in literature, such as industrial ecology, engineering ecology, agroecology, restoration ecology, reclamation ecology, synthetic ecology, bioengineering, ecotechnology, and nature engineering; aquatic, terrestrial, and wetland restoration; biomanipulation; habitat reconstruction and rehabilitation; and so on.
Figure 3.1 Sketches of the exchange of materials and services in the ecological engineering domain. (a) Unified system of environment and technology; (b) traditional boundary of environmental engineering design; (c) boundary of ecological engineering design.
Source: Odum and Odum [40]. © 2003, Elsevier.
The common aim of research by various groups with different backgrounds is to attain and promote the restoration1 and management of the ecosystem. Advances in engineering and environmental sciences during the twentieth century have made an immense contribution to ecological principles. A holistic approach toward the restoration and management of the biosphere with advanced engineering problem‐solving skills has led to the synergistic co‐existence of Nature and developed societies. In the 1960s, contradictory statements were raised in scientific communities on introducing a similar discipline, especially when environmental engineering was already well established. This new discipline integrates science and technology, deals with sustainability and self‐designed ecosystem; and serving the purpose of remediation and prevention of environmental issues and also addressing alarming global problems such as pollution and protecting the environment.
Ecological engineering envisages the practice of engineering methods and designs for ecological sciences, bridging these two disciplines with the interpretation of complex, uncertain, and variable natural systems. This approach can result in a unique archetype for designing engineering methods. Human beings are integral components of the ecosystem, providing the initial elements and composition and influencing the environment significantly. The self‐organizing ecosystem eventually takes over these changes and looks for the best route to adjust to artificial modulations imposed on it.
The approach of ecological engineering can be briefly summarized as (i) improvement of new or existing infrastructure with modern complex building models but using environmentally benign materials and ecofriendly designs, referred to as a “hard” approach2; (ii) incorporation of a “soft” approach, i.e. the replacement of buildings and infrastructure with natural habitats such as salt marshes, mangroves, or oyster reefs; (iii) designing hybrid ecological engineering where natural habitats or vegetation are made to coexist with built infrastructure[10]. The approach of ecological engineering may differ with the environment, geographic locations, resources, requirements etc., but the common goal of all the approaches is to restore the natural habitats with the best possible infrastructural design for the benefit of the environment with the progress of development.
The field of ecological engineering has developed immensely within the research and academic dimensions to achieve higher endeavors for environmental sustainability and mankind. Several essential steps are proposed by researchers as part of ecological engineering activities [2, 31, 33, 35, 50, 60]:
Propose principles.
Design processes and techniques.
Implement the techniques.
Organize research archives.
Create international societies.
Include ecological engineering in academic curricula.
Proposing principles is considered the most significant step as the foundation of ecological engineering will be established upon it. These principles must connect ecological theory with ecological practices on real ground, which has been a challenge to researchers for years. The primary principles of ecological engineering proposed by Ma [28] were designed to formulate species symbiosis, cycling, and regeneration, and harmonize the ecological structure with its function. Later, 12 commandants or guidelines were formulated as principles of ecological engineering [17]:
1 Ecosystem structure and functions are determined by the forcing functions of the system.
2 Homeostasis of ecosystems requires accordance between biological function and chemical composition.
3 It is necessary in environmental management to match recycling pathways and rates to ecosystems to reduce the effect of pollution.
4 Ecosystems are self‐designing systems. The more one works with the self‐designing ability of Nature, the lower the cost of the energy to maintain that system.
5 Processes of ecosystems have characteristic time and space scales that should be accounted for in environmental management.
6 Chemical and biological diversity contribute to the spectrum of buffering capacities and the self‐designing ability of ecosystems.
7 Ecotones (transition zones) are as important for ecosystems as membranes are for cells.
8 The coupling between ecosystems should be utilized to the benefit of the ecosystems in the application of ecotechnology and in environmental management of agricultural systems.
9 The components of an ecosystem are interconnected and interrelated and form a network, which implies that direct as well as indirect effects are important.
10 It is essential to realize that an ecosystem has a history when applying ecotechnology and environmental management in general.
11 Ecosystems are most vulnerable at their geographical edges.
12 Ecosystems are hierarchical systems, and all the components forming the various levels of the hierarchy make up a structure that is important for the function of the ecosystem.
Based on these principles, a few ecotechnology rules can be derived for proper management of the environment and ecosystem. These rules are summarized in Table 3.1. The terms ecological engineering and ecotechnology are used interchangeably, although the former defines the creation and restoration of the ecosystem, while the latter describes ecosystem management.
3.2 Basic Concepts of Ecological Engineering
In addition to the 12 principles, some basic concepts of ecological engineering are involved in solving environmental issues. The following concepts thus individually or collectively explain the benefits with an engineering approach:
1 It is based on the self‐designing capacity of the ecosystem.
2 It can be used as an acid test of ecological theories.
3 It depends on system approaches.
4 It conserves non‐renewable sources of energy.
5 It supports biological conservation.
