Wood Proj P11

The greater number of silver birch trees in square 1 means greater competition for light, forcing the rhododendron to grow upwards to compete. Hence the difference in growth form already noted. The fact that the rhododendron in this area was much shorter than that in square 2 (Fig.3) despite the competition for light, also indicates that conditions in this area are much less favourable for rhododendron growth. The silver birch trees in this area were of small girth and were shorter than in other areas of the site (Fig.5) similarly indicating generally unfavourable conditions for plant growth.

Figure 5. Silver Birch mean height and girth

Silver birch on the project site is mostly tall and slender (Fig. 5 and Plate 9). When compared to trees of comparable age in other areas of the Centre, the trees on the project site are extremely spindly and poorly developed. This is a result of the constant competition with the rhododendron and the continual battle for light. The silver birch attained their greatest height and girth in square 4 (Fig. 5), where the rhododendron was least dense (Fig.3).

Other tree species on the site occurred at a very low density, with densities of 0.05 -0.15 individuals per m² (corresponding to 1 - 3 individuals per 20m square sampled, compared to 18 - 38 for silver birch). Beech, sweet chestnut and yew were all represented by a single specimen on the project site.

Plate 9. Silver Birch Trees on the project site,
in a recently cleared area.

Continued

CONTENTS
Introduction	Site Description	Methods	Results & Discussion	Conclusions	Acknowledgements