Assessment, Conservation and Sustainable Use of Forest Biodiversity

Assessment and Monitoring
50 % of the “typical” forest vascular plant species are in three categories of “really rare plants”. They are
distributed sporadically or peripherically, require specific habitats and have but small populations at a stand.
Many of these species are on the Red data lists of the German states Niedersachsen (NS), Schleswig-Holstein
(SH) or Mecklenburg-Vorpommern (MV), such as the tree species Ulmus minor, Sorbus torminalis, Tilia
platyphyllos, Malus sylvestris, Taxus baccata.
Conclusions
By selection of the research area, the landscape and the sites of an investigation, a certain potential floristic
diversity is already defined implicitly. Comparing species diversity from different investigations has to
consider the comparability of the geographical scale; best to provide species-area-relations in every published
results. In discussions about species protection and nature conservation, not only threat is a relevant criteria
but also rarity is. Rarity has to be seen in the context of the types of geographical and ecological distribution
as well as the population sizes. More than half of the „typical“ forest vascular plant species in the Northern
German Lowlands is somehow rare. There exists little chance to hit them on (rather small) sample plots, even
in case many of them are checked. Rare species have to be looked for with specialized knowledge and skill.
Rare species are to be specifically valued in sustainable forest management as well as sustainable forest
development. Forest managers are not only responsible for the favourable conservation status of rare trees.
Table 1:
Seven types of rarity in “typical” forest vascular plant species in the Northwestern German Lowlands
(297 species). Numbers of species are given. Number of Red data list species in brackets for two northern
German Laender.
GEOGRAPHICAL DISTRIBUTION wide restricted
(more or less than 50% of the
ca. 120 km 2 grids occupied)
HABITAT SPECIFICITY broad narrow broad narrow
(according to the phyto-sociological
status of the species)
28 7 10 15
LOCAL large +/- dominant (0/0) (1/0) (2/3) (8/3)
POPULATION
SIZE small single to few 62 25 86 64
individuals (4/0) (4/3) (60/42) (36/25)
Table 2:
ditto (see Tab.1) .... in the Northeastern German Lowlands (315 species). ....
GEOGRAPHICAL DISTRIBUTION wide restricted
HABITAT SPECIFICITY broad narrow broad narrow
32 10 5 12
LOCAL large (0) (1) (0) (2)
POPULATION
SIZE small 79 31 75 66
(6) (0) (27) (30)
31