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.”
 |
||||
 |
 |
|
 |
|
|
 |
  IMAGE: Today, living alligator juniper first begin to make an appearance on upland slopes of the Catalina Mountains at around 5,000 feet elevation…
|
|
|
|
 |
|
 |
|
|
||||
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.
|
||||
|
|
|
|
|
|
|
 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.
|
|
|
|
|
|
|
|
|
||||
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
Plants everywhere move according to local conditions, so they’d have been at higher elevation and latitude when the MWP rolled around, then back down and south if it got cold there during the LIA.
This article seems to be one of those important but boring articles where the researchers did field work and discovered exactly what was predicted by the theory.
So, they have never seen shifts in plant distribution on the plains? Forests and meadows appear and disappear in a man’s lifetime? It must be shocking to see that happen on the slopes. Everything must remain where it once was, right?
Climate is not the only thing which changed.
The lapse rate for dry air at a 1000 foot Δ is 3°C or over 300% of the alleged global warming. Seems like a poor attempt to tie flora movement to the CO2 Thermageddon®.
Its an interesting article, but what do the records of rainfall show for the region? And temperature? Is it really warmer and dryer now than in the past?
So. . .just exactly how much has the air in the Catalina Mountains at 5000 feet warmed and dried out since 1963? Is there less precipitation there now than in 1963?
Or is this just plant regrowth due to something like an earlier range fire?
Do these people believe this is the first time this sort of thing has happened? In my recent article I noted the following concerning plant life;
http://judithcurry.com/2013/06/26/noticeable-climate-change/
Appendix One-supplementary information concerning the temperature humps noted around 1540 and commencing 1610/15
*In his 1625‘ideal garden sketch’ essay Francis Bacon wrote of the plants that could be grown in their season in the climate of London (then a small city of only 450,000 people)
“Latter Part of November, you must take such Things, as are Greene all Winter; Holly;
Ivy; Bayes; Juniper; Cipresse Trees; Eugh; Pine-Apple-Trees; Firre-Trees; Rose-Mary;
Lavander; Periwinckle, the White, the Purple, and the Blewe; Germander; Flagges;
Orenge-Trees; Limon-Trees; And Mirtles, if they be stooved; & Sweet Marjoram warme
set. There followeth, for the latter Part of January, and February, the Mezerion Tree,
which then blossomes; Crocus Vernus, both the Yellow, and the Gray; Prime-Roses;
Anemones; The Early Tulippa; Hiacynthus Orientalis; Chamaïris; Frettellaria. For March,
There come Violets, specially the Single Blew, which are the Earliest; The Yellow
Daffadill; The Dazie; The Almond.”
http://en.wikisource.org/wiki/Of_Gardens/Of_Gardens
The similarity of seasons around 1625 is striking when compared to the modern
warm period in the UK. (that ended in 2000- Temperatures are now substantially cooler)
*More scientific confirmation of growing warmth is confirmed by Professor Dr C.
Pfister the noted historian and geographer who identified Heat waves in 1525 and 1616 ( roughly
comparable or greater than Europe 2003)
*The compilation book ‘Climate since AD 1500’ edited by Phil Jones and incorporating work by
a number of scientists, notes the warm periods around 1630 and 1550 and the cold interval that
separated them;
*In their summary in Chapter 33 of their book ‘Climatic variations over the last 500
years’ P D Jones and R S Bradley in talking of regional evidence for Europe note; ‘from
the evidence presented –in the book- the climate since 1500 has varied between
extremely warm and extremely cool decades
tonyb
With a lapse rate of 3 deg F per 1000 feet, and a global warming of perhaps 1 deg F since 1950, one would think vegetation might have moved up 330 feet. Plants that have moved from 3500 feet to 5000 feet must be anticipating the IPCC predictions of 5 degrees or more — or something else is the cause.
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.
====
uh guys, that’s a picture of a tree that died of Juniper blight….a fungal disease
So, too, I can show you hundreds of dead junipers at 600 feet ASL. When I was young, I saw the later stages of their extinction, and it puzzled me a lot. I did not know of juniper blight; now I can’t recall any gross symptoms of any disease. They just dried up everywhere in the area. Their former range is now overgrown by deciduous forests, but their trunks can still be found on the ground (they rot slowly). Barring an invisible root disease, I think they were simply outcompeted by faster-growing trees. That happened while the media were still yakking about global cooling, but the (southward) colonisation of the erstwhile prairie by forests in that area continues at about the same rate now as it did in 1960s.
Might CO2 fertilization allow certain plants to live at higher elevations? Thinner air at altitude means less CO2 and this might starve certain species. More CO2 in the air means more CO2 available even when the air is thinner.
(And I realize I’m being pedantic and off-topic here, but the title asks whether or not the writer wonders. Probably true, but shouldn’t the writer just tell us by using a period at the end of the sentence instead of a question mark?)
We have a nice little suburban reservation nearby called Elm Bank. Only problem is, the elms are almost all dead and gone now. Climate Change!! No wait — it was Dutch Elm Disease.
Never mind.
This study is based on one point – 1963 – and changes in the 50 years since then. Climate is cyclical so more than one point is necessary to draw conclusions. For example, the changes could have been underway in 1963.
I wonder how far they walked from the road. Do some seeds get transported uphill by road traffic?
Then there’s the data. The abstract cites overlapping data sets. A 62 year temperature record from 1949 to 2011, a recent 20 year rainfall record, and a transect taken 50 years ago.
Nexxxt.
Bob Whittaker would not have been surprised. And probably not alarmed. He was a very capable scientist who developed his theories of plant communities after looking at empirical evidence. http://en.wikipedia.org/wiki/Robert_Whittaker
juniper blight; now I can’t recall any gross symptoms of any disease. They just dried up everywhere in the area.
====
Gene you just described the symptoms of juniper blight…..exactly
The Arts of Truth strike again. This paper should not have been published without a major qualification to its supposed baseline. The dead giveaway (pun intended) is the dead spruce image below 5000 feet. Enlarge and look carefully, then read on.
The so-called Catalina Highway is 27 mile long Arizona Forest Highway 39 in the Coronado National Forest northwest of Tucson. The USDA FS provides a wealth of information, including the road’s amazing amazing biodiversity ‘ranging from Mexico (sonoran desert floor) to Canada (snowy Mount Lemmon peak)’. It is one of the most scenic byways in the American southwest, and also the only access to Summerhaven, zip code 85619.
Summerhaven’s website describes it as ” a quaint town of shops and restaurants rebounding from the ashes of the 2003 Aspen Wildfire.”
The Aspen wildfire burned from June 17 to July 12, 2003, immolating 132.4 square miles including most of the terrain through which AFH 39 runs, and all of Winterhaven.
The dead juniper was killed by the forest fire as can be seen from the fire scarred trunk, and the landscape behind it is slowly recovering during the past decade of general above average dryness in the Southwest. NOTHING to do with lomger term climate change.
This paper is worse nonsense than the 2013 North Pole Lake. It is worse peer review than upside down Tijlander or agriculturally contaminated Igaliku. It is blantantly deceptive, and should be retracted.
Of course, it is this line from the article which will be remembered by the general public if they read it: “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.”
So….Over the course of 50 years all the plants have adapted to whatever new environment they found themselves in. Therefore the recurring theme of the warmies that because CO2 has warmed, and will warm us so quickly that nothing will adapt in time (hence thermageddon) is proven by this study to be a non starter. Why do they keep disproving their own theories? Can’t they leave anything for us?
Typo in previous post. Summerhaven. Should have used preview. Regards.
I find great humor in people and especially so called scientist who seem to view the world in the confines of their own life span. What was it? 15,000 to 20,000 years ago, there were no forests or grizzly bears in Montana… because it was under an ice sheet!!!
Ah-ha! These are the new, real “climate refugees” then.
There is FAR more evidence of artificial spread of plants than climate change spread of plants. Heck, at our Oregon state borders, one must clean off any boat you bring into the state AND get a permit to bring in that boat, clean or not. And I mean clean it thoroughly. Why? To prevent the spread of non-native flora and fauna. Same goes for Wallowa County in Oregon. Can’t bring in hay from outside the county. Why? To prevent the spread of non-native flora and fauna.
The conclusions of the present study cannot be supported and should be retracted. First rule out the most common causes of flora creep. Climate change is way down the list.
I had a nice trip to the Ancient Bristlecone Pine Forest last year and yep, sure enough the trees that grew up during the Roman Climate Optimum were …..
…. wait for it …….
…… further up the hill.
Whooo hooooo, we’re all going to die.
of course, this is all based on Arizona cooling almost 1 degree since 1950….
http://stevengoddard.wordpress.com/2013/04/07/raising-arizona-3/
There are so many other things to consider than a few tenths of a degree change in air temperature.
A change in the regime of grazers. Cattle, sheep, goats will graze or browse on different plants and grasses. What was this area like pre-settlers? From memory of undergrad and grad Rangeland Management I’m thinking primarily grasslands interspersed with a few trees (<5/acre, or was it hectare?) that could manage to get a leg up above the aforementioned, now suppressed, high frequency-low intensity fires and displaced/replaced/added grazing/browsing regime. Juniper is volatile with its high concentration of turpenes and other flammable waxes and oil. It's relatively low and prostrate growth habit makes it susceptible to fire as well. Therefore it is suppressed by fire.
Additionally, how far uphill are the seeds of these (as the author depicts them) ambulatory trees dispersed by wind? +800' in elevation?! That's a heck of a wind dispersion. I'd look to grazers picking up the seeds in their wool, mohair, or hair and redepositing them. Or if goats, birds, or sheep are picking at juniper berries and depositing the seeds undigested in their manure. With fire suppression, and an increase in brush and trees, one could also expect to see an increase in species of birds that would nest in such habitat. These same birds could also be foraging and dispersing the seeds of the species which ambulated uphill.
I did not see a mention of which face of a slope they were on, nor if they moved from a south slope to the NE or NW, SE or SW. That can certainly make a difference as well with prevailing winds and sunshine desiccating hours.