In Holistic Management one of the key insights is the ‘brittleness scale.’ In parts of the world where the moisture distribution is relatively even throughout the year, habitats regenerate well under the tool of rest; these ecosystems are considered ‘non-brittle.’
In other regions such as Kenya with highly seasonal rainfall, ecosystems are considered 'brittle' and breakdown under complete rest.
Due to the great foresight of the Island owners the Isle of Carna has been free from livestock for over twenty years. This lack of agricultural management gives us a rare glimpse of how effectively a previously overgrazed, treeless landscape will regenerate, unaided, in a temperate region of the world.
As the world population increases and large regions of the world turn to dessert, the temperate parts of the world will be under intense pressure to produce more food. It’s vital we learn how to protect our biodiversity whilst contributing to the provision of food and other ecosystem services.
The long period of rest has allowed woodland and dry heath to develop which supports a wide range of important species.
The new woodland is predominantly birch and the grassland and heathland areas are becoming choked up with deep plant litter which is impeding succession to a more diverse natural habitat.
The woodland regeneration has been hampered by the increase bracken and purple moor grass. In a natural ecosystem, large herbivores, predated by wolves and lynx, would graze down and trample this plant material and open up patches of soil allowing tree saplings to take seed and effectively cycling minerals.