Support Our Work

News & Press

Return to News

ASCA 2015 Annual Conference


Submitted by Bill Hascher

Thanks to the NCUFC for sponsoring my registration to the American Society of Consulting Arborists Annual Conference.   The venue was the Loews Ventana Canyon Resort in Tucson AZ, land of the iconic Saguaro cactus.   My workplace is in the mountains of Western North Carolina, so the Sonoran desert venue was a very interesting, somewhat alien environment.  At the conference I was joined by many arborist colleagues from around the US and Canada, and a few from Europe as well.  Tucson is the land of CAM photosynthesis, i.e. crassulacean acid metabolism, a plant adaptation to arid climates where the stomata remain closed during the day and open at night.


The Tucson area provided a rich learning environment to focus on science and information about trees.  Conference topics focused primarily on climate and tree growth, followed by how trees grow, how they decay, what to do with them when they’re dead, and how to write reports about them that will hold up in court.  My favorite presentation of the conference was by Joel G. Burken, PhD from the Missouri University of Science and Technology.  Its title was “Valuation of Phytotechnology and Green Infrastructure Benefits: Much More Than Just Aesthetically Pleasing”.  This talk resonated in its practicality, compared to some of the other presentations.   Part of this talk explained the methodology behind using trees as “bio-sentinals”(not the Marvel comics variety) in phytoforensics for soil contaminant plume mapping of poisonous solvents like PCE’s (perchloroethylene) and TCE’s (trichloroethylene).  They are using trees to replace monitoring wells, since the tree roots cover such an expansive area, compared with monitoring wells which are limited to a relatively small area compared with a trees root zone.  The process of core-sampling trees for this purpose has been around for a while, but Burken and his students came up with a new sampling protocol using a septum-type plug (like an Arborjet tree injection port)and inserting a sampling device thinner than a pencil lead. Further, they are using a mobile gas chromatography-mass spectrometer to analyze trees on site.   His talk even referenced the “” website, which features topics ranging from ladybugs riding dandelions, to zombie-proof houses.  Much more info about that phytoforensics work can be found at the Missouri University of Science and Technology website. 


Another interesting topic (almost as interesting as zombies), was Francis W.M. R. Schwartze’s presentation about Biological Control of Wood Decay Fungi with Trichoderma spp.  This presentation discussed some amazing results of “mycoparasitism”.  Trichoderma is present in any good compost, and it is an opportunistic virulent parasite of other fungi.   Schwartze told of his experiments working with spore suspensions of trichoderma that he applied to pruning wounds, and found that they reduced discoloration.  He discussed a project in Brisbane Australia where he was fighting the Phellinus noxious fungi, a devastating brown rot fungus.  He introduced a specific antagonistic trichoderma fungus to fight the Phellinus noxious and kill it.  The trichoderma followed the hyphae and completely killed the fungi.  This is very promising information, but the caveat is that one must first find a specific trichoderma that will attack the fungi you wish to eradicate.  This requires procuring “carefully selected antagonists” to develop a tailor made product.  Trichoderma are not a one size fits all solution, but in the future we may be able to develop trichoderma formulations that target our most common rot fungi.  There was also some information about trichoderma and mulch, and that using fresh woodchips as mulch can intr