Monitoring Manual for Grassland, Shrubland and Savanna Ecosystems.

Herrick, J., J.W. Van Zee, K.M. Kavstad, and W.G. Whitford. 2005. Las Cruces: USDA-ARS Jornada Experimental Range, ISBN 978-0-9755552-0-0 (paper), CDN $24.95 (paper).

Ecosystems of the semiarid environment are known to be quite fragile and thus susceptible to degradation if inappropriately utilized. Consequently, there is an urgent need for a guide which could provide readers with field design and sampling techniques which are required for properly assessing and monitoring these ecosystems. This detailed two-volume manual, perhaps the first of its kind, easily fulfills this demand and should be required reading for any scientist or resource manager working in a semiarid environment.

Ecosystem health has three aspects, watershed function, recovery mechanism, and soil stability (National Research Council 1994, Pyke et at., 2002). Based on this notion, the first volume of this manual gives a brief description of how to establish a monitoring program and how to conduct field work. Specific topics addressed in this volume include making management objectives and monitoring strategies, selecting measurements for different aspects of ecosystems degradation monitoring, designing tables of data recording, and methods of canopy indicator calculations. If time is of critical importance, this volume is so descriptive that users need only to read this first volume before initiating their field work. However, it is recommended that further readings be considered in particular when considering the field design, data collection, and results interpretation.

The second volume of this series provides more detailed information about monitoring program design, field design, site selection, sampling methods, data recording, data preprocessing, and results interpretation. Section I of this second volume gives hands-on instruction on general steps of program design, from setting monitoring objectives to establishing sites for long term monitoring. Section II presents supplementary sampling methods for measuring soil compaction, water infiltration, plant production, species richness, vegetation structure, and tree density. Specific attention is given to riparian ecosystems due to their importance relative to other semiarid environment ecosystems. Section III covers methods of data preprocessing and results interpretation. In the final section, a great deal of background information is provided for sampling design, ecosystem functions and disturbances (invasive species, fire, and off-road vehicle use), state and transition models, remote sensing and ecosystem monitoring, and the relationship between soil carbon and ecosystem condition, which are all helpful for results interpretation and field design.

The merits of these volumes are obvious. First, they provide hands-on help in field designing, data recording, preprocessing, and interpretation which is clearly written and presented in a very easy to follow style. Second, the two-volume design is a great idea for organizing the steps required for such field endeavours. Specifically, the user can start with the field design guide without immediately reading the second volume. Third, they provide instructions on making equipment for monitoring soil infiltration, which is both time-and cost-saving for field practitioners. Fourth, the methods provided in these volumes have been practiced in the field for many years, which make the application of the methods presented in these books reliable.

There are of course some shortcomings, in particular with regard to the sampling design and remote sensing sections. For example, the line intercept method is commonly discussed in the booklet since it is quick and therefore cost-saving. However, the line intercept method cannot provide as much information as other methods such as plot/quadrat based sampling. This might be the reason that the authors introduced Whitaker's method for species composition sampling in the second volume. Therefore, it might be better if two or three sampling methods could be combined together in the first volume. Moreover, three transects are set up regularly for the design of upland long-term sampling plots but the authors do not mention how they deal with multi-year sampling. Since transects will be trampled each year, the hypothesis of independent sampling must be false. With regards to remote sensing, the extraction of biophysical information from these data for the purpose of degradation monitoring is becoming increasingly common practice--especially where field data are available, as is the case presented in this manual. However, the manual only briefly introduces the application of remote sensing techniques in stratification of the study area and, moreover, the application of different resolution imagery in extracting ground information is not discussed. A further introduction of spectral image classification and quantitative measurement of biophysical data would be preferred so as to make full use of all information from the field and to better understand observed change.

In spite of these weak points, this two-volume book is highly recommended as it provides readers with a variety of reliable techniques for establishing monitoring programs in ecosystems of semiarid regions. Moreover, given that it is quite concise, well organized and easy to read, it should appeal to a wide range of users including resource managers, engineers, field technicians, and academics.

References:

National Research Council 1994. Rangeland Health. Washington DC: National Academy Press.

Pyke, D.A., Herrick, J.E., Shaver, P. and Pellant, M. 2002. Rangeland health attributes and indicators for qualitative assessment. Journal of Range Management, 55: 584-597.

Reviewed by Chunhua Zhang, Department of Economics, Finance, Geography, and Urban Studies, East Tennessee State University

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