Forstgenetik und Biodiversität

The genetic component of biodiversity in forest ecosystems

Biodiversity

Biodiversity is a broadly known and broadly used concept:

–        subject of international conventions,–        world summits,–        global and regional action plans,–        scientific discussions of various disciplines,–        publications,–        lectures,–        policy texts, etc.

Biodiversity and society

Although the awareness of the concept is not known by a large percentage of the broad public, different groups have used the term, such as:

–        environmentalists,–        politicians,–        stakeholders and end users,–        scientists,

consultants, etc.

Forest biodiversityForest biodiversity is often referred as very high and

valuable. Conservation of forests has gained a significant part of

conventions, treaties and action plans for biodiversity conservation.

• forests are in many parts of the world the most “wild” and complex terrestrial ecosystems and at the same time the most impressive ones,

• forests are decreasing world-wide,• forest science is the most developed applied on the

ground nature management scientific discipline.

While everyone is speaking about biodiversity and all agree that it is important and should be conserved,

almost none can describe or measure it. There is a confusion about its meaning, its

measurement (assessment) and the measures needed for its protection.

Definition of biodiversity

The term “Biodiversity” (biological diversity or biotic diversity) was first used by Walter G. Rosen during the preparation of the National Forum on BioDiversity in 1986.

The first official definition (U.S. OTA 1987): “Biological diversity refers to the variety and variability among living organisms and the ecological complexes in which they occur….”. In the same text, the three main levels of biodiversity are explained: genes, species, ecosystems. 

Definition of biodiversity

IUCN, UNEP and WWF (1991): Caring for the Earth: they give a definition for biodiversity: “The variety of life in all forms, levels and combinations. Includes the variability of ecosystems, species and genetic diversity”.

Biodiversity became broadly known through the 1992 Earth Summit in Rio. Officials from 158 countries have signed the Convention on Biological Diversity – CBD and 166 countries followed in short time. The definition used here is very similar to the ones explained above.

Life on Earth

A consensus exists on the meaning of the term biodiversity.

Most definitions of the term refer to genes, species and ecosystems.

Biodiversity is used to describe the number, variety and variability of living organisms.

This very broad usage, embracing many different parameters, is essentially a synonym of Life on Earth.

Assessment problems

For an assessment of ecosystems and species we will need to find first the boundaries of one unit to the other

We know much little about most species. I.e. the number of microorganisms at any site that are as yet unknown to science.

We know virtually nothing of the genetics of the majority of species on Earth.

It is currently no more possible to assess the biodiversity of a cubic meter of forest than to assess the biodiversity of the entire planet.

Failure of a definitionDefinitions of biodiversity as "genes, species, and

ecosystems" fail both in theory and in practice: 1. they do not recognize the conceptual difficulties in

genes, species, and ecosystems, 2. they ignore the practical and technical problems

involved in making real-world inventories,3. they fail to consider the incommensurabilities between

different levels (how does one equate species with ecosystems in an area?),

4. they make no distinction in the worth of elements of biodiversity within any given level.

An applied science

Biodiversity is not a theoretical concept - is connected with conservation - an applied crisis oriented science.

We do not need to measure biodiversity, but to protect it. For this reason we just need to understand biodiversity, rather than to perform a global assessment of all possible biota.

To protect biodiversity, we need to act. We need to answer the question "If we want to protect biodiversity, what should we do?".

Different perceptions

When we are called to decide where to dedicate our limited resources, a definition of biodiversity that is equivalent to "Life on Earth," or "all genes, species, and ecosystems," is of no help at all.

We must work with more restricted practical definitions.

Conservation decision makers are not referring to all of Life on Earth, but to a specific subset for a specific purpose. Everyone has his / her own own conception of what we are calling biodiversity and that conception is shaped by their values, biases, and interests.

Richness in perception

Real-life assessments and evaluations of biodiversity are neither totally objective nor totally scientific.

Biological diversity (biodiversity) means different things to different people.

Noss proposed a rich characterization, instead of a single definition, for the term biodiversity.

The diversity of human conceptions of biodiversity is a real strength rather than a failing. This is a major hope, that biodiversity will become a part of on-the-ground management techniques.

A global failure

Scientists and policy makers have so far failed to motivate the world towards a solution to the global loss of biodiversity.

Many books have been written about the wealth of nature, or about the ways to measure several taxa diversity.

The conservation of biodiversity has become for many people an academic exercise.

“One of the main threats to global biodiversity is the decrease of the number of taxonomists in the UK in an extent of 7% during the last decade” (!)

What is wrong?1. Biodiversity cannot be measured.2. Most scientists measure species diversity only.3. Even the species level is narrowed down to the

units that are easily identifiable, or just cute and recognisable (charismatic megafauna).

4. Wrong scientific criteria for networks of protected areas, besides their political and managerial failure.

5. Most biodiversity (species richness) is concerned better.

6. The dynamic character of biodiversity is ignored (the values that make it evolve).

Where is the genetic component?

Genetic diversity is maybe the most underestimated part of biodiversity conservation strategies and activities - small paragraphs exist in all texts, having mainly the following focus:

• they all recognise the importance of genetic diversity for the rest of the biodiversity levels,

• they refer to the value of special genetic resources, such as wild relatives of crop plants and

• they insist of the importance of genetic diversity assessments, if possible in DNA sequences, etc.

Forest conservation genetics

Forest genetic resources are included in broader international and national policies, strategies and conventions, mainly as part of the broader envornmental protection and biodiversity conservation subject.

• In situ - actions of strict protection of rare or endangered entities and conservation through use in managed ecosystems in very few cases.

• Ex situ - the protection of endangered or rare tree species and the storage of “usefull” genes.

An integrated approach

Conservation of forest genetic diversity cannot be seen separately from the general use and management of forest resources.

Each country and each region can have different approaches on the subject. The same happens with different parties of interest as well.

Any forest genetic conservation effort should recognise these differences and adjust the measures designed to them.

The challenge

Management techniques that will prevent disturbances in critical ecological and genetic processes are needed.

Biodiversity research should not become a fragmented assessment of three different disciplines.

It should focus on the understanding of the main processes that keep biodiversity alive and allows evolution in space and time.

The challenge

Genetic science should go on performing research and providing information on:

• the incorporation of genetic criteria into more general management procedures,

• the extrapolation of appropriate strategies for most taxa from the results of studies of a few model cases,

• the identification of the genetic aspects that may become limiting for certain species types and

• the monitoring and evaluation of demographic processes.

Besides the targeted conservation of specific resources and units, biodiversity principles of all levels should be integrated into management techniques.

Biodiversity knowledge and understanding should be included in the principles needed for the planning of all nature related human activities.

The challenge is to create space for all possible approaches on biodiversity that exist in our society.