30 yr Danum: the dynamics of a primary rainforest

In this talk I shall attempt to briefly summarize the background, approach, methods and results of our long-term study of the primary forest at Danum between 1985 and 2015. This has involved five full censuses, and one partial census, of the two main 4-ha plots within DVMC; plus four censuses of a set of satellite plots. The key variables are rates of tree mortality, growth and recruitment. Analyses showed a surprisingly high level of variability in population dynamics both between and within tree species, a large portion of which can be attributable to environmental stochasticity driven by climate events, and by demographic stochasticity determined by tree neighbourhood interactions. In 2009 the ‘plurality’ hypothesis was put forward to explain the high complexity of natural forests changing over time. Under the motto “know your system”, it seems that it is really essential to understand what drives changing tree species composition in order to manage and conserve rain forests. Long-term empirical field data are indeed fundamental to all forest ecology. (NOTE: The lecture text, with pointers to the slides, are available in 'Supplementary Materials'.) DMN/Bern/26.09.2016