Paul- While I haven't had a chance to get back with my friend at the Anchorage Forest Sciences Lab, but they would have performed their dual phase LIDAR inventory of forests around Tok Alaska this summer. Dual phase, for dual 'resolutions', the higher resolution able to discern objects the size of a pie plate, lower resolution around a meter, if I recall correctly...the higher resolution will be used to 'train' the lower resolution, once it is ground truthed.
I thought it interesting that Steve Sillet (of recent NatGeo/Redwood fame) has with the support of Nat Geo I suspect, has had LIDAR imagery capture of the redwood strip, and declared no taller redwood's exist, than those most recently found. In the National Geographic Channel, they showed an interesting graphical representation of LIDAR imagery at the end of the Redwood Special. -Don From: [email protected] To: [email protected] Subject: [ENTS] Lidar update Date: Sun, 15 Nov 2009 09:47:35 -0600 Gary, Josh was taking the lead on organizing an article/paper on using Lidar since his group has better software tools and access to local data for ground verification. However, the coarser grids that they have chosen to process with may be better for determining old growth structure than for picking out individual tall trees. It looks like it should be fairly reliable for relatively flat areas, may need further subjective interpretation for steep areas and areas with surface water. It also has false returns for large flocks of birds and other low flying aircraft, for example appearing as 800 foot tall trees! Filtering maximums by realistic tree heights removed most of the false tree height returns. GPS locations provided may be offset from the tree peak due to sloping terrain and the size of the data grid, so the location of the data point in the Lidar height data might not actually be under the tree crown at all. At the least, it would locate most of the tallest trees in an area for further on site investigation. Their is only a small amount of data available for Wisconsin for a small section of distant north-central Wisconsin that has no tall trees. There is limited coverage of bits of Illinois with tall trees but too far to get to with my current schedule. I hope to check it out this winter. There is total free state Lidar coverage of point cloud data, not just useless, filtered, bare earth surface data, for all of North Carolina. A convenient source for much the US is at http://lidar.cr.usgs.gov/LIDAR_Viewer//viewer.php . I did a survey of state government GIS web sites across the country in March when I had some spare time to find the availability of data in the U.S. North Carolina had the best data availability at that time. Other states had or stated that they would soon have partial or complete data online: California, Georgia, Idaho, Indiana, Iowa, Kansas, Louisiana, Minnesota, Ohio, Oregon, Washington, and West Virginia. States that had data available by request only were Delaware and Mississippi. Some states had data available only for a large fee - Maryland, Pennsylvania, and Texas. The free Fusion tools on the internet work fairly well, but the latest version of the data viewer appears to be buggy on my PC, so I use one rev back. http://forsys.cfr.washington.edu/fusion/fusionlatest.html When I have a little more time, I'll provide some basic quick start / getting started instructions on how to use it in another post... Paul Jost ----- Original Message ----- From: Gary A Beluzo To: [email protected] Sent: Sunday, November 15, 2009 8:59 AM Subject: Re: [ENTS] A Large Tree article in 1849 Paul, How is the LIDAR work going? Gary On Nov 15, 2009, at 9:54 AM, Paul Jost <[email protected]> wrote: That's why I think that it may have been a 150'+ double which would be realistic and would provide total cut log lengths of about twice the height.... PJ ----- Original Message ----- From: Gary A Beluzo To: [email protected] Sent: Sunday, November 15, 2009 8:43 AM Subject: Re: [ENTS] A Large Tree article in 1849 I concur when you aver! Gary On Nov 14, 2009, at 10:00 PM, Bob <[email protected]> wrote: Ed, Tim, Gary, Don, et al, White pines that rise significantly above the surrounding canopy are at extra risk from wind events. So our mythical 300-hundred footer would have had to be in an area that received plenty of protection from the wind. Additionally, it would have needed to be in an area that possesses the right kind of soil for tall white pines (sand-silt), receives sufficient moisture, etc. But even if these conditions were met, what would be the incentive for a pine to continue growing to eventually reach such an improbable height? Competition? White pines reach their greatest heights in stands (with rare exceptions). So our mythical pine would have likely had company. The 300-footer would have had 250-footer companions. The scenario becomes wildly improbable. Bob Sent from my iPhone On Nov 14, 2009, at 6:26 PM, "Edward Frank" <[email protected]> wrote: Tim, I always enjoy reading these historical accounts, whether they are deemed accurate or not. If you come across more, please post them to the list. I like the response regarding genetics as well. I must comment however when he talks about some variations have no specific benefit. Well - there might be some examples, but looking at things from the perspective of paleontology, there are very few genetic variations that do not have some adaptive purpose and if they have an adaptive purpose, then they are selected for or against. Things that might not have a "purpose," if I were to postulate that left or right handedness did not have a purpose, then the degree of variation between the two variable opposites tend to be minimal so that selection would not prefer one to the other. Tree height has a very distinct purpose and is selected for dependant on the particular environmental conditions. Therefore the height parameter in one area of the range is different than in other areas of the range. Trees in that portion of the range fall within the heights genetically selected for in that region. In other cases the genes for a variety of different conditions are all present and environmental conditions turn one set of genes on and another off, dependant on conditions. An example is a fish in some Mexican caves. When found in darkness in the depths of the caves, they do not grow eyes, while the same species in surface pools do grow eyes. Parent that are eyeless will spawn eyed fish if moved to the light, and eyed parents will spawn eyeless fish if they are moved to the dark. I don't believe that there is enough variation in genetic height potential to grow a 300 foot tall tree in New England. The other consideration is one of environmental conditions. Overall tree heights seem to correlate with latitude, taller trees are more southerly and shorter trees are found more northerly. I wonder also about weather conditions. The tops of many of the taller trees do not seem to be stopped by reaching a growth limit, but rather a point at which the rate of breakage under the weather/climatic conditions equal the rate of growth. This is especially true once the trees emerge from the generalized canopy height. So perhaps tree height is not only limited by their own genetics, but limited indirectly by the genetics of the trees with which they share the forest. A tree growing among taller species may grow higher than a tree growing among shorter species. Anybody have any comments? [If so maybe we should start a new subject] Ed Frank Check out my new Blog: http://nature-web-network.blogspot.com/ (and click on some of the ads) -- 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] -- 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] -- 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. 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