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Global net change in local plant biodiversity?

A fascinating and apparently increasingly vociferous debate about evidence for change in local biodiversity is happening. As well as just being really interesting and important in its own right (i.e. what is happening to local biodiversity), one side suggests that evidence for no change “directly contradicts the key assumption linking experimental results to ecosystem function as a motivation for biodiversity conservation in nature.” (Vellend et al 2013). Such research was the focus of bitter debate in the late ’90s and early ’00s — its under attack again.

Item for the prosecution number 1: Global meta-analysis reveals no net change in local-scale plant biodiversity over time (Vellend et al 2013). (Accompanying essay by Chris Thomas, and a related essay by Chris Thomas.)

Item for the prosecution number 2: Assemblage Time Series Reveal Biodiversity Change but Not Systematic Loss (Dornales et al 2014).

Item for the defence number 1: Estimating local biodiversity change: a critique of papers claiming no net loss of local diversity (Gonzalez et al 2016). (Accompanying GitHub repo.)

Item for the prosecution number 3: Estimates of local biodiversity change over time stand up to scrutiny (Vellend et al 2016). (Accompanying GitHub repo.)

(Sorry to other relevant articles I’ve not included, I ran out of time…)

What do I think? I found figure 2 in the Gonzalez critique very illuminating and thought provoking. And lessons learned from studies of effects of biodiversity loss on ecosystem processes and services have considerable practical importance when planning the future.