I know its the year of bio-diversity but the question of Sustainability has been nagging at me recently and with articles on Landscape juice such as the ‘acute oak decline disease’ and the recent forum post on permeable paving I thought I would investigate my thoughts further.
I have just completed a project using new oak sleepers, this is what started it all, until this time I believed oak to be a sustainable resource but the article on the oak disease has made me rethink this notion. An oak tree takes 30 years to become useful as frame timber and it takes 120 years to reach its peak, so does this really fit with the description of sustainability.

Brundtland (1987): Sustainable development is development that meets the needs of the present without compromising the needs of future generations to meet their own needs. (http://www.ecifm.rdg.ac.uk/definitions.htm university of reading)
Even if we are planting Oak to replace the harvested they will not be ready for several generations to come.
So does this mean there are different levels of sustainability for example:
Short term: plants and shrubs and recycles products such as composite deck
Medium term: Pine and other quick growing trees
Long term: aggregates, sand and slow growing trees
After all even gravel will be replaced but it takes millions of years for the mountains to erode. So what does this mean for garden designers and landscapers. Well I try to be sustainable but can I really claim to be if you apply the rule of meeting future generations? How important is it to the industry and the people who work in it?
No I don’t think this has answered any questions other than maybe we should be rethinking the uses of any product that falls under the long term sustainable category as our future generations cannot benefit from them. Not being an expert any input from others would be appreciated.