Hans de Kroon

Research

My scientific career is devoted to plant traits, how they are regulated and have evolved, and how they contribute to the success of populations and communities. My emphasis is on plasticity in morphological characteristics, giving the sessile plant individual some necessary mobility in its dynamic environment.

My work is characterized by the combination of novel experimentation with conceptual advancement. In two seminal review papers (Hutchings & de Kroon 1994, Adv Ecol Res; de Kroon & Hutchings 1995 J Ecol) I formulated the now widely used concept of foraging in plant ecology. More recently, I elaborated this concept to how plasticity and foraging operate in plants given their modular construction (de Kroon et al. 2005 New Phytol; de Kroon et al. 2009 Plant Cell Env).

After focusing on clonal plants in my PhD (obtained 1990) and Postdoctoral research (1989-1994), I became fascinated by the unknown world of belowground interactions. I am working on root plasticity affecting nutrient uptake, as well as water as an important resource in some environments (dry patchy environments) and as a mediating factor in others (flooded environments). I am mainly applying the foraging concept in fundamental research questions, but also applied themes are explored. For example, in a collaborative project with Chinese partners, we have studied how root foraging abilities may help to improve crop water acquisition in dry environments. In recently funded projects we are including soil rhizosphere communities in their effects on root responses and plant communities. In 2003 I edited with Eric Visser the Springer volume Root Ecology, summarizing the root ecophysiological and ecological studies at that time.

In order to understand the significance of plant traits in the real world I have always used models to scale up individual plant responses to the long-term development of populations. From the start of my career, I have therefore worked on population dynamical models for a great variety of plant species. Simultaneously, I have contributed to methodological advancements, most notably elasticity analysis (de Kroon et al. 1986, Ecology; de Kroon et al. 2000, Ecology) which is now the prime instrument for investigating what demographic traits contribute to population growth, and used in conservation biology worldwide. My position in this field is further marked as a co-editor of two Special Features on matrix projection models, published in Ecology (March 2000) and in preparation for Journal of Ecology (to be published March 2010).

My interest is broad and I have been involved in matrix modeling projects on a range of plant species (including clonal as well as short-lived perennials, annuals, trees and mosses) from a range of environments, including grasslands, Mediterranean shrublands, and boreal and tropical forests. Equally wide are the factors that I have studied that influence the population dynamics, such as herbivores, pathogen infections, drought, inbreeding, and population management. I am interested in fundamental as well as applied aspects and they have been included in a number of collaborative matrix modelling studies. New projects include modeling the population dynamics of river floodplain species in relation to altered flooding regimes, and the comparative demography of a large number of tropical rainforest tree species.

Stimulated by current questions in biodiversity and ecosystem research, my current goal is to link these successful experimental and modelling lines more intimately and develop new insights in how plant traits contribute to community processes through belowground interactions between individuals, affecting the dynamics of the constituent populations.

Publications by Hans de Kroon

Auestad I, Rydgren K, Jongejans E & de Kroon H (2010) Pimpinella saxifraga is maintained in road verges by mosaic management. Biological Conservation in press
Salguero-Gómez R & de Kroon H (2010) Matrix projection models meet variation in the real world. Journal of Ecology 98:250-254 PDF
Jongejans E, Huber H & de Kroon H (2010) Scaling up phenotypic plasticity with hierarchical population models. Evolutionary Ecology in press PDF
Jongejans E, Jorritsma-Wienk LD, Becker U, Dostál P, Mildén M & de Kroon H (2010) Region versus site variation in the population dynamics of three short-lived perennials. Journal of Ecology 98:279-289 PDF
Davison R, Jacquemyn H, Adriaens D, Honnay O, de Kroon H & Tuljapurkar S (2010) Demographic effects of extreme weather events on a short-lived calcareous grassland species: Stochastic Life Table Response Experiments (SLTRE). Journal of Ecology 98:255-267 PDF
Chen X, Huber H, de Kroon H, Peeters AJM, Poorter H, Voesenek LACJ & Visser EJW (2009) Intraspecific variation in the magnitude and pattern of flooding-induced shoot elongation in Rumex palustris. Annals of Botany 104:1057–1067 PDF
Stuefer JF, Anten NPR, de Kroon H, Peters JL, Smit-Tiekstra A, Vermeulen PJ & During HJ (2009) Genotypic selection shapes patterns of within-species diversity in experimental plant populations. Journal of Ecology 97:1020-1027 PDF
van der Waal C, de Kroon H, de Boer, WF, Heitkönig IMA, Skidmore AK, de Knegt HJ, van Langevelde F, van Wieren SE, Grant RC, Page BR, Slotow R, Kohl EM, Mwakiwa E & Prins HHT (2009) Water and nutrients alter herbaceous competitive effects on tree seedlings in a semi-arid savanna. Journal of Ecology 97:430-439 PDF
Wang J, de Kroon H, Wang L, de Caluwe H, Bögemann GM, van der Weerden GM, Kang S & Smits AJM (2009) Root foraging and yield components underlying limited effects of Partial Root-zone Drying on oilseed rape, a crop with an indeterminate growth habit. Plant and Soil 323:163–176 PDF
de Kroon H, Visser EJW, Huber H, Mommer L & Hutchings MJ (2009) A modular concept of plant foraging behaviour: the interplay between local responses and systemic control. Plant, Cell and Environment 32:704-712 PDF
Banach K, Banach AM, Lamers LPM, de Kroon H, Bennicelli RP, Smits AJM & Visser EJW (2009) Differences in flooding tolerance between species from two wetland habitats with contrasting hydrology: implications for vegetation development in future floodwater retention areas. Annals of Botany 103:341–351 PDF
Kembel SW, de Kroon H, Cahill JF & Mommer L (2008) Improving the scale and precision of hypotheses to explain root foraging ability. Annals of Botany 101:1295-1301 PDF
Jongejans E, de Vere N & de Kroon H (2008) Demographic vulnerability of the clonal and endangered meadow thistle.Plant Ecology198:225-240 PDF
Mommer L, Wagemaker CAM, de Kroon H & Ouborg NJ (2008) Unravelling below-ground plant distributions: a real-time polymerase chain reaction method for quantifying species proportions in mixed root samples. Molecular Ecology Resources 8:947-953 PDF
Weijschedé J, Berentsen R, de Kroon H & Huber H (2008) Variation in petiole and internode length affects plant performance in Trifolium repens under opposing selection regimes. Evolutionary Ecology 22:383–397 PDF
Weijschedé J, Antonise K, de Caluwe H, de Kroon H & Huber H (2008) The effects of cell number and cell size on petiole length variation in a stoloniferous herb. American Journal of Botany 95:41–49 PDF
Ludwig F, de Kroon H & Prins HHT (2008) Impacts of savanna trees on forage quality for a large African herbivore. Oecologia 155:487-496 PDF
Visser EJW, Bögemann GM, Smeets M, de Bruin S, de Kroon H & Bouma TJ (2008) Evidence that ethylene signalling is not involved in selective root placement by tobacco plants in response to nutrient-rich soil patches. New Phytologist 177:457-465 PDF
de Kroon H (2007) How do roots interact? Science 318:1562-1563 Full Text | PDF)
van Kleunen M, Lenssen JPM, Fischer M & de Kroon H (2007) Selection on phenotypic plasticity of morphological traits in response to flooding and competition in the clonal shore plant Ranunculus reptans. Journal of Evolutionary Biology 20:2126–2137 PDF
Wang L, de Kroon H & Smits AJM (2007) Combined effects of partial rootzone drying and patchy fertilizer placement on nutrient acquisition and growth of oilseed rape (Brassica napus). Plant and Soil 295:207-216 PDF
Zuidema PA, Werger MJA & de Kroon H (2007) Testing sustainability by prospective and retrospective demographic analyses: evaluation for palm leaf harvest. Ecological Applications 17:118-128 PDF
Rydgren K, Økland RH, Picó FX & de Kroon H (2007) Moss species benefits from breakdown of cyclic rodent dynamics in boreal forests. Ecology 88:2320-2329 PDF
Jorritsma-Wienk LD, Ameloot E, Lenssen JPM & de Kroon H (2007) Differential responses of germination and seedling establishment in populations of Tragopogon pratensis (Asteraceae). Plant Biology 9:109-115 PDF
Hess L & de Kroon H (2007) Effects of rooting volume and nutrient availability as an alternative explanation for root self/non-self discrimination. Journal of Ecology 95:241-251 PDF
Weijschedé J, Martínková J, de Kroon H & Huber H (2007) Shade avoidance in Trifolium repens: costs and benefits of plasticity in petiole length and leaf size. New Phytologist 172:655–666 PDF
Mommer L, Lenssen JPM, Huber H, Visser EJW & de Kroon H (2006) Ecophysiological determinants of plant performance under flooding: a comparative study of seven plant families. Journal of Ecology 94:1117-1129 PDF
Falik O, de Kroon H & Novoplansky A (2006) Physiologically-mediated self/nonself root discrimination in Trifolium repens has mixed effects on plant performance. Plant Signaling and Behavior 1:116-121 PDF
de Kroon H & Mommer L (2006) Root foraging theory put to the test. Trends in Ecology and Evolution 21:113-116 PDF
van Eck WHJM, Lenssen JPM, van de Steeg HM, Blom CWPM & de Kroon H (2006) Seasonal dependent effects of flooding on species survival and zonation. A comparative study of 10 terrestrial plant species. Hydrobiologia 565:59-69 PDF
Jansen C, van Kempen MML, Bögemann GM, Bouma TJ & de Kroon H (2006) Limited costs of wrong root placement in Rumex palustris in heterogeneous soils. New Phytologist 171:117-126 PDF
Jongejans E, de Kroon H & Berendse F (2006) The interplay between shifts in biomass allocation and costs of reproduction in four grassland perennials under simulated successional change. Oecologia 147:369–378 PDF
Jongejans E, Soons MB & de Kroon H (2006) Bottlenecks and spatiotemporal variation in the sexual reproduction pathway of perennial meadow plants. Basic and Applied Ecology 7:71-81 PDF
Wang L, de Kroon H, Bögemann GM & Smits AJM (2005) Partial root drying effects on biomass production in Brassica napus and the significance of root responses. Plant and Soil 276:313-326 PDF
Jansen C, van de Steeg HG & de Kroon H (2005) Investigating a trade-off in the root morphological responses of plant species to a heterogeneous nutrient supply and to flooding. Functional Ecology 19:952-960 PDF
Mommer L, de Kroon H, Pierik R, Bögemann GM & Visser EJW (2005) A functional comparison of acclimation to shade and submergence in two terrestrial plant species. New Phytologist 167:197-206 PDF
de Kroon H, Huber H, Stuefer JF & van Groenendael JM (2005) A modular concept of phenotypic plasticity in plants. New Phytologist 166: 73-82 PDF
Jongejans E & de Kroon H (2005) Space versus time variation in the population dynamics of three co-occurring perennial herbs. Journal of Ecology 93:681-692 PDF
Lenssen JPM, Hershock C, Speek T, During HJ & de Kroon H (2005) Experimental ramet aggregation in the clonal plant Agrostis stolonifera reduces its competitive ability. Ecology 86:1358-1365 PDF
Lenssen JPM & de Kroon H (2005) Abiotic constraints at the upper boundaries of two Rumex species on a freshwater flooding gradient. Journal of Ecology 93:138-147 PDF
van Eck WHJM, van de Steeg HM, Blom CWPM & de Kroon H (2005) Recruitment limitation along disturbance gradients in river floodplains. Journal of Vegetation Science 16:103-110 PDF
van Eck WHJM, Lenssen JPM & de Kroon H (2005) Ruimte voor de rivier met ruimte voor stroomdalvegetatie. Levende Natuur 106:46-49 PDF
van Mölken T, Jorritsma-Wienk LD, van Hoek PHW & de Kroon H (2005) Only seed size matters for germination in Different populations of the dimorphic Tragopogon pratensis subsp. pratensis (Asteraceae). American Journal of Botany 92:432-437 PDF
van Eck WHJM, Lenssen JPM, Rengelink RHJ, Blom CWPM & de Kroon H (2005) Water temperature instead of acclimation stage and oxygen concentration determines responses to winter floods. Aquatic Botany 81:253-264 PDF
Ludwig F, Dawson TE, Prins HHT, Berendse F & de Kroon H (2004) Belowground competition between trees and grasses may overwhelm facilitative effects of hydraulic lift. Ecology Letters 7:623-631 PDF
van Eck WHJM, van de Steeg HM, Blom CWPM & de Kroon H (2004) Is tolerance to summer flooding correlated with distribution patterns in river floodplains? A comparative study of 20 terrestrial grassland species. Oikos107:393-405 PDF
Lenssen JPM, van Kleunen M, Fischer M & de Kroon H (2004) Local adaptation of the clonal plant Ranunculus reptans to flooding along a small-scale gradient. Journal of Ecology 92:696–706 PDF
Lenssen JPM, van de Steeg HM & de Kroon H (2004) Does disturbance favour weak competitors? Mechanisms of altered plant abundance after flooding. Journal of Vegetation Science 15:305-314 PDF
Pierik R, Voesenek LACJ, de Kroon H & Visser EJW (2004) Density-induced plant size reduction and size inequalities in ethylene-sensing and ethylene-insensitive Tobacco. Plant Biology 6:201-205 PDF
Pierik R, Whitelam GC, Voesenek LACJ, de Kroon H & Visser EJW (2004) Canopy studies on ethylene-insensitive tobacco identify ethylene as a novel element in blue light and plant-plant signalling. The Plant Journal 38:310-318 PDF
Ludwig F, de Kroon H, Berendse F & Prins HHT (2004) The influence of savanna trees on nutrient, water and light availability and the understorey vegetation. Plant Ecology 170:93-105 PDF
Hartemink N, Jongejans E & de Kroon H (2004) Flexible life history responses to flower and rosette bud removal in three perennial herbs. Oikos105:159-167 PDF
Voesenek LACJ, Rijnders JHGM, Peeters AJM, van de Steeg HM & de Kroon H (2004) Plant hormones regulate fast shoot elongation under water: from genes to communities. Ecology 85:16-27 PDF
Sterck FJ, Bongers F, During H, Martinez-Ramos M & de Kroon H (2003) Module responses in a tropical forest tree analyzed with a matrix model. Ecology 84:2751-2761 PDF
Pierik R, Visser EJW, de Kroon H & Voesenek LACJ (2003) Ethylene is required in tobacco to successfully compete with proximate neighbours. Plant, Cell and Environment 26:1229-1234 PDF
Ludwig F, Dawson TE, de Kroon H, Berendse F & Prins HHT (2003) Hydraulic lift in Acacia tortilis trees on an East African savanna. Oecologia 134:293-300 PDF
Wang L, de Kroon H & Smits T (2003) Water use efficiency of Oilseed Rape (Brassica campestris) under even or patchy water supply. Water-saving agriculture and sustainable use of water and land resources (ed. Kang S et al.) 66-69 pp, Shaanxi Science and Technology Press, Xi’an, China
de Kroon H, Mommer L & Nishiwaki A (2003) Root competition: towards a mechanistic understanding. Root Ecology. (ed. de Kroon H & Visser EJW) 215-234 pp, Springer, Berlin PDF
Vervuren PJA, Blom CWPM & de Kroon H (2003) Extreme flooding events on the Rhine and the survival and distribution of riparian plant species. Journal of Ecology 91:135-146 PDF
Picó FX, de Kroon H & Retana J (2002) An extended flowering and fruiting season has few demographic effects in a Mediterranean perennial herb. Ecology 83:1991-2004 PDF
Ludwig F, de Kroon H, Prins HHT & Berendse F (2001) The effects of nutrients and shade on tree-grass interactions in an East-African savanna. Journal of Vegetation Science 12:579-588 PDF
Fransen B, de Kroon H & Berendse F (2001) Soil nutrient heterogeneity alters competition between populations of Festuca rubra and Anthoxanthum odoratum. Ecology 82:2534-2546 PDF
Fransen B & de Kroon H (2001) Long-term disadvantages of selective root placement: root proliferation and shoot biomass of two perennial grass species in a two-year experiment. Journal of Ecology 89:711-722 PDF
Ehrlén J, van Groenendael J & de Kroon H (2001) How reliable is elasticity analysis? - A comment on Mills et al. Conservation Biology 15:278-280 PDF
HilleRisLambers R, Rietkerk M, van den Bosch F, Prins HHT & de Kroon H (2001) Vegetation pattern formation in semi-arid grazing systems. Ecology 82:50-61 PDF
Rydgren K, de Kroon H, Økland RH & van Groenendael J (2001) Effects of fine-scale disturbances on demography and population dynamics of the clonal moss Hylocomium splendens. Journal of Ecology 89 395-405 PDF
Li R, Werger MJA, de Kroon H, During HJ & Zhong ZC (2000) Interactions between shoot age structure, nutrient availability and integration in the giant bamboo Phyllostachys pubescens. Plant Biology 2:437-446
Heppell S, Pfister C & de Kroon H (2000) Special feature: elasticity analysis in population biology: methods and applications. Ecology 81:605-606 PDF
de Kroon H, van Groenendael J & Ehrlén J (2000) Elasticities: a review of methods and model limitations. Ecology 81:617-618 PDF
Fransen B, Blijjenberg J & de Kroon H (1999) Root morphological and physiological plasticity of perennial grass species and the exploitation of spatial and temporal heterogeneous nutrient patches. Plant and Soil 211:179-189 PDF
Fransen B, de Kroon H, de Kovel C & van den Bosch F (1999) Disentangling the effects of selective root placement and inherent growth rate on plant biomass accumulation in heterogeneous environments: a modelling study. Annals of Botany 84:305-311
Berendse F, de Kroon H & Braakhekke WG (1999) Acquisition, use and loss of nutrients. Handbook of functional plant ecology. (ed. by Pugnaire FI & Valladares F), 315-345 pp, Marcel Dekker, New York
Fransen B, de Kroon H & Berendse F (1998) Root morphological plasticity and nutrient acquisition of perennial grass species from habitats of different nutrient availability. Oecologia 115:351-358 PDF
de Kroon H, van der Zalm E, van Rheenen JWA, van Dijk A & Kreulen R. (1998) The interaction between water and nitrogen translocation in a rhizomatous sedge (Carex flacca). Oecologia 116:38-49 PDF
Geber MA, de Kroon H & Watson MA (1997) Organ preformation in mayapple as a mechanism for historical effects on demography. Journal of Ecology 85:211-223 PDF
Geber MA, Watson MA & de Kroon H (1997) Organ preformation, development, and resource allocation in perennials. Plant resource allocation. (ed. by F.A. Bazzaz & J. Grace), pp. 113-141, Academic Press, New York
de Kroon H & van Groenendael J (1997) The ecology and evolution of clonal growth in plants (Backhuys Publishers, Leiden); 18 Chapters, 453 pp
de Kroon H & Bobbink R (1997) Clonal plant dominance under elevated nitrogen deposition, with special reference to Brachypodium pinnatum in chalk grassland. The ecology and evolution of clonal plants. (ed. by de Kroon H & van Groenendael J), pp. 359-379, Backhuys Publishers, Leiden
Stuefer JF, de Kroon H & During HJ (1996). Exploitation of environmental heterogeneity by spatial division of labour in a clonal plant. Functional Ecology 10:328-334 PDF
de Kroon H, Fransen B, van Rheenen JWA, van Dijk A & Kreulen R (1996) High levels of inter-ramet water translocation in two rhizomatous Carex species, as quantified by deuterium labelling. Oecologia 106:73-84 PDF
de Kroon H & Hutchings MJ (1995) Morphological plasticity in clonal plants: The foraging concept reconsidered. Journal of Ecology 83:143-152 PDF
de Kroon H & Kalliola R (1995) Shoot dynamics of the giant grass Gynerium sagittatum in Peruvian Amazon floodplains, a clonal plant that does show self-thinning. Oecologia 101:124-131 PDF
de Kroon H & Olff H (1995) On the use of the guild concept in plant ecology. Folia Geobotanica et Phytotaxonomica 30:519-528 PDF
de Kroon H, Stuefer JF, Dong M & During HJ (1994) On plastic and non-plastic variation in clonal plant morphology and its ecological significance. Folia Geobotanica et Phytotaxonomica 29:123-138 PDF
Dong M & de Kroon H (1994) Plasticity in morphology and biomass allocation in Cynodon dactylon, a grass species forming stolons and rhizomes. Oikos 70:99-106 PDF
Hutchings MJ & de Kroon H (1994) Foraging in plants: The role of morphological plasticity in resource acquisition. Advances in Ecological Research 25:159-238
Stuefer JF, During HJ & de Kroon H (1994) High benefits of clonal integration in two stoloniferous species, in response to heterogeneous light environments. Journal of Ecology 82:511-518 PDF
van Groenendael JM, de Kroon H, Kalisz S & Tuljapurkar S (1994) Loop analysis: Evaluating life history pathways in population projection matrices. Ecology 75:2410-2415 PDF
de Kroon H (1993) Competition between shoots in stands of clonal plants. Plant Species Biology 8:85-94 PDF
de Kroon H, Hara T & Kwant R (1992) Size hierarchies of shoots and clones in clonal herb monocultures: do clonal and nonclonal plants compete differently? Oikos 63:410-419 PDF
de Kroon H & Schieving F (1991) Resource allocation patterns as a function of clonal morphology: A general model applied to a foraging clonal plant. Journal of Ecology 79:519-530 PDF
de Kroon H & Kwant R (1991) Density-dependent growth responses in two clonal herbs: Regulation of shoot density. Oecologia 86:298-304 PDF
de Kroon H, Whigham DF & Watson MA (1991) Developmental ecology of mayapple: Effects of rhizome severing, fertilization and timing of shoot senescence. Functional Ecology 5:360-368 PDF
van der Hoeven EC, de Kroon H & During HJ (1990) Fine-scale spatial distribution of leaves and shoots of two chalk grassland perennials. Vegetatio 86:151-160 PDF
de Kroon H & Knops J (1990) Habitat exploration through morphological plasticity in two chalk grassland perennials. Oikos 59:39-49 PDF
de Kroon H & Schieving F (1990). Resource partitioning in relation to clonal growth strategy. In: Clonal growth in plants: regulation and function (eds van Groenendael J & de Kroon H) SPB, The Hague, the Netherlands. 113-130
van Groenendael JM, de Kroon H & Caswell H (1988) Projection matrices in population biology. Trends in Ecology and Evolution 3:264-269 PDF
de Kroon H, Plaisier A & van Groenendael JM (1987) Density dependent simulation of the population dynamics of a perennial grassland species, Hypochaeris radicata. Oikos 50:3-12 PDF
de Kroon H, Plaisier A, van Groenendael J & Caswell H (1986) Elasticity: the relative contribution of demographic parameters to population growth rate. Ecology 67:1427-1431 PDF
de Kroon H, de Jong H & Verhoeven JTA (1985) The macrofauna distribution in brackish inland waters in relation to chlorinity and other factors. Hydrobiologia 127:265-275 PDF