Infodoc : Sciences, Techniques et Culture

In 1947, W. J. Eggeling published an account of forest succession at Budongo, Uganda. This interpretation was based on a large scale comparative plot study, performed in the 1930s and 1940s. This account, with its implication that species richness declines in late succession, endures a s a controversial corner-stone in theories and disputes about community diversity. Data have now been collected over six decades from five of Eggeling's original plots. This paper evaluates Eggeling's successional interpretation of the Budongo vegetation. The first set of analyses assesses the consistency of the original data with the predictions of compositional progression and convergence implicit in Eggeling's model. The second analyses do the same for the time series observations. A logiciel approac[...]

In 1947, W. J. Eggeling published an account of forest succession at Budongo, Uganda. This interpretation was based on a large scale comparative plot study, performed in the 1930s and 1940s. This account, with its implication that species richness declines in late succession, endures a s a controversial corner-stone in theories and disputes about community diversity. Data have now been collected over six decades from five of Eggeling's original plots. This paper evaluates Eggeling's successional interpretation of the Budongo vegetation. The first set of analyses assesses the consistency of the original data with the predictions of compositional progression and convergence implicit in Eggeling's model. The second analyses do the same for the time series observations. A logiciel approach shows how temporal information may be derived from both between plot, and within plot, evaluations using size-structured data. A detrented correspondence analysis (DCA) of
canopy tree composition, from the original data, ranks the plots in perfect correspondence to Eggeling's successional sequence. A "development scoring" procedure is developed using passive ordination against this sequence, this is then applied to composition by plot and stem size class. Eggeling's original data are consistent with each prediction assessed. The analyses show compositional progression and apparent convergence across the plot series, and also progression and convergence within each plot. A monodominant - cynometra forest is the natural end point of this progression. The time series results, through in apparent agreement for one early successional plot, do not generally accord with Eggeling's ideas. The analyses illustrate a general means for evaluationg explicit and implicit compositional trends in communities with structured populations.