| Citation | Crawley is internationally renowned for his pioneering work on the dynamics of animal-plant interactions. His central research aim is to understand how herbivorous animals influence the distribution and abundance of plants. His great achievement has been to develop a new field from what had previously been the separate, specialist preserves of botanists and zoologists. The fundamental insights are that plant-plant interactions can be modified by selective grazing, and that animal demography can be altered by grazing-induced changes in plants. His distinctive contribution has been the refinement of ecological theory in the light of long-term observations and experiments carried out in the field. He has applied these techniques to practical questions including the biological control of weeds using insect herbivores and the role of alien ungulates in facilitating the invasion of ecosystems by alien plants. He is distinguished for the development of protocols for assessing the environmental risks associated with the deliberate introduction of transgenic (GM) plants, and has carried out the only existing long-term evaluation of the ecological consequences of GM plants in natural habitats. |