Responses of two Anthurium cultivars to high daily integrals of diffuse light
Li, T. ; Heuvelink, E. ; Noort, F. van; Kromdijk, J. ; Marcelis, L.F.M. - \ 2014
Scientia Horticulturae 179 (2014). - ISSN 0304-4238 - p. 306 - 313.
radiation-use efficiency - structural plant-model - yield components - growth analysis - photosynthesis - tomato - interception - architecture - quality - biology
Heavy shading is commonly applied during production of pot-plants in order to avoid damage caused by high light intensities; usually the daily light integral (DLI) is limited to 5–8 mol m-2 d-1 photosynthetically active radiation (PAR). However, shading carries a production penalty as light is the driving force for photosynthesis. Diffuse glass has been developed to scatter the incident light in greenhouses. This study aims at investigating the effect of diffuse glass cover and high DLI under diffuse glass cover on the growth of pot-plants; furthermore, to systematically identify and quantify the yield components which are influenced by these treatments. Experiments were carried out with two Anthurium andreanum cultivars (Royal Champion and Pink Champion) in a conventional modern glasshouse compartment covered by clear glass with DLI limited to 7.5 mol m-2 d-1 (average realized DLI was 7.2 mol m-2 d-1), and another two glasshouse compartments covered by diffuse glass with DLI limited to 7.5 (average realized DLI was 7.5 mol m-2 d-1) and 10 mol m-2 d-1 (average realized DLI was 8.9 mol m-2 d-1). Diffuse glass cover resulted in less variation of temporal photosynthetic photon flux density (PPFD) distribution compared with the clear glass cover. Under similar DLI conditions (DLI limited to 7.5 mol m-2 d-1), diffuse glass cover stimulated dry mass production per unit intercepted PPFD (RUE) in ‘Royal Champion’ by 8%; whilst this stimulating effect did not occur in ‘Pink Champion’. Under diffuse glass cover, biomass production was proportional to DLI in both cultivars (within the range 7.5–9 mol m-2 d-1). Consequently higher DLI led to more flowers, leaves and stems. Furthermore, high DLI resulted in more compact plants without light damage in leaves or flowers in both cultivars. ‘Pink Champion’ produced more biomass than ‘Royal Champion’ in all treatments because of higher RUE which resulted from a more advantageous canopy architecture for light capture and more advantageous leaf photosynthetic properties. We conclude that less shading under diffuse glass cover not only stimulates plant growth but also improves plant ornamental quality (i.e. compactness).
Axillary budbreak in a cut rose crop as influenced by light intensity and red:far-red ratio at bud level
Wubs-Timmermans, A.M. ; Heuvelink, E. ; Marcelis, L.F.M. ; Buck-Sorlin, G.H. ; Vos, J. - \ 2014
Journal of the American Society for Horticultural Science 139 (2014)2. - ISSN 0003-1062 - p. 131 - 138.
photosynthetic photon flux - growth - temperature - shoots - plants - interception - architecture - arabidopsis - responses - density
When flower-bearing shoots in cut rose (Rosa ·hybrida) are harvested, a varying number of repressed axillary buds on the shoot remainder start to grow into new shoots (budbreak). Earlier experiments indicated that light reaching the bud affected the number of budbreaks. In all these studies, whole plants were illuminated with different light intensities or light spectra. The aim of this article is to disentangle the effects of light intensity and light spectrum, in this case red:far-red ratio, at the level of the buds on budbreak in a rose crop. Three experiments were conducted in which light intensity and red:far-red ratio at the level of the buds were independently varied, whereas intensity and red:far-red ratio of incident light on the crop were not changed. Light intensity and red:far-red ratio at the position of the buds were quantified and related to budbreak on the shoot remainders. Removal of vertical shoots increased light intensity and red:far-red ratio as well as budbreak (1.9 budbreaks per shoot remainder compared with 0.4 budbreaks when five vertical shoots were present). No vertical shoots and red light-absorbing shading paper over the plant base mimicked the effect of vertical shoots with respect to light intensity and red:far-red ratio, but budbreak (1.0 budbreaks) was intermediate compared with treatments with and without shoots. This suggested that the presence of shoots exerts an inhibiting effect on budbreak through both effects on light at the bud and correlative inhibition. When plants had no vertical shoots and light intensity and red:far-red ratio at bud level were changed by neutral and red light-absorbing shading paper, there was a positive effect of light intensity on budbreak (0.3 more budbreaks per shoot remainder) and no effect of red:far-red ratio. Combinations of high and low light intensity with high and low red:far-red ratio on axillary buds showed that there was a positive effect of light intensity on budbreak (0.5 more budbreaks per shoot remainder) and no effect of red:far-red ratio. Our study reveals that when light intensity and red:far-red ratio received by the plant are similar but differ at bud level, budbreak was affected by light intensity and not by red:far-red ratio.
Runoff and Sediment load of the Yan River, China: changes over the last 60 yr
Wang, F. ; Mu, X. ; Hessel, R. ; Zhang, W. ; Ritsema, C.J. ; Li, R. - \ 2013
Hydrology and Earth System Sciences 17 (2013). - ISSN 1027-5606 - p. 2515 - 2527.
lower yellow-river - loess plateau - agricultural catchment - impacts - interception - rainfall - dynamics - erosion - canopy - trends
Runoff and sediment load changes are affected by climate change and human activities in an integrated way. Historical insight into these effects can not only improve the knowledge of river processes, but also promote more effective land and water management. In this study, we looked at runoff and sediment change in the Yan River basin, Loess Plateau, China, using data sets on land use and land cover (LUC), monthly data of precipitation and temperature, and observed data on runoff and sediment load from 1952 to 2010 at the Ganguyi Hydrologic Station. Available data on soil and water conservation structures and their effect were also studied. Five main findings emerged from the data analysis. (1) The annual runoff and sediment load varied greatly during the last 60 yr, and both had coefficients of variation that were much larger than those of precipitation and temperature. (2) Annual runoff and sediment load both showed a significant trend of linear decline over the period studied. The climate data showed a non-significant decline in precipitation over the same period, and a very significant increase in temperature; both can help explain the observed declines in runoff and soil loss. (3) Based on a mass curve analysis with anomalies of normalized runoff and sediment load, 4 stages in the change of runoff and soil loss were identified: 1951 to 1971 (Stage I), 1972 to 1986 (Stage II), 1987 to 1996 (Stage III) and 1997 to 2010 (Stage IV). (4)When years were paired based on similar precipitation and temperature condition (SPTC) and used to assess the impacts of human activities, it was found that 6 sets of paired years out of 12 (50 %) showed a decline in runoff, 8 (67 %) a decline in sediment load, and 9 (75 %) a decline in sediment concentration. The other sets show an increasing change with time. It showed the complexity of human impacts. (5) Human impacts relating to LUC change and soil and water measures in this basin were significant because of both the transfer of sloping cropland into non-food vegetation or terraces, and the siltation in the reservoirs and behind check dams. Data indicated that about 56 Mt of sediment was deposited annually from 1960– 1999 as a result of the soil and water conservation structures, which is significantly more than the average 42 Mt, leaving the Yan River basin as sediment load each year. Although the effects of climate change and human action could not be separated, analysis of the data indicated that both had a significant impact on runoff and sediment load in the area.
How plant architecture affects light absorption and photosynthesis in tomato: towards an ideotype for plant architecture using a functional-structural plant model
Sarlikioti, V. ; Visser, P.H.B. de; Buck-Sorlin, G.H. ; Marcelis, L.F.M. - \ 2011
Annals of Botany 108 (2011)6. - ISSN 0305-7364 - p. 1065 - 1073.
carbon gain - leaf - interception - canopy - morphology - yield - assimilation - efficiency - avoidance - capture
Background and Aims - Manipulation of plant structure can strongly affect light distribution in the canopy and photosynthesis. The aim of this paper is to find a plant ideotype for optimization of light absorption and canopy photosynthesis. Using a static functional structural plant model (FSPM), a range of different plant architectural characteristics was tested for two different seasons in order to find the optimal architecture with respect to light absorption and photosynthesis. Methods - Simulations were performed with an FSPM of a greenhouse-grown tomato crop. Sensitivity analyses were carried out for leaf elevation angle, leaf phyllotaxis, leaflet angle, leaf shape, leaflet arrangement and internode length. From the results of this analysis two possible ideotypes were proposed. Four different vertical light distributions were also tested, while light absorption cumulated over the whole canopy was kept the same. Key Results Photosynthesis was augmented by 6 % in winter and reduced by 7 % in summer, when light absorption in the top part of the canopy was increased by 25 %, while not changing light absorption of the canopy as a whole. The measured plant structure was already optimal with respect to leaf elevation angle, leaflet angle and leaflet arrangement for both light absorption and photosynthesis while phyllotaxis had no effect. Increasing the length : width ratio of leaves by 1·5 or increasing internode length from 7 cm to 12 cm led to an increase of 6–10 % for light absorption and photosynthesis. Conclusions - At high light intensities (summer) deeper penetration of light in the canopy improves crop photosynthesis, but not at low light intensities (winter). In particular, internode length and leaf shape affect the vertical distribution of light in the canopy. A new plant ideotype with more spacious canopy architecture due to long internodes and long and narrow leaves led to an increase in crop photosynthesis of up to 10 %.
Towards a functional–structural plant model of cut-rose: simulation of light environment, light absorption, photosynthesis and interference with the plant structure
Buck-Sorlin, G.H. ; Visser, P.H.B. de; Henke, M. ; Sarlikioti, V. ; Heijden, G.W.A.M. van der; Marcelis, L.F.M. ; Vos, J. - \ 2011
Annals of Botany 108 (2011)6. - ISSN 0305-7364 - p. 1121 - 1134.
axillary buds - growth - interception - elongation - canopies - leaves - wheat - shoot - l.
Background and Aims The production system of cut-rose (Rosa × hybrida) involves a complex combination of plant material, management practice and environment. Plant structure is determined by bud break and shoot development while having an effect on local light climate. The aim of the present study is to cover selected aspects of the cut-rose system using functional–structural plant modelling (FSPM), in order to better understand processes contributing to produce quality and quantity. Methods The model describes the production system in three dimensions, including a virtual greenhouse environment with the crop, light sources (diffuse and direct sun light and lamps) and photosynthetically active radiation (PAR) sensors. The crop model is designed as a multiscaled FSPM with plant organs (axillary buds, leaves, internodes, flowers) as basic units, and local light interception and photosynthesis within each leaf. A Monte-Carlo light model was used to compute the local light climate for leaf photosynthesis, the latter described using a biochemical rate model. Key Results The model was able to reproduce PAR measurements taken at different canopy positions, different times of the day and different light regimes. Simulated incident and absorbed PAR as well as net assimilation rate in upright and bent shoots showed characteristic spatial and diurnal dynamics for different common cultivation scenarios. Conclusions The model of cut-rose presented allowed the creation of a range of initial structures thanks to interactive rules for pruning, cutting and bending. These static structures can be regarded as departure points for the dynamic simulation of production of flower canes. Furthermore, the model was able to predict local (per leaf) light absorption and photosynthesis. It can be used to investigate the physiology of ornamental plants, and provide support for the decisions of growers and consultants.
Temporal dynamics of light and nitrogen vertical distributions in canopies of sunflower, kenaf and cynara
Archontoulis, S.V. ; Vos, J. ; Yin, X. ; Bastiaans, L. ; Danalatos, N.G. ; Struik, P.C. - \ 2011
Field Crops Research 122 (2011)3. - ISSN 0378-4290 - p. 186 - 198.
radiation-use efficiency - hibiscus-cannabinus l - leaf nitrogen - growth-stages - interception - photosynthesis - crops - water - leaves - yield
To enhance eco-physiological and modelling studies, we quantified vertical distributions of light and nitrogen in canopies of three Mediterranean bio-energy crops: sunflower (Helianthus annuus), kenaf (Hibiscus cannabinus) and cynara (Cynara cardunculus). Field crops were grown with and without water stress in 2008 and 2009. Canopy vertical distributions of leaf area index (LAI), photosynthetically active radiation (PAR), specific leaf area (SLA), nitrogen concentration (Nconc) and specific leaf nitrogen (SLN) were assessed over time for each crop × year × water input combination. Light and nitrogen distributions were quantified by the Beer's law (exponential model) and extinction coefficients for light (KL) and nitrogen (KN) were calculated. Within a year, KL did not change significantly over the studied period in all irrigated crops, but differences in KL were significant between years (sunflower: 0.74 vs. 0.89; kenaf: 0.62 vs. 0.71; cynara: 0.77). KL estimates were always lower (-48 to -65%) in water-stressed sunflower and kenaf crops because of the reduction in leaf angle. These results should be taken into account, when simulating water-limited biomass production. Vertical SLN distributions were found in canopies when LAI was >1.5 (40 from 51 cases). These distributions were significantly correlated with the cumulative LAI from the top (r2 = 0.75–0.81; P <0.05), providing parameters to upscale photosynthesis from leaf to canopy levels. Vertical SLN distributions followed species-specific patterns over the crop cycle and varied less compared to PAR distributions between years. Lastly, we observed strong associations between SLN and PAR distributions in irrigated sunflower and kenaf canopies (r2 > 0.66; P <0.001). However, observed SLN distributions were less steep than the distributions that would maximize canopy photosynthesis
Water balance in afforestation chronosequences of common oak and Norway spruce on former arable land in Denmark and southern Sweden
Rosenqvist, L. ; Hansen, K. ; Vesterdal, L. ; Salm, C. van der - \ 2010
Agricultural and Forest Meteorology 150 (2010)2. - ISSN 0168-1923 - p. 196 - 207.
forest - soil - transpiration - interception - evaporation - stands - beech - model - conductance - catchment
Precipitation, throughfall and soil moisture were measured, and interception, transpiration and water recharge were estimated in four afforestation chronosequences on former arable land at two Danish locations (Vestskoven and Gejlvang) and at one southern Swedish location (Tonnersjoheden). Afforestation was performed using Norway spruce (Picea abies (Karst.) L) and common oak (Quercus robur L.) at Vestskoven and only Norway spruce at Gejlvang and Tonnersjoheden. Four to five stands of different ages (5-92 years) were studied in each of these chronosequences. Hydrological fluxes were calculated using the soil hydrological model SWAP. Throughfall flux and soil water content were used for calibration of the model. The simulated water recharge decreased with increased stand age within 30-40 years of afforestation. This was mainly due to increased interception evaporation with age. The annual water recharge was higher below oak stands (149-192 mm yr(-1)) than below spruce stands (107-191 mm yr(-1)) of similar age. The relative water recharge was also considerably higher from the sandy glaciofluvial soils at Gejlvang and Tonnersjoheden than from the sandy loamy till soils at Vestskoven.
Verbetering van de lichtonderschepping in een tomatengewas door aanpassing van de rijstructuur: Effecten van de rijstructuur op lichtverdeling, fotosynthese en productie
Dueck, T.A. ; Nederhoff, E.M. ; Nieboer, S. ; Scheffers, C.P. ; Steenhuizen, J.W. ; Chizhmak, S. ; Uenk, D. ; Sarlikioti, V. ; Visser, P.H.B. de - \ 2010
Wageningen : Wageningen UR Greenhouse Horticulture (Rapport GTB 1029) - 46
solanum lycopersicum - tomaten - kasgewassen - teelt onder bescherming - cultuurmethoden - licht - interceptie - ruimtelijke verdeling - adaptatie - positie - effecten - fotosynthese - solanum lycopersicum - tomatoes - greenhouse crops - protected cultivation - cultural methods - light - interception - spatial distribution - adaptation - position - effects - photosynthesis
Doel van dit project was te onderzoeken wat het effect is van de rijstructuur op de lichtverdeling en fotosynthese van een tomatengewas, en de effecten daarvan op de productie. Ook werd gekeken of de bladstand en de fotosynthesecapaciteit van de bladeren zich aanpassen aan wijzigende lichtverdeling. Tevens werd de hypothese getest of alternatieve vormen van tussenplanten zouden leiden tot lagere verdamping en dus tot energiebesparing. Verder is gekeken naar het effect op productie van twee substraten, namelijk kokosmatten type ‘Profit’ van Van der Knaap, en steenwolmat type ‘Master Dry’ van Grodan.
Narrow rows reduce biomass and seed production of weeds and increase maize yield
Mashingaidze, A.B. ; Werf, W. van der; Lotz, L.A.P. ; Chipomho, J. ; Kropff, M.J. - \ 2009
Annals of Applied Biology 155 (2009)2. - ISSN 0003-4746 - p. 207 - 218.
corn zea-mays - crop density - competition - interception - cultivation - suppression - population - varieties - pattern
Smallholder farmers in southern African countries rely primarily on cultural control and hoe weeding to combat weeds, but often times, they are unable to keep up with the weeding requirements of the crop because of its laboriousness, causing them to incur major yield losses. Optimisation of crop planting pattern could help to increase yield and suppress weeds and to reduce the critical period of weed control and the weeding requirements to attain maximum yield. Experiments were carried out in Zimbabwe during two growing seasons to assess the effect of maize density and spatial arrangement on crop yield, growth and seed production of weeds and to determine the critical period for weeding. Planting maize at 60 cm row distance achieved higher yields and better weed suppression than planting at 75 or 90 cm row distance. Increasing crop densities beyond the customary three to four plants m-2 gave modest reductions in weed biomass but also diminished crop yields, probably because of increased competition for water and nutrient resources. Maize planted in narrow rows (60 cm) intercepted more radiation and suffered less yield reduction from delaying hoe weeding than those planted in wider rows (75 or 90 cm), and the duration of the weed-free period required to attain maximum grain yield was 3 weeks shorter in the narrow spacing than that in the 75- and 90-cm row spacings. Weeding was more effective in curtailing weed seed production in the narrow row spatial arrangements than in the wide row planting. The results of these studies show that narrow row spacings may reduce weeding requirements and increase yields
Allometric growth relationships of East Africa highland bananas (Musa AAA-EAHB) cv. Kisansa and Mbwazirume
Nyombi, K. ; Asten, P.J.A. van; Leffelaar, P.A. ; Corbeels, M. ; Kaizzi, C.K. ; Giller, K.E. - \ 2009
Annals of Applied Biology 155 (2009)3. - ISSN 0003-4746 - p. 403 - 418.
leaf-area estimation - biomass accumulation - radiation - crop - light - interception - morphology - fertilizer - diameter - height
Highland bananas are an important staple food in East Africa, but there is little information on their physiology and growth patterns. This makes it difficult to identify opportunities for yield improvement. We studied allometric relationships by evaluating different phenological stages of highland banana growth for use in growth assessment, understanding banana crop physiology and yield prediction. Pared corms of uniform size (cv. Kisansa) were planted in a pest-free field in Kawanda (central Uganda), supplied with fertilizers and irrigated during dry periods. In addition, tissue-cultured plants (cv. Kisansa) were planted in an adjacent field and in Ntungamo (southwest Uganda), with various nutrient addition treatments (of N, P, K, Mg, S, Zn, B and Mo). Plant height, girth at base, number of functional leaves and phenological stages were monitored monthly. Destructive sampling allowed derivation of allometric relationships to describe leaf area and biomass distribution in plants throughout the growth cycle. Individual leaf area was estimated as LA (m2) = length (m) × maximum lamina width (m) × 0.68. Total plant leaf area (TLA) was estimated as the product of the measured middle leaf area (MLA) and the number of functional leaves. MLA was estimated as MLA (m2) = -0.404 + 0.381 height (m) + 0.411 girth (m). A light extinction coefficient (k = 0.7) was estimated from photosynthetically active radiation measurements in a 1.0 m grid over the entire day. The dominant dry matter (DM) sinks changed from leaves at 1118 °C days (47% of DM) and 1518 °C days (46% of DM), to the stem at 2125 °C days (43% of DM) and 3383 °C days (58% of DM), and finally to the bunch at harvest (4326 °C days) with 53% of DM. The allometric relationship between above-ground biomass (AGB in kg DM) and girth (cm) during the vegetative phase followed a power function, AGB = 0.0001 (girth)2.35 (R2 = 0.99), but followed exponential functions at flowering, AGB = 0.325 e0.036(girth) (R2 = 0.79) and at harvest, AGB = 0.069 e0.068(girth) (R2 = 0.96). Girth at flowering was a good parameter for predicting yields with R2 = 0.7 (cv. Mbwazirume) and R2 = 0.57 (cv. Kisansa) obtained between actual and predicted bunch weights. This article shows that allometric relationship can be derived and used to assess biomass production and for developing banana growth models, which can help breeders and agronomists to further exploit the crop's potential
Light-related variation in sapling architecture of three shade-tolerant tree species of the Mexican rain forest
Martinez-Sanchez, J.L. ; Meave, J. ; Bongers, F. - \ 2008
Revista Chilena de Historia Natural 81 (2008)3. - ISSN 0716-078X - p. 361 - 371.
los-tuxtlas - panamanian forest - growth-rate - environment - allometry - interception - plants - checklist - patterns - veracruz
The crown architecture of three shade-tolerant tree species (two subcanopy and one mid-canopy) was analyzed in relation to the light regime of the forest understorey. The aim was to examine to which extent shade-tolerant species variate in their crown architecture. Tree saplings (265) between 50 and 300 cm height, and distributed from understorey to variously-sized canopy gaps, were measured for 13 architectural traits in the lowland rain forest of Los Tuxtlas, Mexico. The analysis showed that the three species changed their architecture as light increased but in a different way. No species conformed to the typical wide-crown type expected for shade-tolerant species, and in contrast they presented some traits of light demanding species. The two sub-canopy species tended to adopt a crown form between a narrow- and wide-crown type, and the mid-canopy species showed more traits of a narrow-crown type. The horizontal crown area appeared as the more related trait to the light and sapling height. It is concluded that despite being shade-tolerant, the Studied species make use of better-lit environments in the forest understorey. The crown architecture of shade-tolerant species is not Lis rigid Lis originally conceived.
Coupling microscale vegetation-soil water and macroscale vegetation-precipitation feedbacks in semiarid ecosystems
Dekker, S.C. ; Rietkerk, M. ; Bierkens, M.F.P. - \ 2007
Global Change Biology 13 (2007)3. - ISSN 1354-1013 - p. 671 - 678.
grazing systems - subgrid variability - atmosphere - climate - interception - enhancement - moisture - balance - regions - models
At macroscale, land¿atmosphere exchange of energy and water in semiarid zones such as the Sahel constitutes a strong positive feedback between vegetation density and precipitation. At microscale, however, additional positive feedbacks between hydrology and vegetation such as increase of infiltration due to increase of vegetation, have been reported and have a large impact on vegetation distribution and spatial pattern formation. If both macroscale and microscale positive feedbacks are present in the same region, it is reasonable to assume that these feedback mechanisms are connected. In this study, we develop and analyse a soil-vegetation-atmosphere model coupling large-scale evapotranspiration¿precipitation feedback with a model of microscale vegetation¿hydrology feedback to study the integration of these nonlinearities at disparate scales. From our results, two important conclusions can be drawn: (1) it is important to account for spatially explicit vegetation dynamics at the microscale in climate models (the strength of the precipitation feedback increased up to 35% by accounting for these microscale dynamics); (2) studies on resilience of ecosystems to climate change should always be cast within a framework of possible large-scale atmospheric feedback mechanism (substantial changes in vegetation resilience resulted from incorporating macroscale precipitation feedback). Analysis of full-coupled modelling shows that both type of feedbacks markedly influence each other and that they should both be accounted for in climate change models.
Measurement and parameterization of rainfall microstructure
Uijlenhoet, R. ; Sempere Torres, D. - \ 2006
Journal of Hydrology 328 (2006)1-2. - ISSN 0022-1694 - p. 1 - 7.
raindrop size distribution - induced cross-polarization - 2-layer stochastic-model - drop size - kinetic-energy - weather radar - interception - dependence - precipitation - distributions
Several environmental processes, both occurring in the atmosphere and at the land surface, depend fundamentally on the structure of rainfall at the scale of individual raindrops. From a hydrological perspective, rainfall interception by vegetation canopies, soil erosion through raindrop impact, and the backscattering and attenuation of weather radar signals in rainfall are probably the most important of these. Detailed knowledge of the discrete microstructure of rainfall is a conditio sine qua non to understand, quantify, and ultimately predict these processes, even at much larger scales. This is the Preface to the Special Issue on ¿Measurement and Parameterization of Rainfall Microstructure¿, containing articles that have for the most part been presented at sessions organized at the 27th and 28th European Geosciences Union (EGU) General Assemblies in Nice, France, in 2002 and 2003.
|Interception in pine and eucalypt forest in central Portugal
Keizer, J.J. ; Coninck, H.L. de; Verzandvoort, S.J.E. ; Coelho, C.O.A. ; Warmerdam, P.M.M. - \ 2005
In: Progress in surface and subsurface water studies at plot and small basin scale, 10th Conference of the Euromediterranean Network of Experimental and Representative Basisns (ERB), Paris, 13-17 October 2004. - Paris : Unesco - p. 53 - 58.
bodem - erosie - interceptie - kroondak - neerslag - modellen - soil - erosion - interception - canopy - precipitation - models
The LISEM soil erosion model has been applied and tested for small experimental catchments located on the west flank of the Serra do Caramulo in central Portugal within EU funded CLIMED project
Relatie bos en waterwinning. 1. Verkenning van samenwerkingsmogelijkheden
Jansen, A.J.M. ; Olsthoorn, A.F.M. - \ 2003
Nederlands Bosbouwtijdschrift 75 (2003)2. - ISSN 0028-2057 - p. 7 - 10.
bossen - bosbomen - bosbeheer - grondwater - grondwateraanvulling - waterkwaliteit - watergebruik - waterrelaties - plant-water relaties - interceptie - transpiratie - waterbalans - bodemwaterbalans - waterwinning - forests - forest trees - forest administration - groundwater - groundwater recharge - water quality - water use - water relations - plant water relations - interception - transpiration - water balance - soil water balance - water catchment
In twee delen wordt een publikatie uit 2001 van KIWA en Alterra over de fysieke relaties tussen waterwinning en bos herdrukt. In deel 1 de invloed van bos- en boomsoorten op de waterkwaliteit en de wijze waarop bos- en boomsoorten de grondwateraanvulling beïnvloeden
A simple method to estimate radiation interception by nursery stock conifers: a case study of eastern white cedar
Pronk, A.A. ; Goudriaan, J. ; Stilma, E.S.C. ; Challa, H. - \ 2003
NJAS Wageningen Journal of Life Sciences 51 (2003)3. - ISSN 1573-5214 - p. 279 - 295.
thuja occidentalis - plantmateriaal - kroondak - interceptie - zonnestraling - schatting - thuja occidentalis - planting stock - canopy - interception - solar radiation - estimation - leaf-area index - lai-2000 - photosynthesis - canopies - stands - model
A simple method was developed to estimate the fraction radiation intercepted by small eastern white cedar plants (Thuja occidentalis 'Brabant'). The method, which describes the crop canopy as rows of cuboids, was compared with methods used for estimating radiation interception by crops with homogeneous canopies and crops grown in rows. The extinction coefficient k was determined at different plant arrangements and an average k-value of 0.48 ± 0.03 (R2 = 0.89) was used in the calculations. Effects of changing plant characteristics and inter- and intra-row plant distances were explored. The fraction radiation intercepted that was estimated with the method for rows of cuboids was up to 20% and for row crops up to 8% lower than estimated with the method for homogeneous canopies at low plant densities and a LAI of 1. The fraction radiation intercepted by small plants of Thuja occidentals 'Brabant' was best estimated by the simple method described in this paper
Opvang en vervoederen van hemelwater op Aver Heino
Verstappen-Boerekamp, J.A.M. ; Wolters, G.M.V.H. ; Schooten, H.A. van - \ 2000
Lelystad : Praktijkonderzoek Rundvee, Schapen en Paarden (Rapport / Praktijkonderzoek Rundvee, Schapen en Paarden 182) - 16
drinken - drinkwater - rundvee - interceptie - regen - neerslag - waterbescherming - waterkwaliteit - alternatieve landbouw - proefbedrijven - rekeningen van landbouwbedrijf - drinking - drinking water - cattle - interception - rain - precipitation - water conservation - water quality - alternative farming - pilot farms - farm accounts
Op Aver Heino wordt sinds het najaar van 1995 van 2000 m2 dakoppervlak hemelwater opgevangen om te gebruiken voor het drenken van vee. In deze 3z jaar is met hemelwateropvang voor 50 % in de waterbehoefte voor het vee voorzien.
Opvang hemelwater loont nog niet
Verstappen-Boerekamp, J. ; Wolters, G. ; Schooten, H. van - \ 2000
Praktijkonderzoek Rundvee, Schapen en Paarden. Praktijkonderzoek 13 (2000)2. - ISSN 1386-8470 - p. 15 - 17.
melkveehouderij - melkvee - drinkwater - waterkwaliteit - regen - neerslag - interceptie - proefbedrijven - drinken - kosten - dairy farming - dairy cattle - drinking water - water quality - rain - precipitation - interception - pilot farms - drinking - costs
Op proefbedrijf Aver Heino is ruim 3z jaar ervaring opgedaan met het opvangen en vervoederen van hemelwater als alternatief voor leidingwater. Van het opgevangen hemelwater is zowel de hoeveelheid als de kwaliteit bepaald. Het water blijkt niet altijdte voldoen aan de kwaliteitseisen van drinkwater voor melkvee. Daarnaast zijn de kosten per kuub nog te hoog.
Dependence of rainfall interception on drop size : a comment
Uijlenhoet, R. ; Stricker, J.N.M. - \ 1999
Journal of Hydrology 217 (1999). - ISSN 0022-1694 - p. 157 - 163.
regen - neerslag - interceptie - modellen - stochastische modellen - schaalverandering - druppelgrootte - hydrologie - rain - precipitation - interception - models - stochastic models - scaling - droplet size - hydrology
|Canopy interactions in a Douglas fir forest. Estimating dry deposition from canopy wetness, throughfall and wet deposition.
Versluis, A.H. ; Vermetten, A.W.M. ; Bouten, N. ; Maas, R. van der; Hofschreuder, P. - \ 1991
In: CORRELACI : identification of traditional and air pollution related stress factors in a douglas fir ecosystem : the aciforn stands : a correlative evaluation of monitoring data on the carbon, nutrient and water cycles / Evers, P.W., Bouten, W., van Grinsven, J.J.M., - p. 85 - 118.
bosbouw - bomen - bosschade - chemische precipitatie - luchtverontreiniging - zouten - depositie - kroon - kroondak - stamafstroming - regen - interceptie - neerslag - zure regen - zure depositie - pseudotsuga menziesii - forestry - trees - forest damage - chemical precipitation - air pollution - salts - deposition - crown - canopy - stemflow - rain - interception - precipitation - acid rain - acid deposition - pseudotsuga menziesii