As the environment is altered through physical means (dredging), the occurring reactions change resulting in a decrease of the availability of nutrients and chemical species to plant species and the ecosystem. This then further changes the physical environment as these species are no longer able to survive. The loss of species then results in further changes to the chemical environment, as they are no longer present to remove excess nutrients. This also changes the physical environment further as the lack of survival of plant species results in open land and increased erosion. The change of the chemical environment also affects the mitigation techniques to be applied for rebuilding of wetlands as the survival of plant species that could potentially be planted depends on the chemical environment, and changes must be monitored for effective mitigation to take place.