A new study by Linda Phillips examines how the diversity of bird species varies across North America in relation to primary productivity. The authors found that they could categorize regions into three groups with three contrasting types of productivity/diversity relationship. In regions of high primary productivity, such as the southeast US, diversity decreased as productivity increased. In regions with intermediate productivity, such as the boreal forests of Canada, the authors found no significant relationship between diversity and productivity. In areas of low productivity, such as the western Great Plains, Great Basin, and interior Alaska, diversity increased with increasing levels of productivity.
Conservation planners in Australia and elsewhere have proposed the ‘greenspot’ approach, in which areas of high and consistent productivity would be prioritized for conservation (see for example, Berry, Sandra; Mackey, Brendan and Brown, Tiffany. Potential Applications of Remotely Sensed Vegetation Greenness to Habitat Analysis and the Conservation of Dispersive Fauna [online]. Pacific Conservation Biology, Vol. 13, No. 2, 2007: [120]-127.
Based on the results of Phillips and colleagues, the greenspot approach might make more sense in arid regions of the western US and Australia, whereas a different approach would be used in higher-productivity regions.