From an OSU press release:
CORVALLIS, Ore. – An analysis of 35 headwater basins in the United States and Canada found that the impact of warmer air temperatures on streamflow rates was less than expected in many locations, suggesting that some ecosystems may be resilient to certain aspects of climate change.
The study was just published in a special issue of the journal BioScience, in which the Long-Term Ecological Research (LTER) network of 26 sites around the country funded by the National Science Foundation is featured.
Lead author Julia Jones, an Oregon State University geoscientist, said that air temperatures increased significantly at 17 of the 19 sites that had 20- to 60-year climate records, but streamflow changes correlated with temperature changes in only seven of those study sites. In fact, water flow decreased only at sites with winter snow and ice, and there was less impact in warmer, more arid ecosystems.
“It appears that ecosystems may have some capacity for resilience and adapt to changing conditions,” said Jones, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “Various ecosystem processes may contribute to that resilience. In Pacific Northwest forests, for example, one hypothesis is that trees control the stomatal openings on their leaves and adjust their water use in response to the amount of water in the soil.
“So when presented with warmer and drier conditions, trees in the Pacific Northwest appear to use less water and therefore the impact on streamflow is reduced,” she added. “In other parts of the country, forest regrowth after past logging and hurricanes thus far has a more definitive signal in streamflow reduction than have warming temperatures.”
LTER sites were established to investigate ecological processes over long temporal and broad spatial scales throughout North America, including the H.J. Andrews Experimental Forest in Oregon, as well as sites in Alaska, New Mexico, Minnesota, New Hampshire, Georgia, Puerto Rico, Antarctica and the island of Moorea. Not all were part of the BioScience study.
In that study, warming temperatures at some of the headwater basins analyzed have indeed resulted in reduced streamflow due to higher transpiration and evaporation to the atmosphere. But these changes may be difficult to perceive, Jones said, given other influences on streamflow, including municipal and agricultural water usage, forest management, wildfire, hurricanes, and natural climate cycles.
“When you look at an individual watershed over a short period of time, it is difficult to disentangle the natural and human-induced variations,” Jones said, “because hydrologic systems can be quite complex. But when you look at dozens of systems over several decades, you can begin to gauge the impact of changing vegetation, climate cycles and climate trends.
“That is the beauty of these long-term research sites,” she said. “They can provide nuanced insights that are crucial to effective management of water supplies in a changing world.”
Jones said the important message in the research is that the impacts of climate change are not simple and straightforward. Through continuing study of how ecosystems adapt to changing conditions, resource managers may be able to adapt policies or mimic natural processes that offer the most favorable conditions for humans and ecosystems to thrive.
###
About the OSU College of Earth, Ocean, and Atmospheric Sciences: CEOAS is internationally recognized for its faculty, research and facilities, including state-of-the-art computing infrastructure to support real-time ocean/atmosphere observation and prediction. The college is a leader in the study of the Earth as an integrated system, providing scientific understanding to address complex environmental challenges
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
At least the author(s) appear to be scientifically honest, for that they deserve a pat on the back. That is to contrast so many of the current papers steamflowing out every day that are pure trash due to their not-so-hidden white lies in either the data or words, many times by omissions of known conflicts.
Most of the senseless discussion on this blog stems from an outmoded concept of science. I have been suffering from this error myself. I thought that science was the application of an ancient concept that was known as “The Scientific Method”. Of course this is bollocks.
Modern science is based on consensus, concern and social justice. The conclusion is formed first, then observations are found to confirm it. Much more efficient. H Pepper knows this. Get with the program guys!
Climate is a much more complex concept than a temperature change of some small magnitude. Surely they did not define climate as just an average warmer temperature. Did they? What about first to last frost? Growing degree units? Precipitation during the high sun or low sun season? Oh well – probably not.
Re: dcb283 says:
April 6, 2012 at 1:33 pm
” ‘Lead author Julia Jones, an Oregon State University geoscientist, said that air temperatures increased significantly at 17 of the 19 sites that had 20- to 60-year climate records, but streamflow changes correlated with temperature changes in only seven of those study sites.’ ”
“Perhaps because most of those sites were probably in cities and the temperature increase was caused by localized UHI? I seriously doubt they had thermometers along forest streams for 60 years.”
There are rural watersheds with somewhat long-term records. For example see Hanson 2001:
ftp://ftp.nwrc.ars.usda.gov/publicdatabase/reynoldscreek/documents/wrr_climate.pdf
This paper refers to the Reynolds Creek Experimental Watershed in Idaho with records that go back to 1964. Hanson 2001 refers to his 1991 investigation into whether time of observation (TOB) had an effect on average daily temperature. The investigation referred to Hanson 1991 which I had mentioned in WUWT:
http://wattsupwiththat.com/2011/10/22/a-preliminary-assessment-of-bests-decline/
Neil Jordan says:
October 22, 2011 at 10:59 pm
A 1991 paper published in Northwest Science “The Effect of Observation Time and Sampling Frequency on Mean Daily Maximum, Minimum and Average Temperature” at
https://research.wsulibs.wsu.edu:8443/xmlui/handle/2376/1631
provides cautions regarding sampling and averaging of daily temperature. From the abstract: “The use of long-term temperature data for climatic, ecohydrologic and other studies must be scrutinized carefully because of the average daily differences due to time of observation (TOB). . . The significance of our findings is that studies which require historical temperature records and where only small changes in temperature are expected, such as climate change modeling, will be difficult to verify. Also, mean daily temperature will change at locations when several readings are used to compute mean daily temperature rather than computing mean daily temperature from the daily maximum and minimum temperatures.”
Hanson 1991 is also archived at:
http://research.wsulibs.wsu.edu/jspui/handle/2376/1631
http://research.wsulibs.wsu.edu/xmlui/bitstream/handle/2376/1631/v65%20p101%20Hanson.PDF?sequence=1
The OSU press release isn’t clear as to whether Reynolds Creek Experimental Watershed was included. If this watershed, or a similar watershed, was included, Hanson 2001 would apply: “No consistent differences between sites were found; however, in the spring and fall, average daily temperatures differed by as much as 1 deg C between 0600 and 1600 TOB. Average daily temperatures computed from 10 min interval data, ending at TOB, were as much as 0.8 deg C less than the average computed from daily maximum and minimum values for 0800 through 1900 TOB.”
Latitude at April 6, 2012 at 1:56 pm inquired as to what Professor Jones considered to be a significant temperature increase and suggested that less than 1 deg would not be significant. If the temperature errors noted in Hanson (up to 1 deg C) were also present in the Jones study, then Hanson 1991 bears repeating: “The significance of our findings is that studies which require historical temperature records and where only small changes in temperature are expected, such as climate change modeling, will be difficult to verify.”
“That is the beauty of these long-term research sites,” (Jones) said. “They can provide nuanced insights that are crucial to effective management of water supplies in a changing world.”
Quite. To understand something, study it. Science.
“It appears that ecosystems may have some capacity for resilience and adapt to changing conditions,” said Jones, a professor in OSU’s College of Earth, Ocean, and Atmospheric Sciences.
Something comes bouncing back after periodic flash fires, floods, droughts, volcanic eruptions, earthquakes, tsunamis, bolide impacts, and having gigatons of ice squatting on top of it, and it *may* have some capacity for resilience?
Gee — ya think?
R^2 = 0.015
dcb283 says:
April 6, 2012 at 1:33 pm
“Lead author Julia Jones, an Oregon State University geoscientist, said that air temperatures increased significantly at 17 of the 19 sites that had 20- to 60-year climate records, but streamflow changes correlated with temperature changes in only seven of those study sites.”
Perhaps because most of those sites were probably in cities and the temperature increase was caused by localized UHI? I seriously doubt they had thermometers along forest streams for 60 years.
Central England warming is different for each month:
January showed no warming until th 1980s
February rose 3°C up to the 1990s then fell 1°C
March nothing until the 1990s then up 3°C whereas the minimum rose 2.5 then fell back 1.5.
April a steady climb of 2.5°C
May rises 2.5°C until the 1990s then fell 2.0°C but the minimum rose 1°C.
June no rise in mimimum but maximum up 2.5°C
July no rise at all
August rises 2°C up to 2002 then falls 2°C
September rises 3°C up to 2006 then falls 3°C, the minimum didn’t rise.
October a steady climb of 2°C
November 0.5°C rise
December no rise.
Make sense of that!
Kelvin Vaughan says:
April 7, 2012 at 6:00 am
September rises 3°C up to 2006 then falls 3°C
kadaka (KD Knoebel) says:
April 6, 2012 at 7:56 pm
Simply marvelous! Good I put my coffee down before I started your post!
“So when presented with warmer and drier conditions, trees in the Pacific Northwest appear to use less water and therefore the impact on streamflow is reduced,”
Surely the “less water” must be reflected in stream flow!! Let’s see… if the “less water” is because the trees are using less and it can then go to the stream, then there is obviously enough for the trees to use more…..something wrong here.
Jones said the important message in the research is that the impacts of climate change are not simple and straightforward.
Well, yes. Ecosystems are indeed complex, so scientists often say simpler things. This OSU study is an example. Nowhere in this study did anyone suggest that increasing carbon dioxide tends to lower evapotranspiration, because plants tend to keep their stomatal apertures smaller in higher carbon dioxide levels. Over the past few decades, carbon dioxide levels have increased enough to expect some sort of response at the ecosystem level.
This might have a couple of implications. One is that better water use efficiency can be expected, perhaps leading to less correlation between stream flow and temperature. Another might be that total plant productivity might increase along with the carbon dioxide levels. This is well known to occur in greenhouses, but in open environments, perhaps not so much. Too many other potential limiting factors can intervene.
This kind of complexity does not discourage scientists from proposing policy implications based on flimsy evidence. A typical example might be this extrapolation from a few dozen plots in a grassland all the way to global policy regarding carbon controls.
“But our experiment shows that we can’t count on the natural world, the unmanaged world, to save us by pulling down all the atmospheric CO2.” http://www.sciencedaily.com/releases/2002/12/021206075233.htm
Ugh. This study did not show much beyond the obvious, which is that plant growth depends upon more than one thing. It certainly did not show anything about the “unmanaged world.” Nor did the relatively short durations in the OSU study.
The hardest part of studying complicated things is that they are not simple. Rats.
“But our experiment shows that we can’t count on the natural world, the unmanaged world, to save us by pulling down all the atmospheric CO2.”
The unmanaged world has managed to do that quite nicely for several hundred million years — but now (magically), it’s *different*…
Seven out of 17. That’s easily within the limits of random chance, especially with such a small sample size over such a short time span. I hardly think such a limited study justifies any conclusions. The headline should read: “No, wait a minute! We don’t have any results yet dummy!!”