Research program
- Research at the NHN is based on a comparative and integrative approach, including molecular and morphological-anatomical analyses. On the one hand it comprises long-term research projects such as of Floras and Monographs, on the other hand it includes short-term projects that deal with various phylogenetic and evolutionary topics, explore characters on macro- and microscopic, ultrastructural and molecular level, and investigate various topics in biogeography topics.
- Flora projects
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- The NHN coordinates a number of traditional Flora projects: Flora Agaricina Neerlandica, Flora of Gabon, Flora of the Guianas, Flora Malesiana, and Flora van Nederland, and is closely involved in a number of related Flora projects (Flora of China, Flora of Thailand). For all these Flora's we provide contributions based on our present monographic research and expertise. This traditional floristic work provides the impetus for various follow-up studies, including systematic, molecular and ecological research on critical taxa, and for research into the influences of climate change and human activities on floristic diversity.
- Systematic studies
In view of the increasing need of species identification and species-specific elementary plant information (ecology, distribution, uses, etc.) for conservation and sustainable use of natural resources, α-taxonomic revisions remain the core activity and the basis for all research of the NHN.
This research is focused on a number of species-rich plant families: the flowering plant families Annonaceae, Euphorbiaceae, Leguminosae, and Orchidaceae, and various groups of pteridophytes, bryophytes, agaric fungi, and algae.Apart from this taxon-oriented approach, our research questions can be grouped under the thematic headings Morphology and evo-devo; Phylogenetics and phylogenomics; Biogeography and Global change biology
- Morphology and evo-devo
We aim to understand the evolution and homology of characters (of flowers, pollen, seeds, wood, etc.) by applying comparative paleobotanical, morphological and anatomical studies. By applying new techniques, e.g. confocal microscopy, CT-scanning, image analysis, dating methods, etc. we will expand and refine these investigations.
Homology assessments are deepened by applying evolutionary and developmental genetics (evo-devo), in collaboration with the Biosystematics research group at Wageningen-UR and the Hortus botanicus Leiden.Current evo-devo work concentrates on characters of orchid flowers, but may be expanded to other character sets (e.g. wood anatomy).
Palynological and wood anatomical projects are mostly carried out in conjunction with ongoing taxonomic and phylogenetic studies.
Paleobotanical research is focused on comparative studies of the macro- and microflora of the Maastrichtian Type Area.
- Phylogenetics and phylogenomics
We aim to contribute to the understanding and building of the Tree of Life by carrying out in-depth phylogenetic studies of selected clades.
In these phylogenies we integrate geological and paleobotanical data to be able to position evolutionary novelties in their chronological, developmental and geological context.
- Biogeography
Biogeography is an element of many of the systematic research projects of the NHN.
The number of geo-referenced and taxonomically verified data in our collection databases for Borneo, West Africa and the Guianas have been increased considerably over the last years. These data-sets are used for data mining and floristic analyses that serve both base-line regional and local inventories, and studies of biogeographical patterns and processes.
Historical biogeography of pathways, islands and continental refuges are addressed in both practical and theoretical frameworks. Specimen data derived from our collections are used to differentiate between present-day factors and historical constraints, and to recognize general patterns like areas of endemism, borderlines between biota, areas of speciation/radiation.
Building upon the expanding phylogenetic data assembled over the years and the huge and rapidly growing electronic specimen data bases, the biogeographic analysis of Malesian plant diversity will be continued and extended with on the one hand dating of vicariance events, and on the other hand data mining for spatial pattern analyses.
- Global change biology
The NHN-collections provide information that is highly relevant for nature conservation and sustainable use of plant resources. Herbarium collection data are used with increasing effectiveness due to the growing amount of high-quality digitized data, and the development of new methodologies for the use of these data.
Climate change threatens biodiversity because many organisms are unable to adapt to rapidly changing habitats. We will produce integrated species databases and combine them with information on ecosystem structure and function, species distribution models, climate models, and geological and paleontological reconstructions of previous biodiversity crises.
With regard to environmental monitoring, we closely collaborate with FLORON for monitoring changes in the Dutch flora.
