152 FORESTS, WOODS, AND TEEES 



As ash trees approaching maturity stand far apart, the 

 volume of timber per acre is small when compared with the 

 yield of shade-bearing trees. Few actual measurements of 

 well-stocked stands of ash have been made in this country ; 

 but it is the yield from thinnings that helps to make the 

 returns satisfactory. It is doubtful if the annual increment 

 of the volume of ash timber — final crop and thinnings being 

 added together — ever exceeds in England over 30 to 40 

 cubic feet (quarter-girth measurement). Stands of white 

 ash in the United States average at 70 years old, per 

 acre, on first quality soils, 5600 cubic feet of timber over 

 3 inches in diameter, or an average annual increment of 

 80 cubic feet (quarter-girth measurement) per acre. The 

 plots which gave these results were, however, fully-stocked 

 natural stands on alluvial land, much superior to any soil 

 on which ash would be planted in England, Though the 

 volume in England is small, it must be remembered that there 

 is no wood in which there is less waste than ash, as even 

 the earliest thinnings can be used. The faster ash is grown, 

 tlie better is the quality of the timber ; hence the importance 

 of selecting for this species the best sites in any planting 

 area. 



Oak. — As is well known, there are two distinct species 

 of native oak, different in their habitats and in their sylvi- 

 cultural requirements. The pedunculate oak needs for its 

 proper development great depth of soil, associated with 

 a large content of water ; while the sessile oak is satisfied 

 with a shallower soil containing a lesser supply of water. 

 The pedunculate oak originally covered with forests the 

 clays, loams, and deep sands of the southern and midland 

 counties of England, and is now dominant in the coppice- 

 with-standards woods which prevail in these counties. The 

 original pedunculate oak forests in the alluvial tracts along 

 the great rivers disappeared at an early period. The sessile 

 oak is now met with in Wales, in the south-west and north 

 of England, in Scotland and Ireland, where it thrives on the 

 thin soils which rest on the palaeozoic and igneous rocks. 



