THE GENETIC MANAGEMENT OF NATIVE SPECIES IN SCOTLAND

Changes in forestry policy have increased the importance and extended the scope of genetic management of native species. Recent debate on ge netic management prescriptions has been conducted with insufficient ac cess to sound scientific information. This paper attempts to remedy th is by: (1) presenting an overview of genetic variation and the process es which control it; (2) reviewing current measures; and (3) proposing a range of improvements ti, policy and practice. Genetic variation in Scottish tree and shrub populations is a neglected field of research, except for Scots pine (Pinus sylvestris). Some useful information can be provided by considering the history, ecology and biology of specie s together with genetic theory. Current patterns of variation reflect both the historical origins (as demonstrated by biochemical markers) a nd adaptation through natural selection (as indicated by provenance re search). Existing populations probably still retain significant elemen ts of adaptive variation; though this will vary according to species, with some showing close correlation between patterns of adaptive varia tion and environmental factors and others being more plastic. Indigeno us genepools have been modified by fragmentation, changes in the fores t environment, and introduction of foreign material, much of which is maladapted to upland sites. With some exceptions, the levels of geneti c variation in existing indigenous populations comprise an adequate ba sis for restoring and expanding native woodland. The current undiscrim inating use of continental provenances needs to be strongly discourage d; but equally restricting choice of seed sources to the most local pr ovenances can also be inappropriate. Use of Scottish material from the same region and similar site type as the planting site needs to be en couraged. Current genetic management measures are rudimentary and fail to address adequately key issues of provenance choice, genetic conser vation, seed supply or provision of selected or improved material, esp ecially in broadleaves. Changes in legislation, regulation, seed suppl y, advice and research are proposed to address these shortcomings. The need for more provenance research is highlighted.