or many years, managers have used the carbohydrate reserve theory to decide when grazing should occur to maintain healthy plants. This theory states that the soluble carbohydrates stored in the roots and crowns of plants indicate plant health and ability to regrow following grazing. According to the theory, during the early vegetative stage of plant growth, carbohydrate "reserves" are low, so plants should not be grazed. During late vegetative and early reproductive stages of growth, carbohydrate "reserves" are higher, and plants can better tolerate grazing (see figure 1). Over the years, a great deal of research has been conducted to produce carbohydrate concentration curves for grasses, forbs, and shrubs, as illustrated below.