Habitat loss and isolation, results of spatial processes such as fragmentation, dissection, perforation, shrinkage and attrition, necessitate the establishment of connections within the landscape. In the face of these challenges, it is ever more fundamental to preserve the integrity of landscape corridors, such as wildlife corridors and river systems can as well be thought as barriers to wildlife movement, as in the example of roadways, railroad and canals (Dramstad et al., 1996). Pattern and scale can be used to assess the integrity of a landscape (Table 3).
|
Corridors |
Barriers |
Stream and River Corridors |
|
For species movement |
Road and windreak barriers |
|
|
Controls on corridors functions |
Roads and other "trough" |
Stream corridor and |
|
Corridor gap effectiveness |
corridors |
dissolved substances |
|
Structural versus floristic similarity |
Wind erosion and its |
Corridor width for main |
|
control |
stream |
|
|
Stepping Stones |
Corridor width for a river Connectivity of a stream |
|
|
Stepping stone connectivity Distance between stepping stones Loss of a stepping stone Cluster of stepping stones |
corridor |
|
Table 3. Catagorize of corridors and connectivity |
|
2.4 Mosaics As abovementioned, the connectivity of the corridors within a landscape is an indicator of its ecological condition. These corridors often form networks of connectivity, circuitry, and mesh size and are useful for planners to assist movements across a land mosaic (Dramstad et al., 1996) (Table 4). |
||
|
Networks |
Fragmentation and Pattern |
Scale |
|
• Network connectivity |
• Loss of total versus |
• Grain size of mosaics |
|
and circuitry |
interior habitat |
• Animal perceptions of |
|
• Loops and alternatives |
• Fractal patches |
scale of fragmentation |
|
• Corridor density and mesh size |
• Suburbanization, |
• Specialists and generalists |
|
• Intersection effect |
exotics, and |
• Mosaic patterns for |
|
• Species in a small connected patch • Dispersal and small connected patch |
protected areas |
multihabitat species |
|
Table 4. Networks, fragmentation and pattern, and scale |
