Degraded ecosystems


“Land degradation can occur either through a loss of biodiversity, ecosystem functions or services. From an ecological perspective, land degradation may include complete transformation in the class or use of the ecosystem, such as the conversion of natural grassland to a crop field, delivering a different spectrum of benefits, but also degradation of the “natural” or “transformed” system. Natural ecosystems are often degraded prior to being transformed. The transformed ecosystem that results from this conversion can, in turn, be degraded and see a reduction in the delivery of its new functions (e.g. an agricultural field where soil degradation and reduced soil fertility leads to reduced crops). The same concepts are applicable to the degradation of marine and freshwater ecosystems. It may take the form of changed trophic structures in a marine community (through fishing pressure and selective removal of species, transformation of the soft and hard benthos (through repetitive sweeps of contacting gears, such as trawls) or artificial reef construction, to cite only a few examples. In the case of aquatic freshwater ecosystems, the construction of dams and reservoirs over river courses or the conversion of natural wetlands into rice paddies are examples of ecosystem transformation”.

CBD (2019) 1