NOTES AND QUERIES
165
only about 70% of that outside the canopy. Also, within the Acacia community the windspeed was markedly reduced.
The initial effect of fire was to kill the leaves and most branches of the Acacia trees, and to remove essentially all of the grasses and herbs, and the plant remains (litter) on the surface. Subsequently, the acacias produced new branches and the understorey plants grew again. Some of these changes can be summarized as follows:
Acacia confusa: % cover by living crown Understorey plants: weight in g. per sq. metre Bare ground (without living plants): % Litter: weight in g. per sq. metre
1976 1977
5 24
318 523
80 38
56 447
Obviously the vegetation was re-establishing itself rapidly after the fire, but the effect of planting the trees had been put back by roughly four years. As will be suggested below, a cover of trees can improve the countryside in several ways so that their destruction must be prevented as far as possible.
Countryside Management II
If anyone doubts the long term importance and value of protecting the countryside from damage by fire he should stop at the pavilion on the left hand side of Route Twisk as it descends to Shek Kong (altitude about 400 m.). Below is the air-strip at Shek Kong. To the north, the hills are covered with rough grasses and are yellow or brown in color for much of the year; these hills centre upon Kai Kung Leng (#572 m.). The impression is one of neglect. To the south, the ridges running down from Tai Mo Shan toward Tai Lam Chung are tree-covered and remain green throughout the year; the impression is one of well-being.
(雞公嶺)
The difference is due simply to the kind of management given to the two regions. The northern hills are outside the forestry management areas of the Agriculture and Fisheries Department and receive little or no protection from fire. By contrast, the ridges to the south have long been given protection from fire and have been planted with trees. Quite apart from the visual improvement, this kind of long-term management gives a tangible return in higher recreational potential, reduced soil erosion, and a better yield of water to reservoirs.