Let me first off start by saying I have no numbers or spreadsheet, graphs or charts to back up any of these findings. This is simply my observations as a 50 Botanist in my attempts at gathering.
Firstly, we all know trees move on a timed rotation (~1hr). Once the timer is up, the first person to complete their gather will force the node to move.
What I would like to add in my second point is how the gathering of items works over time. While SE introduced messages to help us find specific points through notching, this fine tuning has lead me to believe there is more to it than swinging a hatchet.
Each item is unique in DoL, yew log and yew log +1 are seperate items as far as the game is concerned. Each item has a 24 hour "cool down" timer from what I have found.
The more of an item you get in a period of time the less of the item you will get.
On day 1 I had not gathered in several days, I was getting plenty of logs, both yew and walnut. By the end of the 1-1.5 hours of gathering, before "gather fatigue" was reached I could hardly pull down any more logs, even while notching at the correct spots.
The next day, rather about 18 hours later, I returned to continue gathering. As I gathered, my log count was still gimped compared to the previous day. However, when I did pull down logs they were almost all HQs, +1 and a lot more +2s. The day prior was almost entirely NQ logs.
This leads me to believe there is a 24? hour soft cap on items gathered while doing DoL, along with the gather fatigue impose as well.
Notes: I am 50 BTN gathering in Cedarwood. Pulled roughly ~120-130 logs in ~1 hour (walnut and yew) I alternated between 2 trees and a mining node.
If anyone else has similar findings about DoL, please share :)