Senescence and Rejuvenation in Ungrazed Chalk Grassland (Grassland B) in Breckland: The Significance of Litter and of Moles

The Park Grass plots at Rothamsted provide a convincing demonstration of change in the floristic composition of a grassland by the use of fertilizers (summarized in Thurston 1969). But it is not sufficiently emphasized that the maintenance of the change depends on the removal of the crop (in this case, hay) that is, of potential litter which itself would act as a further differentiating factor. Also in the Rothamsted experiment, disturbance, e.g. breaches of the continuity of the sward and exposure of the mineral soil, is excluded. No such strictures apply in the natural ungrazed chalk grassland of Foxhole Heath where old plants die, litter decays in situ and small mammals (moles) disrupt the continuity of turf and expose mineral soil.