In 1955, an area of upland heathland on an ironpan soil in the North York Moors was cultivated and planted with five broadleaved species (sessile oak, beech, silver birch, grey alder, and sweet chestnut) grown pure and in mixtures with Japanese larch,and Japanese larch and Scots pine, Four other broadleaved species (downy birch, red oak, rauli and roble) were also planted, but only in nursing mixture with conifers. Apart from grey alder and downy birch, all species have established and produced closed canopy stands After some 47 years, rauli was the most vigorous of the species tested and had the straightest stems, while sweet chestnut was more vigorous than either sessile oak or beech. In those species where pure plots and mixtures could be compared the best growth and stem form was generally found in the broadleaves that had been grown in mixture with the conifers with silver birch being the only exception, There was no difference in growth or form between the two types of mixtures. This is another instance of the 'nursing mixtures' effect already reported for mixtures of Sitka spruce with Scots pine or larch. It suggests that conifer nurses may have a valuable role to play in successful creation of broadleaved woodland on infertile soils in upland Britain.
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