A recent article by Veron et al. (2006) has a very good discussion on the history of desertification assessments and popular press reactions to scientific articles (much of that from an book chapter by Reynolds and Stafford Smith 2002). They explain that desertification is a really inclusive term, making desertification difficult to document and assess. They propose a method that could give some insight into desertification that is quite interesting: evaluating the relationship between annual precipitation and ANPP. In some cases desertification will not impact ANPP (at least in the short term), but will impact the pulse-decline response to wet or dry conditions. They go on to explain that these resposnes ought to be obervable using remotely sensed data. This approach could get to the center of desertification observation by focusing on what's important - NPP. I for one am excited to see results from such studies!

Veron, S.R., Paruelo, J.M., Oesterheld, M., 2006. Assessing desertification. J. Arid. Environ. 66, 751-763.

Take a look at the recent news feature on microbial ecology in Nature by Nick Lane (link). He uses a brief discussion of the anammox reaction as a launching point for a review of basic microbial biochemistry and a higher-level investigation of the meaning of microbial processes for studying ecosystem function. Diversity is important because of the diversity of energy releasing – redox – reactions that take place. However, diversity happens. Communities of microorganisms in ecosystems seem to be assembled to get as much energy out of the environment as possible. Thus studying the diversity of processes is interesting, but understanding how organisms function necessitates studying the behavior and efficiencies of communities, not individuals. Reducing systems to understand them has limited insofar as it decouples organisms that function in a complimentary way. What do the ideas presented here mean for understanding nitrogen and carbon cycling agricultural ecosystems?