As plants grow in their development, they undergo many changes either due to climate change or other environmental issues that affect plants but I want to know how false growth rings form and why they do not end their development.
What exactly is your definition of "false" growth rings? I see some abnormalities during the 1317-1319 growing seasons, but the normal rings are still very easy to count by eye. Do you have some context for what happened during growing seasons 1317, 1318 and 1319? It could be climate-related (see previous comments), or it could be something related to the health or physiology of the tree. Was there a blight or an insect invasion during these years? Perhaps this species of tree begins to change its bark structure as the tree matures? (What species is this? Where did it grow?) It would be helpful if you included more context in your question so we can help you make an educated guess.