using an accurate map produced by Samuel Hearne. He was a well qualified biologist and botanist using Latin names for species. His studies of the Arctic Fox are still considered the best available. He also contributed a considerable amount of material used by Thomas Pennant in his 1784 book “Arctic Zoology”.
“Historical Evidence and Climatic Implications of a Shift in the Boreal Forest Tundra Transition in Central Canada”, Climatic Change 1986, Vol. 7, pp. 218-229
Hearne commented on the evidence that the “tree limit”as he called it, had retreated considerably, which he accurately attributed to cooling. He didn’t know about the decline from the Mediaeval Warm Period (MWP) to the Little ice Age but saw evidence of the cooling. I compared his tree limit with one created in 1972 and found that on average it had moved 200km in approximately 200 years. This is a remarkable 1 km per year in one of the harshest climate regions in the world. Even if the move was half that amount it would still be very remarkable.
As I discovered it was attacked because of the alarmist claim, created by the impact studies of Working Group II of the IPCC, that the change we were causing with our CO2 was too rapid for nature to adapt. This thinking is rooted in the dominance of uniformitarianism in western science. This holds that change is very gradual over long periods of time.
We have seen this argument presented in a different and veiled form in the article Anthony posted here;
http://wattsupwiththat.com/2013/08/01/claim-climate-change-is-10x-faster-than-ever-before/
I am familiar with the tree line in Canada from my research but also from five years of flying search and rescue in northern and arctic regions. The tree line is a remarkably distinct line, especially in central Canada. True, the trees diminish in size, but it is still a very visible boundary. The only boundary I have seen so clearly delineated on such a scale is the clearly defined, by colour and transparency of the water between the cold water of the Labrador Current and the warm water of the North Atlantic Drift (Gulf Stream). I saw this countless times while flying anti submarine patrols over the North Atlantic.
Adaptation to change in nature is far greater than current thinking, especially alarmist AGW thinking allows. I have also studied and written often about the natural fluctuations in animal populations. I wrote about these in these articles
http://drtimball.com/2011/83-percent-of-all-statistics-are-made-up-on-the-spot/
http://drtimball.com/2011/tipping-points-are-natural-environmentalists-exploit-them/
They reference the work of Charles Elton who published in the 1930s and 40s and is reputedly the first to use the word ecology.
The other area of climate studies that speaks to these changes in vegetation and is virtually ignored, likely because its a threat to uniformitarianism, is Palynology. It records the changes in vegetation over time and it is clearly time to revisit what it shows about the dynamics of change.
All of these remarks are further evidence of my claim that the IPCC set climatology back 30 years.
klem is quite rigth saying: “I have no reason to be skeptical about plants moving up and down the sides of mountains due to changes in climate.”
This has been observed in many parts of the world for instance in the Swedish Scandes. Professor Leif Kullman has studied the changes for 40 years and written many articles on the subject. The treeline has advanced more than 100 m uphill during recent decades.
In one of his articles, Alpine flora dynamics – a critical review of responses to climate change in the Swedish Scandes since the early 1950s. Nordic Journal of Botany 28, 398-408, he writes: “The key finding is that the species pool has increased by 60–170% since the 1950s and later.”
Abstract can be read here: http://onlinelibrary.wiley.com/doi/10.1111/j.1756-1051.2010.00812.x/abstract
Local plant migration proves nothing about any human influence on climate. It simply proves what we have known all along, i.e. that growing conditions vary somewhat with NATURAL variation in climate.
The whole AGW hoax has been successful in part because too many of us now live our lives indoors in hermetically sealed urban environments. We simply don’t get enough opportunity to observe the natural world for ourselves and to develop a common sense view.
In New England there are signs it was warmer in the past, and that species retreated south, (or advanced south,) during the Little Ice Age, which was in full swing when the Puritans arrived and kept the first records we have to this day.
The range of sugar maples retreated to the north in the MWP, and though Puritans transplanted it south when they arrived in the Little Ice Age the Indians in southern New England sneered at “sugar-eaters,” while those to the north relished maple sugar. (The southern clans wouldn’t touch cane sugar, which the English had hoped to use as a trade item.)
I once found a small enclave of plants usually seen to the south of New Hampshire by a pond tucked into a sunny bay on the south side of a hill: Catbriar and Sassafras and so forth. It was a small quarter-acre area that looked like Cape Cod, up in the cold mountains. I imagine it was survivors from a warmer time, hanging on and hoping the warmth would return.
So from comments I see tree diseases, rain, fire management issues, co2 fertilization, co2 drought resistance, invasive species, Arizona cooling, etc. The report said:
What did this study actually tell us??? Maybe the researchers were suffering from the ‘Decline Effect’.
The solution is for planners to mandate fewer parking places and parking lots than there are cars.
A year ago I walked the Glorieta Pass Battlefield trail in New Mexico. Various old photo showed a landscape free of present day trees were canons had long lines of sight in 1862. Today that trail area is covered with trees. More use of old photos should be made in local climate change and plant diversity studies. The area I refer to he is located on I-25 exact of Santa Fe. The exit at 307 gives access to Pecos, the battlefield, and the Pecos Pueblo ruins.
Jim you have got to be kidding! What half-brain thinks that dredging harbors would lower ocean sea levels????
In Roman times it was easy to move Elephants across the Alps when the passes were not snow blocked. Climate change predates industrial CO2 emissions. A study of the know history should be a prerequisite to predictions about future climate. man adapts, and the plants and animals do too,
I was born and raised on a cattle ranch right in the heart of the sky islands near the Santa Ritas. Our ranch elevation was between 3500 and 5000 feet. Re routing cleared juniper from the land as it made cattle sick. Fifty years ago the cattle Industry was in its infancy. We had open range access to large portions of state and federal lands. As the area became more populated we had grazing rights reduced and therefore “managed” what grass we had more diligently. In other words we got rid of all the junipers.
http://farmprogress.com/story-cows-eating-juniper-risk-loss-calves-9-93766
Just reading the above comments, it looks like “climate change” is the last thing the authors should be looking at as the cause of the vegetation shirt.
Due present day higher levels of CO2 effect plant growth at higher elevation ? Isn’t more vegetation at higher altitude a good thing ?