Paul, Thanks for the comprehensive update. I hope to have some time to explore LIDAR data in January during the intercession.
Gary On Nov 15, 2009, at 10:47 AM, Paul Jost wrote: > 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 > athttp://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] -- 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]
