It's sad to see the Transformation Tree transforming into death, but instead of feeling those negative emotions when in the copse, I experienced a sense of vitality. The blackthorn is rampant.
Given a few years, that will have taken over the whole copse and there'll be very little ground flora. Now, that's almost limited to nettles, brambles and lords and ladies. But, the poplars will fall, crushing the thorns beneath them... and then what? Light and space will open up.
Actually, I am fascinated. I wish I could see the copse in five, ten, twenty, fifty, a hundred years - being left, just sorting itself out. Maybe the roe deer are large enough to open some pathways and glades?
What of the soil? Atop the hill, the poplar copse doesn't get so much run off... maybe all the bacteria and fungi could turn the soil into a micro-heaven?
I looked across at the other circular copse, as corvids cawed and flew - I think they'd been mobbing a kite. Then I walked down to the old oak, which is where the video ends.
This reminds me of the park woods where I regularly walk. The woods were heavily damaged by Hurricane Fiona two years - and many mature trees fell. And like you it's very interesting to see what's happening, for example the growth of elderberries and other shrubs/small trees who are soaking up the lights provided by the openings.