[hinkley]

A group of trees is called 'a wood'. And while it's really hard to have a forest without trees, it's really easy to have a bunch of trees but not a forest. The apex tree species in a forest don't come until much later. They are in many cases the tree that grows in the space left by the death of a tree that grew in the space left by the death of yet another tree.

Your friend had a field full of pioneer tree species. Those trees stopped his field from being a meadow (a badly, badly damaged meadow) but they have to die to make way for the real forest building species.

For instance, a pioneer tree dies. A hemlock, which likes to grow on fallen trees (nurse logs) takes its place. When the hemlock grows old and dies, your old-growth species might establish in the same spot, or it may wait to replace whatever grew after the hemlock.

[adtechperson]

True, although the notion of a climax forest in New England is a bit of a myth, since they are constantly changing. For example, there is something called a "fir wave" where waves of fir trees die and are replaced with other trees.

https://en.wikipedia.org/wiki/Fir_wave

For more information, this book: https://www.goodreads.com/book/show/9698421-nature-guide-to-... has wonderful information about how northern forests change over time.

[hinkley]

Don't think I knew about fir waves, but from a human perspective, most of the interesting things happen at the edges of a forest (much of the stuff we can eat grows in clearings or edges), so windbreaks falling like dominoes makes a good deal of sense.

Where humans are involved in planting the trees, I'd expect statistical clusters, because if you plant a thousand oak trees in the same year, many will die within the same decade or so. My forestry friend in college complained about how every time trees died on campus, they'd replace them all with some other species, creating waves of dead trees every few decades, whether disease or old age, instead of a tree or two every year.

But then even without humans, nut trees are born in statistical clusters as well, ('masting' is an adaptation to overwhelm predator populations) so it stands to reason they'd die in clusters too. And a bad spring may result in more seeds germinating the following year.

[adtechperson]

Fir waves are pretty obscure.

Agree about the clusters. I am most familiar with the northern forests of New England (strictly as an amateur) and they are a wonderfully dynamic place. From big events like the Hurricane of '38, to small wind storms, fires, ice storms, and just an individual tree getting old and falling over, they are in a wonderful constant state of flux.

One of the saddest things is the loss (or coming loss) of so many important species. The American Chestnut and Elms are long since gone. The Hemlock and Ash are also under threat from pests and the Beech may be as well.

[hinkley]

Chestnut may be coming back. Hemlock is an important success tree so I'm not sure what happens when those are in trouble.