Comparison of the quality of red and silver beech (Nothofagus) seeds in Nelson Lakes National Park, New Zealand

Red (Nothofagus fusca) and silver (N. menziesii) beech seeds were collected during 1995 using 100 seedfall trays. This was a mast year for red beech (74% viability) but only a partial mast year for silver beech (28% viability). Differences between triquetrous and flat seeds are probably confined to shape, since weight and percent germination were the same for both types of red beech seeds. There was a trade-off between the number of seeds and seed weight for red beech, but little evidence of one for silver beech. The weight, viability, germination, and NPK content of red beech seeds were greater than for silver beech. Both species had a similar energy content per gram of seeds, but the larger red beech seeds contained three times more energy per seed (180 kJ) than silver beech (60 kJ). Greater reserves of energy and nutrients might produce more vigorous seedlings, but make seed predators prefer red beech seeds.