Davidsonia

Editor, Iain Taylor looks at current issues of the botanical world.

This paper summarizes the historical mapping of the major areas of Quercus garryana (Garry oak) ecosystems, from immediate pre-European settlement to present day. Less than 10 percent of the original Garry oak ecosystem remains on south-eastern Vancouver Island, British Columbia, Canada. Originally, there were two major ecosystem types, one on deep soils, known as Parkland Garry oak ecosystems, and the second on shallow soils, often referred to as scrub oak ecosystems because the oak trees are often of low stature. Little of the deep soil ecosystem remains, because these communities were the first areas cleared for agriculture and urban development. More of the shallow soil ecosystem remains, as many of these rocky areas were more difficult to develop in the early days of settlement and were not good for agriculture. However, many of these sites are presently being lost to development if they are not in protected areas. Much of the remaining area of these ecosystems is dominated by invasive alien plant species, so that less than 5 percent of the original area remains in natural condition.

Vascular plant species lists were compiled for all the major prairies that remain in south Puget Sound, Washington State, USA. Overall, 278 species were recorded in 15 prairies that ranged in area from 12-3,000 ha. Fifty-nine percent of these were native taxa, with forbs the most frequently represented life form (74%). Seventy percent of the species were perennials. Annuals were most common in Ft. Lewis prairies, which may reflect higher levels of disturbance. On average, introduced annuals outnumbered the native annuals 2:1. Twenty-three native species were widespread, occurring in >80% of the prairies; all but one of these were perennial. In contrast, 5 of the 18 most widespread non-natives were annuals. Forty percent (64) of the native species were found in only 1 or 2 prairies, and another 61 prairie species were documented from a variety of sources as formerly or currently growing in the south Puget Sound region, but not currently known from the 15 prairies we studied. Our results provide a basis for identifying species potentially appropriate for including in prairie restoration efforts in this region. Our findings also suggest taxa that are uncommon, rare, or locally extirpated, and which may only persist in this region if active efforts are made to establish them in extant sites.

A species list of the vascular plant flora of the South Puget Sound Prairies, Washington, USA.

Andrew Riseman, Assistant Professor in Agroecology at UBC and Plant Breeder at UBC Botanical Garden and Centre for Plant Research reviews Breeding Field Crops 5th Ed. by D.A Sleper and J.M Poehlman. 2006.

Editor, Iain Taylor comments on some recent botanical publications of interest.