Bioengineering is a method of restoring damaged terrestrial and aquatic ecosystems. It emphasizes the use of live plants as the basic building blocks that begin the restoration process, and then, continue, on their own, the healing process that leads to a stable, climax plant and animal community. In its most refined form, bioengineering uses the physical properties of plants, such as their sheer resistance, tensile strength, and flexibility, to construct stabilizing structures such as live slope fascines and hedge brush layers, to stabilize earth slumps and landslides; live woven willow fences and willow brush mattresses and hydraulic fascines to protect and revegetate damaged stream banks; live siltation baffles, to rebuild washed out stream banks and flood terraces.
Bioengineering developed historically as did the practices of medicine, engineering, and architecture, beginning as a number of discrete techniques developed to solve specific problems. Knowledge of these techniques was part of the body of folk wisdom accumulated in prehistoric times and passed orally from generation to generation. In the last two centuries, this knowledge was compiled and codified, and finally in fairly recent times, it has been taught formally and practiced as a profession.
The system of technologies which we today call bioengineering can be traced to the ancient peoples of Europe and Asia. Some of the early western visitors to China told of river banks and dikes stabilized with large baskets woven of willow hemp or bamboo, and filled with rocks. There are fifteenth century scrolls showing villagers planting willow sprigs in stream banks.
In Europe during the nineteen twenties and thirties German, Austrian and Italian engineers and foresters began studying the methods that villages, both in Europe and Asia had evolved to repair their own damaged landscapes, and they added a scientific component, doing extensive testing of the many properties of plants, their rooting capabilities, their soil tolerance, temperature range, altitude range, salinity tolerance, drought tolerance, rooting methods, seeding methods. They learned the tensile strength of willow roots to be twenty five hundred pounds per square inch and that of fir roots to be eighty five hundred pounds.
They refined these ancient, labor intensive techniques, and applied them to modern ecological problems, discovering that this style of repair work becomes indistinguishable from the surrounding natural landscape in just a few short years.
Evan Engber