Some plants absorb excess nitrates or oxalates from the soil and store them in plant tissues. Toxicity problems can occur in animals which feed on these plants.
Thinning is the term foresters apply to removal of some trees from a stand to give others more room (and resources) to grow. It is a tool for improving timber value, making sites more productive, and — perhaps most commonly — for keeping trees healthy. Learn when to thin and how much to cut, and learn why the answer may be "it depends."