Book review.

DOI:10.2458/azu_rangelands_v27i1_Scarnecchi

A viewpoint: using multiple variables as indicators in grazing research and management.

Multi-variable analysis of grazing research has seen little conceptual development and even less application. To advance research on the multiple relationships of livestock grazing, computer-based analyses using multiple variables are needed. Dynamic variables describing livestock-herbage relationships must be developed to describe dynamic processes such as herbage growth and disappearance. Such variables could be used either alone or in combination with other variables as indicators to analyze and manage grazing. This paper presents 4 arrays of derived variables and discusses their individual and combinational value in analyzing and managing grazing. Greater power in analyzing grazing will come from use of combinations of variables rather than relying on single variables, e.g., stocking level. The variables described are useful in comprehensive analyses of research or in ad hoc roles aiding decisions in management. The paper also discusses possible future uses of variables as indicators in computerized analyses of other ecological systems

The rangeland condition concept and range science's search for identity: a systems viewpoint.

This paper analyzes the rangeland condition concept, and discusses how the search for a general concept has been part of the larger search for the identity of range science. It distinguishes between the concept and the assessment of rangeland condition, and distinguishes between the concept and ecological theories used in condition assessment. It proposes a general condition concept of modular character in which different ecological theories and field data are interchangeable components applied locally on appropriate, specific areas. It discusses past distinctions between range management and range science, implores the development of range management science, and discusses efforts needed in research, education, and administration to pursue its development. It interprets past and current events related to range science, including the advent of rangeland health, and discusses their relationships to range science's unfulfilled development as a management science. The paper encourages systematic design of concepts needed to allow range science to fulfill its philosophical potential as a management science

Viewpoint: concept design in range management science.

This paper is an analysis of general principles involved in designing concepts for range science. It discusses the diversity of conceptuality in range science, from dimensional units to variables to simple models to more complex decision-aiding models. It examines how considerations of abstraction, confounding, and generalization allow development of multi-objective concepts needed in a range management science of many variable, interactions, and models. Examples related to each principle are provided. The paper discusses the importance of avoiding internal confounding within concepts and the necessity that such confounding be avoided in order to allow clear analyses. Ad hoc indices are characterized as inadequate substitutes for explicit models of more complex concepts such as preference and diet selection. Design efforts emphasizing multiple objectives will produce concepts of general use in range management science