Interesting study that reinforces angler conventional wisdom.
The short version here is that a study was done of fallen tree cover in Blue Marsh Lake and the study revealed larger numbers of fish congregating around trees than shoreline areas without the fallen trees. In particular, crappies and carp were very fond of the trees. Bass were about twice as likely to be in the trees. In my experience in streams and rivers, carp are especially fond of schooling up under the branches of fallen trees.
While I don't often fish BM Lake, I do fish Marburg which has similar structure and felled trees. Many anglers on Marburg, esp those targeting crappies (a very popular fish on PA lakes) focus their entire efforts on these fallen trees.
Anyway, no surprise on the results....but a worthwhile study to quantify the positive aspects of the tree felling program.