My impression to start is that fallen branches have a predominance of lichen, jellies and other fungi on them when they fall and land on the ground. Growth on the branches includes millimeter sized fungi. Often the branch looks very overgrown to the point where the bark is simply not visible. Some key questions of interest that come to mind are: what macroinvertebrates live in these coverings on these dead branches; do they provide food foraging sites for birds; is there weight added to a dead branch by living colonizing growth especially if is holds water which would be the major weight element. So far I have found one springtail on a fallen branch but it looks similar to the predominant species I am currently photographing on fallen leaves, long fallen tree trunks and the living vegetation.
Issues to resolve are whether the fallen branch is from a 100% dead tree or from a living tree.
Comparisons to make can include living things colonizing a fallen tree on the ground left full in tact which I have several that i have followed that have been down for several years on my yard which is my sample territory.

I am photographing the total fallen branch length via one photograph with a length scale of a one foot ruler.
I think at the present branch diameter will be most interesting and informative, thicker branches might fall sooner or last longer, TBD HYPOTHESIS!.
Thinner branches cannot hold the same size and number of organisms a thicker branch might, TBD HYPOTHESIS!
I need a better ruler, the transparent ruler is not working well.
Scoring notes on approximate FALL AGE of the branch or tree will allow the determination of how time on the ground or on the living tree a community might take to assemble.

I am finding mostly either no growth on branches fallen or a large community of different species. Are these cooperate assemblages of fungi? How do they interact? I will be posting more photographs of these species dense branches. Is there a succesion of predicatable species that appear on a clean empty branch? Are some species keystone in enhancing these communities maybe by improved water retention? or nutrients?

I am aiming to compare species colonizing: tree falls, chopped wood blocks, brush pile trimmed tree branches and branches naturally fallen directly from trees on 2 acres. I am leaving out preserved treated 4x4 path borders and the house or porch boards since the treatment of the wood change or preclude natural colonization which is what i am more interested in. This will allow me to see if there are different species for these different wood substrates. If wood is the only element necessary for wood-associating and eating organisms to settle on the species distributions should be the same.
I am not seeing any life appearing on cut down branches thrown and piled on brush piles.
The fallen trees are covered with large shelf fungi and moss carpets.
Storm dropped fallen branches in contrast are heavily laden with many different species of lichen, jellies and other fungi i have not found commonly in over ten years of photographing nature on the same 2 acres.
It suggests tree top dead wood is providing a novel substrate and environmental conditions that are nourishing a distinct community of lichen and fungi.
It would be nice to know if any animal species are unique to this microhabitat.
I see lots of springtails on fallen wood but they are very common ion the leaf litter surrounding this material.
I will NOT be rappeling between or climbing up into the trees but it would be interesting!!!