The final, least obvious but perhaps most immutable criterion for what constitutes ‘ecological’ is that the vegetation is subject to, and able to respond to, ecological processes and, in particular, natural selection, the key agent of evolutionary change. Ecological processes include factors such as regeneration, competition, death and decay, and nutrient recycling. In traditionally cultivated vegetation, irrespective of origin, spatial arrangement and husbandry, we grossly inhibit these processes. These processes are not tied to national origin, they are blind and completely value neutral, although as human beings we are intensely interested in making our own value judgements on the outcomes. That ecological worth may be more tied up in notions of process rather than a product is an unsettling idea, as it undermines the foundations of many of our values, which are grounded in commodities, a perspective in time and the current boundaries of the nation state. Ultimately, the semantics of what ‘ecological’ means are pointless as it is impossible to separate perspectives from cultural relativism. All we can do is attempt to gain acceptance that it is a broad church, especially in urban contexts.
Thus far the discussion in this chapter has tried to establish some of the principles that underpin the creation and management of naturalistic planting design. This type of planting is, however, still relatively rare in most countries, even where some of the philosophical background is long established, as for example in Germany What are some of the factors that are restricting the popularity of this style? This question is pondered in greater detail by Noel Kingsbury in chapter three, however in Germany it appears that insufficient knowledge of plants and their requirements, plus the costs of detailing complex naturalistic plantings, and the funds and skills needed for a selective maintenance regime, limit the practical application of this style. Many of these limitations are less evident in the less horticultural, anthropogenic planting style, however this type of vegetation is still attractive enough to be valued by the public. The authors see this style as more practical for more general landscape application, especially given that in Britain and many other countries, vegetation management skills in urban green space have often declined, placing considerable limitations on what can be achieved. To operate in this environment requires the development of new knowledge on: plant establishment and, in particular, planting and sowing mixes for a range of different site conditions; plant tolerance of less closely regulated competition; the long-term dynamics of plant communities; and, finally, how this knowledge can be used to create and manage this type of vegetation within landscape practice. We hope that this book will contribute to developing and propagating this knowledge.