INTRODUCTION

Plants can be devasted by attacks from adversaries. Recall the near total damage to vegetation caused by plagues of locusts down the centuries or the wiping out of entire crops by disease as in the infamous example of the potato blight in Ireland in the mid-nineteenth century.

Yet, green plants still dominate the landscape in spite of their countless enemies; plants make up a major proportion of the world's biomass, the total weight of all living things. They have evolved an impressive array of strategies, physical and chemical, to defend themselves. Some plants even seem to use their weaponry to ward off competition from their own kind.

PLANT DEFENSES AGAINST PREDATORS

Indeterminate growth

Plants have an amazing ability to renew themselves even as they are being attacked. Grazing animals may spend major amounts of time cropping their preferred food sources, yet these same plants usually maintain healthy and vigorous growth as long as environmental conditions continue to be favorable. Disease may devastate a plant in the wild but rarely is the attack so complete as to wipe out an entire species. Renewal almost inevitably occurs, given enough time, because plants have an indeterminate growth style.

Physical defenses

Another partial answer to the question of why plants dominate the world is that many of them have developed effective physical defenses.