Do commonly observed spatial relationships also exist over time? As an example of attempting to answer this question, this article examines whether the frequently observed diversity-biomass-productivity-relationships over space can also be seen over time. Syntheses of long-term data and literature show that when the full successional cycles are examined, diversity and productivity are usually positively related to each other but unimodally related to biomass. These relations are consistent with frequently observed patterns over space. The mechanisms underlying the spatial relationships regarding how these three variables affect each other may also apply to the temporal patterns. However, as diversity, biomass, and productivity are temporally correlated and change simultaneously with physical factors and with time, identifying any causal relationships among them would need experimental confirmation.
Guo, Qinfeng. 2008. Interactive Effects of Diversity and Biomass on Productivity: Insights from Succession. In: Lectures in Modern Ecology (IV) Theory and Applications, Ch. 3, p. 59-73