{"id":241,"date":"2011-06-21T06:25:50","date_gmt":"2011-06-21T06:25:50","guid":{"rendered":"http:\/\/africa-and-science.com\/?p=241"},"modified":"2011-06-29T00:49:15","modified_gmt":"2011-06-29T00:49:15","slug":"candidate-mr-adrien-djomo","status":"publish","type":"post","link":"https:\/\/africa-and-science.com\/?p=241","title":{"rendered":"Candidate: Mr. Adrien DJOMO"},"content":{"rendered":"

\"\"<\/a>On November 12th, 2010, Mr. Adrien DJOMO defended his PhD thesis at the\u00a0Institute of Bioclimatology, University of G\u00f6ttingen (Germany). Members of the Jury were\u00a0Prof. Dr. Gode Gravenhorst (Doctor Father), Prof. Dr. Joachim Saborowski and Prof. Dr. Ralph Mitl\u00f6hner. His research was on the\u00a0\u00ab\u00a0Ecological Management of Tropical forests: Implications for climate change and Carbon Fluxes\u00a0\u00bb. For details on his research interests: www.adriendjomo.com<\/a>.<\/p>\n

\u00a0<\/strong><\/span><\/p>\n

Summary<\/strong><\/span><\/p>\n

Tropical deforestation and forest degradation contributes to more than 20% of the global green house gaze emitted. Deforestation and its impacts can be more easily estimated with satellite images. Concerning forest degradation, it is difficult with the actual satellite image resolutions to evaluate accurately logging and biomass damage resulting from this activity though it contributes substantially to carbon emissions in the tropics. With increasing CO2 in the atmosphere, there is an urgent need of reliable biomass estimates and carbon pools in tropical forests, most especially in Africa where there is a serious lack of data.<\/p>\n

Moist tropical forests store large amounts of carbon and need accurate allometric regressions for their estimation. In Africa the absence of species-specific or mixed-species allometric equations has lead to broad use of pan moist tropical equations to estimate tree biomass. This lack of information has raised many discussions on the accuracy of these data, since equations were derived from biomass collected outside Africa. Developing site-specific equations and pan-moist tropical equations including data from Africa is becoming very important for most ecologists for accurate estimations of this contribution extend, necessary for adaptation and mitigation strategies on climate change impacts. Allometric equations are key tools for climate change scenarios since they are used for estimating biomass and carbon pool at local, regional and world level. Information on net primary production (NPP) resulting from direct biomass field measurements is crucial in this context, to know how forest ecosystems will be affected by climate change and also to calibrate eddy covariance measurements.<\/p>\n

The overall objective of this study was to provide a scientific contribution for adaptation or mitigation of moist tropical forests on climate change impacts. The specific objectives were to (1) Analyze the stand development of a forest in the eastern Cameroon and discuss a methodology for estimating the potential carbon emissions or reductions from forest degradation. (2) Develop allometric equations for accurate estimations of biomass and carbon pools in moist forests in Cameroon and also in Africa. (3) Estimate carbon pools and Net Primary Productivity (NPP) and their spatial distribution on different strata and land use types of the Campo-Ma\u2019an area forest in Cameroon.<\/p>\n

This dissertation presents results from two field studies conducted at the neighbourhood of Yokadouma in the eastern Cameroon and also in the Campo-Ma\u2019an forest in the southern Cameroon. The study conducted at Yokadouma resulted in a paper addressing forest degradation after selective logging and its implications for REDD and carbon estimations. To address this situation, a post-logging stand development of a semi-deciduous natural forest in Cameroon was modelled for one felling cycle (30 years) after selective logging. To simulate how different management practices influence post-logging forest dynamics, we modelled how changes in the minimum felling diameter (MFD) affect stem density, basal area and the related carbon biomass at the end of the felling cycle.<\/p>\n

The study conducted in Campo-Ma\u2019an resulted in two other articles. The first article addressed site-specific allometric equations and also pan-moist tropical equations which can be used at other locations in moist tropical forests where there are no specific allometric equations. We used for this study 91 destructive sample trees to develop mixed-species allometric equations applying different input variables such as diameter, diameter and height, product of diameter and height, and wood density. Our biomass data were added to 372 biomass data collected across different moist tropical forests in Asia and South America to develop new pan moist tropical allometric regressions. Species-specific and mixed-species height diameter regression models were also developed to estimate heights using 3833 trees. The second article used our site-specific allometric equations to estimate aboveground and belowground biomass and carbon pools. The NPP was estimated using the growth rates obtained from tree ring analysis. A carbon biomass map was also developed in this last paper using GIS technology to show the distribution in the different land uses and vegetation types.<\/p>\n

The main findings were following:<\/p>\n

Forest degradation studies:<\/span><\/p>\n