Fourth in a series of proceedings of symposia on wildland shrubs, this publication brings together current knowledge of interactions between plants and herbivores. Topics addressed by the 31 papers include plant chemistry, palatability, nutrition and physiology, herbivore foraging behavior, and plant response to browsing.

Atriplex is a widespread genus with species dispersed over almost all continents. Many taxa within this genus perform outstandingly under a variety of stress conditions and are often an important source of forage for herbivores. Such attributes have drawn the attention of many researchers who have conducted extensive studies on Atriplex across a wide variety of environments and management scenarios. This report reviews much of the literature dealing with aspects of the biology of Atriplex from an animal-plant interaction perspective.

The 51 papers in this proceedings include an introductory keynote paper on ecotones and hybrid zones and a final paper describing the mid-symposium field trip as well as collections of papers on ecotones and hybrid zones (15), population biology (6), community ecology (19), and community rehabilitation and restoration (9). All of the papers focus on wildland shrub ecosystems; 14 of the papers deal with one aspect or another of sagebrush (subgenus Tridentatae of Artemisia) ecosystems. The field trip consisted of descriptions of biology, ecology, and geology of a big sagebrush (Artemisia tridentata) hybrid zone between two subspecies (A. tridentata ssp. tridentata and A. t. ssp. vaseyana) in Salt Creek Canyon, Wasatch Mountains, Uinta National Forest, Utah, and the ecotonal or clinal vegetation gradient of the Great Basin Experimental Range, Manti-La Sal National Forest, Utah, together with its historical significance. The papers were presented at the 10th Wildland Shrub Symposium: Shrubland Ecotones, at Snow College, Ephraim, UT, August 12-14, 1998.

The 26 papers in these proceedings are divided into five sections. The first two sections are an introduction and a plenary session that introduce the principles and role the shrub life-form in the High Plains, including the changing dynamics of shrublands and grasslands during the last four plus centuries. The remaining three sections are devoted to: fire, both prescribed fire and wildfire, in shrublands and grassland-shrubland interfaces; water and ecophysiology shrubland ecosystems; and the ecology and population biology of several shrub species.