Doctor of Science Deegre Research

Tropical forest floral communities exhibit a fairly high diversity of tree species on a per hectare basis.This diversity is a great obstacle for forest managers wishing to draw management plans with the principal aim of sustainable wood production from sample plots where several species may be present in too small numbers for any meaningful analysis. One solution to this problem is to aggregate tree species into a few ecological guilds or groups of individuals with similar ecological characteristics relative to response to logging and forest management in general. However even with this problem solved trees are fairly long lived organisms and management decisions need to be made now which will affect the forest in the decades or even centuries to come. Simulation models offer a practical and essential tool by which to draw management plans because using limited and fragmentary information it is possible to make predictions concerning the impact of specific harvesting and other related management interventions on the long term compositional dynamics of the forest.

My research for the doctorate, focused on identifying the factors in stand level functional composition that drive response and to make one specific area recover more quickly and with less changes to a gradient of selective logging practices in relation to another with different composition. Data came from the Brazilian and Peruvian Amazon . The research question was addressed at two levels. First at the level of performance of the individual ecological guilds relative to each other and secondly at the level of the forest stand using a gradient in forest functional composition and both levels over a gradient of logging disturbance regimes .Suitable simulation models where used to explore the later question. As an independent test to assist towards the objective of the research I also looked at the performance of ecological guilds relative to each other to the natural analogue of logging disturbance in these forests which is drought induced canopy tree death for an area of forest which is exhibiting very high diversity in functional forms but at the same time no clear dominance of any at the sample plot level-and hence neutral conditions in terms of relevant ecological effects- for a site in the Central Brazilian Amazon in the State of Amazonas.

During the time of my doctoral research I also analyzed data from the Curua Una Experimental station in Para State Brazil with the goal of determining the effect of varying long term silvicultural treatments starting in 1955 on the functional composition and ecology of the forest as well as implications with respect to the economics of logging

I was affiliated with Imperial College London, United Kingdom and the Smithsonian Center for tropical forest science through their biological dynamics of forest fragments project(BDFFP) in Brazil for this research

More information on this research as well as details and potential implications of the results can be found at section “Scientific publications and news media” of this website.