unit area as the most common measurements of the biodiversity at landscape to
continental scales.
There are currently a huge number of Red Lists or similar indicator systems.
However, these often focus on the rarity or endangerment of species groups or
habitats in a certain political region. This often has the effect that a species or habitat
is evaluated as critically endangered or even extinct while the species or habitat type
is not threatened in other regions. These terms are often a bit misleading if used in a
regional context.
An optimal indicator for alarming trends with respect to the biodiversity should
be simple, accurate, informative, and cost-efficient. Such an indicator has not yet
been developed, and is most likely impossible.
However, several indicators that already exist might be adapted to achieve greater
cost-efficiency or simplicity, for example. In some cases every country has its own
methodology and an international agreement or exchange of information would
increase the accuracy and information value of the indicators.
For example, Linum leonii is a vascular plant species that is restricted to France
and Germany with a restricted yet scattered distribution. Thus, France and Germany
are responsible for the survival of this species according the Convention on Biological Diversity (CBD). The number of populations of this plant species has declined
during recent decades (http://www.floraweb.de/webkarten/karte.html?taxnr¼3458,
http://www.tela-botanica.org/bdtfx-nn-39429-repartition#; accessed 2/2019). However, Linum leonii is a typical example of shared responsibility, which results in a
diffusion of accountability in both countries.
Different states or countries in different parts of the world have published lists of
species—often endemics or subendemics—for which they consider themselves to
have high national responsibility considering not only the distributions within the
political region but also the global distribution of the related species and threats. The
Federal Agency for Nature Conservation in Germany (BfN), for example, characterized 40 native species (25 animals and 15 plants) as species of national responsibility (Verantwortungsarten). Recently, the list was elaborated to include many
more species in the category high (!) and highest (!!) national responsibility. Clearly,
the list is still incomplete and the categorization is somewhat questionable with
respect to global distribution patterns, the number and size of remaining populations
and current trends (https://biologischevielfalt.bfn.de/bundesprogramm/
foerderschwerpunkte/verantwortungsarten.html; accessed 2/2019). Linum leonii,
for example, is still not on the list even if other listed plant species have larger
ranges and are less heavily endangered. It can be assumed that the awareness of
species that occur in more than a single country is lower than country-endemics
(Hobohm 2014).
Looking at populations of native species or habitats that are globally rare and
declining is one simple measure to indicate problems for regional biodiversity.
Another possibility would be to focus on species that are regionally extinct and
might simply be reintroduced. An example is Oenanthe fluviatilis, which is not on
the list of species of national responsibility simply because the species is already
extinct in Germany, where it was last seen in the SW of the country (Netzwerk
164
C. Hobohm
continental scales.
There are currently a huge number of Red Lists or similar indicator systems.
However, these often focus on the rarity or endangerment of species groups or
habitats in a certain political region. This often has the effect that a species or habitat
is evaluated as critically endangered or even extinct while the species or habitat type
is not threatened in other regions. These terms are often a bit misleading if used in a
regional context.
An optimal indicator for alarming trends with respect to the biodiversity should
be simple, accurate, informative, and cost-efficient. Such an indicator has not yet
been developed, and is most likely impossible.
However, several indicators that already exist might be adapted to achieve greater
cost-efficiency or simplicity, for example. In some cases every country has its own
methodology and an international agreement or exchange of information would
increase the accuracy and information value of the indicators.
For example, Linum leonii is a vascular plant species that is restricted to France
and Germany with a restricted yet scattered distribution. Thus, France and Germany
are responsible for the survival of this species according the Convention on Biological Diversity (CBD). The number of populations of this plant species has declined
during recent decades (http://www.floraweb.de/webkarten/karte.html?taxnr¼3458,
http://www.tela-botanica.org/bdtfx-nn-39429-repartition#; accessed 2/2019). However, Linum leonii is a typical example of shared responsibility, which results in a
diffusion of accountability in both countries.
Different states or countries in different parts of the world have published lists of
species—often endemics or subendemics—for which they consider themselves to
have high national responsibility considering not only the distributions within the
political region but also the global distribution of the related species and threats. The
Federal Agency for Nature Conservation in Germany (BfN), for example, characterized 40 native species (25 animals and 15 plants) as species of national responsibility (Verantwortungsarten). Recently, the list was elaborated to include many
more species in the category high (!) and highest (!!) national responsibility. Clearly,
the list is still incomplete and the categorization is somewhat questionable with
respect to global distribution patterns, the number and size of remaining populations
and current trends (https://biologischevielfalt.bfn.de/bundesprogramm/
foerderschwerpunkte/verantwortungsarten.html; accessed 2/2019). Linum leonii,
for example, is still not on the list even if other listed plant species have larger
ranges and are less heavily endangered. It can be assumed that the awareness of
species that occur in more than a single country is lower than country-endemics
(Hobohm 2014).
Looking at populations of native species or habitats that are globally rare and
declining is one simple measure to indicate problems for regional biodiversity.
Another possibility would be to focus on species that are regionally extinct and
might simply be reintroduced. An example is Oenanthe fluviatilis, which is not on
the list of species of national responsibility simply because the species is already
extinct in Germany, where it was last seen in the SW of the country (Netzwerk
164
C. Hobohm