Synthetic ecosystems are human-built, integrated assemblages of species and technological components which have little shared history. Such recombination leads to novelty which can extend the breadth. While the idea has a long history (Odum, Patten), its realization is becoming technically feasible and economically attractive, particularly in the field of microbial ecology. Synthetic ecosystems thus emerge as promising targets for research and application. Here we identify those emerging systems that are best described as synthetic and the features that define them. To this end, we critically examine extreme and intermediate cases of ecological engineering involving different degrees of ecological synthesis; from comparatively simple (a monoculture, slash and burn agriculture) to most complex (food production and waste disposal in aquaponics or future Moon/Mars bases). Why bother? Our guiding premise is that building synthetic ecosystems – an effort that complements ecological analysis (of patterns, dynamics, and relationships) – can greatly advance ecology and society through testing knowledge about complex systems and engaging with non-academic actors (e.g. sustainability-oriented industries) to achieve socio-ecological goals. Here, we ask the questions:
Results/Conclusions
Important features of Synthetic Ecosystems. Several crucial dimensions change along the complexity gradient above. Component number, components modularity (groupings), internal feedbacks, diversity of non-biological components (sensors, flow controls, partitions), autonomous operation, component specialization, and functional integration functions stand out. Consequently, Synthetic Ecosystems can be described as: (a) showing a guided self-organization similar to ecological engineering’s self-design, (b) using biodiversity as pivotal functional elements, (c) regulating functions of its own components (coupling and feedbacks), (d) having a large degree of autonomy in their internal processes and, (e) interacting with humans primarily via predefined material inputs and outputs. Unique benefits of Synthetic Ecosystems include new functions (e.g., plant-microbial fuel cells), enhance efficiencies (e.g., aquaponic systems), provide new services (e.g., waste processing, new habitat patches), can be installed in new settings (e.g., urban centers, mine tailings), positively affect human values (e.g., biodiversity, science education), and offer insights along the way by inadvertently or intentionally testing ecological knowledge. Furthermore, SEs are likely to become an engine of AI development for environmental applications and for incorporating AI into their own design to can help with the internal regulation of functions. Take home message: Synthetic ecosystems will likely make contribute to ecology by a) a strategic shift to employment of ecological phenomena and b) drawing on lessons learned from applications funded by the market.