National Forest Inventories in North America for monitoring forest tree species diversity

Abstract

A successful forest tree diversity-monitoring programme delivers reliable estimates of rates of occurrence, the spatial extent and the abundance of all forest-dwelling tree species. Sample-based estimators of these characteristics are provided for North American national forest inventories and discussed in the context of monitoring for forest tree diversity. The expected performance of the Canadian, the United States, and Mexican national forest inventory is quantified for three regions in each country. As expected, estimates for many less common and rare species are imprecise and sometimes these species are missed completely. We suggest augmenting existing national forest inventories by purposive sampling for these species.

Key words:

• Population size
• species richness
• occurrence
• sample design
• power
• change estimates

Acknowledgements

We are indebted to Paul Boudewyn (Canadian Forest Service), Patrick Miles (US Forest Service), and Rigoberto Palafox, Adriana Rodríguez and Roberto Torres in Mexico for their assistance in compiling the tree species occurrence data for our study regions.