Re: climate change case studies
Lucas Moyer-Horner wrote: > Anita, Below are two excellent case studies that are near > and dear to my heart. As far as i know, this is the first > evidence of a small-medium sized mammal being extirpated > by rising temperatures. > Beever, E.A., Brussard, P.F. and Berger, J. 2003. Patterns of > apparent extirpation among isolated populations of pikas > (Ochotona princeps) in the Great Basin. Journal of Mammalogy > 84(1):37-54 > Grayson, D.K. 2005. A brief history of Great Basin Pikas. > Journal of biogeography 32:2103-2111. Lucas, according to this article: http://www.hcn.org/servlets/hcn.Article?article_id=15849 "In the early 1990s, E.A Beever revisited 25 Great Basin pika populations recorded by Eugene Raymond Hall and others about half a century earlier and found six of the 25 populations had completely disappeared." The 25 pika populations that were monitored were located primarily within Nevada: http://i85.photobucket.com/albums/k75/4af/pikaa.jpg Now lets look at how much temperatures rose in Nevada between 1920 and 1993 using National Climate Center Data http://www.ncdc.noaa.gov/oa/climate/research/cag3/cag3.html Here is the winter (Dec-Feb) temperature graph for Nevada the period 1920-1993: http://i85.photobucket.com/albums/k75/4af/pikab.jpg A very slight warming trend is apparent Here is the summer (June-August) temperature graph for Nevada for the period 1920-1993: http://i85.photobucket.com/albums/k75/4af/pikad.jpg A slight cooling trend is apparent. Here is the overall annual temperature graph for Nevada for the period 1920-1993: http://i85.photobucket.com/albums/k75/4af/pikac.jpg A very slight cooling trend is apparent. Lucas, I am now wondering why you and other scientists think the Great Basin pika "is the first evidence of a small-medium sized mammal being extirpated by rising temperatures". Paul Cherubini El Dorado, Calif.
Re: climate change case studies
It is curious that your graphs go to 1920 and no further back, despite the availability of data. Looking solely at the summer temperatures it appears that 1922 and 23 have a considerable impact on the trend. Alas I've not been able to duplicate the sort of figures you're produced but messing around on the site seems to indicate a very, very different trend if you include 1895 through to 1993. Also, if you skim through the Beever et al. 2003 paper, you'll find that pika are purportedly quite sensitive to what you seem to view as small temperature changes, and that it is maximums not averages that seem to be primary factors. Ned Dochtermann Quoting Paul Cherubini <[EMAIL PROTECTED]>: > Lucas Moyer-Horner wrote: > > > Anita, Below are two excellent case studies that are near > > and dear to my heart. As far as i know, this is the first > > evidence of a small-medium sized mammal being extirpated > > by rising temperatures. > > > Beever, E.A., Brussard, P.F. and Berger, J. 2003. Patterns of > > apparent extirpation among isolated populations of pikas > > (Ochotona princeps) in the Great Basin. Journal of Mammalogy > > 84(1):37-54 > > > Grayson, D.K. 2005. A brief history of Great Basin Pikas. > > Journal of biogeography 32:2103-2111. > > Lucas, according to this article: > http://www.hcn.org/servlets/hcn.Article?article_id=15849 > > "In the early 1990s, E.A Beever revisited 25 Great Basin pika > populations recorded by Eugene Raymond Hall and others > about half a century earlier and found six of the 25 populations > had completely disappeared." > > The 25 pika populations that were monitored were located > primarily within Nevada: > http://i85.photobucket.com/albums/k75/4af/pikaa.jpg > > Now lets look at how much temperatures rose in Nevada > between 1920 and 1993 using National Climate Center Data > http://www.ncdc.noaa.gov/oa/climate/research/cag3/cag3.html > > Here is the winter (Dec-Feb) temperature graph for Nevada > the period 1920-1993: > http://i85.photobucket.com/albums/k75/4af/pikab.jpg > A very slight warming trend is apparent > > Here is the summer (June-August) temperature graph for > Nevada for the period 1920-1993: > http://i85.photobucket.com/albums/k75/4af/pikad.jpg > A slight cooling trend is apparent. > > Here is the overall annual temperature graph for > Nevada for the period 1920-1993: > http://i85.photobucket.com/albums/k75/4af/pikac.jpg > A very slight cooling trend is apparent. > > Lucas, I am now wondering why you and other scientists > think the Great Basin pika "is the first evidence of a > small-medium sized mammal being extirpated by rising > temperatures". > > Paul Cherubini > El Dorado, Calif. >
Re: climate change case studies
Paul, In the Beever et al (2003) article, you can see that the extirpated sites are primarily located in the northwest corner of Nevada and southern Oregon, so temperature averages for the entire state of Nevada are not particularly informative. In this paper, the authors found that the strongest predictor of extirpation was maximum talus elevation. That is to say that the lowest elevation sites were being lost disproportionately. Given this fact and knowledge of the adiabatic lapse rate, it is not particularly surprising that extirpated sites had 7.7 - 10% higher daily maximum temperatures than those of extant sites during June, July, and August (months during which pika are most actively foraging). At this point the connection between pika extirpation and temperature is correlative, but there is good evidence that pika are particularly sensitive (physiologically) to even moderately high temperatures (AT Smith. 1974. Ecology 55:1368-1376). Work is now being done by myself and others to explore mechanistic hypotheses. Lucas Moyer-Horner UW-Madison
Re: climate change case studies
Maybe you should read the actual peer reviewed paper instead of a news article... http://faculty.washington.edu/grayson/grayson-pikas.pdf This study was covering the last 40,000 years. Currently we are dealing with global temperatures, local and regional temperatures may decline despite rising global averages. IF you are familiar with averages, you will realize that Nevada could have a mild cooling, while other areas have even moderate warming and still result with an overall rise in temperature. For hypothetical example: year 1 Ave Temperature in Nevada = 70F year 1 Ave T in Texas = 69F year 2 ave T in Nev = 69 F year 2 ave T in Texas = 71F Under this hypothetical example the temperature in Nevada dropped 1F while the temperature in TX rose 2F so... The ave year 1 temp = (70+69)/2 = 139/2 = 69.5F The ave year 2 temp = (69+71)/2 = 140/2 = 70F In the above realistic example, the average temperature rose by 0.5F but the local NV temperature dropped. Anyone with the capacity for basic addition, subtraction, multiplication, and division skills, and the time, can collect the data from around the globe and calculate the results, an increased global temperature. Back to the Pika paper.. They are comparing temperatures over geologic time periods. It is fairly well known that 10,000 years ago a glacier (the great wisconsian)covered much of the US and that NV was much colder then than it is now. I think we learn about the glaciers in secondary school, at least I did in 5 th grade. Of course, the variation in public and private education varies much across the U.S. I hope this helps you understand the math and the concept. For more information, you can read the full reports of the Intergovernmental Panel on Climate Change: http://www.ipcc.ch/ Certainly, if you can read the document (it doesn't require scientific training, but it would help) you will find much explanation of how they arived at their conclusions, how they collected the data, how they interpreted it, and ultimately why we think temperatures are rising. Enjoy. On Thu, October 25, 2007 2:48 am, Paul Cherubini wrote: > Lucas Moyer-Horner wrote: > >> Anita, Below are two excellent case studies that are near >> and dear to my heart. As far as i know, this is the first >> evidence of a small-medium sized mammal being extirpated >> by rising temperatures. > >> Beever, E.A., Brussard, P.F. and Berger, J. 2003. Patterns of >> apparent extirpation among isolated populations of pikas >> (Ochotona princeps) in the Great Basin. Journal of Mammalogy >> 84(1):37-54 > >> Grayson, D.K. 2005. A brief history of Great Basin Pikas. >> Journal of biogeography 32:2103-2111. > > Lucas, according to this article: > http://www.hcn.org/servlets/hcn.Article?article_id=15849 > > "In the early 1990s, E.A Beever revisited 25 Great Basin pika > populations recorded by Eugene Raymond Hall and others > about half a century earlier and found six of the 25 populations > had completely disappeared." > > The 25 pika populations that were monitored were located > primarily within Nevada: > http://i85.photobucket.com/albums/k75/4af/pikaa.jpg > > Now lets look at how much temperatures rose in Nevada > between 1920 and 1993 using National Climate Center Data > http://www.ncdc.noaa.gov/oa/climate/research/cag3/cag3.html > > Here is the winter (Dec-Feb) temperature graph for Nevada > the period 1920-1993: > http://i85.photobucket.com/albums/k75/4af/pikab.jpg > A very slight warming trend is apparent > > Here is the summer (June-August) temperature graph for > Nevada for the period 1920-1993: > http://i85.photobucket.com/albums/k75/4af/pikad.jpg > A slight cooling trend is apparent. > > Here is the overall annual temperature graph for > Nevada for the period 1920-1993: > http://i85.photobucket.com/albums/k75/4af/pikac.jpg > A very slight cooling trend is apparent. > > Lucas, I am now wondering why you and other scientists > think the Great Basin pika "is the first evidence of a > small-medium sized mammal being extirpated by rising > temperatures". > > Paul Cherubini > El Dorado, Calif. > Malcolm L. McCallum Assistant Professor of Biology Editor Herpetological Conservation and Biology http://www.herpconbio.org [EMAIL PROTECTED] [EMAIL PROTECTED]
Re: climate change case studies
Lucas Moyer-Horner wrote: > Anita, Below are two excellent case studies that are near > and dear to my heart. As far as i know, this is the first > evidence of a small-medium sized mammal being extirpated > by rising temperatures. > Beever, E.A., Brussard, P.F. and Berger, J. 2003. Patterns of > apparent extirpation among isolated populations of pikas > (Ochotona princeps) in the Great Basin. Journal of Mammalogy > 84(1):37-54 > Grayson, D.K. 2005. A brief history of Great Basin Pikas. > Journal of biogeography 32:2103-2111. Lucas, according to this article: http://www.hcn.org/servlets/hcn.Article?article_id=15849 "In the early 1990s, E.A Beever revisited 25 Great Basin pika populations recorded by Eugene Raymond Hall and others about half a century earlier and found six of the 25 populations had completely disappeared." The 25 pika populations that were monitored were located primarily within Nevada: http://i85.photobucket.com/albums/k75/4af/pikaa.jpg Now lets look at how much temperatures rose in Nevada between 1920 and 1993 using National Climate Center Data http://www.ncdc.noaa.gov/oa/climate/research/cag3/cag3.html Here is the winter (Dec-Feb) temperature graph for Nevada the period 1920-1993: http://i85.photobucket.com/albums/k75/4af/pikab.jpg A very slight warming trend is apparent Here is the summer (June-August) temperature graph for Nevada for the period 1920-1993: http://i85.photobucket.com/albums/k75/4af/pikad.jpg A slight cooling trend is apparent. Here is the overall annual temperature graph for Nevada for the period 1920-1993: http://i85.photobucket.com/albums/k75/4af/pikac.jpg A very slight cooling trend is apparent. Lucas, I am now wondering why you and other scientists think the Great Basin pika "is the first evidence of a small-medium sized mammal being extirpated by rising temperatures". Paul Cherubini El Dorado, Calif.
