Sala, O. E., and A. T. Austin. 2000. Methods of estimating aboveground net primary production. Pages 31-43 in O. E. Sala, R. B. Jackson, H. A. Mooney, and R. W. Howarth, editors. Methods in Ecosystem Science. Springer Verlag, New York. (Abstract)

------There is not a best method to measure aboveground primary productivity. Decisions about methods are even more complicated, because methods which reduce one kind of errors increase other kind of errors. It is somehow counterintuitive that the more complicated and expensive methods which take into account most of the flows involved in primary productivity may yield results with the largest errors. Although these methods are closest to the concept of primary productivity they may yield results which are the farthest from the real value of productivity. Uncertainty in the variables used to estimate primary productivity result in greater uncertainty in the final estimates of productivity. Because of the way productivity is calculated, uncertainty in the input variables results always in overestimation of productivity estimates. This chapter provides description of the kinds of errors associated with each method and how they relate to the ecosystem characteristics as well as the cost and benefits of the different methodological alternatives. The best method will depend on the characteristics of the ecosystem such as turnover time, seasonality, etc and on the objectives of the study.