The growth of some New Zealand trees

Summary Growth of Acer pseudoplatanus was compared with the New Zealand species Fuchsia excorticata. Aristotelia serrata, and Hoheria glabrata (deciduous) and Nothofagus menziesii, N. fusca, and N. solandri (evergreen) under long, short, and natural days in a greenhouse and outdoors. Acer rapidly became dormant in short days, as has been reported from the Northern Hemisphere. The New Zealand species, however, continued growth through the summer in all day lengths, and stopped only when temperatures began to decline with the approach of winter. Then all species became dormant, most rapidly in natural day lengths with the plants in short days usually soon following. In Hoheria and Fuchsia, however, dormancy was delayed in short days. In all species it was delayed in long days. It thus appears that the shortening days of autumn are involved in producing the natural dormancy of New Zealand trees, but are effective only in conjunction with declining temperature. In Northern Hemisphere trees, by contrast, it is...