Scientific Principles 



Principle 1. The abundance, productivity and diversity of"or<janisms are integrally linked to the character- 

 istics of their ecosystems. 



The plnsical and biological components of ecosystems together produce the di\ersity. abundance and productivity of plant 

 and animal species, including humans. The combination of suitable habitats and necessary ecological functions forms the 

 ecosystem structure and conditions needed to provide the desired abundance and productivity of specific species. 



Principle 2. Ecosystems are dynamic, resilient and develop over time. 



Although ecosystems have definable structures and characteristics, their behavior is highly dynamic, changing in response 

 to internal and external factors. The system we see today is the product of its biological, human and geological legacy. 

 Natural disturbance and change are normal ecological processes and are essential to the structure and maintenance of 

 habitats. 



Principle 3. Biological systems operate on various spatial and time scales that can be organized hierarchically. 



Ecosystems, landscapes, communities and populations are useflilly described as hierarchies of nested components distin- 

 guished by their appropriate spatial and time scales. Higher-level ecological patterns and processes constrain, and in turn 

 reflect, localized patterns and processes. There is no single, intrinsically correct description of an ecosystem, only one 

 that is useful to management or scientific research. The hierarchy should clarify the higher-level constraints as well as 

 the localized mechanisms behind the problem. 



Principle 4. Habitats develop, and are maintained, by physical and biological processes. 



Habitats are created, altered and maintained by processes that operate over a range of scales. Locally observed conditions 

 often reflect more expansive or non-local processes and influences, including human actions. The presence of essential 

 habitat features created by these processes determines the abundance, productivity and diversity of species and com- 

 munities. Habitat restoration actions are most etTective when undertaken with an understanding and appreciation of the 

 underlying habitat-fonning processes. 



Principle 5. Species play key roles in developing and maintaining ecological conditions. 



Each species has one or more ecological functions that may be key to the development and maintenance of ecological 

 conditions. Species, in eftect, have a distinct job or occupation that is essential to the structure, sustainability and 

 productivity of the ecosystem over time. The existence, productivity and abundance of specific species depend on these 

 functions. In tum. loss of species and their functions lessens the ability of the ecosystem to withstand disturbance and 

 change. 



Principle 6. Biological diversity allows ecosystems to persist in the face of environmental variation. 



The diversity of species, traits and life histories within biological communities contributes to ecological stability in the face 

 of disturbance and environmental change. Loss of species and their ecological functions can decrease ecological stability 

 and resilience. It is not simply that more diversity is always good; introduction of non-native species, for example, can 

 increase diversity but disrupt ecological structure. Diversity within a species presents a greater range of possible solutions 

 to environmental variation and change. Maintaining the ability of the ecosystem to express its own species cotiiposition and 

 diversity allows the system to remain productive in the face of environmental variation. 



Principle 7. Ecological management is adaptive and experimental. 



The dynamic nature, diversify, and complexity of ecological systems routinely disable attempts to command and control 

 the environment. Adaptive management - the use of management experiments to investigate biological problems and to 

 test the efficacy of management programs -- provides a model for experimental management of ecosystems. Experimental 

 management does not mean passive "learning by doing," but rather a directed program aimed at understanding key 

 ecosystem dynamics and the impacts of human actions using scientific experimentation and inquiry. 



Principle 8. Ecosystem function, habitat structure and biological performance are affected by human actions. 



As humans, we often view ourselves as separate and distinct from the natural wurld. 1 lowever, we are integral pails of 

 ecosystems. Our actions have a pervasive impact on the structure and function of ecosystems, while at the same time, 

 our health and well being are tied to these conditions. These actions must be managed in ways that protect and restore 

 ecosystem structures and conditions necessary for the survival and recovery offish and wildlife in the basin. Success 

 depends on the extent to which we choose to control our impacts so as to balance the various services potentially prov ided 

 by the Columbia River Basin. 



2000 Columbia river Basin Fish and Wildlife Program 15 



