NATURAL REGENERATION OF BROADLEAVED TREES IN BRITAIN .3. GERMINATION AND ESTABLISHMENT

The viability and germination of broadleaved tree seed are discussed within the context of natural regeneration. A survey of the literature showed that viability of seedlots is variable. Ash is dormant until the second spring after seed fall and can remain in the soil seedbank for several years but other species germinate in spring of the year following their production. Field studies have shown that germination depends on the position of the seed and that preparation of a seedbed is advantageous for some species. The effects of browsing, competition and shade on the establishment of seedlings are briefly described. A wide variety of browsing animals can adversely affect the success of natural regeneration by reducing tree growth and influencing the proportion of species regenerating. Although competition will reduce growth, the severity of this effect depends on many factors including soil type and species of competing weeds. Overstorey trees suppress growth by casting shade and providing root competition. Possible areas for future research are discussed.