Research Group: Plant Diversity and Ecology

Flowering plants contains a rich diversity of species and populations that interact and evolve with each other, with other organisms, and with the abiotic environment in which they occur.

Plants constitute a most important resource for human food production, ornamentals, and other commodities. At the same time, plants may deteriorate these biodiversity goods as weeds and invasive plants. We use basic ecological, evolutionary science and systematics to develop solutions in agriculture, human influenced habitats and the management of plant communities. Our research methods include plant identification and DNA barcoding, field and greenhouse experiments and assessments, modelling, DNA and plant chemical defence analyses.

The overall focus of the Research Group in Plant Diversity and Ecology is

  • Plant diversity, systematics, and relationships among cultivated plants and wild relatives
  • The potential of plant genetic resources
  • Plant ecology in human influenced habitats
  • Interactions among plants, insects, microorganisms and the environment
  • Applied ecology and biodiversity in the management of plant communities


Examples of topics covered by our group.

  • Plant defence against herbivores and pathogen, including microbe-induced resistance
  • Plant-plant interactions, including crop-weed competition
  • Plant growth, resource allocation and life history
  • Application of ecological and evolutionary theory to plant production
  • Molecular and morphological identification of plants at all levels
  • Molecular methods in plant systematics and phylogeny
  • Genetic resources for future breeding
  • Plant inventory (morphological, cytological and molecular)
  • We offer botanical services.


  • Demonstrate the use of DNA-phylogeny to understand evolution within and among closely related species combined with the evolution of chemical compounds, morphological characteristics and herbivore resistance.
  • Contribute to resolve taxonomical problems among closely related and threatened orchid species.
  • Demonstration of defense-priming in plants by association with fungi, which are otherwise known as insect pathogens, to their roots: shown for myrosinase and glucosinolates in cauliflower
  • Fine-scale compensatory responses in photosynthesis of plant leaves attacked by insects.
  • Elucidation of the relationship between individual fitness and population yield in crops.
  • The ecological basis for agricultural sustainability.
  • Density-biomass relationships in plant communities
  • Demonstration of the occurrence of widespread natural hybridization in tropical plants in the Southeast Asian region.



The group members have course responsibility for the following courses: Animal and Plant Diversity Botany, Natural Science for Landscape Architects (2A and 2B), Botany for Garden and Landscape Architects, Trees and Shrubs, Plants in Populations and Communities. We contribute teaching to the following courses: Diversity of Organisms, Natural Resources and Ecology, Evolutionary Ecology. We supervise numerous master and bachelor projects, PUK-, PREP- and projects with private firms. Our goal is to generate enthusiasm for plant biodiversity, systematics and ecology at all levels and in all fields of studies at the university.


We offer botanical services via PLENs homepage. We have held courses in plant identification, plant names, and plant systematics as well as made plant identifications in parks and on noise barriers, communicating research activities to the public and to relevant professions.

  1. Bjørn, M.C. and Ørgaard, M. Semi-naturlige urteagtige vegetationstyper i og omkring byer: etablering og udvikling. Videnblade Park og Landskab: 2s
  2. Bjørn, M.C. and Ørgaard, M. Hvordan fremmer vi biodiversitet i byområder? Momentum 2: 10-13.
  3. Jacobsen, N. & M. Ørgaard. Die Bestäubung der Gattung Cryptocoryne (Araceae). Aqua Planta 45 (1): 1, 4-19.
  4. Jacobsen, N., H. B. Ganapathy, N. A. Mangsor, A. S. Othman, S. N. A. Rahman, R. Rosazlina & J. Siow. 2020. Wasserpflanzen in einem Fluss mit Gezietenzone am Sungai Sedili Kechil, Johor, Malaysia. Aqua Planta 45 (4): 129-139.
  5. Kruse, D.D., Horst, K.K. and Lange, C.B.A. DNA-stregkoder som botanisk redskab. URT 4: 22-27.
  6. Mortensen, N.B.E. & Lange, C.B.A. 2019. Invasive arter – en udfordring. Momentum 1: 4-7.
  7. Lange, C.B.A. and Lange C. 2017. Landbohøjskolens Botaniske Samlinger før, nu og i fremtiden. URT 4: 16-21.
  8.  Jacobsen, N., J. D. Bastmeijer, S. Wongso & M. Ørgaard. 2019. Lagenandra keralensis und L. meeboldii. Aqua Planta 41 (3): 84-91.



  • “Give Peas a Chance”. Exploring potential in Old Danish pea cultivars.
  • Phylogeny of palms (Arecaceae). How can phylogeny help us understand the diversification and geographical distribution of palms and improve the current classification?
  • Phylogeny and molecular identification of Trifolium (clover). We develop DNA-barcodes to all clover species and try to understand the relationship among these lovely plants
  • Systematics of Barbarea. Can evolution and radiation in this genus help us understand the development of chemical defence systems found in some of these plants.
  • Plant –insect and plant –insect-microbe interactions: Saponin-based plant defence in Barbarea vulgaris; defence priming of Brassica by root-associated fungi
  • Evolutionary Agroecology. Applying evolutionary theory to plant production.
  • Allometry and yield stability in cereal crops. The quantitative analysis of the relationship between growth and reproduction determines yield stability.
  • Biodiversity of noise barriers; possibilities for enhancing diversity.
  • Evolution and diversification related to geographical distribution.
  • Cryptocoryne. Evolution and diversification related to geographical distribution.
  • Crocus. Evolution and diversification related to geographical distribution.


MiRA ", a Horizon 2020 ITN/" training 15 PhD students across Europe in Microbe-induced Resistance to Agricultural pests, and its context dependency

Molinia”, Molecular plant identification using DNA barcodes. How efficient is molecular identification and how can we best use this tool in modern management of natural and cultivated systems

Træer i Arboretet”, a botanical guide to trees in the Arboretum, Hørsholm

Noise barriers, ecology and plant diversity

Noise barriers, flora and fauna


We collaborate with Thy National Park.
Network on plant–insect-microbe interactions among European scientists
Extensive collaborations with numerous universities and research institutes in Europe and China. Collaboration with University Sains Malaysia, Penang regarding Aquatic plant genera, and the Indonesian NGO: Komunitas Cryptocoryne Indonesia.





  1. Agerbirk, N., Hansen, C.C., Kiefer, C., Hauser, T.P., Ørgaard, M., Lange, B.A., Cipollini, D., Koch, M.A. .2021. Comparison of glucosinolate diversity in the crucifer tribe Cardamineae and the remaining order Brassicales highlights repetitive evolutionary loss and gain of biosynthetic steps. Phytochemistry 185, 112668
  2. Agerbirk, N., Hansen, C.C., Olsen, C.E., Kiefer, C., Hauser, T.P., Christensen, S., Jensen, C.R., Ørgaard, M., Pattison, D.I., Lange, C.B.A., Cipollini, D., Koch, M.A. 2021. Glucosinolate profiles and phylogeny in Barbarea compared to other tribe Cardamineae (Brassicaceae) and Reseda (Resedaceae), based on a library of ion trap HPLC-MS/MS data of reference desulfoglucosinolates. Phytochemistry 185, 112658

  3. Cachapa, J.C., Meyling, N.V., Burow, M., Hauser, T.P., 2021. Induction and Priming of Plant Defense by Root-Associated Insect-Pathogenic Fungi. J. Chem. Ecol. 47, 112–122. doi:10.1007/s10886-020-01234-x

  4. Hauser, T.P., Christensen, S., Kuzina, V., Thines, M., Ploch, S., Bak, S., 2021. Effects of a saponin-based insect resistance and a systemic pathogen resistance on field performance of the wild crucifer Barbarea vulgaris. Arthropod Plant Interact. doi:10.1007/s11829-021-09858-w.

  5. Jacobsen, N. 2021. Josef Bogner – and the genus Cryptocoryne. Aroideana 44 (1): 82-109.

  6. Jacobsen, N., H. Ganapathy, I. Ipor, K. R. Jensen, T. Komala, K. N. A. Mangsor, F. A. Nordin, A. S. Othman, R. Rosazlina, J. Siow, S. Wongso & M. Ørgaard. 2021. A reassessment of the genus Barclaya (Nymphaeaceae) including three new species from Peninsular Malaysia. Nordic J. Botany.

  7. Yang, R., Weiner, J., Shia, X., Wang, Y., Zhang, R., Zan, S. 2021.  Effect of reductive soil disinfestation on the chemical and microbial characteristics of rhizosphere soils associated with Salvia miltiorrhiza production in three cropping systems. Applied Soil Ecology, 103865. doi: 10.1016/j.apsoil.2020.103865
  1. Wu, Y., Xi, N., Weiner, J. and Zhang, D.-Y. 2021. Differences in weed suppression between two modern and two old wheat cultivars at different sowing densities. Agronomy 11, 253, doi: 10.3390/agronomy11020253.

  2. Rosazlina, R., Jacobsen, M. Ørgaard & A. S, Othman. 2021. Molecular evidence of the hybrid origin of Cryptocoryne ×purpurea Ridl. nothovar. purpurea (Araceae). PLOS ONE 16(1) e0239499.

  3. Shi, Z., Weiner, J., Cavalieri, A., Liu, H., Li, T., Cai, J. Jiang, Y. 2021. The interaction between N and P ferilization on grassland soil acid buffering capacity is regulated by precipitation. Soil Science and Plant Nutrition. doi: 10.1080/00380768.2021.1892457

  4. Damgaard, C. and Weiner, J. The need for alternative plant species interaction models. Journal of Plant Ecology 14, 771-780. doi: 10.1093/jpe/rtab030

  5. Jensen, P.M., Sørensen, M. and Weiner, J. Human Total Fertility Rate affected by ambient temperatures in both the present and previous generations. International Journal of Biometeorology. doi: 10.1007/s00484-021-02140-x
  1. Weiner, J., Du, Y.-L., Zhao, Y.-M. and Li, F.-M. 2021 Allometry and yield stability of cereals. Frontiers in Plant Science 12, doi: 10.3389/fpls.2021.681490.
  1. Bastmeijer, J. D. & Jacobsen. 2020. Lagenandra ’Cora Bastmeijer’, an artificial hybrid between the Indian L. meeboldii and the Sri Lankan L. thwaitesii (Araceae). Aroideana 43 (3 & 4): 54-58.
  1. Bastmeijer, J. D. & Jacobsen. 2020. Artificial hybrids in Lagenandra (Araceae). Aroideana 43 (3 & 4): 59-96.

  2. Jacobsen, N., D. Bastmeijer, T. Idei, S. Wongso & Ørgaard, M. 2020. Artificial hybrids in Cryptocoryne (Araceae) 6: Hybridization between various species. Aroideana 43 (1 & 2): 225-239.
  1. Jacobsen, N., D. Bastmeijer, K. R. Jensen, A. S. Othman & M. Ørgaard. 2020. Cryptocoryne hybrids (Araceae) 2: Two Cryptocoryne hybrids from southern Peninsular Malaysia. Aroideana 43 (1 & 2): 240-254.
  1. Jacobsen, N., D. Bastmeijer, H. Ganapthy, I.B. Ipor, K.R. Munk, A.S. Othman, R. Rosazlina, J. Siow, T. Komala & M. Ørgaard. 2020. Cryptocoryne hybrids (Araceae) 3: Hybrids between Cryptocoryne cordata and Cryptocoryne nurii from southern Peninsular Malaysia. Aroideana 43 (1 & 2): 255-284.
  2. Wan, N.-F., Su, H., Cavalieri, A., Brack, B., Wang, J.-Y., Weiner, J., Fan, N.-N., Ji, X.-Y., Jiang, J.-X. 2020.  Multispecies co-culture promotes ecological intensification of vegetable production. Journal of Cleaner Production 257, 120851.

  3. Cavalieri, A., Bak, F., Garcia, A.M., Weiner, J., Nicolaisen, M.H. and Nybroe, O. 2020. Effects of intra- and interspecific plant density on rhizosphere bacterial communities. Frontiers in Microbiology 11, 1045. doi: 10.3389/fmicb.2020.01045

  1. Du, Y.-L., Xi, Y., Cui, T., Anten, N.P.R., Weiner, J., Li, X., Turner, N.C., Zhao, Y.-M. and Li, F.-M. 2020. Yield components, reproductive allometry and the tradeoff between grain yield and yield stability in dryland spring wheat. Field Crops Research 257, 107930.

  2. Wongso, S., Hendrik, R. Jensen, M. Ørgaard & N. Jacobsen. 2020. A new Cryptocoryne species (Araceae) from the Schwaner mountains, West Kalimantan, Indonesia. Nordic Journal of Botany. 38 (4): 1-5. e02716.

  3. Wongso, S., J. D. Bastmeijer, T. Idei, R. Jensen, M. Ørgaard & N. Jacobsen. 2020. Cryptocoryne hybrids (Araceae) 4: A Cryptocoryne hybrid from the Meratus mountains, South Kalimantan, Indonesia. Aroideana 43 (1 & 2): 285-298.

  4. Liu, Q., Khakimov, B., Cárdenas, P.D., Cozzi, F., Olsen, C.E., Jensen, K.R., Hauser, T.P., Bak, S., 2019. The cytochrome P450 CYP72A552 is key to production of hederagenin-based saponins that mediate plant defense against herbivores. New Phytol. 222, 1599–1609.

  5. Christensen, S., Enge, S., Jensen, K.R., Müller, C., Kiær, L.P., Agerbirk, N., Heimes, C., Hauser, T.P., 2019. Different herbivore responses to two co-occurring chemotypes of the wild crucifer Barbarea vulgaris. Arthropod Plant Interact. 13, 19–30. doi:10.1007/s11829-018-9633-x

  6. Bjørn, M.C., Weiner, J., Kollmann, J. and Ørgaard, M. 2019. Increasing local biodiversity in urban environments: Community development in semi-natural species-rich forb vegetation. Landscape and Urban Planning 184, 23-31.

  7. Jacobsen, N. & Ørgaard, M. 2019. Natural hybridization – recombination – an ever-ongoing process. Thai Forest Bulletin, BOT. 47(1): 19 – 28.

  8. Jacobsen, N. & Ørgaard, M. 2019. Artificial hybrids in Cryptocoryne (Araceae). Hybridization between Sri Lankan species within the 2n = 28 chromosome group. Aroideana 42 (1): 76-106.

  9. Jacobsen, N., J. D. Bastmeijer, A. S. Othman, D. Sookchaloem & M. Ørgaard. 2019. Artificial hybrids in Cryptocoryne (Araceae) 2: Hybridization between species of the Malay Peninsula. Aroideana 42 (1): 107-137.

  10. Jacobsen, N., J. D. Bastmeijer, T. Idei, I. B. Ipor, S. Wongso & Marian Ørgaard. 2019. Artificial hybrids in Cryptocoryne (Araceae) 3. Hybridization between species from Borneo. Aroideana 42 (2-3): 97-90.

  11. Jacobsen, N., J. D. Bastmeijer, T. Idei, S. Wongso & Marian Ørgaard. 2019. Artificial hybrids in Cryptocoryne (Araceae) 4. Hybridization between species from Malay Peninsula and Borneo. Aroideana 42(2-3): 91-118.

  12. Jacobsen, N., J. D. Bastmeijer, A. Waser, S. Wongso & M. Ørgaard. 2019. Artificial hybrids in Cryptocoryne (Araceae) 5: Hybridization with species from Sumatera, Indonesia. Aroideana 42(2-3): 119-138.
  1. Rasmussen, C.R., Weisbach, A.N., Thorup-Kristensen, K. and Weiner J. Size-asymmetric root competition in deep, nutrient-poor soil. Journal of Plant Ecology 12, 78-88.

  1. Zhu, Y.-H., Weiner J., Yu, M.-X. and Li, F.-M. 2019. Evolutionary agroecology: trends in root architecture during wheat breeding. Evolutionary Applications 12, 733-743.


  1. Wan, N.-F., Shuang-Xi Li, S.-X, Tao-Li, Cavalieri, A., Weiner, J., Zheng, X.-Q, Ji, X.-Y, Zhang, J.-Q., Zhang, H.-L., Zhang, H., Bai, N.-L., Chen, Y.-J., Zhang, H.-Y., Tao, X.-B., Zhang, H.-L., Lv, W.-G., Jiang, J.-X. and Li. B. 2019. Ecological intensification of rice production through rice-fish co-culture. Journal of Cleaner Production 234, 1002-1012.


  1. Zhu, Y.-H., Weiner J. and Li, F.-M. 2019. Root proliferation in response to neighboring roots in wheat (Triticum aestivum). Basic and Applied Ecology 39, 10-14. doi: 10.1016/j.baae.2019.07.001


  1. Weiner J. Looking in the wrong direction for higher-yielding crop genotypes. Trends in Plant Science 24, 927-933.


  1. Wongso, S., N. P. S. Asih, J. D. Bastmeijer, W. Reichert, R. Jensen, M. Ørgaard & N. Jacobsen. 2019. Four new Cryptocoryne (Araceae) taxa from Sumatera, Indonesia: a new variety and three interspecific natural hybrids. Taiwania 64 (3): 326-338.

  2. Wynns, J.T., Munk, K.R. and Lange, C.B.A. 2018. Molecular phylogeny of Plagiothecium and similar hypnealean mosses with a revised sectional classification of Plagiothecium. Cladistics 34, 469-501.


  1. Husáková, I., Weiner, J. and Münzbergová, Z. 2018. Species traits and shoot-root biomass allocation in 20 dry-grassland species. Journal of Plant Ecology 11, 273-285.


  1. Jacobsen N., Bastmeijer J. D., Jensen K. R. & Ørgaard M. 2018: A new tetraploid variety of Cryptocoryne ciliata (Araceae) from Sarawak. – Willdenowia 48: 425 – 431. DOI:


  1. Jacobsen, N., M. Ørgaard. On the Diptera pollinators of Cryptocoryne (Araceae). Aroideana 41 (2-3): 218 - 236.


  1. Jacobsen, D. Bastmeijer & M. Ørgaard. 2018. The opening twist (ptyxis) of the spathes of Lagenandra and Cryptocoryne (Araceae). Aroideana 41 (2-3): 201 - 217.


  1. Larsen, , Z. Migicovsky, A. Aa. Jeppesen, K. Gardner, T. B . Toldam-Andersen, S. Myles, M.Ørgaard, M. A. Petersen, C. Pedersen 2019. Genome-Wide Association Studies in Apple Reveal Loci for Aroma Volatiles, Sugar Composition and Harvest Date. Plant Genome 12, 2, 15 p.


  1. Yang, Y.-B., Weiner, J., Wang, G. and Ren, Z.-W. 2018. Convergence of community composition during secondary succession on Zokor rodent mounds on the Tibetan Plateau. Journal of Plant Ecology 11, 453-464


  1. Wang, P., Shu, M., Mou, P. and Weiner, J. Fine root responses to temporal nutrient heterogeneity and competition in seedlings of two tree species with different rooting strategies. Ecology and Evolution 8, 3367-3375.


  1. Wan, N.-F., Cai, Y.-M., Shen, Y.-J., Ji, X.-Y., Wu, X.-W., Zheng, X.-R., Cheng, W., Li, J., Jiang, Y.-P., Chen, X., Weiner, J., Jiang, J.-X., Nie, M., Ju, R.-T., Yuan, T., Tang, J.-J., Tian, W.-D., Zhang, H. and Li, B. 2018. Increasing plant diversity with border crops reduces insecticide use and increases crop yield in urban agriculture. eLife, 10.7554/eLife.351037


  1. Qiu, S., Xu, X., Liu, S., Liu, W., Liu, J., Nie, M., Shi, F., Zhang, Y., Weiner, J. and Li, B. 2018. Latitudinal pattern of flowering synchrony in an invasive wind-pollinated plant. Proceedings of the Royal Society, Series B, 285. doi: 10.1098/rspb.2018.1072


  1. Byrne, S.L., Erthmann, P.Ø., Agerbirk, N., Bak, S., Hauser, T.P., Nagy, I., Paina, C., Asp, T., 2017. The genome sequence of Barbarea vulgaris facilitates the study of ecological biochemistry. Sci. Rep. 7, 40728. doi:10.1038/srep40728


  1. Idei, T., J.D. Bastmeijer & Jacobsen. 2017.Stories from the Mekong, part 2: The Cryptocoryne (Araceae) habitats in the Chiang Khan district, Loei province, Thailand. - Thai Forest Bulletin (Botany) 45 (1): 58 - 78. DOI:


  1. Wang, S., Callaway, R.M., Zhou, D.-W. and Weiner, J. Experience of inundation or drought alters the responses of plants to subsequent water conditions. Journal of Ecology 105, 176-187.


  1. Rasmussen, C.R. and Weiner, J. Modelling the effect of size-asymmetric competition on size inequality: Simple models with two plants. Ecological Modelling 343, 101-108.


  1. Dueholm, B., Bruce, D., Weinstein, P., Semple, S., Møller, B.L. and Weiner, J. Spatial analysis of root hemiparasitic shrubs and their hosts: a search for spatial signatures of above- and belowground interactions. Plant Ecology 218, 185-196.


  1. Damgaard, C.F. and Weiner, J. It's about time - a critique of macroecological inferences concerning plant competition. Trends in Ecology and Evolution 32, 86-87


  1. Weiner, J. Applying plant ecological knowledge to increase agricultural sustainability. Journal of Ecology 105, 865-870.


  1. Cai, J., Weiner, J., Wang, R., Luo, W., Zhang, Y., Liu, H., Xu, Z., Li, H., Zhang, Y., Jiang, Y. 2017. Effects of nitrogen and water addition on trace element stoichiometry in five grassland species. Journal of Plant Research 130, 659–668.


  1. Weiner, J., Du, Y.-L., Zhang, C., Qin, X.-L., Li, F.-M. 2017. Evolutionary agroecology: Individual fitness and population yield in wheat (Triticum aestivum). Ecology 98, 2261–2266.


  1. Wille, W.K.-M., Pipper, C.B., Rosenqvist, E., Andersen, S.B. and Weiner, J. Reducing shade avoidance in a cereal crop. AoB Plants 9, doi: 10.1093/aobpla/plx039


  1. Yuan, J., Wang, P., Weiner, J., Bian, H., Tang, Z. and Sheng, L. 2017. The effects of soil drying on the growth of a dominant peatland species, Carex lasiocarpa. Wetlands 37, 1135–1143.

  2. Wongso, S., Bastmeijer, J. D., Budianto, H., Ipor, I. B., Munk, K. R., Ørgaard, M. & Jacobsen, N. 2017. Six new Cryptocoryne taxa (Araceae) from Kalimantan, Borneo. Willdenowia 47(3): 325 - 339.


Group members

Name Title Phone E-mail
Conny Bruun Asmussen Lange Associate Professor +4535332803 E-mail
Jacob Weiner Professor +4535332822 E-mail
Marian Ørgaard Associate Professor +4535332816 E-mail
Marten Sørensen Emeritus +4551947887 E-mail
Niels Jacobsen Professor Emeritus +4535332805 E-mail
Nikoleta Rubil PhD Student   E-mail

Contact research group leader

Conny B. Asmussen Lange
Associate Professor
+45 35 33 28 03