Ecological Engineering

Summary

Ecological engineers design sustainable systems using ecological principles to create, restore, and conserve natural systems. The multidisciplinary synergy of the engineering sciences and biological knowledge makes it possible to design and maintain strong, self-evolving ecosystems to support a variety of life forms in a wide range of habitats. Human communities are planned so that they contribute to the balanced flow of energy and products to the surrounding environment. Plant and animal communities are created or restored, often in keeping with regulatory guidelines that mandate the restoration of particular locales to their original, prehuman conditions. Scales of applicability range from microscopic exchanges to the processes of much larger ecosystems.

Definition and Basic Principles

The field of ecological engineering represents the synthesis of a variety of knowledge sets coordinated to address the challenges of holistic ecosystem design. Ecological engineering seeks to redress the fragmentation of scientific thought and activity, particularly in reference to the natural world and its processes. The term was first coined by Howard T. Odum, a prolific writer and researcher noted for founding the Center for Wetlands at the University of Florida. He was the son of Howard W. Odum, a noted sociologist and director of the Institute for Research in the Social Sciences at the University of North Carolina. The young Odum and his older brother, Eugene, helped establish the intellectual and scientific foundations of ecology in the twentieth century. The Odum brothers coauthored Fundamentals of Ecology, a successful textbook published in 1953 in which they state that mathematics and statistics were essential to the development of a unified system of ecosystem dynamics.

During the nineteenth and twentieth centuries, ecologists made substantial contributions to the knowledge of undisturbed ecosystems. Therefore, it is only within the past century that human relationships have been taken into account in the study of the evolution of natural systems. In 2004, the Ecological Society of America published a report to its governing board outlining a set of responses to the growing need for including sustainable ecological precepts in all phases of land use and development. Plans for a sustainable future are based on four basic principles:

• The rise of human-dominated ecosystems is inevitable.

• Ecosystems of the future will include a variety of conserved, created, and restored landscapes.

• Ecological science must become a core body of knowledge influencing global economics and policies.

• New and unprecedented regional and global partnerships among private and public entities are necessary to promote sustainable life systems.

Practitioners are careful to point out that ecological engineering is not synonymous with environmental engineering or biotechnology. Ecological engineers rely on the self-organizing capacities of ecosystem dynamics to create, restore, or conserve particular communities and habitats. Ecological systems designers have a wealth of research materials available for consultation and comparison. These include efforts in habitat reconstruction, stream and wetland restoration, and a variety of wastewater, reclamation, and conservation projects. The scientific practices of observation, measurement, and documentation of the complex procedures and results of an ecosystem project are essential. The results of many restoration projects provide valuable information for understanding the processes of succession, the formation of biological macrocommunities in particular locales, and their relationships within broader ecosystems. Time is a fundamental component of ecosystem design. Many projects are undertaken with the realization that their fulfillment will exceed the lifetimes of their founders. Biodiversity, adaptation systems, and succession patterns are important dimensions of ecosystem design that require time.

Background and History

The use of myriad tools and technologies to construct and engineer life systems is an ancient human practice and a key factor in the evolution of the human species. Many tools and technologies are artifacts of cultures rooted in particular biological communities. Some sustainable traditions have been practiced for centuries and have made important contributions to the design and maintenance of contemporary ecosystems.

In the nineteenth century, the Industrial Revolution accelerated the rate of technological innovation in profound ways. Awareness of the aesthetic value of the natural landscape deepened as whole cultures and biological species disappeared in the wake of rapid urbanization, progressive conservation, and the colonization of the wilderness. Advances in urbanization; the consumption of fossil fuels; the mass fabrication of commodities; the mechanization of agriculture; the transformation of wetlands and deserts into vast farmlands; the unregulated extraction of minerals, metals, and inorganic materials for industrial expansion; increased demands for hydroelectric and nuclear power; a rapidly developing transportation and communications network; widespread deforestation; the unprotected destruction of wildlife; the release of radioactive isotopes, airborne pesticides, and vehicle emissions; and the creation of synthetic chemicals and materials in the wake of World War I and World War II ravaged European and American landscapes. Accelerated industrial production in the postwar period lifted economies while creating vulgar panoramas of urban blight: air and waterways darkened with toxic industrial, agricultural, and residential wastes; scarred mountains and forests; and a host of health and sanitation issues directly related to the toxic environment of the modern world.

The natural world is the subject of many of the supreme artistic and literary expressions of human culture. It is the basis of unique knowledge systems, the value of which is of particular importance to local communities. Since antiquity, classical treatises on the subject of natural history have included detailed studies that have formed the foundation for continuing work in the fields of medicine, chemistry, physics, biology, botany, mineralogy, geography, astronomy, and geology. Natural historians made remarkable contributions to the study of natural systems in the eighteenth and nineteenth centuries. The concept of evolution is an ever-present thread in the dialogue of natural philosophers. That tendril of thought took root in the discourse that followed the publication of On the Origin of Species by Means of Natural Selection by Charles Darwin in 1859. In the twenty-first century, evolution is understood as a complex process of genetic variation. That reality drives modern research in ecology.

The environmental movement of the twentieth century created the grassroots momentum for a global reassessment of the controversial roles of science and technology in designing structures and processes that are functional, aesthetically pleasing, and sustainable. Environmental justice was an important topic of sociopolitical inquiry. Following the enactment of the National Environmental Policy Act in 1970, tens of thousands of regulations were enforced. Under the Toxic Substances Control Act of 1976, more than 86,000 toxic substances were registered by the Environmental Protection Agency (EPA) by the mid-2020s. Similar standards have been adopted worldwide. Extensive research in pollution control provided new sources of expertise needed to remediate critical environmental conditions. Advances in computational technologies greatly facilitated the creation of detailed data sets, microassays, simulations, and measurement technologies. Extensive land surveys helped to substantiate the terms and application of soil and marine biotechnologies. Thermophiles and acidophils, xenobiotics, endocrine disrupters, bioaccumulation, biofilters, bioscrubbers, activated sludge, wastewater stabilization ponds; biosubstitutions, terrestrial phyto systems, and genetic manipulation: These and other terms form a common vocabulary and are found in all substantive research and textbooks addressing topics of environmental engineering and biotechnology.

How It Works

Ecological engineering is know-how applied to the design of a variety of environments. The mechanics of ecological self-maintenance are the foundations of healthy ecosystem design. Practitioners adopt a wide variety of natural techniques and materials to create, manage, or remediate a range of ecosystems.

Technologies rely on the chemical processes of sunlight, soil, temperature, and water in the design of living landscapes that assist in ecosystem management. For instance, constructed wetlands are designed so that natural biofilms and open spaces are formed to break down pollutants into usable bioproducts. Plant evaporation and transpiration, composting, and biogas production are other natural processes with a wide range of applications worldwide. The maintenance of designed ecosystems is similar to that of horticulture. This includes the routine maintenance of beds and screens and sampling and documentation of fluids and solids. The treatment of wastewater effluents in natural systems includes the removal of large solids, the aerobic and anaerobic treatment of organic materials, and regular sampling of safely reusable organic by-products.

Applications and Products

The ecological engineering literature embraces ecological technologies compatible with cultures and practices around the globe. Biological processes are the basis for these technologies. The complexity of biological relationships is the essential reality that all ecological engineers strive to replicate and support.

Phytoengineering. Phytoengineering technologies rely on plants as primary ecosystem providers. Designs and processes are coordinated for wastewater treatment, environmental remediation, wetlands remediation, and sustainable processes for industry, agriculture, and urban communities. Traditional biotechnologies favored the removal or destruction of contaminated soils. Phytoremediation is a successful in situ alternative. Plants work with contaminated soils to decompose toxins, accumulate chemical wastes, and create nutrient-rich composting materials.

Natural Wastewater Treatment Systems. Wastewater and storm-water effluents can be treated and reused in natural systems of plants, algae, and other living organisms. Sequenced constructed ecosystems mimic the natural processes of land and water habitats. Applications include greenhouses, rain gardens, aquatic systems, and wetlands remediation.

Wetlands Remediation. For some localities, wetlands are an essential component of wastewater treatment. In the Northern European countries of Denmark, Norway, Finland, and Sweden, full-scale filter-bed systems are used to recapture phosphorus from septic effluents. In the European Union, groundwater is treated as a living ecosystem. Microorganisms and subterranean fauna are valuable indicators of the health of a particular source. The mapping of aquifers and other groundwater structures is an essential prerequisite for the accurate assessment and classification of these habitats. Similar assessments of groundwater resources and dependent wetlands, legislated under the Water Framework Directive, set in motion a systematic testing of all groundwater-dependent water resources in Europe. In April 2009, the International Commission on Groundwater of the International Association of Hydrological Sciences and the UNESCO Division of Water Sciences convened a special session to evaluate the results of this testing program. Sweden, Denmark, Norway, Finland, the Netherlands, England, Wales, Scotland, and Austria participated in the consortium to assess risks of damage to related wetlands. Groundwater salinity is of particular concern to residents of Ravenna, Italy, where subsidence has introduced saltwater into groundwaters that feed pine forests. The forests are dying as a consequence of these shifts in water quality.

Green Roof Technologies. Roofs constructed of living plants and grasses are recognized for absorbing sunlight and serving as effective solar wastewater evaporation systems. Sod roofs were ubiquitous features of Northern European landscapes, where birch bark and turf grasses were plentiful. Many plant, flower, bird, and insect species thrived on established terraces. By 2011, some species were found only in green roof habitats, and approximately 10 percent of all German homes had green roofs. Half of all new construction in Germany must include vegetative covering. Green roofs are an important component of that compliance, and the market increased by about 7 percent annually in the 2010s. In Switzerland, flat green roof vegetation is required for renovated structures. Singapore began adding green roofs to busses and bus stops in the late 2010s and early 2020s as part of the “Garden on the Move” bus campaign.

Similar innovations are occurring in North America. According to Green Roofs for Healthy Cities, there was a 15 percent increase in the number of green roofs in North America in the 2010s. Cities such as San Francisco, California, mandated green considerations, including green roofs, solar power, or a combination. However, the adoption of green roof technology in North America was much slower than in Europe despite evidence supporting green roofs' benefits. The EPA estimated that 700,000 square feet of green roof space installed between 1999 and 2020 eliminated 384 pounds of nitrogen oxide, 734 pounds of sulfur dioxide, and 269 tons of carbon dioxide in 2020.

Ecological Sanitation. Composting toilets provide a safe and healthy option for sanitation systems worldwide. It relies on “dry” biochemical processes that do not require water. Aerobic decomposition of human feces is a viable technology particularly in rural and desert communities where water is unavailable for flushing toilets.

Agroecology. Self-sustaining agricultural systems engineered to accommodate climate change are of great interest to nations throughout the world. Agroecology addresses these systemic concerns with the intent of balancing crops and animal stocks to maximize their relationships with their environment. This includes impacts on soil quality, effective pest control, discharges into water supplies, and the release of noxious gases and particulate matter into the atmosphere. For example, in southern Mexico, researchers worked with the Lacandon Maya to recover indigenous agroforestry systems of soil fertility and rainforest conservation. These centuries-old practices included the collection of plant species and management of the succession processes of the forest. In Europe and the Americas, similar efforts are underway to restore vast tracts of grasslands and their species and populations.

Light Detection and Ranging (Lidar) Systems. Laser-generated light beams are unique in that they are emitted in a single direction with a constant wavelength and amplitude and total phase correspondence. These characteristics allow for very detailed mappings of surfaces, topical variations, the height of surface objects, and the physical characteristics of different terrains. Low-level and high-level airborne laser scanning provides data of varying resolutions. Digital terrain models (DTMs) provide valuable information about forest roads and vegetation, changes in beach topography, and channel flows of river floodplains and monitor flood events.

Wireless Sensor Networks (WSNs). Computation and the use of wireless sensors have greatly enhanced scientific knowledge about soil microenvironments. Light, humidity, and temperature in a particular locale can be measured using high-resolution grids of autonomous sensors organized to provide minute-by-minute descriptions of the soil's condition.

Atlantic Rainforest Sensor Net Research. Microsoft Research collaborated with researchers from Johns Hopkins University, the Universidade de São Paolo, the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), and the Instituto Nacional de Pesquisas Espaciais (INPE, the Brazilian National Institute for Space Research) to collect data about the microecology of the Serra do Mar rainforest located in the southeast corner of Brazil. To collect the data, a grid of hundreds of wireless sensors collected 18 million data points over four weeks. Scientists hope similar data sets will help better understand the relationship of the rainforest to its environment.

Ecosystem Bioinformatics (Ecoinformatics). Undergraduate courses in ecological or ecosystem bioinformatics teach the analysis of gene sequencing and expression within microbial communities. Increasing knowledge in molecular biology and the capacities of computer data systems make it possible to construct algorithms to calculate the mechanics of gene expression within biological systems.

Careers and Course Work

In 2009, Oregon State University offered the nation's first accredited ecological engineering degree program. Since then, other universities have begun offering similar accredited programs of study. These include Ohio State University; Purdue University; University of California, Berkeley; University of Maryland; Texas A&M University; and Washington State University.

The bachelor's degree in ecological engineering is remarkable for its breadth and multidisciplinary program of study. Typical requirements include core engineering courses in fluid mechanics, thermodynamics, circuits, vector calculus, differential equations, and mechanics. It will also include coursework in ecology, organic chemistry, biology, microbiology, hydrology, biosystems modeling, statistical methods, and environmental technology and design. Graduate and doctoral programs in ecological engineering focus on issues, systems, and technologies related to ecological design. These include water-resource management and pollution control, biotechnology, environmental sensing, systems modeling, informatics, and soil and wetland treatment programs. Ecological engineering graduates pursue careers as environmental engineering project managers and risk advisers, researchers, statisticians, and land use and public policy consultants. Specific design projects include riparian restoration, ecological monitoring with sensor arrays, and the development of sustainable urban, industrial, and agricultural systems. Professionals play important roles in both the private and public sectors. As environmental consultants, they work in multidisciplinary teams to design and engineer systems for the remediation of wastewater and recycling soil nutrients and contaminants. They work in federal agencies to plan natural resource protection and utilization systems. Bioremediation, water conservation, and the protection of endangered species are important dimensions of healthy ecosystem design.

Social Context and Future Prospects

There is a universal recognition that environmental protection is not enough to address the continuing degradation of the natural environment. The pace of chemical production and distribution continues accelerating to meet global demand for industrial and agricultural products. Natural resources continue to be depleted to meet the needs of expanding communities worldwide. Ecological engineering represents a paradigm shift that favors ecological principles as the foundation of global economic and cultural prosperity. Sustainable design is an essential feature of that paradigm and is the basis of the practice of ecological engineering. Traditional engineering practices and technologies are adapted for use in various self-sustaining ecosystem designs. Many systems accommodate human lifestyle patterns while protecting biodiversity. Other systems are designed to restore or remediate particular biological systems such as a forest, river, farmland, pasture, or industrial site. Sustainable cities can be found in locations around the globe.

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