Man continues to make use of an ever-increasing number of natural resources, both on a local and global scale.
    The tempo is increasing.
     The risks are increasing.
     And the effects on the ecosystem are increasing. Toxins are released; land areas destroyed and seas are fished dry. Now simply reducing these effects is not sufficient. We have to help nature so that it may cope with all these disturbances.
     We must build up ecological resilience.

ill: Lina Hedberg

Resilience [1] is a scientific concept, which has long existed within ecology. However, it was not before the 1970's that it was used in the sense that is now quickly filtering through society and is taken up in this article.
     It was the researcher into ecosystems; C.S. Holling [2] who headed the cross discipline research, which started from the basic premise that man, is an integral part of the ecosystem. He asserted that an ecosystem can find itself in different states of equilibrium, each with differing structures and functions. He meant that an ecosystem that has been subject to a disturbance could jump over to a new state of equilibrium with a new structure and new functions (see The Ecosystem). It is, for example, known that many lakes can swing between two different states of equilibrium: one being nutrient poor with pike and other fish who thrive in clear waters with little algae; the other being nutrient rich with perch and other fish who thrive in murky waters with algae. C.S. Holling also asserted that an ecosystem that does not jump over to a new state of equilibrium after a disturbance, staying instead in its original position is one that has resilience [3].
     In other words, an ecosystem that has a good buffer capacity against disturbances can be called resilient.

Since the 1970's more and more researchers have tried to study the interplay between nature and man. This so-called ecosystem research has been developed at, among other places, the Department of Systems Ecology, Stockholm University. It is there that a study has been set up into disturbances in coral reef life (see Can the coral reef survive man's impact?)
     When a coral reef is subject to some form of natural disturbance such as a storm, or toxic discharge, or some other man made disruption, pieces of coral break off or die. After such a disturbance the reef can develop in several different ways.
     If the coral reef has a broad biological diversity of plants and animals carrying out a variety of functions then the buffer capacity is usually high. When a disturbance hits and certain species are temporarily taken out of the system there are other species able to take over and fulfill their functions. The coral consequently has the opportunity to gradually grow back after the disruption. If the coral reef's capacity to cope and organise itself during both the disturbance and rebuilding phase is good (see The Ecosystem) then the reef is said to be resilient.
     If, however, the reef is already under pressure due to over fishing and overfeeding and has few fish species, its buffer capacity come a disturbance is low. The coral's functions are not as easily replaced and thus risks losing its position in the system to fast growing algae. The reef then finds itself in a new state of equilibrium dominated by algae instead of coral and with totally new functions. In other words the coral reef lacked resilience.
     To precisely measure a coral reef's resilience is difficult, if not impossible according to the Professors Carl Folke and Nils Kautsky who lead the studies in resilience and coral reefs at Stockholm University.
     They suggest that we should examine the biological diversity of the coral reef. A coral reef with many species having similar eating habits and methods of breeding fulfill similar functions in the ecosystem and therefore can replace each other in the event of a disturbance.
     It is also important to find out where the different species live and if they are able to move from one area to another if required. That a species may move around both within the coral reef and between other reefs is of considerable importance if the reef is to remain in a coral dominated state of equilibrium after a disturbance.
     A coral reef with many species functioning in a similar way and able to easily move from place to place is one that has good signs of resilience.

Take note! It isn't always a positive thing that an ecosystem is resilient. This is pointed out by the newly founded Resilience Alliance, a cross discipline forum set up by prominent researchers from around the world. The main task of the Resilience Alliance is to support and pursue research into resilience and the links between man and nature. Their definition of resilience suggests that we as humans do not always appreciate how well an ecosystem can deal with disturbances.
     In a marine ecosystem where fishing numbers have plummeted, as has happened in the Baltic, we try and make changes for the better. However the currently eutrophicated and over fished Baltic Sea seems difficult to change and can consequently be described as resilient. Whether resilience is good or bad varies from case to case and is ultimately up to the beholder to determine.
     Simply put, it can be said that as long as resilience leads to a sustainable development of society then it is a good thing. A coral reef that we humans have not damaged by toxins or over fishing and which is resilient against disturbances is one which corresponds with our visions for the future. The eutrophicated Baltic with its plummeting fish numbers is also resilient but hardly leads to the sustainable development we envisage, where fish are plentiful and beaches algae free.
     The key to understanding the scientific concept of ecological resilience is to link it to how we want society and the ecosystem to develop. Resilience is a positive characteristic in an ecosystem when it contributes to ensuring that our use of natural resources is carried out in an ecologically, economically and socially sustainable manner. Thus making sure that our grandchildren may have the same possibilities as us to a life enriched by beautiful natural surroundings, clean air, healthy oceans and food free from toxins.

Man dominates life on earth and leaves his mark over the whole globe in terms of exploitation, toxins, greenhouse gases, and through large-scale land changes via forestry, agriculture and mining. As a result of this we often have a negative effect on resilience.
     However, we also have the possibility to affect resilience in a positive manner. We have the ability to improve the ecosystem's capacity to deal with disturbances.
     The number of species with similar functions can be preserved and their routes for moving within and between different ecosystems protected or even improved. Trying to "build resilience" in this manner is particularly important for areas such as coastlines, cities, agricultural land and industrial zones which are often hit by our disturbances. It is often these same areas that we value most, both economically and aesthetically, and which society is most dependent upon.