Sustainability classification & nested hierarchies
We have, of course, devised plant classifications in all of the above categories but not, perhaps, with the degree of dedication that we have applied to formal scientific classification. Scientific plant classification organises plants in a boxes within boxes way such that no plant can be a member of more than one group: the plants are ranked into families, which are then divided into genera, divided in turn into species, and so on. The specific criteria used to group the plants are their physical characteristics, and the classification becomes progressively inclusive. There are over 350 plant families and over 350,000 species. An example of the way this works would be the single category ‘seed plants’ which is then divided into the groups ‘flower-bearing plants’ and ‘cone-bearing plants’. The flower-bearing plants can then be divided into those which have one seed leaf (monocotyledons)
and those which have two seed leaves (dicotyledons).
So how would we divide and subdivide plants based on criteria of sustainability? Ideally we would start with the most general characteristic of sustainabilty and proceed to mutually exclusive items of lesser significance. The characters used to establish major groupings of seed plants – whether the plants have flowers or cones – are uncontroversial and mutually exclusive. The organisation and justification for sustainabiity categories within the idea of sustainabilty are discussed elsewhere. Here is a list of useful categories frequently associated with the discussion of sustainability: social organisation, population, biophysical resource consumption, technology, transport and communication, materials, energy, food, water, biodiversity.
A number of problems immediately arise. Firstly, sustainability is itself an imprecise idea so creating a universally accepted and stable definitional category would be difficult. Secondly, there is the intrusion of value as subjectivity which in scientific classifications is reduced to an absolute minimum. However we define sustainability it relates to environmental impact and how that impact occurs will be both causally complex and value-laden. Environmental costs must be assessed against benefits. There is the further complication that because of the complexity of sustainability the development of neatly mutually exclusive groupings is unlikely.
We can examine sustainability obliquely by categorizing the many ways that humans use plants. For example, the many plant categories that relate to their utility: use for agriculture, forestry, and horticulture; as food, fibres, medicines, poisons.
We use plants as food; food and drink additives; psychoactive plants; poisons; as medicines and drugs; fibres; dyes; perfumes and aromas; oils, fats, waxes; resins; rubber; wood and timber for fuel and paper; for structural materials, decoration, and ceremony.
We can also categorize plants more generally through the contextual idea of Ecosystem Services which is convenient shorthand for the many ways in which humans benefit from nature. The overall goal is to maximize the well-being of humans as freedom of choice and action which is only possible by also maximizing the well-being of the community of life which entails care of the wider environment of planet Earth. There are several basic constituents of well-being: security (as personal safety, and maximum protection from political and natural disasters); access to basic material resources (jobs, food and goods, shelter); health (access to clean air and water, and medical attention); and good social relations through mutual respect and support. From this perspective, if we are to maximise human well-being then we need to know how Ecosystem Services contribute to the constituents of well-being. The Millennium Ecosystem Report proposes four ways in which this can done: by provisioning (e.g. food or fresh water, materials), regulating (e.g. climate, flood, disease etc.), supporting (e.g. nutrient cycling, soil formation, primary production, pollinators), and finally cultural (aesthetic, spiritual, educational, recreational).
This draws our attention to several key points All plant classifications relate to human utility although scientific classification uses characters that are not necessarily so. plants can be classified in many ways with formal plant classification relating mostly to the plants themselves and other classifications relating mostly to human utility. Almost all classifications that we apply to plants relates to their utility; the prioritization of these methods of classification is itself a matter of conscious or unconscious prioritization or policy.
Plants, people, planet
This web site has as its central theme the role of plants, especially those in Australia, in the future of planet Earth. Plants and Australia are categories that lie within the grander theme of life, planet, people. Though people are part of ife their influence on the furure is overwhelming and therefore requires special attention.
We therefore need the best possible progressive classification through which to address this theme. The interrelated taxonomic units within this system are contentious and are discussed elesewhere, but stated simply here they are the physical objects plants, planet, and people. Their relationship as determined by the interaction of environmental, social, and economic processes. The goal of the classification, its purpose, is sustainability – which is the long-term mutual interdependence of all life-forms and their life-support systems. Life-forms are interdependant in such complex ways that singling out individual kinds for special treatment although humans are an obvious case and plants have been selected for special consideration on this web site.
Long-term survival of humanity depends on the protection of the organisms and ecosystems on which people depend. However, humanity is likely to place itself ahead of other species for survival. One way of protecting all life, but humanity in particular, has been expressed through the notion of ecosystem services: provision (food, wood, fresh water, fuel etc.); regulation (climate, floods, water purification etc.); culture (aesthetics, spirituality, education recreation etc.); support (soil formation, nutrient cycling, primary production etc.).
Sustainability operates at many scales: it therefore crosses several domains of discourse which therefore complicates the elucidation of causal connections.
One major difficulty to overcome is that of scale. On the one hand without plants there would possibly be no life – plant impact has been total and planetary-wide affecting all organisms. On the other hand particular individual plants can be of great importance to individual people, and not all aspects can be considered all at once. How are we to deal with the huge gulf between macro and micro scales of interest?
In the first instance we must try to trade the blandness but comprehensiveness of generality against the inaccuracy but utility of specificity. We need to find the best mix of these two forces.
Certainly one approach is to see how the plants on the surface of the planet have been altered in their composition and distribution by human activity.