Mátyás C.  

Challenges of gene conservation in a changing climate, with special regard to the forest-steppe zone

A static interpretation of conserving forest genetic resources has been based on the principle of roughly constant environmental conditions, the populations have become adapted to, during long time epochs. The predicted climatic changes introduce a new element in gene conservation and raise new questions, such as
- considering the speed of expected changes, will the genetic and reproductive system of trees provide sufficient potential for adaptation?
- which new tasks of gene conservation emerge in a dynamic situation?
- do certain threatened regions need specific measures?
Optimist views of adaptability of forest trees consider the genetic system of trees able to follow these changes, because fluctuation of the environment has been a constant element of the evolutionary past, and spontaneous migration follows climatic shifts. Consequently, the unrivalled level of within-population genetic diversity of trees, combined with effective gene flow enable a constant genetic adjustment.
Some of these presumptions simply do not hold, and the conditions close the lower limits of distribution and of the closed forest belt (“xeric limit”) represent specific challenges. It has to be considered that
- compared to past millennia, climate shifts in this century are unprecedented;
- predicted changes are very fast and will happen within one generation time;
- therefore evolutionary potential is limited and only the genetic resources of the extant (available) populations can be relied on;
- gene flow is ineffective, especially close to the xeric limits;
- threatened drought tolerant populations a the xeric limits may need specific conservation measures;
- spontaneous processes are inhibited also by human interference, strongest in the forest-steppe transition zone.
Therefore the review of principles of gene conservation and the rules for forest reproductive material (FRM) use is especially urgent in the forest-steppe border zone. This includes
- instead of geographic, primarily ecological (climatic) criteria should be used for planning and formulating rules;
- strategy of conservation of genetic resources should be based on adaptive traits instead of neutral markers;
- plasticity is a trait of high importance and should gain priority in conservation and use;
- existing gene reserves have to be evaluated for possible threats and if necessary, evacuated;
- rethinking of seed/provenance regions and their application in FRM deployment;
- new, unconventional sources for future FRM have to be created;
A dynamic approach to gene conservation has to become an integral part of active preparation to adapt forest ecosystems to the challenges of a changing environment. Beside ongoing genetic research of QTLs of adaptive importance, an improved knowledge about plasticity (phenotypic response) as well as adaptation and selection cannot be missed, based on the results of well designed field trials.
 


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