ABSTRACT
Plant response to herbivory is mediated by a variety of interactive processes in grassland ecosystems, it is necessary to examine not only individual plants, but also plants growing in mixtures in the field, to appreciate the causal mechanisms involved in plant responses to herbivory. This chapter reviews a number of individual plant responses to grazing, and ways in which these responses may be modified by other environmental variables in the field. It focuses on important species native to the western Great Plains; results of experiments on plants from other rangelands are discussed when necessary to illustrate a point. The defoliated plant, however, typically consists of a mixture of partially damaged leaves, undamaged leaves, and young leaves which expanded following grazing. The allocation of a high proportion of current photosynthates to synthesis of new leaf blades at the expense of other plant parts in defoliated plants appears to be an adaptation which permits rapid restoration of plant photosynthetic capacity following grazing.
