5. Decrease of territorial coverage: remnants of habitats which are already
endangered;
6. Influence of neophytes: potential danger of neophytes due to new invasive
species or changing territorial coverage;
7. Dependency on groundwater and surface water in water balance: sensitivity of
habitats which depend on water to changing temperature and precipitation
patterns.
For each habitat type each criteria was evaluated from the experts between the
values “low” (1), “medium” (2), and “high” (3) sensitive. Afterwards, these values
are summed and categorised to describe the overall sensitivity of a habitat type.
Thereby, the categories were named similar to the evaluation values (Table 8.3).
This evaluation was done from regional experts for the Alpine, Continental and
Pannonian biogeographical region.
To get an overall impression of the status per region, the sensitivity values of
each habitat type from each investigation area within HABIT-CHANGE were
grouped using the statistical median according to their biogeographical region.
The variability of the ecological envelope of habitats was assessed by indicator
values which were derived from the characteristic species composition of the
habitats. As above, the biogeographical regions define the type of plant indicator
scheme used for the assessment (Table 8.4). This differentiation was made because
indicator schemes are based on the plant species response to climatic
(e.g. temperature) and edaphic (e.g. moisture) habitat parameters, which are varying between the biogeographical regions (Englisch and Karrer 2001). Following
Ellenberg (1992), different authors adapted the ecological preference of plants for
their region. Each scheme categorises this ecological preference into ordinal scaled
systems.
Temperature values as climatic parameter and moisture values as edaphic
parameter were selected in the framework. The temperature describes the plants
response to air temperature gradients during the vegetation period. Moisture values
indicate the degree of soil moisture needed by the plant during the vegetation
period. Since the approach should be locally valid and transferrable to other
biogeographical regions, the indicator schemes were re-categorised into three
values each (Tables 8.5 and 8.6). Thereafter, the categorised indicator values
were used to calculate an overall indicator value based on the statistical median
for each habitat type listed by the investigation area.
The frequency of the categorised indicator values per habitat, investigation area
and biogeographical region was used in the sensitivity assessment. The proportion
of the categories defined the main direction, therefore also the sensitivity of the
habitat against changes in direction of the other category (Table 8.7). For instance,
freshwater habitats are characterised in their moisture by moist to wet category and
therefore are sensitive to drought periods.
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I. Wagner-Lu ¨cker et al.
endangered;
6. Influence of neophytes: potential danger of neophytes due to new invasive
species or changing territorial coverage;
7. Dependency on groundwater and surface water in water balance: sensitivity of
habitats which depend on water to changing temperature and precipitation
patterns.
For each habitat type each criteria was evaluated from the experts between the
values “low” (1), “medium” (2), and “high” (3) sensitive. Afterwards, these values
are summed and categorised to describe the overall sensitivity of a habitat type.
Thereby, the categories were named similar to the evaluation values (Table 8.3).
This evaluation was done from regional experts for the Alpine, Continental and
Pannonian biogeographical region.
To get an overall impression of the status per region, the sensitivity values of
each habitat type from each investigation area within HABIT-CHANGE were
grouped using the statistical median according to their biogeographical region.
The variability of the ecological envelope of habitats was assessed by indicator
values which were derived from the characteristic species composition of the
habitats. As above, the biogeographical regions define the type of plant indicator
scheme used for the assessment (Table 8.4). This differentiation was made because
indicator schemes are based on the plant species response to climatic
(e.g. temperature) and edaphic (e.g. moisture) habitat parameters, which are varying between the biogeographical regions (Englisch and Karrer 2001). Following
Ellenberg (1992), different authors adapted the ecological preference of plants for
their region. Each scheme categorises this ecological preference into ordinal scaled
systems.
Temperature values as climatic parameter and moisture values as edaphic
parameter were selected in the framework. The temperature describes the plants
response to air temperature gradients during the vegetation period. Moisture values
indicate the degree of soil moisture needed by the plant during the vegetation
period. Since the approach should be locally valid and transferrable to other
biogeographical regions, the indicator schemes were re-categorised into three
values each (Tables 8.5 and 8.6). Thereafter, the categorised indicator values
were used to calculate an overall indicator value based on the statistical median
for each habitat type listed by the investigation area.
The frequency of the categorised indicator values per habitat, investigation area
and biogeographical region was used in the sensitivity assessment. The proportion
of the categories defined the main direction, therefore also the sensitivity of the
habitat against changes in direction of the other category (Table 8.7). For instance,
freshwater habitats are characterised in their moisture by moist to wet category and
therefore are sensitive to drought periods.
120
I. Wagner-Lu ¨cker et al.