PLANTING OF WATER CATCHMENT AREAS 107 
trees than if left in its present state as poor grazing 
land. 
The hill pasture is often common land, serving as grazing 
for sheep and occasionally cattle in the summer months, and 
in such cases it is troublesome to purchase the grazing 
rights from the numerous owners who occupy the farms 
below. The Birmingham Corporation had great difficulty 
in getting rid of these rights on their catchment area in 
Wales. Prof. Somerville estimates that the average 
amount of mutton produced on poor hill pasture in 
Wales and in Scotland is about 10 Ibs. per acre 
annually. Afforestation of the hill pasture would appar- 
ently displace the sheep and to some extent diminish the 
meat supply of the nation, These calculations do not, 
however, take into account the amelioration in climate 
brought about in high-lying districts by afforestation. 
The shelter provided by plantations in the zone of hill 
pasture has a marked effect in improving the value of the 
grazing and arable lands in the farms immediately below. 
In the mountains of Denbighshire and Wicklow wherever 
there are farms protected by plantations, the farmers are 
enabled to keep sheep out in the winter, and all stock thrive 
better. The upper limit of the arable land is pushed higher 
when there are sheltering plantations, and the gain to the 
district is considerable. 
The last point is of considerable importance. Most 
writers advocate the afforestation of mountain waste land 
in large continuous blocks, and do not consider the effect 
upon the adjoining land. It is possible that a joint scheme 
of afforestation and reclamation would be more profitable 
than a scheme of afforestation only. Mountain slopes might 
be planted in widely separated blocks, joined on the upper 
side by narrow belts, the intervening blank areas being 
utilised for grazing and farming. The pasture of these 
areas might often be much improved by draining and by 
manuring with basic slag, which induce the production of 
grass in greater quantity and of better quality. Where 
there are great numbers of small farmers, as in Wales and 
