how to survive

Bud burst, the day when a tree or plant's leaf or flower buds open,is occurring earlier in the year for some species.For every one degree Celsius rise in temperature,bud burst happens five days earlier than usual.Differences in timing affect not only plants,but the insects and birds that depend on the plants for food.For example, oak trees in the Arnhem Forest of the Netherlands now experience bud burst ten days earlier,as compared to twenty years ago.New oak leaves are a favorite food of winter moth caterpillars.To survive, the caterpillars adapted to the change in the tree's timing,and now hatch 15 days earlier than before.