FW-R-4: Conservation of forest-genetic resources

The picture shows a tree climber working high up in the crown of a deciduous tree. Click to enlarge
Genetic conservation is also extended to tree species which are less common in forests today.
Source: Photograph: © Amt für Waldgenetik; Teisendorf

2019 Monitoring Report on the German Strategy for Adaptation to Climate Change

Table of Contents

 

FW-R-4: Conservation of forest-genetic resources

It was possible to expand the in-situ and ex-situ conservation resources in recent years. They ensure that the genetic diversity is retained for frequent and rare tree species. This has created the basic requirements for conserving the adaptability of forests.

The column chart shows the area per hectare of stands used for conservation in the natural habitat of the species (in situ) and established stands and seed orchards used for conservation outside the natural habitat of the species (ex situ) in the years 2004, 2010, 2012 and 2017. The areas of in situ stands clearly predominate. There was a very significant increase between 2006 and 2010. The area of ex situ stands has increased successively, albeit slightly.
FW-R-4: Conservation of forest-genetic resources

The column chart shows the area per hectare of stands used for conservation in the natural habitat of the species (in situ) and established stands and seed orchards used for conservation outside the natural habitat of the species (ex situ) in the years 2004, 2010, 2012 and 2017. The areas of in situ stands clearly predominate. There was a very significant increase between 2006 and 2010. The area of ex situ stands has increased successively, albeit slightly.

Source: Bundesanstalt für Landwirtschaft und Ernährung (gene conservation objects: GENRES (information system on genetic resources); FGRDEU (national inventory of forest genetic resources ))
 

Genetic diversity – key to adaptation

As part of the wider progress of climate change extreme weather events and their consequences increase the pressure on the selection of appropriate tree species for forest stands. It is only the genetically adapted individuals, i.e. individual trees, which can survive, grow and reproduce within greater populations. In view of the multitude of interactions and the dynamics of individual factors it is not possible to predict to which individuals or populations this will apply. This dilemma can only be resolved by maintaining a sufficiently large number and diversity of potentially adaptable individuals. The reason for this is the fact that genetic diversity is the basis for adaptability and species richness, both at the level of individuals and populations. This is why the monitoring and maintenance of genetic diversity and the genetic system has been the focus of measures to conserve genetic resources for almost 100 years32. Of particular importance is the ongoing determination and recording of genetic suitability of various indigenous tree species occurring in various parts of Germany.

The measures to conserve genetic resources for forestry purpose can be differentiated as in-situ and ex-situ. The in-situ measures are part of dynamic conservation. Their purpose is to conserve the relevant genetic resources as so-called ‘gene conservation object’ at the site where they occur. Natural regeneration safeguards and transmits its genetic information to the next tree generation. Particularly endangered species or varieties are kept in specially established archives and where necessary in ex-situ seed plantations. The ex-situ measures are static measures with the objective to safeguard the current character of genetic diversity. This includes taking measures for the long-term storage under controlled conditions of seed material, pollen, plants or plant components as carriers of genetic information. Such conservation strategies are characterised by requiring differing amounts of surface area, investment costs, utilisation and monitoring. This is why expensive ex-situ conservation is less frequently used than in-situ conservation.

In Germany the individual Länder have the remit for gene conservation measures. It is the Länders’ individual concepts which create the framework for the conservation of genetic resources for forestry measures. Nationwide the genetic information on the indication of all genetic conservation objects is collated in a National Inventory of Forest Genetic Resources (FGRDEU). The data are updated and supplemented every few years.

A straight-forward interpretation of changes in number und surface area of genetic conservation objects in Germany is not possible. This is because genetic adaptability to changing climatic conditions is influenced by numerous factors and cannot be estimated other than with utmost difficulty. The number of genetic conservation objects per tree species and the size of conservation areas can only convey a rough idea. In principle, the interpretation of these data require detailed silvicultural knowledge and the application of specific indicators (e.g. conservability, ecological conservation index). For example stating the ‘in-situ conservation area’ for rare and secondary tree species would exaggerate the conservation status of small population numbers or low numbers of individuals. On the other hand, the number of overall genetic conservation objects does not give any clues regarding the size of the population. Besides, genetic inventories which would meet the principles of silvicultural monitoring are still in their infancy. It is therefore unreasonable to apply a one-dimensional principle such as ‘the more genetic conservation objects, the better’ because for every tree species there is a meaningful extent of genetic conservation stock beyond which any increase in surface area or amount of stored genetic conservation objects would not result in improving the safeguarding conditions.

Overall, the conservation of forest-genetic resources has made distinct progress. This is reflected e.g. in the nationwide uniform approval of designation criteria for genetic conservation objects, the increasing application of genetic markers for the characterisation of forest-genetic resources and the establishment of nationwide monitoring programmes ( currently for copper beech and spruce trees) in terms of population genetics and evolutionary issues. These developments provide an additional basis for assessing the genetic adaptability of trees under climate change conditions.

In Germany the areas used for in-situ and ex-situ genetic conservation objects have increased in recent years. Just between 2010 and 2012 there was a minor reduction in the extent of in-situ stands. As far as the more frequently occurring forest tree species are concerned – for which the Forest Reproductive Material Act (Forstvermehrungsgutgesetz/ FoVG) governs the production , the trading, and the import and export of forest reproductive material – the surface area of in-situ stands increased from 12,681 to 32,681 hectares between 2004 and 2017. Rare and endangered tree species are not governed by the FoVG. For pubescent oak, wild service tree, true service tree, crab apple, wild pear, yew, field maple, green alder, grey alder and bird cherry, data were collected in a systematic and homogeneous manner. The factors examined were topography, population size, vitality status and age structure of the occurrences. By 2017 the in-situ stands reported were found to have expanded to approximately 4,560 hectares. The surface area of cultivated stands and seed plantations established for the purpose of (ex-situ) genetic conservation was found to have expanded too, i.e. from 1,777 hectares in 2004 to 2,470 hectares in 2017.

32 In the early 20th century, the conservation of genetic resources important to forestry – in places such as gene archives or seed stock banks – provided important cornerstones for plant breeding in the forestry sector. Ever since, the conservation of forest-genetic resources for a great variety of tree and shrub species as well as genetic monitoring have been key objectives in the field of forest genetics. While it was possible to mitigate the emission of air pollutants in the 1980s, it has so far not been possible to get to grips with the regional impacts of global climate change. This makes safeguarding the great variety of genetic resources (in the sense of information on biological services) a fundamental prerequisite for adapting forests to climate change and to develop a sustainable forest economy.

 

Interfaces

FW-R-1: Mixed stands

 

Objectives

Conserving the diversity and an adapted gene pool of tree and shrub species (Forstliche Genressourcen inDeutschland, p. 29)

Conserving the genetic diversity of forest plants (Waldstrategie2020, p. 23)