297 9 Conclusions These ecosystems, as we may call them, are of the most various kinds and sizes. — A. G. Tansley, 1935 THE EMERGENCE OF NEW ECOSYSTEMS A central theme of this book has been the development of the concept that new ecosystems can be designed, constructed, and operated for the benefit of humanity through ecological engineering. The concept of new ecosystems was introduced in Chapter 1 and was elaborated in subsequent chapters that focused on particular case studies. New ecosystems originate through human management, along with the self- organizational properties of living systems. The mix of engineered design with nature’s self-design makes these ecosystems unique. The study of new ecosystems is often marked with surprises because they are not yet fully understood (Loucks, 1985; O’Neill and Waide, 1981). Like genetically engineered organisms, these eco- systems have never existed previously. Those who design, construct, and operate the new ecosystems are therefore exploring new possibilities of ecological structure and function. In this sense, ecological engineering is really a form of theoretical ecology. This book is an introduction to the new ecosystems that are emerging all around us through self-organization in different contexts. Humans have been creating new ecosystems for thousands of years, but it is only in the last 30 years or so that these ecosystems have been recognized as objects for study by ecologists. Some of these ecosystems have been intentionally created while others have developed for various unintended reasons. Agriculture is probably the best example of a system that has been intentionally created. The origin of agriculture, on the order of 10,000 years ago, consisted of domesticating certain wild plants and animals and creating production systems from these species in modified natural ecosystems. Thus, plants were raised on cropland and grazing animals were raised on pastures or rangeland. Early agriculture differed little from natural ecosystems, but the modifications increased over time with greater uses of energy subsidies. Although the agricultural system is dominated by domesticated species, a variety of pest species has self-organized as part of the system. Manage- ment of agricultural land involves inputs of energy to channel production to humans and away from pests, and to reduce losses due to community respiration. In their modern forms, agricultural systems differ greatly from natural ecosystems, often with very low diversity (i.e., monocultures), large inputs of fossil fuel-based energies (i.e., mechanized tillage, fertilizers, etc.), and regular, orderly spatial patterns of component units (i.e., row crops arrangements). The idea that agricultural systems actually were ecosystems evolved in the early 1970s. This occurred concurrently with the wide use of the ecosystem concept in 298 Ecological Engineering: Principles and Practice the International Biological Program. Previously, ecologists almost exclusively stud- ied natural ecosystems or their components. During this time agricultural systems themselves were studied by applied scientists with narrow focus in agronomy, entomology, or animal science. The ecosystem concept allowed ecologists to “dis- cover” agriculture as systems of interest and for the applied scientists to expand their view to a more holistic perspective. Antecedent ecological studies of agricul- tural crops had been undertaken, with emphasis on primary production and energy flow (Bray, 1963; Bray et al., 1959; Gordon, 1969; Transeau, 1926), but this work had relatively little influence on the science of ecology. After the early 1970s, however, whole system studies of agriculture by ecologists became common (Cox and Atkins, 1975; Harper, 1974; Janzen, 1973; Loucks, 1977) and similar studies by the traditional agricultural scientists followed soon after. In fact, a journal named Agroecosystems was initiated in 1974 as a special outlet for ecological studies of agricultural systems. This line of research is very active with many useful contribu- tions on nutrient cycling (Hendrix et al., 1986; Peterson and Paul, 1998; Stinner et al., 1984), conservation biology (Vandermeer and Perfecto, 1997), and the design of sustainable agroecosystems (Altieri et al., 1983; Ewel, 1986b). Around this same time period the ecosystem concept was applied to other new systems. For example, Falk (1976, 1980) studied suburban lawn ecosystems near Washington, DC. Lawns are heavily managed ecosystems that provide aesthetic value to humans. Falk identified food chains, measured energy flows, and docu- mented management techniques using approaches developed for natural grassland systems. This work was an in-depth study of a new ecosystem type that later was expanded on by Bormann et al. (1993). Much more significant has been research on urban ecosystems. This work began in the 1970s (Davis and Glick, 1978; Stearns and Montag, 1974) and steadily increased, especially in Europe (Bernkamm et al., 1982; Gilbert, 1989; Tangley, 1986). Urban areas include many fragments of natural habitats along with entirely new habitats (Kelcey, 1975) and have unique features as noted by Rebele (1994): … there are some special features of urban ecosystems like mosaic phenomena, specific disturbance regimes, the processes of species invasions and extinctions, which influence the structure and dynamics of plant and animal populations, the organization and characteristics of biotic communities and the landscape pattern as well in a different manner compared with natural ecosystems. On behalf of the ongoing urbanization process, urban ecosystems should attract increasing attention by ecologists, not only to solve practical problems, but also to use the opportunity for the study of fundamental questions in ecology. Much research is currently being carried out on urban ecosystems (Adams, 1994; Collins et al., 2000; Pickett et al., 2001; Platt et al., 1994; Rebele, 1994), including significant projects funded by the National Science Foundation at two long-term ecological research sites in Baltimore, MD, and Phoenix, AZ (Parlange, 1998). In addition, a journal named Urban Ecosystems was begun in 1996 for publishing the growing research on this special type of new system. Conclusions 299 In a sense, then, there has been a paradigm shift in ecology since the 1970s with ecologists embracing the idea that humans have created new ecosystems. Most ecologists probably still prefer to study only natural systems, but research is estab- lished and growing on agroecosystems and urban ecosystems. This work is not necessarily considered to be applied research, though it is certainly an easy and logical connection to make. Rather, there are a number of ecologists who are studying agriculture and urban areas as straightforward examples of ecosystems. These are new systems with basic features (energy flow, nutrient cycling, patterns of species distributions, etc.) common to all ecosystems but with unique quantitative and qualitative characteristics that require study to elucidate. Ludwig (1989) called these anthropic ecosystems because of their strong human influence and proposed an ambitious program for their study. There are many examples of new ecosystems beyond those mentioned above and throughout this book. Hedgerows, fragmented forests, brownfields, rights-of- way, and even cemeteries (Thomas and Dixon, 1973) are examples of new terrestrial systems, and there are many aquatic examples as well. H. T. Odum originally began referring to polluted marine systems as new ecosystems and developed a classifica- tion system that can be generalized to cover all ecosystem types. His ideas developed from research along the Texas coast in the late 1950s and early 1960s. This work involved ecosystem metabolism studies of natural coastal systems and those altered by human influences. The latter included brine lagoons from oil well pumping, ship channels, harbors receiving seafood industry waste discharges, and bays with mul- tiple sources of pollution. H. T. Odum first referred to these systems as “abnormal marine ecosystems” (H. T. Odum et al., 1963), then as “new systems associated with waste flows” (H. T. Odum, 1967), and finally as “emergent new systems coupled to man’s influence” (H. T. Odum and Copeland, 1972). The concept of emergent new systems is best articulated in the classification system developed for U.S. coastal systems (Copeland, 1970; H. T. Odum and Copeland, 1969, 1972). This system classified ecosystems by their energy signatures with names associated with the most prominent feature or, in other words, the one that had the greatest impact on the energy budget of the ecosystem. A whole category in this classification was given to new ecosystems (Table 9.1) with examples of all major types of human-dominated estuarine systems. This is a philosophically important conceptualization. Although H. T. Odum acknowledged that these ecosystems were “unnaturally” stressed by humans, he chose to refer to them as new systems rather than stressed systems. This distinction may at first seem subtle, but it is not. It carries with it a special notion of ecosystem organization. The concept of new ecosystems implies that the human influence is literally a part of the system and therefore an additional feature to which organisms must adapt (Figure 9.1A). Thus, human pollution is viewed the same as natural stressors such as salt concentration or frost, and ecosystems exposed to pollution reorganize to accommodate it. The tendency to consider humans and their stressors as being outside of the ecosystem is common in modern thought. This conception generally holds that human influence, such as pollution, leads to a degraded ecosystem (Figure 300 Ecological Engineering: Principles and Practice 9.1B). However, is it appropriate only to think of an ecosystem as degraded when a source of pollution is added to the energy signature? What actually happens is that the ecosystem reorganizes itself in response to the new pollution source. Thus, degradation (Figure 9.1B) is really reorganization of a new ecosystem (Figure 9.1A). This seems like a contradiction because degradation carries a negative connotation while reorganization has a more positive sense. Both views in Figure 9 are valid. What is advocated here is the straightforward notion that ecosystem identity (i.e., elements of structure and function) is determined by the energy signature, and if the energy signature is changed, then a new ecosystem is created. In another sense the concept of emergent new systems attempts to reduce value judgment in ecosystem classification. Rather than considering ecosystems with human pollution as degraded natural systems, the classification labels them as new systems. The value-free approach frees thinking so that the organization of new TABLE 9.1 Classification of New Estuarine Ecosystems Name of Type Characteristic Energy Source or Stress Sewage waste Organic and inorganic enrichment Seafood wastes Organic and inorganic enrichment Pesticides An organic poison Dredging spoil Heavy sedimentation by man Impoundment Blocking of current Thermal pollution High and variable temperature discharges Pulp mill waste Wastes of wood processing Sugarcane waste Organics, fibers, soils of sugar industry wastes Phosphate wastes Wastes of phosphate mining Acid waters Release or generation of low pH Oil shores Petroleum spills Piling Treated wood substrates Salina Brine complex of salt manufacture Brine pollution Stress of high salt wastes and odd element ratios Petrochemicals Refinery and petrochemical manufacturing wastes Radioactive stress Radioactivity Multiple stress Alternating stress of many kinds of wastes in drifting patches Artificial reef Strong currents Source: Adapted from Odum, H. T. and B. J. Copeland. 1972. Environmental Framework of Coastal Plain Estuaries. The Geological Society of America, Boulder, CO. Conclusions 301 systems can be more clearly understood. Of course, the trick is to not throw out the value-laden thinking. It is important to understand and account for human influences which society judges to be negative. Some new systems are “good” (cropland agriculture dominated by domesticated exotic species) and some are “bad” (forest invaded by exotic species), but this distinction is determined by human social convention, not by ecological structure or function. Consider another application of this way of thinking. A distinction is made between native species and exotic species in ecosystems as discussed in Chapter 7. Native species are those that are found in a particular location naturally or, in other words, without recent human disturbance, while exotic species are those that evolved in a distant biogeographical region but have invaded the particular location under discussion. The reference point in the distinction between natives and exotics is location. However, in the energy theory of ecosystems the reference point is the energy signature that exists at the location, not the location itself. A causal relationship is implied which matches a set of energy sources to ecosystem com- ponents. Thus, if the energy signature of a location changes, then the species native to the location may no longer be as well adapted to it as compared with exotic species that invade. Under these circumstances nature favors the exotic species which are preadapted to the new energy signature, while human policy favors the old native species due to an inappropriate respect for location. Exotics are said to be the problem, when really the problem is that the energy signature has changed. Clear examples of this circumstance are the tree species that invade where hydrol- ogy has changed dramatically as in the southwest U.S. with salt cedar (Tamarix sp.) and in South Florida with melaleuca (Melaleuca quinquenervia). Tree-of- heaven (Ailanthus altissima) is another example of an exotic tree species which occupies urban areas and roadside edges (Parrish, 2000). These habitats have FIGURE 9.1 Comparison of philosophical positions or interpretations of the effects of human influence on ecosystems. (A) View focusing on change to a new system. (B) View focusing on degradation. (A) Value-Free Perspective (B) Value-Laden Perspective Human Influence Previous System New System Human Influence Natural System Degraded System 302 Ecological Engineering: Principles and Practice different energy signatures as compared with the surrounding forests in the eastern U.S. and tree-of-heaven can dominate under these new conditions. Humans are everywhere changing old energy signatures and creating new ones that never existed previously, and the results are changing ecosystems. The issue is how to choose reference points to interpret changes. This requires a philosophical position and the position advocated here is that new ecosystems are being created which have few or no reference points for comparison in the past. Thus, the future will require new ways of thinking about the new ecosystems that are being created as humans change the biosphere. The concept of new ecosystems may be especially useful for the ecological engineer who designs ecosystems. What criteria will be used to judge the new systems? Will new designs be limited to native species that are no longer fully adapted or can exotic species be used? Can humans allow nature to perform some of the design, even if it results in unanticipated or unde- sirable species compositions? What are the limits to ecological structure and function that can be achieved through design? THE ECOLOGICAL THEATER AND THE SELF- ORGANIZATIONAL PLAY Study of the new systems that are emerging unintentionally is especially instructive. These systems demonstrate the process of self-organization, and their study can be a guide to the intentional engineering of new systems. The two main classes of unintentional new systems are (1) those ecosystems exposed to human stresses, in one form or another, for which they have no adaptational history and (2) those ecosystems with mixes of species that didn’t evolve together (i.e., native and exotic species). These kinds of unintentional new systems are coming to dominate land- scapes, and therefore, they deserve study even independent of ecological engineering. A very interesting common feature of these systems is that the traditional Darwinian evolution concept no longer provides the fullest context for understanding them. This common feature comes from the fact that the new systems lack direct or explicit adaptations for some features of their current situation because humans have changed conditions faster than evolution can occur. New systems differ from what are nor- mally considered to be natural systems in which a more or less stable set of associated species has evolved together, in the Darwinian sense, over a long period of time with a given external environment. G. E. Hutchinson described the natural situation as the “ecological theater and the evolutionary play” (Hutchinson, 1965), in which ecology and evolution act together to produce organization in ecosystems. This is a wonderful metaphor that captures the way that nature consists of multiple, simulta- neous time scales. Populations interact over the short-term in the “ecological theater” while simultaneously being subjected to natural selection over the long-term in the “evolutionary play.” However, in the view presented here for the new unintentional systems, the conventional concept of evolution is becoming less important, and perhaps a new evolutionary biology will be required. This is a strong statement that requires elaboration. First, consider those eco- systems stressed by human influences that never existed in the natural world. There Conclusions 303 are, of course, many kinds of pollution that have been created by humans; many new kinds of habitats have also been created, especially in agricultural and urban landscapes. A whole new field of stress ecology has arisen to understand these systems with many interesting generalizations (Barrett and Rosenberg, 1981; Barrett et al., 1976; Lugo, 1978; E. P. Odum, 1985; Rapport and Whitford, 1999; Rapport et al., 1985). These references indicate that many changes in natural ecosystems caused by human impacts are similar and predictable, such as simplification (reduc- tions in diversity) and shifts in metabolism (increased production or respiration). A good example is the set of experiments done in the 1960s which exposed ecosystems to chronic irradiation from a 137 Cs source, such as at Brookhaven National Lab- oratory in New York. These experiments were conducted to help understand the possible consequences of various uses of atomic energy by society. In these studies point sources of radiation were placed in forests for various lengths of time and ecosystem responses were studied. At Brookhaven, “the effect was a systematic dissection of the forest, strata being removed layer by layer” (Woodwell, 1970). Thus, a pattern of concentric zones of impact emerged outward from the radiation source, perhaps best characterized by these vegetation zones (Figure 9.2): 1. Central zone with no higher plants (though with some mosses and lichens) 2. Sedge zone of Carex pennsylvanica 3. Shrub zone with species of Vaccinium and Gaylussacia 4. Zone of tolerant trees (Quercus species) 5. Undisturbed forest FIGURE 9.2 Patterns of vegetation extending out from a radiation source in the temperate forest at Brookhaven, New York. (From Woodwell, G. M. and R. A. Houghton. 1990. The Earth in Transition: Patterns and Processes of Biotic Impoverishment. G. M. Woodwell (ed.). Cambridge University Press, Cambridge, U.K. With permission.) 8 10 6 4 2 1 0 400 200 100 50 20 10 30 50 100 200 10 5.0 1.0 0.5 0.2 Carex Percent cover Lichens Rubus Oaks Gaylussacia Vaccinium Pinus R/day (June 1976) Distance from surface(m) 304 Ecological Engineering: Principles and Practice In this case the ecosystem had no adaptational history to the stress but self- organization took place in the different zones of exposure, resulting in viable but simpler systems based on genetic input from the surrounding undisturbed forest. It is interesting to note that Woodwell (1970) found similarities between the new stress of radiation and the “natural stress” of fire. Some species in this forest were adapted to fire, and there was a direct correspondence in species adaptation between fire frequency and radiation exposure. Thus, with high fire frequency Carex pennsylvan- ica dominates vegetation just as it does with relatively high radiation exposure. This is an example of preadaptation, which has been noted as being important in stress ecology by Rapport et al. (1985). A general model for the special case described above is shown in Figure 9.3. Concentration of the pollutant declines away from a point source along a linear transect in the model. Associated with the decline in pollutant concentration is a longitudinal succession of species, shown by the series of bell-shaped species performance curves. Each curve represents the ability of a species to exploit resources within the context of the pollution gradient (see Figure 1.8). This pattern of species is characteristic of a variety of ecological gradients and Robert Whittaker developed an analytical procedure for studying the pattern called gradient analysis (Whittaker, 1967). When there is no adaptational history for the pollutant, then the species closest to the point source can be said to be preadapted to the pollutant. In the classic river pollution model (Figure 2.3) the species closest to the sewage outfall are classified as tolerant. Using an alternative line of reasoning, these species are preadapted to the high sewage concentrations, and the proximity of the peak in their performance curves to the point source is an index of the degree of preadaptation. The decline in pollutant concentration in the model is due to various biogeochemical processes. When species have a role to play in the decline, then ecological engineering is possible to enhance treatment capacity of the pollution. To some extent the sequential design of John Todd’s living machines (see Chapter 2) corresponds with the species patterns shown in Figure 9.3. Perhaps an adaptation of Whittaker’s gradient analysis can be used as a tool for living machine design (see the upcoming section on a universal pollution treatment ecosystem). FIGURE 9.3 Model of longitudinal succession caused by a pollutant source, illustrating the position of preadapted species. Preadapted Pollutant Conc. Species Performance Distance from Source of Pollution Pollutant Concentration Conclusions 305 The other class of unintentional system is the system dominated by exotic species. The situation here is that species with no common evolutionary history are being mixed together by enhanced human dispersal at rates faster than evolution. The results, as described in Chapter 7, are new viable communities with some exotic and some native species. In both cases of unintentional systems then, evolution does not provide full understanding or predictive value of the new systems. There are a few examples of evolution taking place in the new systems, such as resistance to pesticides in insect pests or to antibiotics by bacteria and tolerance to heavy metals by certain plants (Antonovics et al., 1971; Bradshaw et al., 1965), but these are exceptions. Certain species with fast turnover can adapt to rapid changes caused by humans (Hoffmann and Parsons, 1997), but this is not possible for all species. Soule’s (1980) discussion of “the end of vertebrate evolution in the tropics” is a dramatic commentary on the inability of some species with low reproductive rates to adapt, in this case, to loss of habitat due to tropical deforestation. The idea that Soule refers to is loss of genetic variability in vertebrate populations due to declining population sizes. Natural selec- tion operates on genetic variability to produce evolution, so with less genetic vari- ability there is less evolution. Thus, the new systems are being organized at least in part by new processes. Janzen (1985) discussed this situation and proposed the term ecological fitting for these processes. Self-organization is proposed as the general process organizing new systems in this book. To address this new situation, Hutchinson’s classic phrase may need to be reworded as “the ecological theater and the self-organizational play.” A key feature of the organization of new systems is preadaptation. The new systems are often dominated by preadapted species, whether they be native species that are tolerant of the new conditions or exotic species that evolved in a distant biogeographical region under conditions similar to the new system. There appear to be two avenues of preadaptation: those species that are preadapted through physi- ology and those that are preadapted through intelligence or the capacity to learn. The best example of physiological preadaptation is for species that have been used as indicator organisms. These species indicate or identify particular environ- mental conditions by their presence or absence, or by their relative abundance. Indicator organisms can be either tolerant, (i.e., those present and/or abundant under stressful conditions) or intolerant, (i.e., those absent or with reduced abundance under stressful conditions). Only tolerant organisms are preadapted and they indicate the existence of new systems. Tolerant indicator organisms have been widely used in water quality assessments, dating back to the German Saprobien system in the early 1900s. A large literature exists in this field (Bartsch, 1948; Cairns, 1974; Ford, 1989; Gaufin, 1973; Patrick, 1949; Rosenberg and Resh, 1993; Wilhm and Dorris, 1968), and it can be an important starting point to developing an understanding of preadaptation as a phenomenon. Hart and Fuller (1974) provide a tremendous amount of information about the adaptations and preadaptations of freshwater inver- tebrates in relation to pollution. Another example of indicator organisms is plant species found on soils with unusual mineral conditions. Methods of biogeochemical prospecting have been developed by identifying particular indicator species of plants 306 Ecological Engineering: Principles and Practice (Brooks, 1972; Cannon, 1960; Kovalevsky, 1987; Malyuga, 1964); this approach could be important in selecting species for phytoremediation of waste zones in the future (Brown, 1995). The study of tolerant organisms for the purpose of under- standing preadaption is similar to the approach of genetic engineers who study “super bugs” or microbes adapted to extreme environmental conditions (Horikoshi and Grant, 1991). These microbes have special physiological adaptations that the genetic engineers hope to exploit when designing microbes for new applications. Species can be found with adaptations for high (thermophilic) and low (psychrophilic) temperature, high salt concentrations (halophilic), low (acidophilic) and high (alka- liphilic) pH, and other extreme environments. The other avenue of preadaptation involves intelligence or the capacity to learn. This is primarily found in vertebrate species with sophisticated nervous systems. Intelligence or the capacity to learn allows organisms to react to new systems. A. S. Leopold (1966) provided a discussion of this kind of preadaptation in the context of habitat change. Animals that can learn are able to adjust to new systems by avoiding stressful or dangerous conditions and by taking advantage of additional resources or habitats. Many examples exist including urban rats and suburban deer, along with a variety of bird species, which take advantage of new habitats: falcons in cities (Frank, 1994), gulls at landfills (Belant et al., 1995), terns on roof tops (Shea, 1997), and crows in a variety of situations (Savage, 1995). Although some empirical generalities exist such as those from the field of stress ecology or from the long history of use of indicator organisms, little or no theory exists to provide an understanding of the organization of new emerging ecosystems. As mentioned earlier (see Chapter 1), preadaptation is little discussed in the con- ventional evolutionary biology literature, yet it is a major source of species that become established and dominate in the new systems through self-organization. More research on preadaptation is clearly needed. Can there be a predictive theory of preadaptation? Or is it simply based on chance matching of existing adaptations with new environmental conditions? Is a new evolutionary biology possible based on preadaptation? One interesting topic from ecology that offers possibilities for an explanation of new systems is the theory of alternative stable states (see Chapter 7). This theory suggests that alternative equilibria or states, in terms of species composition, exist for ecosystems and that a system may move between these alternatives through bifurcations caused by environmental changes. Several authors have suggested pos- sible views of alternative stable states in terms of human impact (Bendoricchio, 2000; Cairns, 1986b; Margalef, 1969; Rapport and Regier, 1995; Regier et al., 1995) and Gunderson et al. (2002) propose a theory called “panarchy” to explain how systems can shift between alternative states. This theory describes system dynamics across scales of hierarchy (hence the name panarchy) with a four-phase cycle of adaptive renewal. One view of the alternative stable state concept is shown in Figure 7.5 with a Venn diagram in which different sets represent alternative states. A system moves within a set due to normal environmental variations, but can jump to another set, representing a new system in the terminology of this chapter, due to some major environmental change (Parsons, 1990). The states differ qualitatively in their basic [...]... to planetary and applications of biodiversity, technology, and social action Some directions rely on futures 312 Ecological Engineering: Principles and Practice TABLE 9. 2 Questions for the Future of Ecological Engineering What is the rationale for ecological engineering and what are its goals? What are the major concepts of ecological engineering? What are the boundaries of ecological engineering? ... ecological engineering education? How will we integrate the ecological and the engineering paradigms? Under what conditions will ecological engineering flourish or disappear? Source: Adapted from Mitsch, W J 199 8 Ecological Engineering 10:1 19 130 with expanding energy resources (technoptimism) while others require less energy (technopessimism) ECOLOGICAL NANOTECHNOLOGY The smallest size ecological engineering. .. surface so that it can support life (Fogg, 199 5) While this application is still in the realm of science fiction, it is receiving credible attention Some interesting theory about biosphere-scale ecological engineering is being discussed, especially in terms of Mars (Allaby and Lovelock, 198 4; Haynes and McKay, 199 1; McKay, 199 9; Thomas, 199 5) Mars has a thin atmosphere and probably has water frozen in various... interfaces in his “Ecocyborg Project.” Along with his students and colleagues Kok published many designs and analyzes for ecosystems with artificial intelligence control networks (Clark et al., 199 6, 199 8, 199 9; Kok and Lacroix, 199 3; Parrott et al., 199 6) Blersch (in preparation) has built this kind of design around a wetland soil microcosm (Figure 9. 8) The microcosm is part of a hardware system that attempts... sense growth conditions for fishes (Ebeling, 199 4), and computerized greenhouses (Goto et al., 199 7; Hashimoto et al., 199 3; Jones, 198 9) Ecological engineers may design more complex technoecosystems For example, studies by R Beyers and J Petersen were described in Chapter 4 for microcosms which sensed ecosystem metabolism and regulated light inputs Wolf ( 199 6) constructed a similar system which regulated... engineering or “the art and science of building complex, practical devices with atomic precision” (Crandall, 199 9) It involves working at the scale of billionths of a meter with microscopic probes This field was first articulated by physicist Richard Feynman in 195 9 and has been championed by futurist Eric Drexler ( 198 6, 199 0) While nanotechnology is very early in its development (Stix, 199 6), small-scale... (Rubin and Fish, 199 4; Schmink et al., 199 2), and biocultural surveys must be conducted with care and respect Alternate ways of thinking about ecological engineering can be expected to occur because different human societies are known to develop unique material cultures, such as house form (Rapoport, 196 9) or agriculture (Gliessman, 198 8) Todd ( 199 6b) has warned against the disappearance of regional and. .. (Reichel-Dolmatoff, 197 6); or perhaps some new technology such as a novel living fence (Steavenson et al., 194 3) tucked away in a Mayan field in the highlands of Guatemala can be discovered and incorporated into Western ecological engineering Can the sacred groves of India (Gadgil and Vartak, 197 6; Marglin and Mishra, 199 3; Reddy, 199 8) provide designs for socially integrated urban rain gardens and riparian... efficiency John and Nancy Todd’s work on bioshelters is another expression of ecological architecture that also emphasizes food production and wastewater treatment designs (Todd and Todd, 198 4) Reviews of these approaches to architecture are given by Steele ( 199 7) and Stitt ( 199 9) Several initiatives of ecological architecture represent new directions for collaboration between architects and ecological. .. or electrode, and (3) associated signal processing electronics Environmental applications of biosensors have focused on continuous monitoring for water quality evaluation (Grubber and Diamond, 198 8; Harris et al., 199 8; Rawson, 199 3; Riedel, 199 8) An example employing respiratory behavioral toxicity testing with fish (American Society for Testing and Materials, 199 6) is shown in Figure 9. 7 In this case . (Bartsch, 194 8; Cairns, 197 4; Ford, 198 9; Gaufin, 197 3; Patrick, 194 9; Rosenberg and Resh, 199 3; Wilhm and Dorris, 196 8), and it can be an important starting point to developing an understanding of preadaptation. 198 6; Peterson and Paul, 199 8; Stinner et al., 198 4), conservation biology (Vandermeer and Perfecto, 199 7), and the design of sustainable agroecosystems (Altieri et al., 198 3; Ewel, 198 6b). Around. Morowitz ( 199 6) and Weaver ( 194 7). It is proposed here that the new discipline of ecological engineering should utilize a distinct, alternative 308 Ecological Engineering: Principles and Practice method