I contribute a tropical perspective in a new paper out in Global Ecology and Biogeography that takes a fresh look at the question of how productivity varies with latitude, with some new analyses of old data and notably a contribution of our recently compiled data from the usually data-poor tropics. Contrary to some recent arguments, the new data show quite convincingly that productivity does tend to be higher in the wet tropics than at high latitudes (the main reason being the lack of a winter and hence a longer growing season).
Gillman, L. N., Wright, S. D., Cusens, J., McBride, P. D., Malhi, Y. and Whittaker, R. J. (2014), Latitude, productivity and species richness. Global Ecology and Biogeography. doi: 10.1111/geb.12245. Supplementary Material
Yadvinder Malhi is an ecosytem ecologist and Professor of Ecosystem Science at Oxford University