Bryophyte ecology: strategies, patterns, and dynamics

Most of my research stems from my fascination for small plants: how do bryophytes, or the tiny plants of Nanocyperion flavescentis communities, manage to thrive among much bigger, competitive neighbours? The answer to this question depends to a large extent on the life history strategy of the species involved, but generally small-scale disturbances in combination with positive interactions between plants seem to play a decisive role.

Started as a follow-up of my early phytosociological work and Bart van Tooren's Ph.D. work on the ecological role of bryophytes in the chalk grassland ecosystem, permanent grid studies in several vegetation types revealed intense fine-scale dynamics in multispecies bryophyte stands. While investigating whether interactions (notably competition) between the species in a chalk grassland might explain these dynamics, we realized ourselves that a dense canopy not only implies competition for light, but also a reduction of wind speed and so, of evaporation rates, which may strongly influence the growth of poikilohydric plants such as bryophytes. The construction of a simulation model to test the consistency of our ideas on the effects of density on bryophyte growth and coexistence lead to further experimental work on water relations in bryophyte canopies, and on the regulation of branching in such plants. The programs written to analyze the permanent grid data have proved to be useful in the analysis of problems concerning pattern and dynamics in various other contexts.

Another line of research concerns bryophyte diaspore banks in the soil, inspired by my colleague Jo Willems. In grasslands, mediterranean shrublands, various forests and a tropical savanna, the soil appears to contain large numbers of diaspores (spores, gemmae, tubers, stem fragments etcetera) of many bryophytes, usually species which seem to be rare if only their above-ground presence is considered. A simulation model suggests, that populations of such species are primarily regulated by below-ground density-dependent activities of pathogens or herbivores.

Apart from research and teaching, I am one of the editors of the bryological journal Lindbergia.

Some publications:

• During, H.J. 1979. Life strategies of bryophytes: a preliminary review. Lindbergia 5: 2-18.

• During, H.J. & J.H. Willems 1984. Diversity models applied to a chalk grassland. Vegetatio 57: 103-114.

• Keizer, P.J., H.J. During & B.F. van Tooren 1985. Effects of bryophytes on seedling emergence and establishment of short-lived forbs in chalk grassland. J. Ecol. 73: 493-504.

• During, H.J. & B.F. van Tooren 1987. Recent developments in bryophyte population ecology. Trends Ecol. Evol. 2: 89-93. {pdf 1MB}

• Tooren, B.F. van & H.J. During 1988. Viable plant diaspores in the guts of earth worms. Acta Bot. Neerl. 37: 181-185.

• Hoeven, E.C. van der, H. de Kroon & H.J. During 1990. Fine scale spatial distribution of leaves and shoots of two chalk grassland perennials. Vegetatio 86: 151-160.

• During, H.J. & B.F. van Tooren 1990. Bryophyte interactions with other plants. Bot. J. Linn. Soc. 104: 79-98.

• During, H.J. 1990. Clonal growth patterns among bryophytes. In: J. van Groenendael & H. de Kroon (eds.), Clonal growth in plants: regulation and function, pp. 153-176. SPB Scientific Publ., The Hague.

• During, H.J. 1992. Ecological classifications of bryophytes and lichens. In: J.W. Bates & A.M. Farmer (eds), Bryophytes and lichens in a changing environment, pp. 1-31. Clarendon Press, Oxford.

• Van der Hoeven, E.C., Huynen, C.I.J. & During, H.J. 1993. Vertical profiles of biomass, light intercepting area and light intensity in chalk grassland mosses. J. Hattori Bot. Lab. 74: 261-270.

• Stuefer, J.F., During, H.J. & de Kroon, H. 1994. High benefits of clonal integration in two stoloniferous species, in response to heterogeneous light environments. J. Ecol. 82: 511-518.

• During, H.J. 1995. Population regulation in tuber-bearing mosses: a simulation model. Lindbergia 20: 26-34.

• Herben, T., During, H.J. & Krahulec, F. 1995. Spatiotemporal dynamics in mountain grasslands: species autocorrelations in space and time. Folia Geobot. Phytotax. 30: 185-196.

• During, H.J. & F. Lloret 1996. Permanent grid studies in bryophyte communities 1. Pattern and dynamics of individual species. J. Hattori Bot. Lab. 79: 1-41.

• Gonzalez-Mancebo, J.M. & H.J. During 1997. Reproductive effort of some mosses with different life strategies growing epiphytically in Salix forest in the Biesbosch, The Netherlands. Lindbergia 22: 36-42.

• During, H.J. 1997. Bryophyte diaspore banks. Advances in Bryology 6: 103-134.

• Van der Hoeven, E.C. & H.J. During 1997. The effect of density on size frequency distributions in chalk grassland bryophyte populations. Oikos 80: 533-539.

• Li, R., H.J. During, M.J.A. Werger & Z.C. Zhong 1998. Positioning of new shoots relative to adult shoots in groves of giant bamboo, Phyllostachys pubescens. Flora 193: 315-321.

• Stuefer, J.F., H.J. During & F. Schieving 1998. A model on optimal root-shoot allocation and water transport in clonal plants. Ecol. Modelling 111: 171-186 {pdf 295kb}

• Leeflang, L., H.J. During & M.J.A. Werger 1998. The role of petioles in light acquisition by Hydrocotyle vulgaris L. in a vertical light gradi­ent. Oecologia 117: 235-238 {pdf 344kb}.

• Pechackova, S., H.J. During, V. Rydkova & T. Herben 1999. Species- specific spatial pattern of below‑ground plant parts in a montane grass­land community. J. Ecol. 87: 569-582 {pdf 348kb}.

• Skalova, H., F. Krahulec, H.J. During, V. Hadincova, S. Pechackova & T. Herben 1999. Grassland canopy composition and spatial heterogeneity in the light quality. Plant Ecology 143: 129‑139 {pdf 121kb}.

• Zander, R.H. & H.J. During 1999. Neophoenix (Pottiaceae), a new African moss genus found through soil diaspore bank analysis. Taxon 48: 657‑662.

• Herben, T., H.J. During & R. Law 2000. Spatio‑temporal patterns in grassland communities. pp. 48‑64 in: U. Dieckmann, R. Law & J.A.J. Metz (eds.), The geometry of ecological interactions: simplifying spatial complexity. Cambridge Univ. Press, Cambridge {pdf 329kb}.

• Li, R., M.J.A. Werger, H. de Kroon, H.J. During & Z.C. Zhong 2000. Interactions between shoot age structure, nutrient availability and physiological integration in the giant bamboo Phyllostachys pubescens. Plant Biology 2: 437‑446.

• Verburg, R., J. Maas & H.J. During 2000.Clonal diversity in differently aged populations of the pseudo‑annual clonal plant Circaea lutetiana L. Plant Biology 2: 646‑652.

• During, H.J. & F. Lloret 2001. The species‑pool hypothesis from a bryo­logical perspective. Folia Geobotanica 36: 63‑70.

• During, H.J. 2001. Diaspore banks. The Bryologist 104: 92‑97 {pdf 74kb}.

• Huber, H. & H.J. During 2001. No long‑term costs of meristem allocation to flowering in stoloniferous Trifolium species. Evolutionary Ecology 14: 731‑748 {pdf 282kb}.

• Van der Velde, M., H.J. During, L. van der Zande & R. Bijlsma 2001. The reproductive biology of Polytrichum formosum: clonal structure and paternity revealed by microsatellites. Molecular Ecology 10: 2423‑2434 {pdf 254kb}.

• Stuefer, J.F., H. van Hulzen and H. J. During 2002. A genotypic trade-off between the number and size of clonal offspring in the stoloniferous herb Potentilla reptans. J. Evol. Biol. 15: 880-884 {pdf 111kb}.

• Söderström, L. & During, H.J. 2005. Bryophyte rarity viewed from the perspectives of life history strategy and metapopulation dynamics. Journal of bryology, 27, 259-266 {pdf 97kb}.

• Jägerbrand, A.K. & H.J. During. 2006 Effects of simulated shade on growth, number of branches and biomass in Hylocomium splendens and Racomitrium
  lanuginosum. Lindbergia 30: 117-124 {pdf 496kb}.

   

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