Permaculture+Criticisms

John Robin has criticized permaculture for its potential to spread environmental [|weeds]. [|[32]]. For example, permaculture projects may introduce plants such as [|Mesquite], which is beneficial to farming in many ways but impossible to remove, and can grows out of control when mismanaged. This plant is considered by the [|World Conservation Union] as one of the most problematic invasive species, and benefits from its introduction has been limited by its management requirements in parts of Africa, Asia and Australia [|[33]]. Proponents of permaculture respond that permaculture, like ecology, consider dangerous to carelessly introduce new opportunistic (or invasive) plants in an environment, and careful planning is required to keep them under monitoring and control.

Some critics have questioned on which scientific data is based the claim of "higher productivity of more mature ecosystems" promoted by permaculture advocates [|[34]]. This claims is based on [|Odum] extensive work on ecosystem productivity, and [|ecological succession] theory. Some critics also claim that woods can not be more highly productive than farmland, as [|ecological succession] states that net productivity declines when forests mature. Proponents of permaculture respond that this is true only if one compares data from between woodland forest and climax vegetation, but not when comparing farmland vegetation with woodland forest [|[35]]. [|Ecological succession] more precisely states that land productivity first rises with forest establishment until reaching the woodland state, with 66% of tree cover, before declining until full maturity [|[36]]. [|Primary production] concept explore this aspect in details.

Although permaculture basic concepts ground in traditional scientific knowledge of ecology, critics found it is often difficult to find scientifically tested data that validate certain claims promoted by permaculture advocates, and conclude that they neglect the scientific approach [|[34]]. Proponents of permaculture respond that supporting its basic concepts, permaculture design applies and combines scientific findings from organic gardening, agroforestery and ecology research, such as plant companionship, composting or mycorhizhal benefits. Such classic scientific data demonstrates the benefit on productivity of growing mutual beneficial plants together compared to growing them separately [reference needed]. But for more elaborate concepts, such as raised bed design and efficiency, extensive scientific data is still lacking.

Proponents of permaculture admit that historically permaculture developed first as a collection of farming practices rather than a scientific theory, and as such did not yet developed a large corpus of scientifically validated data. But they argue that complexity in permaculture, as in applied ecology, make it inherently difficult to validate scientifically. Permaculture design take advantage of multiple relationship to build non-linear systems, known to be to difficult to predict, isolate and test in the lab with traditional methods. This inadequacy of science with living system complexity is largely described by an early permaculture inspirer, [|Fukuoka], and attested by his career radical conversion from pathological botanics research to philosophical natural farming. More recently, Owen Hablutzel made a step forward, and associated permaculture design with chaos mathematics and ecology concepts, such as ecological succession and attractors, to apply permaculture in a field study on draught and salinity remediation with impressive empirical scientific results of pH, salinity and compaction reduction, and water infiltration rise. [|[37]]

Some other critics and practitioners, identify permaculture to a set of spiritual, ethic and moral rules, and claim that permaculture is a system of belief and behavior that has or need no scientific justification. Permaculture conceptual proximity with biodynamics can lead to similar confusions. As an example, companion plants determination from chromatography in biodynamics, is highly disregarded from most permaculture practitioners. Finally, permaculture critics also focused on the lack of clarity and scientific inexactitude of certain authors and teachers, especially when expressing outside of their domain of expertise. In his books “Sustainable Freshwater Aquaculture” and "Farming in ponds and dams", Nick Romanowki expresses the view that the presentation of aquaculture in Bill Mollison's books is unrealistic and misleading. [|[38]] Linda Chalker-Scott claims that Toby Hemenway's views regarding [|invasive species] in the permaculture book "Gaia's Garden" are pseudo-science [|[39]][|[40]].