Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Data from: Seasonal drivers of understorey temperature buffering in temperate deciduous forests across Europe
    Zellweger, Florian ; Coomes, David A. ; Lenoir, Jonathan ; Depauw, Leen ; Maes, Sybryn L. ; Kirby, Keith J. ; Brunet, Jörg ; Kopecký, Martin ; Máliš, František ; Schmidt, Wolfgang ; Heinrichs, Steffi ; Ouden, Jan den; Jaroszewicz, Bogdan ; Buyse, Gauthier ; Spicher, Fabien ; Wulf, Monika ; Verheyen, Kris ; Frenne, Pieter De - \ 2019
    macroclimate - Temperature Buffering - Global warming - Canopy Density - climate change - Forest Structure and Composition - understorey - Microclimate
    Seasonal drivers of understorey temperature buffering in temperate deciduous forests across Europe
    Zellweger, Florian ; Coomes, David ; Lenoir, Jonathan ; Depauw, Leen ; Maes, Sybryn L. ; Wulf, Monika ; Kirby, Keith J. ; Brunet, Jörg ; Kopecký, Martin ; Máliš, František ; Schmidt, Wolfgang ; Heinrichs, Steffi ; Ouden, Jan den; Jaroszewicz, Bogdan ; Buyse, Gauthier ; Spicher, Fabien ; Verheyen, Kris ; Frenne, Pieter De - \ 2019
    Global Ecology and Biogeography 28 (2019)12. - ISSN 1466-822X - p. 1774 - 1786.
    canopy density - climate change - forest composition - forest structure - global warming - macroclimate - microclimate - temperature buffering - understorey

    Aim: Forest understorey microclimates are often buffered against extreme heat or cold, with important implications for the organisms living in these environments. We quantified seasonal effects of understorey microclimate predictors describing canopy structure, canopy composition and topography (i.e., local factors) and the forest patch size and distance to the coast (i.e., landscape factors). Location: Temperate forests in Europe. Time period: 2017–2018. Major taxa studied: Woody plants. Methods: We combined data from a microclimate sensor network with weather-station records to calculate the difference, or offset, between temperatures measured inside and outside forests. We used regression analysis to study the effects of local and landscape factors on the seasonal offset of minimum, mean and maximum temperatures. Results: The maximum temperature during the summer was on average cooler by 2.1 °C inside than outside forests, and the minimum temperatures during the winter and spring were 0.4 and 0.9 °C warmer. The local canopy cover was a strong nonlinear driver of the maximum temperature offset during summer, and we found increased cooling beneath tree species that cast the deepest shade. Seasonal offsets of minimum temperature were mainly regulated by landscape and topographic features, such as the distance to the coast and topographic position. Main conclusions: Forest organisms experience less severe temperature extremes than suggested by currently available macroclimate data; therefore, climate–species relationships and the responses of species to anthropogenic global warming cannot be modelled accurately in forests using macroclimate data alone. Changes in canopy cover and composition will strongly modulate the warming of maximum temperatures in forest understories, with important implications for understanding the responses of forest biodiversity and functioning to the combined threats of land-use change and climate change. Our predictive models are generally applicable across lowland temperate deciduous forests, providing ecologically important microclimate data for forest understories.

    FEM growth and yield data monocultures - Common beech, revised version
    Goudzwaard, L. ; Jansen, J. ; Oosterbaan, A. ; Oldenburger, J.F. ; Lu, H. ; Mohren, G.M.J. - \ 2017
    Wageningen University & Research
    Growth and yield, even-aged monoculture forest - understorey - tree diameter - tree height - crown class - coordinates stem positions - age - top height - dominant height - dominant diameter - monitoring - Common beech - Fagus sylvatica
    The current database is part of the FEM growth and yield database, a collection of growth and yield data from even-aged monocultures (douglas fir, common oak, poplar, Japanese Larch, Norway spruce, Scots pine, Corsican pine, Austrian pine, red oak and several other species with only a few plots, even-aged mixed species forest plots, uneven-aged natural forest, uneven-aged selection forest and roadside plantations of poplar. The FEM growth and yield data base is currently supervised by Jan den Ouden and Frits Mohren.
    Super-performance in a palm species
    Jansen, Merel - \ 2016
    Wageningen University. Promotor(en): Niels Anten; Pieter Zuidema, co-promotor(en): Frans Bongers; M. Martínez-Ramos. - Wageningen : Wageningen University - ISBN 9789462579996 - 193
    chamaedorea elegans - understorey - tropical forests - spatial variation - leaves - growth - population ecology - defoliation - genetic variation - chamaedorea elegans - onderlaag - tropische bossen - ruimtelijke variatie - bladeren - groei - populatie-ecologie - ontbladering - genetische variatie

    The world is changing rapidly due to anthropogenic disturbance. Effects include: global warming, massive pollution, a changed global nitrogen cycle, high rates of land-use change, and exotic species spread. This has a tremendous impact on both natural and agricultural systems. To understand these impacts, good understanding of ecological systems and underlying drivers is necessary. Ecological systems can be studied at different levels of aggregation. Different levels of aggregation influence each other and are also influenced by external drivers like the environment. The population level is of particular interest, because many important ecological processes occur at the population level, like evolution, extinction, and invasion. Ecologists are increasingly recognizing that population processes are strongly influenced by one level of aggregation lower, the individual level. Individual heterogeneity (i.e. differences between individuals in performance), determines many population processes including population growth rate. However, the exact relations between individual heterogeneity, the external drivers of it, and the population level are not always well understood. Furthermore, methods to analyze these relations are not always available.

    Individual heterogeneity occurs at different temporal scales, ranging from short- to long-term performance differences between individuals, where short- and long-term refer to the expected lifespan of the species in question. Short-term differences between individuals are relatively easily identifiable and are common in almost all species. But long-term differences are much harder to determine especially for long-lived organisms. Long-term differences between individuals in reproduction have been identified for several animal species, and in growth for several tree species, but less is known about the existence of such differences in other life forms (e.g. palms, lianas or clonal plants). Quantifying the extent to which individuals differ is essential for understanding the influence of individual heterogeneity on population processes. Super-performing individuals (i.e. individuals that persistently grow faster and reproduce more than others), probably contribute more to the growth of the population and therefore to future generations. Future populations will, therefore, have the genetic characteristics of the super-performers. Which characteristics this will be, depends on the genetic and environmental drivers of super-performance. Full understanding of the influence of individual heterogeneity on population processes, therefore, requires knowledge of the underlying causes of individual heterogeneity.

    For many species, it is known that spatial variation in environmental conditions can cause short-term performance differences between individuals, but it is often not clear if the same environmental factors that cause short-term performance differences are also the environmental factors that cause long-term performance differences. Furthermore, genetic variation is known to cause performance differences, but to what extent is not well studied in natural long-lived plant populations. Within-population genetic variation can be maintained in habitats that are characterized by strong temporal or spatial heterogeneity in environmental conditions if the performance of a genotype relative to others depends on the environment it experiences.

    Super-performing individuals possibly play an important role in the resistance and resilience of populations to disturbance (i.e. maintaining and recovering population growth rate under stress), because super-performers potentially contribute more to the recovery of the population. However, this depends on the relative tolerance to disturbance of super-performers compared to under-performers. A positive relation between performance and tolerance would make super-performers more important, while a negative relation would make them less important. Many types of disturbances entail leaf loss and tolerance to leaf loss is associated with performance being larger than what one would assume based on the amount of leaf area loss. Tolerance can be achieved by compensating for leaf loss in terms of growth rate, which entails either allocating more new assimilates to leaves, allocating new assimilates more efficiently to leaf area (i.e. by increasing specific leaf area), or growing faster with existing leaf area (i.e. by increasing net assimilation rate). Genetic variation in tolerance and compensatory responses would allow populations to adapt to changes in disturbance events that entail leaf loss.

    Individual heterogeneity could also have implications for management. Plant and animal populations are managed at many different levels ranging from harvest from natural populations to modern agricultural practices. When harvesting from natural populations, it might be beneficial to spare the individuals that are most important for future production. Individuals could be spared, either because they contribute most to population growth, because they are tolerant to harvesting (which is relevant when only part of a plant is harvested), or when they start producing less or lower quality product. The productivity of natural populations could also be increased by actively promoting those environmental conditions and genotypes that allow for high productivity, which is the basis of agriculture and common practice in forest management. To determine how this can best be done, knowledge of the causes of individual heterogeneity is necessary.

    The general aim of this thesis is to identify and quantify the mechanisms that determine individual heterogeneity and to determine how this heterogeneity, in turn, affects population level processes. This aim was divided into four main questions that I addressed: (1) To what extent do individuals differ in performance? (2) What causes individual heterogeneity in performance? (3) What are the demographic consequences of individual heterogeneity? (4) Can individual differences be used to improve the management of populations? To answer these questions, we used the tropical forest understorey palm Chamaedorea elegans as a study system, of which the leaves are an important non-timber forest product that is being used in the floral industry worldwide. We collected demographic data, measured spatial variation in environmental conditions, and applied a defoliation treatment to simulate leaf harvesting, in a natural population in Chiapas, Mexico. Furthermore, we grew seedlings from different mothers from our study population in the greenhouses of Wageningen University, where we also applied a defoliation treatment.

    In Chapter 2 we quantified the extent to which individuals differ in long-term growth rate, and analyzed the importance of fast growers for population growth. We reconstructed growth histories from internodes and showed that growth differences between individuals are very large and persistent in our study population. This led to large variation in life growth trajectories, with individuals of the same age varying strongly in size. This shows that not only in canopy trees but also in species in the light limited understorey growth differences can be very large. Past growth rate was found to be a very good predictor of current performance (i.e. growth and reproduction). Using an Integral Projection Model (i.e. a type of demographic model) that was based on size and past growth rate, we showed that fast-growing individuals are much more important for population growth than others: the 50% fastest growing individuals contributed almost two times as much to population growth as the 50% slowest growing individuals.

    In Chapter 3 we analyzed the extent to which observed long-term growth differences can be caused by environmental heterogeneity. Short-term variation in performance was mainly driven by light availability, while soil variables and leaf damage had smaller effects, and spatial heterogeneity in light availability and soil pH were autocorrelated over time. Using individual-based simulation models, we analyzed the extent to which spatial environmental heterogeneity could explain observed long-term variation in growth, and showed that this could largely be explained if the temporal persistence of light availability and soil pH was taken into account. We also estimated long-term inter-individual variation in reproduction to be very large. We further analyzed the importance of temporal persistence in environmental variation for long-term performance differences, by analyzing the whole range of values of environmental persistence, and the strength of the effect of the environmental heterogeneity on short-term performance. We showed that long-term performance differences become large when either the strength of the effect of the environmental factor on short-term performance is large, or when the spatial variation in the environmental factor is persistent over time. This shows that an environmental factor that in a short-term study might have been dismissed as unimportant for long-term performance variation, might, in reality, contribute strongly.

    In Chapter 4 we tested for genetic variation in growth potential, tolerance to leaf loss, compensatory growth responses, and if growth potential and tolerance were genetically correlated in our study population. We quantified compensatory responses with an iterative growth model that takes into account the timing of leaf loss. Genetic variation in growth potential was large, and plants compensated strongly for leaf loss, but genetic variation in tolerance and compensatory growth responses was very limited. Growth performances in defoliated and undefoliated conditions were positively genetically correlated (i.e. the same genotypes perform relatively well compared to others, both with and without the stress of leaf loss). The high genetic variation in growth potential and the positive correlation between treatments suggests that the existence of super-performing individuals in our study population likely has (at least in part) a genetic basis. These super-performing individuals, that grow fast even under the stress of leaf loss, possibly contribute disproportionately to population resistance and resilience to disturbance. The low genetic variation in tolerance and compensatory responses, however, suggests that populations might have limited ability to adapt to changes in disturbance regimes that entail increases in leaf loss. Furthermore, the high genetic variation in growth potential could potentially be used in management practices like enrichment planting.

    In Chapter 5 we explore the potential of using individual heterogeneity to design smarter harvest schemes, by sparing individuals that contribute most to future productivity. We tested if fast and slow growers, and small and large individuals, responded differently to leaf loss in terms of vital rates, but found only very limited evidence for this. Using Integral Projection Models that were based on stem length and past growth rate, we simulated leaf harvest over a period of 20 years, in several scenarios of sparing individuals, which we compared to “Business as usual” (i.e. no individuals being spared, BAU). Sparing individuals that are most important for population growth, was beneficial for population size (and could, therefore, reduce extinction risk), increased annual leaf harvest at the end of the simulation period, but cumulated leaf harvest over 20 years was much lower compared to BAU. Sparing individuals that produced leaves of non-commercial size (i.e. <25cm), therefore allowing them to recover, also resulted in a lower total leaf harvest over 20 years. However, a much higher harvest (a three-fold increase) was found when only leaves of commercial size were considered. These results show that it is possible to increase yield quality and sustainability (in terms of population size) of harvesting practices, by making use of individual heterogeneity. The analytical and modeling methods that we present are applicable to any natural system from which either whole individuals, or parts of individuals, are harvested, and provide an extra tool that could be considered by managers and harvest practitioners to optimize harvest practices.

    In conclusion, in this thesis, I showed that in a long-lived understorey palm growth differences are very large and persistent (Chapter 2) and that it is likely that long-term differences in reproduction are also very large (Chapter 3). I also showed that spatial heterogeneity in environmental conditions can to a large extent explain these differences and that when evaluating the environmental drivers of individual heterogeneity, it is important to take the persistence of spatial variation into account (Chapter 3). Individual heterogeneity also is partly genetically determined. I showed that genetic variation in growth potential to be large (Chapter 4), and that fast growers keep on growing fast under the stress of leaf loss (Chapters 4,5). Therefore it is likely that genetic variation contributes to long-term differences between individuals. Genetic variation for tolerance and compensatory responses was estimated to be low (Chapter 4), suggesting that the adaptive potential of our study population to changes in disturbance events that entail leaf loss might be low. I also showed that super-performing individuals are much more important for the growth of the population (Chapter 2) and that individuals that are important for future production could be used to improve the management of natural populations (Chapter 5).

    This study provides improved insight into the extent of individual heterogeneity in a long-lived plant species and its environmental and genetic drivers, and clearly shows the importance of individual heterogeneity and its drivers for population processes and management practices. It also presents methods on how persistent performance differences between individuals can be incorporated into demographic tools, how these can be used to analyze individual contributions to population dynamics, to extrapolate short-term to long–term environmental effects, and to analyze smart harvesting scenarios that take differences between individuals into account. These results indicate that individual heterogeneity, underlying environmental and genetic drivers, and population processes are all related. Therefore, when evaluating the effect of environmental change on population processes, and in the design of management schemes, it is important to keep these relations in mind. The methodological tools that we presented provide a means of doing this.

    Israel cultiveren nederlands
    Livestock Research, - \ 2012
    [S.l.] : YouTube
    melkveehouderij - loopstallen - dierlijke meststoffen - cultivateren - onderlaag - compostering - vloertypen - israël - dairy farming - loose housing - animal manures - chiselling - understorey - composting - floor type - israel
    Nadat de eerder opgeslagen mest weer wordt uitgereden op de vloer van de Israelische loopstal en met een cultivator met de onderlaag is gemengd, wordt het mengsel bekeken en beoordeeld.
    The spatial pattern of grasses in relation to tree effects in an arid savannah community: Inferring the relative importance of canopy and root effect
    Xu, C. ; Liu, M.S. ; Zhang, M. ; Chen, B. ; Huang, Z. ; Uriankhai, T. ; Sheng, S. - \ 2011
    Journal of Arid Environments 75 (2011)10. - ISSN 0140-1963 - p. 953 - 959.
    below-ground competition - positive interactions - plant-communities - soil-water - facilitation - distributions - ecosystems - woody - productivity - understorey
    Both aboveground and belowground processes play important roles in tree-grass interactions in savannas. Little consideration has been given to within-site heterogeneity in the strengths of co-occurring canopy and root effects of trees on grasses in savanna communities. Here, we attempted to correlate the spatial pattern of grass morphological traits with the strengths of canopy and root effects. The results from a spatial analysis suggested that the grass traits had lower variability within the operating domain of the root effect than within that of the canopy effect in sub-canopy areas; in contrast, the operating domain of the root effect presented higher variability of grass traits than that of the canopy effect in inter-canopy areas. Combined with root investigations on vertical distribution patterns, these results suggested that the root effect appeared to outweigh the canopy effect in the sub-canopy areas, where apparent vertical root separation between trees and grasses was shown; while the canopy effect could outweigh the root effect in the inter-canopy areas, where root separation was not observed. This study could provide correlative information on the relative importance of canopy and root effects, and has some useful implications on within-site heterogeneity in terms of aboveground and belowground components in savannas.
    The effects of logging on the architecture of Bornean rainforest trees
    Sterck, F.J. ; Hille Ris Lamberis, R. ; Bongers, F.J.J.M. - \ 2003
    Journal of Tropical Forest Science 15 (2003)4. - ISSN 0128-1283 - p. 593 - 603.
    lowland dipterocarp forest - danum-valley - growth - dynamics - gaps - understorey - disturbance - neighbors - seedlings - patterns
    Tree parameters were compared between trees in a logged (logged eight years ago) and an unlogged forest in Borneo. This comparison was made for 3 to 10 cm diameter at breast height (dbh) trees of four tree species, namely, Mallotus penangensis, M. wrayi, Shorea johorensis and S. parvifolia. The crown position index indicated that light levels tended to be lower in the logged forest. This probably resulted from the higher tree densities in the 10 to 30 cm dbh class. Leaf display parameters did not differ between the forests. Logged forest trees had narrower crowns than unlogged forest trees, except for M. wrayi. Mallotus wrayi and S. parvifolia had relatively thick holes in logged forest. These responses to logging may reflect recent competition for light and space (narrow crowns), and high light levels shortly after logging (thicker holes). These architectural responses to logging did not parallel architectural responses to increased light levels. After eight years the canopy of the logged forest had already closed, and light levels above juvenile trees were low. This indicated that the effects of increased light levels quickly reduced during the first years after logging.
    Spontane ontwikkeling van bos: gevolgen voor flora en vegetatie
    Bijlsma, R.J. ; Siebel, H.N. - \ 2003
    Vakblad Natuurbeheer 42 (2003)4. - ISSN 1388-4875 - p. 55 - 58.
    bossen - bosbeheer - opstandsontwikkeling - opstandsstructuur - opstandskenmerken - flora - wilde planten - vegetatie - onderlaag - botanische samenstelling - plantensuccessie - plantenecologie - bosecologie - forests - forest administration - stand development - stand structure - stand characteristics - flora - wild plants - vegetation - understorey - botanical composition - plant succession - plant ecology - forest ecology
    In dit eerste artikel in de nieuwe reeks met als thema 'de gevolgen van niets doen voor ...' komt aan de orde welke gevolgen het meer natuurlijke bosbeheer van de laatste decennia heeft voor de bosflora en vegetatie. Voor eikenbossen, beukenbossen en dennenbossen op hogere zandgronden en heuvelland worden de veranderende condities als gevolg van spontane ontwikkeling van de boom- en struiklaag beschreven, en de effecten op vaatplanten en mossen. Er blijken voor Nederland nieuwe bostypen te ontstaan waarvoor geen referenties bestaan; de ontwikkeling van gesloten opgaand bos biedt geen garanties voor het behoud van de bosflora
    Oude lindenbossen op Jutland; referentiebeelden voor bosontwikkeling in Nederland?
    Hommel, P.W.F.M. ; Waal, R.W. de; Spek, T. - \ 2003
    Nederlands Bosbouwtijdschrift (2003)2. - ISSN 0028-2057 - p. 13 - 21.
    bossen - bosbomen - tilia - bosecologie - opstandsstructuur - opstandskenmerken - ecosystemen - plantenecologie - vegetatie - botanische samenstelling - bosgronden - onderlaag - bosstrooisel - bodemvorming - denemarken - forests - forest trees - tilia - forest ecology - stand structure - stand characteristics - ecosystems - plant ecology - vegetation - botanical composition - forest soils - understorey - forest litter - soil formation - denmark
    In het kader van het Alterra-onderzoeksproject 'boomsoortkeuze op verzuringsgevoelige bodem' werden in Jutland vijf lindenbossen bezocht, die als referentiebeeld kunnen fungeren voor bosecosystemen op de Nederlandse pleistocene zandgronden. De winterlinde kan hier een belangrijke rol spelen in de ontwikkeling van natuur- en multifunctionele bossen. Een beschrijving van de bosgebieden, met vooral aandacht voor de relatie boomsoort-strooisellaag-ondergroei, hydrologie, verjonging en vraat, 'verbeuking' en menging
    Bospaden: een vertrouwd vangnet voor bosplanten
    Bijlsma, R.J. ; Blitterswijk, H. van; Clerkx, A.P.P.M. ; Jong, J.J. de - \ 2002
    Nederlands Bosbouwtijdschrift 74 (2002)1. - ISSN 0028-2057 - p. 10 - 15.
    planten - wilde planten - bossen - bosecologie - plantenecologie - vegetatie - flora - verspreiding - distributie - ruimtelijke verdeling - bosbeheer - bosbedrijfsvoering - wegen - paden - bospaden - onderlaag - oude bossen - bos - ecologie - historie - Gelderland - plants - wild plants - forests - forest ecology - vegetation - flora - dispersal - forest administration - forest management - roads - paths - forest trails - distribution - spatial distribution - plant ecology - understorey - old-growth forests
    Bespreking van de resultaten van een onderzoek in bosterreinen in Gelderland naar het voorkomen van oud-bosplanten langs bospaden en -wegen en in het bos zelf, in relatie tot de ecologische functies van paden (refugium, vestigingsmilieu en transportroute). De oud-bossoorten blijken in toenemende mate alleen nog langs paden en wegen voor te komen; het streven naar een meer natuurlijk bosbeheer vormt een ernstige bedreiging. Met suggesties voor beheer in oude bossen gericht op behoud van ecologisch en historisch waardevolle infrastructuur en van habitats voor oud-bosplanten
    Terug naar het lindenwoud? alternatieve boomsoortkeuze verhoogt ecologische en recreatieve waarde van bossen op verzuringsgevoelige gronden
    Hommel, P.W.F.M. ; Spek, T. ; Waal, R.W. de; Hullu, P.C. de; Ouden, J. den - \ 2001
    Nederlands Bosbouwtijdschrift 73 (2001)6. - ISSN 0028-2057 - p. 12 - 23.
    bossen - bosecologie - vegetatie - tilia - plantenecologie - verbetering van bosterreinen - botanische samenstelling - humus - bosstrooisel - strooisel - humusvormen - moder - mor - mul - bodemvruchtbaarheid - bodemchemie - bodemvorming - bodemtypen (ecologisch) - bodemtypen - bosgronden - onderlaag - bodemverzuring - boomsoort - bosbeheer bosbouw - ecologie - milieu - recreatie - voedselrijkdom - forests - forest ecology - vegetation - tilia - plant ecology - amelioration of forest sites - botanical composition - humus - forest litter - litter (plant) - humus forms - moder - mor - mull - soil fertility - soil chemistry - soil formation - soil types (ecological) - soil types - forest soils - understorey
    Uitleg over de relatie tussen bostype en boomsoorten enerzijds en bodemvormende processen anderzijds, met name de humusvorming onder invloed van de kwaliteit van het strooisel. Vooral op matig voedselrijke, verzuringsgevoelige gronden kunnen processen van verarming en verzuring van de bosbodem worden tegengegaan door aanplant van boomsoorten met goed verterend strooisel; daardoor ontstaat een rijkere ondergroei en een recreatief aantrekkelijk en ecologisch rijker bos. Vooral de linde biedt in dit verband perspectief. In een apart kader de geschiedenis van de opkomst en achteruitgang van de linde in de het Noordwesteuropese bos, in relatie met bodemsoort, klimaatverandering en toenemende bosexploitatie door de mens
    Modellering van bosbeheer in SUMO
    Wamelink, G.W.W. ; Wegman, R. ; Slim, P.A. ; Dobben, H.F. van - \ 2000
    Wageningen : Alterra (Alterra-rapport 66)
    bosbedrijfsvoering - bosbouwkundige handelingen - biomassa - bossen - velling - dunnen - struiken - simulatie - modellen - nederland - onderlaag - forest management - forestry practices - biomass - forests - felling - thinning - shrubs - simulation - models - netherlands - understorey
    In het vegetatievoorspellingsmodel SUMO is de beheermodule uitgebreid met twee vormen van bosbeheer: regulier bosbeheer en hakhoutbeheer. Het regulier bosbeheer bestaat uit elke vijf jaar dunnen en kaalkap aan het eind van de omloopperiode. De omloopperiode en het dunningspercentage zijn per boomsoort verschillend. De effecten van het beheer zijn een variërende stikstofbeschikbaarheid (gering na dunnen en groot na kappen) en een betere simulatie van de biomassa: teruggang in biomassa van de bomen na dunnen, en na kappen een enorme toename van de biomassa van de kruiden. Ook het hakhoutbeheer (voor eiken-, wilgen- en elzenhakhout) heeft veel invloed op de biomassa, al is verder onderzoek naar de biomassaverdeling over de functionele typen noodzakelijk. Toevoeging van beide beheersvormen geeft een duidelijke verbetering te zien van de simulatie van de bosontwikkeling.
    Veranderingen in de kruidlaag in bosreservaten
    Dort, K.W. van; Bouwma, L.M. ; Broekmeyer, M.E.A. ; Koop, H.G.J.M. - \ 1999
    De Levende Natuur 100 (1999)5. - ISSN 0024-1520 - p. 154 - 157.
    bossen - bosbouw - bosecologie - planten - grondvegetatie - grondbedekking - grasbestand - onderlaag - plantensuccessie - plantengemeenschappen - soortendiversiteit - botanische samenstelling - zandgronden - forests - forestry - forest ecology - plants - ground vegetation - ground cover - herbage - understorey - plant succession - plant communities - species diversity - botanical composition - sandy soils
    Algemene waargenomen trends in de ontwikkeling van de kruidlaag in bossen op voedselarme zandgronden. In de natuurlijke bosdynamiek spelen licht en voedingstoestand een belangrijke sturende rol
    Eerste opname van de ondergroei in het Meetnet Bosvitaliteit
    Dobben, H.F. van; Vocks, M.J.M.R. ; Bouwma, I.M. - \ 1997
    Wageningen : IBN-DLO (IBN - rapport 321) - 29
    bosbouw - grondbedekking - grasbestand - mossen - korstmossen - milieu - verontreiniging - monitoring - achteruitgang, bossen - levensvatbaarheid - nederland - onderlaag - forestry - ground cover - herbage - mosses - lichens - environment - pollution - monitoring - forest decline - viability - netherlands - understorey
    The photosynthetic capacity and leaf nitrogen concentration as related to light regime in shade leaves of a montane tropical forest tree, Tetrorchidium rubrivenium
    Anten, N.P.R. ; Hernandez, R. ; Medina, E.M. - \ 1996
    Functional Ecology 10 (1996)4. - ISSN 0269-8463 - p. 491 - 500.
    Co-ordination - model - optimization - photosynthesis - understorey

    1. In order to evaluate quantitatively the photosynthetic performance and related nitrogen allocation of understorey plants in relation to the light environment in which they grow, two approaches may be used: the optimization theory and the co-ordination theory. 2. The optimization theory assumes that there is an optimal leaf nitrogen concentration (N(op)) at which photosynthesis per unit nitrogen is maximized. The co-ordination theory, on the other hand, hypothesizes that plants maintain the nitrogen concentration in the leaves such as to keep a balance between the processes which potentially limit photosynthesis, namely the Rubisco- and the electron-transport-limited rates of carboxylation. 3. These approaches were applied to analyse the photosynthesis-N relationship of trees (1.4-1.8 m in height) of the species Tetrorchidium rubrivenium (Euphorbiaceae) growing in the traderstorey of a tropical montane rain forest in northern Venezuela. Light-distribution patterns in the understorey and photosynthetic variables in relation to leaf N concentrations (N(L)) and light were measured. The optimal N(L) values (N(op)) and the N(L) at which the processes which limit photosynthesis are in balance (N(crday)) were calculated. 4. Measured N(L) values were considerably higher than the calculated values of N(op) and N(crday). However, the N(L) values were close to the values at which carbon gain per unit leaf area is maximal. 5. It was suggested that growth and therefore probably leaf-area production of Tetrorchidium in the understorey are limited by light and not by nitrogen availability. Under these conditions, maximization of photosynthesis per unit of leaf area might be more important than maximization of photosynthesis per unit of N(L).

    Influence des arbres agroforestiers sur le sol et la strate herbacée du Sud du Sahel : étude particuliere du phosphore
    Radersma, S. - \ 1996
    Wageningen : AB-DLO (Rapports PSS 26) - 106
    bosbouw - bomen - agroforestry - grondbedekking - grasbestand - bodemvorming - planten - bodemprofielen - bodem - fosfor - onderlaag - forestry - trees - agroforestry - ground cover - herbage - soil formation - plants - soil profiles - soil - phosphorus - understorey
    Het vochtgehalte in de strooisellaag onder verschillende vegetaties in twee grove-dennenopstanden
    Clerkx, A.P.P.M. ; Hees, A.F.M. van - \ 1993
    Wageningen : IBN (IBN - rapport 040) - 34
    bosbouw - bodemwater - permeabiliteit - absorptie - hygroscopiciteit - bosstrooisel - strooisel - grondbedekking - grasbestand - bomen - pinus sylvestris - nederland - onderlaag - utrecht - forestry - soil water - permeability - absorption - hygroscopicity - forest litter - litter (plant) - ground cover - herbage - trees - pinus sylvestris - netherlands - understorey - utrecht
    Effects of acidification, liming and fertilization on the undergrowth of a pine forest stand in central Sweden
    Dobben, H.F. van; Dirkse, G.M. ; Braak, C.J.F. ter - \ 1992
    Wageningen : IBN-DLO (RIN report 92/21) - 26
    bosbouw - bomen - bosschade - zure regen - grondbedekking - grasbestand - kalk - gips - krijtkalk - atmosfeer - luchtverontreiniging - chemicaliën - zweden - onderlaag - bosopstanden - bemesting - forestry - trees - forest damage - acid rain - ground cover - herbage - lime - gypsum - chalk - atmosphere - air pollution - chemicals - sweden - understorey - forest stands - fertilizer application
    Effect van bekalking en bemesting met fosfor, magnesium en kalium op de ondergroei van eiken- en dennenopstanden op arme grond
    Dobben, H.F. van; Vocks, M.J.M.R. - \ 1992
    Wageningen : DLO-IBN (RIN - rapport 92/22) - 20
    biomassa - krijtkalk - mengmeststoffen - kunstmeststoffen - achteruitgang, bossen - bosbouw - grondbedekking - gips - grasbestand - lagenstructuur - kalk - nederland - periodiciteit - plantengemeenschappen - plantensuccessie - synecologie - bomen - vegetatie - levensvatbaarheid - onderlaag - bemesting - bosopstanden - biomass - chalk - compound fertilizers - fertilizers - forest decline - forestry - ground cover - gypsum - herbage - layer structure - lime - netherlands - periodicity - plant communities - plant succession - synecology - trees - vegetation - viability - understorey - fertilizer application - forest stands
    Effecten van experimentele bekalking en bemesting op de ondergroei van enkele eiken- en dennenbossen op arme zandgrond in Nederland : beschrijving van de uitgangssituatie
    Goeij, S. de; Siebum, M. - \ 1990
    Leersum : RIN (Intern rapport / Rijksinstituut voor Natuurbeheer 90/2) - 24
    krijtkalk - bosbouw - grondbedekking - gips - grasbestand - kalk - periodiciteit - plantensuccessie - vegetatie - nederland - onderlaag - bemesting - bosopstanden - noord-brabant - chalk - forestry - ground cover - gypsum - herbage - lime - periodicity - plant succession - vegetation - netherlands - understorey - fertilizer application - forest stands - noord-brabant
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