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128 associated with dry habitats. Similarly, Kruckeberg (1979, 1992) reported higher richness of dry habitat associated species for ultramafic sites in British Columbia and Washington as compared with the surrounding floras. Thirty-seven species are entirely or nearly excluded from ultramafic soils at the study site (Table 5). The main functional groups are deciduous broadleaved trees and shrubs (18 species) and mesic to moist habitat associated herbs (11 species). The exclusion of broad-leaved trees and shrubs from ultramafic soils has been previously documented (Whittaker 1954). These functional groups may be restricted to non-ultramafic substrates partly because of soil chemistry, and partly because the greater canopy cover, shade and soil moisture conditions better meet the habitat requirements of the particular species. The exclusion of dry habitat-associated herbs (six species) and the fern Cheilanthes gracillima, from ultramafic substrates is an interesting pattern since ample habitat appeared to be available on the ultramafic side of the mountain. These species may be directly excluded by ultramafic soil factors. Thirty-four species representing all functional groups except ferns were widespread on all three soil types (Table 6). These bodenvag species may be exhibiting one of two responses to ultramafic soils: 1. they may be indifferent to the adverse chemical and physical soil environment or 2. those individuals occurring on ultramafic soils may represent edaphic races or ecotypes tolerant of soil conditions. Evidence for ecotypic differentiation has been shown for bodenvag species from California (Kruckeberg 1951; Rajakaruna and Bohm 1999) and the Pacific Northwest (Kruckeberg 1967). For example, Kruckeberg (1967) found strong ecotypic response in Achillea millefolium and Potentilla glandulosa, partial ecotypic response in Antennaria racemosa, Juniperus communis, Pinus contorta, Pseudoroegneria spicata and Taxus brevifolia. These species, therefore, may exist as ecotypic races on the different soil types. He found no ecotypic response in Rubus parviflorus which may simply be indifferent to ultramafic soil conditions. We conclude that the ultramafic soils of Grasshopper Mountain exert an influence on plant growth which is similar to the vegetational response in Oregon and California. While richness and diversity levels are similar across substrates at Grasshopper Mountain, the floristics and ecological relationships are distinct. The presence of ultramafic soils within a matrix of nonultramafic soils is important for increasing local and regional diversity and
<strong>Davidsonia</strong> <strong>14</strong>:4 129 Figure 1. Simplified diagram of photosynthetic apparatus. PS I and II are photosystem I and II, respectively; OEC is the oxygen-evolving complex; P i is inorganic phosphate; e - represents electrons; H + represents protons; CH 2 O represents carbohydrate products of photosynthesis. Photos: Rob Guy Figure 2. Colour changes later in younger leaves. Figure 3. Isolated tissues turn before areas adjacent to major veins in this Acer rubrum (red maple) leaf.
Page 1 and 2: Volume 14, Number 4 October 2003 Da
Page 3 and 4: Davidsonia 14:4 109 Editorial Small
Page 5 and 6: Davidsonia 14:4 111 Autumn Colours
Page 7 and 8: Davidsonia 14:4 113 Although ideall
Page 9 and 10: Davidsonia 14:4 115 them. Indeed, o
Page 11 and 12: Davidsonia 14:4 117 The complex and
Page 13 and 14: Davidsonia 14:4 119 There is a simp
Page 15 and 16: Davidsonia 14:4 121 A floristic and
Page 17 and 18: Davidsonia 14:4 123 ranges are affe
Page 19 and 20: Davidsonia 14:4 125 plots. The valu
Page 21: Davidsonia 14:4 127 habitats within
Page 25 and 26: Davidsonia 14:4 131 Photo: Rob Guy
Page 27 and 28: Davidsonia 14:4 133 Photo: Gary Lew
Page 29 and 30: Davidsonia 14:4 135 Photo: Hugh Dau
Page 31 and 32: Davidsonia 14:4 137 for the mainten
Page 33 and 34: Davidsonia 14:4 139 Ministry of Emp
Page 35 and 36: Davidsonia 14:4 141 Total Number of
Page 37 and 38: Davidsonia 14:4 143 Local Ultramafi
Page 39 and 40: Davidsonia 14:4 145 The North Ameri
Page 41 and 42: Davidsonia 14:4 147 chilling requir
Page 43 and 44: Davidsonia 14:4 149 traits being lo
Page 45 and 46: Davidsonia 14:4 151 Crops. Edited b
Page 47 and 48: Davidsonia 14:4 153 arguta with muc
Page 49 and 50: Davidsonia 14:4 155 Volume 14 Index
Page 51 and 52: Table of Contents Editorial Taylor

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