A critique for meta-analyses and the productivity-diversity relationship.

It is an exciting time to be an ecologist. Over the past several decades, our discipline has matured from one focused on the assembly of case studies based on natural history, to one that has seen improved conceptual frameworks and mathematical models that help explain ecological phenomena from species coexistence to elemental cycling. The maturation of our discipline has been fostered by many things, including improved technology, increased availability of data, and emergent methods for analyzing large data sets. One factor that has played a central role in the modern synthesis is meta-analyses. Gurevitch et al. (1992) introduced meta-analyses to ecologists and catalyzed their entrance into the ecological literature as a powerful statistical means to assess the generality of pattern and process. Soon after, the U.S. National Science Foundation established the National Center for Ecological Analysis and Synthesis (NCEAS) whose mission it is to bring together ecological data sets so that we could synthesize pattern and process using meta-analysis and many other analytical tools. NCEAS was so successful that it was soon after mimicked by other scientific disciplines (e.g., NESCent, the National Evolutionary Synthesis Center). However, when our initial honeymoon with ''synthe-sis'' was over, criticisms began to surface, exposing the inherent warts and flaws of a growing discipline. Some argued that data sets were now being analyzed, and syntheses performed, by researchers who knew little about (or perhaps had never even seen) the systems they were trying to understand. Such ''remote ecology'' reduces an appreciation for natural history, and may lead to incorrect conclusions because one doesn't understand the intricacies and contingencies of each system that reveal how pattern is linked to process. Some argued that meta-analyses were proliferating more rapidly than the methods needed for quality control, and that the concatenation of data sets was leading to a propagation of errors. These are essentially the arguments levied by Whit-taker (2010, from now on W2010). W2010 strongly criticizes the use of meta-analyses in ecology, and uses three syntheses of a fundamentally important ecological pattern (the productivity-diversity relationship, PDR) to illustrate why he believes there are flaws in the use of this tool. He especially criticizes the first of these analyses by Mittelbach et al. (2001) (from now on M2001). He argues that these meta-analyses have lacked stringent and transparent criteria in study selection, have ignored important correlates of the relevant independent and response variables (e.g., spatial scale), and have been …