Viscin Cells in the Dwarf Mistletoe Arceuthobium ... - Davidsonia

Davidsonia 17:3 95
Figure 5: Scatterplot of scores on principal component 1 (PC 1) vs. PC 2 from a
PCA of cover scale values for Sanicula crassicaulis, Dactylis glomerata, Lomatium utriculatum,
Camassia quamash, Ranunculus occidentalis, Dodecatheon hendersonii, Sanicula crassicaulis
and grass/forb ratios at two Gary oak communities on southern Vancouver Island.
Ellipses enclose 68% of samples within a group. Values in parenthesis indicate
percent variation explained by component..
compared to Site 2 as the latter had excluded agricultural ruminants for
a longer period of time, perhaps giving this population time to increase
its density. A greater grass/forb ratio at Site 1 relative to Site 2 (Table 1)
implies that invasive plant taxa comprised a greater part of the flora at
Site 1 than at Site 2 as invasive Bromus spp. and Dactylis glomerata were
a large component of the grass flora at these sites. A site with high
biodiversity is generally to be preferred over one with low biodiversity,
particularly if that biodiversity is in the form of native species. Invasive
species tend not to have the allelic variation inherent to natives due to
founder effects (Lande, 1988) and can also demonstrate more plasticity
in resource use and therefore fewer novel adaptations (Kolar and
Lodge, 2001) so biodiversity is often a good measurement of priority
for selection, should the conservationist need to choose between any