The Growth of Seedlings of Quercus Petraea
1960; Wiley; Volume: 48; Issue: 3 Linguagem: Inglês
10.2307/2257332
ISSN1365-2745
Autores Tópico(s)Forest ecology and management
ResumoAcorns were planted in a variety of soils in each of three cages (1.3 m high x 3-7 m long x 2*4 m wide) constructed to reproduce artificially different canopy densities. The acorns were collected in the grounds of Wray Castle near Lake Windermere in November of 1955 from under a group of four mature trees of Q. petraea and were well mixed before planting. The seedlings were measured over a three-year growing period. Field tests showed that large numbers of acorns are eaten by birds and small rodents so each cage was completely covered with half-inch (13 mm) mesh galvanized wire netting to prevent any loss of acorns in this way. The effects of different intensities of canopy cover in modifying micro-climate were simulated by using green nylon net to cover the top and sides of the cages, one cage (B) being covered with a single layer of net, a second (C) with two layers and the third (A) having no nylon net cover. The nylon netting proved to be comparable to a forest canopy in that it effectively reduced light intensity and precipitation in the cages. Light, measured by a selenium photoelectric cell during dry, evenly lighted periods, was reduced up to 85, 45 and 15 % of that in the open for cages A, B and C resspectively whilst in the same cage order, only 96, 83 and 54 % of the precipitation reached ground level. Rain, trapped on the nylon, either evaporates back into the
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