Eli- A lot can be found out regionally I suspect. I know that when seeking reference conditions for the forested ecosystems of Grand Canyon National Park, we tapped all the historical accounts (narratives and photographs), and then natural reference conditions by proxy (macrofossil analysis, pollen analysis) and found that the four forest ecosystems on the North Rim/Kaibab Plateau; pinon-juniper, pure ponderosa, mixed conifer, and spruce fir had "marched" up and down the plateau several kilometers, at several different times in the preceding 12,000 years, in response to changing climatic conditions.
Palynology is a pretty cool thing for assessing vegetation presence/absence over time, especially if you have relatively undisturbed ponds, lakes, or bogs to gather data from. -Don Date: Wed, 18 Nov 2009 07:01:36 -0800 From: [email protected] Subject: RE: [ENTS] Bristlecone Pines as signals of climate change To: [email protected] That's really interesting Don. Being at the southern extent of the natural range of Tsuga canadensis here in Atlanta I wonder what the boundaries of their range were in years past (pre-Adelgid) and if they were truly native to places like old growth Fernbank Forest here in the city. You're right though- there are many factors at play here, affecting many different facets in the ecosystem. Kind of mind boggling to think about. Eli --- On Tue, 11/17/09, DON BERTOLETTE <[email protected]> wrote: From: DON BERTOLETTE <[email protected]> Subject: RE: [ENTS] Bristlecone Pines as signals of climate change To: [email protected] Date: Tuesday, November 17, 2009, 2:41 PM Eli- I think an even more interesting study would be gradient analyses of moisture, temperature, UV at the geographic extents of the bristlecones (lats, longs, elevations). One of the questions posed in a ecological restoration class I took was "How will global climate change impact the geographic extents of _____________(choose a species)". My choice was Quaking Aspen (Populus tremuloides) in Northern Arizona on San Francisco Peaks...I predicted that the aspen were somewhat less mobile, that they were likely to die out at lower elevations due to increased predation by forest pathogens with rising temperatures, and to stabilize at higher elevations. Lots more to it than that, but the idea is that it just takes a few degrees (in this case adiabatic temperature change) change to have significant impact on many facets of an ecosystem. When enough of those subtle 'facets' accumulate, major differences will be noticed. Particularly at the geographic extents, where the natural limits already in place get exceeded. Attaching an image of bristlecones as they reach the edge of their 'ecotone'... -Don Date: Tue, 17 Nov 2009 13:05:58 -0800 From: [email protected] Subject: [ENTS] Bristlecone Pines as signals of climate change To: [email protected] Great article about how Bristlecone Pines near the treeline have grown more rapidly in the 2nd half of the 20th century than in any other 50 year period in the last 4600 years: http://news.discovery.com/earth/oldest-trees-global-warming-growth.html Eli -- Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected] Windows 7: I wanted simpler, now it's simpler. I'm a rock star. -- Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected] -- Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected] _________________________________________________________________ Windows 7: I wanted simpler, now it's simpler. I'm a rock star. http://www.microsoft.com/Windows/windows-7/default.aspx?h=myidea?ocid=PID24727::T:WLMTAGL:ON:WL:en-US:WWL_WIN_myidea:112009 -- Eastern Native Tree Society http://www.nativetreesociety.org Send email to [email protected] Visit this group at http://groups.google.com/group/entstrees?hl=en To unsubscribe send email to [email protected]
