Testing the niche-breadth-range-size hypothesis: habitat specialization vs. performance in Australian alpine daisies.

Relatively common species within a clade are expected to perform well across a wider range of conditions than their rarer relatives, yet experimental tests of this "niche-breadth-range-size" hypothesis remain surprisingly scarce. Rarity may arise due to trade-offs between specialization and performance across a wide range of environments. Here we use common garden and reciprocal transplant experiments to test the niche-breadth-range-size hypothesis, focusing on four common and three rare endemic alpine daisies (Brachyscome spp.

Extensive variation, but not local adaptation in an Australian alpine daisy.

Alpine plants often occupy diverse habitats within a similar elevation range, but most research on local adaptation in these plants has focused on elevation gradients. In testing for habitat-related local adaptation, local effects on seed quality and initial plant growth should be considered in designs that encompass multiple populations and habitats. We tested for local adaptation across alpine habitats in a morphologically variable daisy species, Brachyscome decipiens, in the Bogong High Plains in Victoria, Australia.

Niche breadth predicts geographical range size: a general ecological pattern.

The range of resources that a species uses (i.e. its niche breadth) might determine the geographical area it can occupy, but consensus on whether a niche breadth-range size relationship generally exists among species has been slow to emerge.