Biodiversity & Wildlife
The availability and quality of habitat for specific wildlife species is determined by tracking the area and area-weighted value of different landscape types, and by defining the response curve of different habitat attributes (for example, stand age, forest structure, herbaceous vegetation, linear disturbance, etc) to habitat quality.
Features include:
- User-defined distribution of wildlife among landscape types
- Dynamically ranked importance values of different habitat elements to wildlife
- Tracked changes in habitat quantity and quality through time
- Effects of buffering footprints (roads, seismic, cutblocks, wellsites) on quantity and quality of wildlife habitat (buffers may be areas of complete exclusion by wildlife or can support a gradient response defined by the User)
HSI habitat modelling
The wildlife habitat module allows the user to explore changes in habitat availability and habitat quality of selected wildlife species in response to different trajectories of human landuse practice and such natural disturbance regimes as fire.
There are 4 questions for the ALCES user to answer
1. What proportion of each landscape types is occupied by a wildlife species?
2.Which habitat attributes are important to a given wildilfe species and what is the relative importance of each habitat attribute?
3. What is the response curve between changes in levels of habitat attributes and their value to wildlife habitat.
4. Which anthropogenic linear features need to be buffered, what is the buffer width(in meters), and what is the buffer response curve?
Habitat Quality
In Table 1 entitled "Landscape Type Value for habitat", the user identifies the relative probability of finding a population in each landscape type. The values can range from 0 (0= no level of expected use) to 1 (100% level of expected use). The value should not be confused with density, but simply whether a population resides on a portion of a landscape type over a long time period. The user should reduce the level of use of a particular landscape type as habitat if there is evidence that a portion is unusable for reasons of climate, geography, or incompatible landuse.
The level of habitat available to wildlife species can be further altered by identifying partial-use buffers on such linear features as seismic lines, roads, wellsites, pipelines, cutblocks, etc. The distance from those disturbance type edges affecting habitat available to each wildlife species is entered entered in the brown data input table (Table 4). If buffers are identified for a given linear feature, the ALCES user must identify the buffer use response curve.
By clicking on the "Buffer Use Response" button, ALCES will navigate the user to a series of user-defined input devices that describe the pattern of use within the buffer region. The X axis of 0 to 1 represents the full range of the buffer and the Y axis ranges from 0 (no use) to 2. A value of 1 on the Y axis indicates random use, whereas a value of 2 indicates use at a given distance from a feature that is twice as high as would expected if the feature were not there.
If you wish to activate the calculations pertaining to buffers on linear features, click the linear buffer switch up.
Habitat Quality
In Table 3 entitled "Weighting of Habitat Attributes", the user needs to evaluate the relative importance of different habitat attributes to selected wildlife species of interest. These features include forest age, stand age, natural landscape edge (km/km2), anthropogenic landscape edge (km/km2), and biomass density of snags, herbs, shrubs, and litter (tonnes/hectare). Appropriate selection of habitat attributes important to individual wildlife species can be approached by considering the following questions: "For which types of habitat attributes do wildlife ecologists need to know information in order to predict the quality of habitat". A total of 1 point (100%) must be "spent" by the user on assigning relative value of these habitat features. For example, a value of .8 for stand age and .2 for anthropogenic edge means that biologists feel the stand age and anthropogenic edge are the major drivers of habitat quality and that stand age is 4 times as important as edge created by anthropogenic edge.
Once the user has defined which habitat attributes are important to a wildlife species, the user must define the relationships between changes in the amount of a habitat attribute and its value to wildlife habitat. A value of 1 refers to the level of the attribute when it is of maximal value fo the wildlife species, while a value of 0 refers to the level of no value. Habitat value ofr stand age is handled within the brown table, while the others (shrubs, herbs, snags, lfh, habitat fragmentation, and road density) are defined using the green radio buttons at the bottom of the screen.
Once the user have provided input on habitat availability and habitat quality, ALCES will generate a simulation that provides output on temporal changes in habitat availability ("Landscape Hab Avail"), habitat quality ("Ave Habitat Quality"), and an integrated measure of both habitat quality and availability ("T Hab Qual x Avail").
Species response curves for habitat relationships
In this module, it is possible to specify the relationship between habitat quality for a given wildlife species and several environmental variables, including human density, the amount of cultivated land and energy sector development, herbaceous vegetation, shrubs, standing dead trees, grassland structure, road density, and anthropogenic edge.
Buffer response
In this module, it is possible to describe the relationship between use of buffers on linear features and the distance away from the border between the feature and the buffer. Features that can be buffered include seismic lines, pipelines, roads, trails, cutblock edges, and recreational features.
The value of 0 on the X axis refers to the edge of the feature and the value of 1 refers to the furthest width of the buffer feature. The Y axis ranges from 0 (no use) to 2 (a double of average habitat value). A value of 1.0 indicates random use. A value of 1.0 on the Y axis indicates that animals use the defined buffer width in a manner that is random. Values below 1.0 describe proportional non-use of the buffer. For example a value. of .25 at .5 indicates that use of the buffer at 50% of total buffer width has been reduced by 75%. The ALCES user can also define buffers that provide above-average habitat value to a given wildlife species. For example a value of 1.5 indicates a 50% increase in habitat value. The curve allows users to define partial use patterns of buffer strips by wildlife species. For example, the ALCES user can demonstrate a relationship whereby species are excluded from the first 25% of the buffer, and then increase their use linearly such that full use occurs by the time they extend out to the full buffer strip width.