Tuesday, October 03, 2006

The ragwort dies

The large plant of ragwort, Senecio jacobaea, finished flowering and lost all its leaves so on 1 October I cut it back to the level of the stake of beech driftwood I call 'The Gnomon'. I have watched it through many transformations: as a small seedling, as a great cabbage of a rosette this spring. Then as the five stalks climbed upwards to well over a metre tall and attracted a wide range of insects.

Despite the summer size and vigour of this ragwort, the other plants round about, as the picture shows, seem to have grown without undue check. It is a mystery to me quite where the nutrient comes from.

Another puzzle is why large, robust plants like this die after a season while other, often much smaller species may persist for many years. Just behind The Gnomon there is a baby birch, now two years old. Above it some hypericum that struggled while the ragwort grew, but is now claiming its placed in the sun. Somehow the ragwort seems programmed to die young while the birch,in fifty to seventy years time may die due to windthrow or fungal attack, but not because it is programmed to die after a given period.

The annuals and biennials do, maybe, evolve more rapidly, but it will be many years before the birches and other young trees can reproduce. Over long periods of time have the annuals survived better in some contexts and the perennials better in others? If they have it is difficult to explain why the two now grow so happily together, though the short-lived do make good 'nurse crops' for the longer lived.

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