The robustness or fragility of the landscape, and of the habitats and wildlife it contains, is termed its carrying capacity. The landscape’s resilience to wear and tear, and its ability to recover from damage, are key factors in determining what can or cannot be provided.
Rock and soil are the first aspects to be considered. Hard rock is hard-wearing, but alluvial soils, scree and talus are fragile and easily dislodged. Wet soils, clays, soft rocks and peat are easily eroded, so that significant access is acceptable only if specially surfaced paths are constructed and maintained. Unrestricted trampling over peat moss in the English Peak District has shown how difficult it is to put right the serious effects of this type of damage. Sand dunes are the most vulnerable of all (see above). Volcanic lava is very uncomfortable to walk over, even in tough boots, for any distance.
Vegetation is another important aspect to assess. In high alpine mountains or polar regions, vegetation grows very slowly, and site recovery after damage is extremely slow. Hence significant access should be avoided. Pasture grass may be one of the most robust surfaces, but it can only stand so much wear and tear. Forest vegetation may be dense and impenetrable, but when opened by paths offers opportunities for access without too much risk of people straying from the trail.