Summer on a Shoestring

Beech Bark Disease by Tony
July 22, 2012, 4:45 am
Filed under: Forest Health | Tags:


(Fig. 1)  Diseased Beech Tree

American Beech (Fagus grandifolia Ehrh.) is one of the three dominant tree species in Northern hardwood forest. Beech bark disease is a disease complex which has been found in North America around 1890. Now the disease has been spread around the Northeastern part of this country (Fig 2.).Obviously, our experimental sites in New Hampshire are the victims of this disaster. The initial inventory data which we collected in 2005 and 2011 has indicated that the mean disease severity is much higher in old stands. And the latest inventory data from 2011 showed that the disease is much more serious than before. However, there are still no effective ways to control this disease complex. Many trials carried out by various researchers have resulted into failures.

So, the first step of our whole research plan on beech bark disease is to figure out how the disease progress in specific trees. Because the methodology we used in the past was just very qualitative and could just provide a general understandings about how the disease develop from a stand or plot viewpoint. We do not yet know how the disease like scales or fungus occupy and get the whole tree infected and dead. And subjection caused by different investigators using a vague scale would also affect the final result. Thus, a new rating system or technique is really needed.

Fortunately we have Jon Cale, a PhD student from ESF who is an expert on BBD, joined our crew this summer. He introduced the image analysis method to us which I think could better describe and quantify how the scales and fungus develop without subjection. We will take pictures in each selected tree from four cardinal directions at three height levels (0m, 1m, 2m). Then analyzing these pictures by a program called ImageJ.

Another thing we could expect is to see how the fertilization influences the disease. We have divided each site into 4-5 plots with different fertilization treatments (N, N+P, P, Ca) which began in spring 2011. It is reported by some researchers that the reason young beech trees are less infected than old trees is because of the low nitrogen content in young beech trees. So our inventory is also intended to discover whether these nutrient additives would ease or facilitate the disease.

Surely this kind of inventory would be very interesting and you would definitely get the feeling of saving the earth planet by doing this! Welcome to join us!



Fig 1. Distribution of BBD around North America (Provided by USDAForest Service, 2005)