Concepts for the aggregation of tropical tree species into functional types and the application on Sabah's lowland rain forests

For analysing field data as well as for modelling purposes it is useful to classify tree species into a few functional types. Inthis paper a new aggregation of tree species of the dipterocarp rain forests in Sabah (Borneo), Malaysia, is developed. Theaggregation is based on the two criteria successional status and potential maximum height. Three classes of successionalstatus (early, mid and late successional species) and five classes of potential maximum heights (36 m) lead to a combination of 15 functional types. The criteria of the developed classication are chosen to suit forapplications with process-based models, such as FORMIX3 and FORMIND, which are based on photosynthesis productionas the main process determining tree growth. The concept is universal and can easily be applied to other areas. With thisnew method of grouping a more realistic parametrization of process-based rain forest growth models seems to be possible

A process-based model to assess forest management strategies in tropical rain forests

For analysing field data as well as for modelling purposes it is useful toclassify tree species into a few functional types. In this paper a newaggregation of tree species of the dipterocarp rain forests in Sabah(Borneo), Malaysia, is developed. The aggregation is based on the twocriteria successional status and potential maximum height. Three classesof successional status (early, mid and late successional species) and fiveclasses of potential maximum heights (36 m)lead to a combination of 15 functional types. The criteria of the developedclassication are chosen to suit for applications with process-based models,such as FORMIX3 and FORMIND, which are based on photosynthesis productionas the main process determining tree growth. The concept is universal andcan easily be applied to other areas. With this new method of grouping amore realistic parametrization of process-based rain forest growth modelsseems to be possible

Comparison of measured and modelled growth on permanent plots in Sabahs rain forests

In this paper previously unpublished eld data from 25 ha of permanent samplingplots (PSPs) in Sabah, Malaysia, in four different forest reserves areanalysed for mortality rates and basal area development. Field data of anobservation length of 9 to 20 years were available. These data then formthe basis of several benchmark tests for the evaluation of theindividual-oriented tropical rain forest growth model FORMIND.A new version of the FORMIND is presented. The model in its version FORMIND1.1includes enhanced submodels for mortality and tree growth. The modelevaluation is focused on the model components for tree growth, competitionand mortality. Data for tree recruitment were not available. Results showa good agreement between simulation and eld data for the main output variablesbasal area and stem number indicating a reasonable behaviour of the modelcomponents we focused on. Furthermore the results show that differences insite conditions inuence tree growth and mortality. Site characteristics shouldbe included in the model in the future

The process-based stand growth model FORMIX3-Q applied in a GIS-environment for growth and yield analysis in a tropical rain forest

Managing tropical rain forests is difficult because few long-term field data on forest growth and the impact of harvesting disturbance are available. Growth modelsmay provide a valuable tool for managers of tropical forests, particularly if applied to the extended forest areas of up to 100,000 ha that typically constitute theso-called forest management units (FMUs). We used a stand growth model in a geographic information system (GIS) environment to simulate tropical rain forestgrowth at the FMU level.We applied the process-based rain forest growth model Formix 3-Q to the 55,000 ha Deramakot Forest Reserve (DFR) in Sabah, Malaysia. The FMU was consideredto be composed of single and independent small-scale stands differing in site conditions and forest structure. Field data, which were analyzed with a GIS, comprised aterrestrial forest inventory, site and soil analyses (water, nutrients, slope), the interpretation of aerial photographs of the present vegetation and topographic maps.Different stand types were determined based on a classification of site quality (three classes), slopes (four classes), and present forest structure (four strata). Theeffects of site quality on tree allometry (height-diameter curve, biomass allometry, leaf area) and growth (increment size) are incorporated into Formix 3-Q. Wederived allometric relations and growth factors for different site conditions from the field data. Climax forest structure at the stand level was shown to depend stronglyon site conditions. Simulated successional pattern and climax structure were compared with field observations. Based on the current management plan for the DFR,harvesting scenarios were simulated for stands on different sites. The effects of harvesting guidelines on forest structure and the implications for sustainable forestmanagement at Deramakot were analyzed. Based on the stand types and GIS analysis, we also simulated undisturbed regeneration of the logged-over forest in theDFR at the FMU level. The simulations predict slow recovery rates, and regeneration times far exceeding 100 years

Modellierung von Bestandeswachstum, Stoff- und Energieumsaetzen mit TREEDYN am Beispiel Solling F1 Anwendung des Bestandessimulationsmodells TREEDYN3 auf die Fichten-Versuchsflaeche Solling F1. Modellierung der Bodentemperatur als Bestandteil eines Baumwachstumsmodells. Methodische Untersuchungen zur Wasserhaushaltsmodellierung im Rahmen der Waldoekosystemforschung

SIGLEAvailable from TIB Hannover: RO 4548(45) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Simulating growth dynamics in a South-East Asian rain forest threatened by recruitment shortage and tree harvesting

There is increasing evidence that the futurerecruitment in South-East Asian dipterocarp treesspecies depending on mast-fruiting events mightbe endangered by climate change or enhancedseed predation in forest fragments. Especially incombination with the ongoing tree harvesting inthis region the recruitment threat imposes asevere danger on the species richness andforest structure of the whole area. We here assesswith the process-based forest growth modelFormind2.0 the impacts of common tree loggingstrategies in those recruitment endangered forests.Formind2.0 is based on the calculations of thecarbon balance of individual trees belonging to13 different plant functional types. Even singlelogging events in those rain forests threatenedby a lack of recruitment led to shifts in theabundances of species, to species loss, and toforest decline and dieback. The results show thatcurrent logging practices in South-East Asiaseriously overuse the forests especially in thelight of changing climate conditions