In order to survive, plants rely on a variety of environmental factors. The primary ones are climate, soils, and geology which are delineated within these pages. However, there are many other specific ecological factors (termed ecofactors here) that impact plants. Plants are part of complex, non-linear nested systems. What is meant by this? Simply, that plants do not exist as lone entities—they are inextricably tied to other organisms, interactions with these organisms and even human or social systems of value, management and use.