‘The Twittering Tree’ — Real-time stress detectie van bossen op basis van het individueel monitoren van bomen

Jonas von der Crone
‘Twittering Trees’: bomen die vertellen hoe het met hen gaat Jonas von der CroneUniversiteit Gent, Laboratorium voor Plantecologie  Met hoogtechnologische plantsensoren is het mogelijk om bomen te laten twitteren over hoe het met hen gaat. Tijdens dit onderzoek werd het belang van deze technologie aangetoond tijdens het groeiseizoen van 2014. Ongeveer 385 miljoen jaar geleden ontstonden de eerste prehistorische bomen op onze aarde. Vandaag is 30% van het totale landoppervlak of 4.03 miljard hectare bedekt met bos, wat meer dan 1300 maal de oppervlakte van België is.

‘The Twittering Tree’ — Real-time stress detectie van bossen op basis van het individueel monitoren van bomen

‘Twittering Trees’: bomen die vertellen hoe het met hen gaat 

Jonas von der CroneUniversiteit Gent, Laboratorium voor Plantecologie  Met hoogtechnologische plantsensoren is het mogelijk om bomen te laten twitteren over hoe het met hen gaat. Tijdens dit onderzoek werd het belang van deze technologie aangetoond tijdens het groeiseizoen van 2014. Ongeveer 385 miljoen jaar geleden ontstonden de eerste prehistorische bomen op onze aarde. Vandaag is 30% van het totale landoppervlak of 4.03 miljard hectare bedekt met bos, wat meer dan 1300 maal de oppervlakte van België is. Bossen zijn cruciaal voor het leven op aarde en leveren tal van ecosysteemdiensten. Ze voorzien papier en hout, zorgen voor voedsel, slaan koolstof op, zuiveren lucht en water, herbergen een grote biodiversiteit, bieden bescherming, en bieden een habitat voor mens en dier. De lijst lijkt bijna eindeloos en maakt van bomen ware ‘ecosysteem ingenieurs’. Bossen zijn dan ook uitermate belangrijk, niet alleen in ecologische, maar ook in maatschappelijke context. Globale klimaatsverandering is ondertussen een feit. De luchttemperatuur en atmosferische CO2 concentratie stijgen en zullen nog een tijdje blijven toenemen. Er werd aangetoond dat een verhoogd CO2 niveau voor een verbeterde plantengroei kan zorgen, op voorwaarde dat er voldoende water en voedingsstoffen aanwezig zijn. Klimaatsopwarming leidt tot een verlengd groeiseizoen, maar een te sterke opwarming kan nadelig zijn voor onze bossen. Namelijk niet enkel het groeiseizoen voor planten wordt langer, maar ook de levenscyclus van schadelijke insecten, zoals bijvoorbeeld de eikenprocessierups, wordt alsmaar langer. Het resultaat van de klimaatsverandering is dus niet eenduidig, en vele vragen betreffende het geïntegreerde effect op bossen blijven onbeantwoord. Technieken die vandaag ingezet worden in een poging om op deze prangende vragen een antwoord te geven zijn teledetectie, eddy covariantie en visuele vitaliteitscontrole. Ze hebben als gemeenschappelijk doel de gezondheidstoestand van bomen en bossen in een veranderend klimaat te evalueren, maar geen van deze technieken meet rechtstreeks op de boom. En laat het nu net deze dynamische processen zijn, die zich in de boom zelf afspelen, die ons kunnen vertellen hoe bomen, en bij uitbreiding bossen, reageren op hun omgeving en het klimaat. Met hoogtechnologische plantsensoren die rechtstreeks op de boom worden geïnstalleerd is het mogelijk om de boom als het ware te laten vertellen hoe hij zich voelt: hoe goed hij groeit en hoeveel water hij iedere dag drinkt. Variaties in stamdiameter en sapstroom werden in dit onderzoek iedere minuut gemeten en draadloos doorgestuurd naar een server om zo de respons van de boom in real-time te kunnen visualiseren via de software PhytoSense (Phyto-IT). Over welke plantsensoren gaat het precies? Het waterverbruik van de boom werd gemeten met een sapstroomsensor en variaties in boomdiameter werden gemeten met een dendrometer (Appendix A). Inderdaad diametervariatie, want een boom krimpt en zwelt elke dag. Tijdens de dag verliest de boom water via bladtranspiratie of verdamping doorheen de huidmondjes (kleine poriën op het bladoppervlak) en omdat dit water niet snel genoeg kan opgenomen worden via de wortels, zal water uit interne reserves gebruikt worden die zich bevinden in levende cellen van o.a. de stam en de takken. Hierdoor krimpen deze boomorganen. Tijdens de nacht worden de interne reserves opnieuw aangevuld, waardoor de boom zwelt en groeit. De dagelijkse krimp en zwel werd opgevolgd voor beuk en eik tijdens het groeiseizoen 2014 (Appendix B). Het monitoren van deze individuele bomen toonden hun verschillende respons op een gelijk microklimaat aan: zo groeide eik in het begin van het groeiseizoen beter dan beuk, tot op een bepaald punt (A) waar droogte optrad. Tussen 7 juni en 9 juli viel namelijk amper 12 mm neerslag, terwijl tijdens een gemiddelde zomermaand 60 à 70 mm verwacht mag worden. Na de droge periode (10 juli, punt B in Appendix B) viel op korte tijd heel veel neerslag (36.8 mm). Terwijl beuk rustig verder groeide, was dit niet het geval voor eik. Eik stopte met groeien, waarschijnlijk ten gevolge van cavitatie of het breken van de waterkolom door de aanhoudende droge periode.  Dit toont aan dat het rechtstreeks monitoren van individuele bomen noodzakelijk is om het effect van wijzigingen in het klimaat volledig te begrijpen. Via een sapstroomsensor en een dendrometer konden we vertalen hoe beuk en eik zich op elke dag, elk moment, en dit doorheen het volledige groeiseizoen ‘voelden’. Het real-time visualiseren en bestuderen van de dynamiek van krimp, zwel, groei en waterverbruik zijn noodzakelijk om de respons van bomen op een alsmaar meer wijzigend (micro)klimaat beter te kunnen begrijpen. De geavanceerde technologie die we binnen dit onderzoek gebruikt hebben, maakt het mogelijk om bomen te laten ‘twitteren’ over hoe ze zich voelen. Een online netwerk van verschillende Twittering Trees heeft zo het potentieel een unieke tool te vormen waarbij zowel educatie, wetenschap en sensibilisering omtrent klimaatverandering centraal staan.

Bibliografie

·       Allen, R. G., Pereira, L. S., Raes, D., Smith, M., et al. 1998. Crop evapotranspiration - guidelines for computing crop water requirements - fao irrigation and drainage paper 56. FAO, Rome, 300(9).

·       Angelsen, A. et al. 2008. Moving ahead with REDD: issues, options and implications. Cifor.


·       Aris, R. 1978. Mathematical modelling techniques. Courier Corporation.


·       Atwell, B. J., Kriedemann, P. E., and Turnbull, C. G. 1999. Plants in action: adaptation in nature, performance in cultivation. Macmillan Education AU.


·       Aubinet, M., Vesala, T., and Papale, D. 2012. Eddy covariance: a practical guide to measurement and data analysis. Springer Science & Business Media.


·       Baldocchi, D. D. 2003. Assessing the eddy covariance technique for evaluating carbon dioxide exchange rates of ecosystems: past, present and future. Global Change Biology, 9(4):479–492.


·       Baldocchi, D. D. 2009. ESPM 228, Advanced topics in biometeorology and micrometeorology. Lecture.

·       Barford, C. C., Wofsy, S. C., Goulden, M. L., Munger, J. W., Pyle, E. H., Urbanski, S. P., Hutyra, L., Saleska, S. R., Fitzjarrald, D., and Moore, K. 2001. Factors controlling long-and short-term sequestration of atmospheric CO2 in a mid-latitude forest. Science, 294(5547):1688–1691.

·       Baycheva, T., Inhaizer, H., Lier, M., Prins, K., and Wolfslehner, B. 2014. Implementing criteria and indicators for sustainable forest management in Europe. Report.


·       Bechtold, W. A. 2003. Crown-diameter prediction models for 87 species of stand-grown trees in the eastern united states. Southern Journal of Applied Forestry, 27(4):269–278.


·       Beer, C., Reichstein, M., Tomelleri, E., Ciais, P., Jung, M., Carvalhais, N., Rödenbeck, C., Arain, M. A., Baldocchi, D. D., Bonan, G. B., et al. 2010. Terrestrial gross carbon dioxide uptake: global distribution and covariation with climate. Science, 329(5993):834–838.


·       Berninger, F., Hari, P., Nikinmaa, E., Lindholm, M., and Merilaïnen, J. 2004. Use of modeled photosynthesis and decomposition to describe tree growth at the northern tree line. Tree Physiology, 24(2):193–204.


·       Berry, C. 2000. A reconsideration of Wattieza Stockmans (here attributed to Cladoxylopsida) based on a new species from the Devonian of Venezuela. Review of Palaeobotany and Palynology, 112(1):125–146.

·       Bitterlich, W. et al. 1984. The relascope idea. Relative measurements in forestry. Commonwealth Agricultural Bureaux.


·       Boisvenue, C. and Running, S. W. 2006. Impacts of climate change on natural forest productivity – evidence since the middle of the 20th century. Global Change Biology, 12(5):862–882.


·       Bollmann, M. et al. 2010. World ocean review 1: living with the oceans. chapter 1: Earth’s cli- mate system – a complex framework. Digital image from http://worldoceanreview.com/en/wor-1/climate-system/earth-climate-syste….


·       Bower, D. R. and Blocker, W. W. 1966. Notes and observations: Accuracy of bands and tape for measuring diameter increments. Journal of Forestry, 64(1):21–22.


·       Boyer, J. S. 1995. Thermocouple psychometry. In Measuring the water status of plants and soils, chapter 3. Academic Press, Inc.

·       Brandon, K. 2014. Ecosystem services from tropical forests: Review of current science. Technical report, CGD Working Paper 380, Center for Global Development, Washington DC.

·       Buchmann, N. and Schulze, E.-D. 1999. Net CO2 and H2O fluxes of terrestrial ecosystems. Global Biogeochemical Cycles, 13(3):751–760.

·       Burba, G. and Anderson, D. 2007. Introduction to the Eddy Covariance method: general guidelines, and conventional workflow. LI-COR Biosciences.

·       Burgess, S. S., Adams, M. A., Turner, N. C., Beverly, C. R., Ong, C. K., Khan, A. A., and Bleby, T. M. 2001. An improved heat pulse method to measure low and reverse rates of sap flow in woody plants. Tree Physiology, 21(9):589–598.

·       Burgess, S. S. and Dawson, T. E. 2008. Using branch and basal trunk sap flow measurements to estimate whole-plant water capacitance: a caution. Plant and Soil, 305(1-2):5–13.

·       Bussotti, F., Gravano, E., Grossoni, P., and Tani, C. 1998. Occurrence of tannins in leaves of beech trees (fagus sylvatica) along an ecological gradient, detected by histochemical and ultrastructural analyses. New Phytologist, 138(3):469–479.

·       Canadell, J. G. and Raupach, M. R. 2008. Managing forests for climate change mitigation. Science, 320(5882):1456–1457.

·       Carter, J., Schmid, K., Waters, K., Betzhold, L., Hadley, B., Mataosky, R., and Halleran, J. 2012. Lidar 101: An introduction to lidar technology, data, and applications. National Oceanic and Atmospheric Administration (NOAA) Coastal Services Center.

·       Carter, R. 2011. Tree topics: The barlett tree experts blog. drought stress crown dieback. Digital image from http://blog.bartlett.com/?attachment_id=761.

·       Cermak, J. and Kucera, J. 1990. Scaling up transpiration data between trees, stands and watersheds. Silva Carelica (Finland).

·       Cermak, J., Kucera, J., and Nadezhdina, N. 2004. Sap flow measurements with some thermodynamic methods, flow integration within trees and scaling up from sample trees to entire forest stands. Trees, 18(5):529–546.

·       Ceulemans, R. J. 1999. Forest ecosystem modelling, upscaling and remote sensing. Kugler Publications.

·       Chapin III, F. S., Eugster, W., and McFadden, J. P. 2002. Arctic tundra flux study in the Kuparuk river basin (Alaska), 1994-1996. Available on-line [http://www.daac.ornl.gov] from Oak Ridge National Laboratory Distributed Active Archive Center, Oak Ridge, Tennessee, U.S.A.


·       Chapin III, F. S., Matson, P. A., and Vitousek, P. 2011. Principles of terrestrial ecosystem ecology. Springer Science & Business Media.
Clark, N. A., Wynne, R. H., and Schmoldt, D. L. 2000. A review of past research on dendrometers. Forest Science, 46(4):570–576.


·       Cochard, H. and Tyree, M. T. 1990. Xylem dysfunction in Quercus: vessel sizes, tyloses, cavitation and seasonal changes in embolism. Tree Physiology, 6(4):393–407.


·       Cohen, Y., Fuchs, M., and Green, G. C. 1981. Improvement of the heat pulse method for determining sap flow in trees. Plant, Cell & Environment, 4(5):391–397.


·       Daudet, F.-A., Ame ́glio, T., Cochard, H., Archilla, O., and Lacointe, A. 2005. Experimental analysis of the role of water and carbon in tree stem diameter variations. Journal of Experimental Botany, 56(409):135–144.


·       David, T. S., Pinto, C. A., Nadezhdina, N., Kurz-Besson, C., Henriques, M. O., Quilho ́, T., Cermak, J., Chaves, M. M., Pereira, J. S., and David, J. S. 2013. Root functioning, tree water use and hydraulic redistribution in Quercus suber trees: A modeling approach based on root sap flow. Forest Ecology and Management, 307:136–146.

·       De Schepper, V. and Steppe, K. 2010. Development and verification of a water and sugar transport model using measured stem diameter variations. Journal of Experimental Botany, 61(8):2083–2099.

·       De Swaef, T., Hanssens, J., Cornelis, A., and Steppe, K. 2013. Non-destructive estimation of root pressure using sap flow, stem diameter measurements and mechanistic modelling. Annals of botany, 111(2):271–282.


·       De Swaef, T. and Steppe, K. 2010. Linking stem diameter variations to sap flow, turgor and water potential in tomato. Functional Plant Biology, 37(5):429–438.


·       Decagon Devices 2015. Soil moisture sensors. GS3 Greenhouse Sensor. Volumetric water content, electrical conductivity, and temparture. 2365 NE Hopkins Ct / Pullman, WA 99163 USA.


·       Dixon, M. and Downey, A. 2013. PSY1 Stem Psychrometer Manual. ICT International, 4.4 edition.

·       Drew, D. M. and Downes, G. M. 2009. The use of precision dendrometers in research on daily stem size and wood property variation: a review. Dendrochronologia, 27(2):159–172.


·       Drew, D. M., Downes, G. M., and Battaglia, M. 2010. Cambium, a process-based model of daily xylem development in eucalyptus. Journal of Theoretical Biology, 264(2):395–406.


·       Eichhorn, J., Roskams, P., Ferretti, M., Mues, V., Szepesi, A., and Durrant, D. 2010. Visual assessment of crown condition and damaging agents. Manual on methods and criteria for harmonized sampling, assessment, monitoring and analysis of the effects of air pollution on forests. Manual Part IV. UNECE ICP Forests Programme Co-ordinating Centre.


·       EXELIS 2012. ITT Exelis delivers imaging system for next-generation, high-resolution GeoEye-2 satellite. Press release.


·       Fagan, M. and DeFries, R. 2009. Measurement and monitoring of the world’s forests. a review and summary of remote sensing technical capability 2009-2015. RFF REPORT.


·       FAO 2010. Global forest resources assessment (FRA) 2010: Main report. Food and Agriculture Organization of the United Nations.


·       Fisher, J. B., Tu, K. P., and Baldocchi, D. D. 2008. Global estimates of the land–atmosphere water flux based on monthly avhrr and islscp-ii data, validated at 16 fluxnet sites. Remote Sensing of Environment, 112(3):901–919.

·       Foley, J. A., Asner, G. P., Costa, M. H., Coe, M. T., DeFries, R., Gibbs, H. K., Howard, E. A., Olson, S., Patz, J., Ramankutty, N., et al. 2007. Amazonia revealed: forest degradation and loss of ecosystem goods and services in the Amazon Basin. Frontiers in Ecology and the Environment, 5(1):25–32.

·       ForNaLab 2007. Uitgebreid bosbeheerplan aelmoeseneiebos 26 november 2007, eindversie. UGent Laboratorium voor Bosbouw.

·       Frank, D., Poulter, B., Saurer, M., Esper, J., Huntingford, C., Helle, G., Treydte, K., Zimmermann, N., Schleser, G., Ahlström, A., et al. 2015. Water-use eciency and transpiration across european forests during the anthropocene. Nature Climate Change.

·       Gamfeldt, L., Snäll, T., Bagchi, R., Jonsson, M., Gustafsson, L., Kjellander, P., Ruiz-Jaen, M. C., Fröberg, M., Stendahl, J., Philipson, C. D., et al. 2013. Higher levels of multiple ecosystem services are found in forests with more tree species. Nature communications, 4:1340.

·       Gea-Izquierdo, G., Bergeron, Y., Huang, J., Lapointe-Garant, M., Grace, J., and Berninger, F. 2014. The relationship between productivity and tree-ring growth in boreal coniferous forests. Boreal Environment Research, 19.

·       Gibbs, H. K., Brown, S., Niles, J. O., and Foley, J. A. 2007. Monitoring and estimating tropical forest carbon stocks: making REDD a reality. Environmental Research Letters, 2(4).

·       Givnish, T. J. 1988. Adaptation to sun and shade: a whole-plant perspective. Functional Plant Biology, 15(2):63–92.

·       Goldstein, G., Andrade, J. L., Meinzer, F. C., Holbrook, N. M., Cavelier, J., Jacksosn, P., and Celis, A. 1998. Stem water storage and diurnal patterns of water use in tropical forest canopy trees. Plant, Cell & Environment, 21(4):397–406.

·       Granier, A. 1985. Une nouvelle m ́ethode pour la mesure du flux de s`eve brute dans le tronc des arbres. Annales des Sciences Forestieres, 42:193–200.

·       Green, S., Clothier, B., and Perie, E. 2008. A re-analysis of heat pulse theory across a wide range of sap flows. In VII International Workshop on Sap Flow 846, pages 95–104.

·       Hake, K., Cassman, K., Whisler, F., and Upchurch, D. 1990. Root physiology and management. Newsletter of the Cotton Physiology Education Program — NATIONAL COTTON COUNCIL, Physi- ology Today.

·       Hao, G.-Y., Wheeler, J. K., Holbrook, N. M., and Goldstein, G. 2013. Investigating xylem em- bolism formation, refilling and water storage in tree trunks using frequency domain reflectometry. Journal of experimental botany, 64(8):2321–2332.

·       Hathway, D. 1958. Oak-bark tannins. Biochemical Journal, 70(1):34.


·       Hemery, G., Savill, P., and Pryor, S. 2005. Applications of the crown diameter–stem diameter relationship for different species of broadleaved trees. Forest Ecology and Management, 215(1):285–294.

·       Holmgren, P. 2008. Role of satellite remote sensing in REDD. UN-REDD PROGRAMME, page 11.

·       Holmgren, P. and Thuresson, T. 1998. Satellite remote sensing for forestry planning - a review. Scandinavian Journal of Forest Research, 13(1-4):90–110.


·       Huber, B. and Schmidt, E. 1937. Eine kompensationsmethode zur thermoelektrischen messung langsamer saftströme.


·       ICT International 2015. Hrm heat ratio method. Digital image from http://www.ictinternational.com/products/heat-ratio-method/hrm-heat-rat….


·       Imboden, D. M. and Pfenninger, S. 2012. Introduction to systems analysis: mathematically modeling natural systems. Springer Science & Business Media.


·       IPCC 2013. Summary for policymakers. In Stocker, T., Qin, D., Plattner, G.-K., Tignor, M., Allen, S., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P., Eds., Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, page 1535. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

·       Jansen, J. J., Sevenster, J. G., and Faber, P. 1996. Opbrengst tabellen voor belangrijke boomsoorten in Nederland. Landbouwuniversiteit Wageningen, IBN-DLO.

·       Jones, C. G., Lawton, J. H., and Shachak, M. 1996. Organisms as ecosystem engineers. In Ecosystem Management, pages 130–147. Springer.

·       Keeland, B. D. and Sharitz, R. R. 1993. Accuracy of tree growth measurements using dendrometer bands. Canadian Journal of Forest Research, 23(11):2454–2457.

·       Keeland, B. D. and Young, P. J. 2014. Installation of traditional dendrometer bands. US Geological Survey, 23.

·       King, S. L., Allen, J. A., and McCoy, J. W. 1998. Long-term effects of a lock and dam and greentree reservoir management on a bottomland hardwood forest. Forest Ecology and Management, 112(3):213– 226.

·       Lee, X., Massman, W. J., and Law, B. E. 2006. Handbook of micrometeorology: a guide for surface flux measurement and analysis, volume 29. Springer, Science & Business Media.

·       Lindner, M., Fitzgerald, J. B., Zimmermann, N. E., Reyer, C., Delzon, S., van der Maaten, E., Schelhaas, M., Lasch, P., Eggers, J., van der Maaten-Theunissen, M., et al. 2014. Cli- mate change and European forests: What do we know, what are the uncertainties, and what are the implications for forest management? Journal of environmental management, 146:69–83.

·       Liu, D., Cai, W., Xia, J., Dong, W., Zhou, G., Chen, Y., Zhang, H., and Yuan, W. 2014. Global validation of a process-based model on vegetation gross primary production using eddy covariance ob- servations. PloS one, 9(11).

·       Lorenz, M., Becher, G., Mues, V., Fischer, R., Becker, R., Calatayud, V., Dise, N., Krause, G. H. M., Sanz, M., and Ulrich, E. 2012. Forest condition in Europe. Thu ̈nen-Institut, Bundes- forschungsinstitut fu ̈r Ländliche Räume, Wald und Fischerei.

·       Lövdahl, L. and Odin, H. 1992. Diurnal changes in the stem diameter of norway spruce in relation to relative humidity and air temperature. Trees, 6(4):245–251.

·       Lowman, M. D. 2009. Canopy research in the twenty-first century: a review of arboreal ecology. Tropical Ecology, 50(1):125.

·       Lubczynski, M. W. 2009. The hydrogeological role of trees in water-limited environments. Hydrogeology Journal, 17(1):247–259.

·       Lutz, J. A., Larson, A. J., Freund, J. A., Swanson, M. E., and Bible, K. J. 2013. The importance of large-diameter trees to forest structural heterogeneity. PloS one, 8(12).

·       Lutz, J. A., Larson, A. J., Swanson, M. E., and Freund, J. A. 2012. Ecological importance of large-diameter trees in a temperate mixed-conifer forest. PLoS One, 7(5).

·       Matyssek, R., Paoletti, E., Bytnerowicz, A., Kozovits, A. R., Wieser, G., and Feng, Z. 2015. Supersites for superior forest science. IUFRO Spotlight 29.

·       McLaughlin, S. B., Wullschleger, S. D., and Nosal, M. 2003. Diurnal and seasonal changes in stem increment and water use by yellow poplar trees in response to environmental stress. Tree Physiology, 23(16):1125–1136.

·       Meinzer, F. C., Brooks, J. R., Domec, J.-C., Gartner, B. L., Warren, J. M., Woodruff, D. R., Bible, K., and Shaw, D. C. 2006. Dynamics of water transport and storage in conifers studied with deuterium and heat tracing techniques. Plant, Cell & Environment, 29(1):105–114.

·       Meinzer, F. C., Clearwater, M. J., and Goldstein, G. 2001. Water transport in trees: current perspectives, new insights and some controversies. Environmental and Experimental Botany, 45(3):239– 262.

·       Meinzer, F. C., James, S. A., and Goldstein, G. 2004. Dynamics of transpiration, sap flow and use of stored water in tropical forest canopy trees. Tree Physiology, 24(8):901–909.

·       Meinzer, F. C., Woodruff, D. R., Eissenstat, D. M., Lin, H. S., Adams, T. S., and McCulloh, K. A. 2013. Above-and belowground controls on water use by trees of different wood types in an eastern us deciduous forest. Tree physiology, 33(4):345–356.

·       Meiresonne, L., Sampson, D. A., Kowalski, A. S., Janssens, I. A., Nadezhdina, N., Cermak, J., Van Slycken, J., and Ceulemans, R. 2003. Water flux estimates from a belgian scots pine stand: a comparison of different approaches. Journal of Hydrology, 270(3):230–252.

·       Mencuccini, M., Hölttä, T., Sevanto, S., and Nikinmaa, E. 2013. Concurrent measurements of change in the bark and xylem diameters of trees reveal a phloem-generated turgor signal. New Phytologist, 198(4):1143–1154.

·       Meroni, M., Rossini, M., Guanter, L., Alonso, L., Rascher, U., Colombo, R., and Moreno, J. 2009. Remote sensing of solar-induced chlorophyll fluorescence: Review of methods and applications.  Remote Sensing of Environment, 113(10):2037–2051.


·       Michalak, R. 2014. Forest monitoring in europe and its importance to clean air policies and sustainable forest management. In Forests under pressure - Local responses to global issues, chapter 26, page 411.  IUFRO Special Project World Forests, Society and Environment (IUFRO WFSE).


·       Michel, A., Seidling, W., and editors 2014. Forest Condition in Europe: 2014 Technical Report of ICP Forests. Report under the UNECE Convention on Long-Range Transboundary Air Pollution (CLRTAP). Vienna: BFW Austrian Research Centre for Forests. BFW-Dokumentation, 18.


·       Miller, G. R., Chen, X., Rubin, Y., and Baldocchi, D. D. 2007. A new technique for upscaling sap flow transpiration measurements to stand or landscape scale fluxes. American Geophysical Union, Fall Meeting Poster.


·       Misson, L. 2004. Maiden: a model for analyzing ecosystem processes in dendroecology. Canadian Journal of Forest Research, 34(4):874–887.


·       Mooney, H., Cropper, A., and Reid, W. 1996. Ecosystems and human well-being: a framework for assessment.

·       Mooney, H., Larigauderie, A., Cesario, M., Elmquist, T., Hoegh-Guldberg, O., Lavorel, S., Mace, G. M., Palmer, M., Scholes, R., and Yahara, T. 2009. Biodiversity, climate change, and ecosystem services. Current Opinion in Environmental Sustainability, 1(1):46–54.

·       Morales, P., Hickler, T., Rowell, D. P., Smith, B., and Sykes, M. T. 2007. Changes in European ecosystem productivity and carbon balance driven by regional climate model output. Global Change Biology, 13(1):108–122.

·       Morison, J. I. L. and Lawlor, D. W. 1999. Interactions between increasing CO2 concentration and temperature on plant growth. Plant, Cell & Environment, 22(6):659–682.

·       Motohka, T., Nasahara, K. N., Oguma, H., and Tsuchida, S. 2010. Applicability of green-red vegetation index for remote sensing of vegetation phenology. Remote Sensing, 2(10):2369–2387.

·       Nadezhdina, N., Vandegehuchte, M. W., and Steppe, K. 2012. Sap flux density measurements based on the heat field deformation method. Trees, 26(5):1439–1448.

·       Nadrowski, K., Wirth, C., and Scherer-Lorenzen, M. 2010. Is forest diversity driving ecosystem function and service? Current Opinion in Environmental Sustainability, 2(1):75–79.

·       Nobel, P. S. 1976. Photosynthetic rates of sun versus shade leaves of hyptis emoryi torr. Plant Physiology, 58(2):218–223.

·       Pan, Y., Birdsey, R. A., Fang, J., Houghton, R., Kauppi, P. E., Kurz, W. A., Phillips, O. L., Shvidenko, A., Lewis, S. L., Canadell, J. G., et al. 2011. A large and persistent carbon sink in the world’s forests. Science, 333(6045):988–993.

·       Pan, Y., Birdsey, R. A., Phillips, O. L., and Jackson, R. B. 2013. The structure, distribution, and biomass of the world’s forests. Annual Review of Ecology, Evolution, and Systematics, 44:593–622.

·       Pautasso, M., Dehnen-Schmutz, K., Holdenrieder, O., Pietravalle, S., Salama, N., Jeger, M. J., Lange, E., and Hehl-Lange, S. 2010. Plant health and global change–some implications for landscape management. Biological Reviews, 85(4):729–755.

·       Peel, M. C., Finlayson, B. L., and McMahon, T. A. 2007. Updated world map of the Köppen-Geiger climate classification. Hydrology and earth system sciences discussions, 4(2):439–473.

·       Pivovaroff, A. L., Sack, L., and Santiago, L. S. 2014. Coordination of stem and leaf hydraulic con- ductance in southern california shrubs: a test of the hydraulic segmentation hypothesis. New Phytologist, 203(3):842–850.

·       Prentice, I. C., Farquhar, G. D., Fasham, M. J. R., Goulden, M. L., Heimann, M., Jaramillo, V. J., Kheshgi, H. S., LeQue ́re ́, C., Scholes, R. J., and Wallace, D. W. R. 2001. The carbon cycle and atmospheric carbon dioxide. In Climate Change 2001: The Scientific Basis. Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change, chapter 3, pages 184–238. Cambridge University Press.

·       Rainforest Foundation US 2015. Commonly asked questions and facts. http://www.rainforestfoundation.org/commonly-asked-questions-and-facts.

·       Ramoelo, A., Dzikiti, S., van Deventer, H., Maherry, A., Cho, M. A., and Gush, M. 2015. Potential to monitor plant stress using remote sensing tools. Journal of Arid Environments, 113:134– 144.

·       Reddy, A. R., Rasineni, G. K., and Raghavendra, A. S. 2010. The impact of global elevated CO2 concentration on photosynthesis and plant productivity. Current Science, 99(1):46–57.

·       Reyes-Acosta, J. L. and Lubczynski, M. W. 2013. Mapping dry-season tree transpiration of an oak woodland at the catchment scale, using object-attributes derived from satellite imagery and sap flow measurements. Agricultural and forest meteorology, 174:184–201.

·       RMI 2015. Average climate values in ukkel, belgium (1981-2010) from the royal meteorological institute of belgium. http://meteo.be/.

·       Rocha, A. V., Goulden, M. L., Dunn, A. L., and Wofsy, S. C. 2006. On linking interannual tree ring variability with observations of whole-forest CO2 flux. Global Change Biology, 12(8):1378–1389.

·       Samson, R., Nachtergale, L., Schauvliege, M., Lemeur, R., and Lust, N. 1997. Experimental set-up for biogeochemical research in the mixed deciduous forest Aelmoeseneie (East Flanders). Silva Gandavensis, 61:1–14.

·       Sano, Y., Okamura, Y., and Utsumi, Y. 2005. Visualizing water-conduction pathways of living trees: selection of dyes and tissue preparation methods. Tree Physiology, 25(3):269–275.

·       Santos, R. and Bond, S. 2014. New York Asian Longhorned Beetle Eradication Program announces its efforts for 2014. United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service.

·       Sato, T. and Madgwick, H. A. I. 1982. Forest biomass. Springer Science & Business Media.

·       Schaphoff, S., Lucht, W., Gerten, D., Sitch, S., Cramer, W., and Prentice, I. C. 2006. Terrestrial biosphere carbon storage under alternative climate projections. Climatic Change, 74(1-3):97–122.

·       Schelhaas, M.-J., Eggers, J., Lindner, M., Nabuurs, G., Pussinen, A., Païvinen, R., Schuck, A., Verkerk, P., Van der Werf, D., and Zudin, S. 2007. Model documentation for the European forest information scenario model (EFISCEN 3.1. 3). Alterra Wageningen, The Netherlands.


·       Schott, J. 2007. Remote sensing. Oxford University Press.


·       Schowengerdt, R. 2007. Remote sensing: models and methods for image processing. Academic press.

·       Schulze, E.-D., Cermak, J., Matyssek, M., Penka, M., Zimmermann, R., Vasicek, F., Gries, W., and Kucera, J. 1985. Canopy transpiration and water fluxes in the xylem of the trunk of Larix and Picea trees – a comparison of xylem flow, porometer and cuvette measurements. Oecologia, 66(4):475–483.

·       Seidl, R., Schelhaas, M., and Lexer, M. J. 2011. Unraveling the drivers of intensifying forest disturbance regimes in Europe. Global Change Biology, 17(9):2842–2852.

·       Sioen, G. and Roskams, P. 2014. Bosvitaliteitsinventaris 2013. resultaten uit het bosvitaliteitsmeetnet (Level 1). Rapporten van het Instituut voor Natuur- en Bosonderzoek 2014. Instituut voor Natuur- en Bosonderzoek, Brussel.

·       Slik, J. W., Paoli, G., McGuire, K., Amaral, I., Barroso, J., Bastian, M., Blanc, L., Bongers, F., Boundja, P., Clark, C., et al. 2013. Large trees drive forest aboveground biomass variation in moist lowland forests across the tropics. Global Ecology and Biogeography, 22(12):1261–1271.

·       Sonnentag, O., Hufkens, K., Teshera-Sterne, C., Young, A. M., Friedl, M., Braswell, B. H., Milliman, T., O’Keefe, J., and Richardson, A. D. 2012. Digital repeat photography for phenological research in forest ecosystems. Agricultural and Forest Meteorology, 152:159–177.

·       Steppe, K., De Pauw, D. J., and Lemeur, R. 2008. Validation of a dynamic stem diameter vari- ation model and the resulting seasonal changes in calibrated parameter values. Ecological Modelling, 218(3):247–259.

·       Steppe, K., De Pauw, D. J. W., Doody, T. M., and Teskey, R. O. 2010. A comparison of sap flux density using thermal dissipation, heat pulse velocity and heat field deformation methods. Agricultural and Forest Meteorology, 150(7):1046–1056.

·       Steppe, K., De Pauw, D. J. W., Lemeur, R., and Vanrolleghem, P. A. 2006. A mathematical model linking tree sap flow dynamics to daily stem diameter fluctuations and radial stem growth. Tree physiology, 26(3):257–273.

·       Steppe, K. and Lemeur, R. 2004. An experimental system for analysis of the dynamic sap-flow charac- teristics in young trees: results of a beech tree. Functional Plant Biology, 31(1):83–92.

·       Steppe, K. and Lemeur, R. 2007. Effects of ring-porous and diffuse-porous stem wood anatomy on the hydraulic parameters used in a water flow and storage model. Tree physiology, 27(1):43–52.

·       Steppe, K., Sterck, F., and Deslauriers, A. 2015a. Diel growth dynamics in tree stems: linking anatomy and ecophysiology. Trends in Plant Science.

·       Steppe, K., Vandegehuchte, M. W., Tognetti, R., and Mencuccini, M. 2015b. Sap flow as a key trait in the understanding of plant hydraulic functioning. Tree Physiology, 35(4):341–345.

·       Stockmans, F. 1968. V ́eg ́etaux m ́esod ́evoniens r ́ecolt ́es aux confins du massif du Brabant (Belgique). Institut royal des sciences naturelles de Belgique.

·       Stoy, P. C., Richardson, A. D., Baldocchi, D. D., Katul, G. G., Stanovick, J., Mahecha, M. D., Reichstein, M., Detto, M., Law, B. E., Wohlfahrt, G., et al. 2009. Biosphere-atmosphere exchange of CO2 in relation to climate: a cross-biome analysis across multiple time scales. Biogeosciences, 6(10):2297–2312.

·       Taiz, L. and Zeiger, E. 2010. Plant Physiology. Sinauer Associates Inc., 5th revised edition.

·       Thenkabail, P. S., Lyon, J. G., and Huete, A. 2011. Hyperspectral remote sensing of vegetation. CRC Press.


·       Tobin, B. and Nieuwenhuis, M. 2012. Forest carbon research in ireland: The importance of long-term monitoring of forest growth and climate. Earthzine.


·       Tol, C., Berry, J., Campbell, P., and Rascher, U. 2014. Models of fluorescence and photosynthesis for interpreting measurements of solar-induced chlorophyll fluorescence. Journal of Geophysical Research: Biogeosciences.


·       Tyree, M. T. and Ewers, F. W. 1991. The hydraulic architecture of trees and other woody plants. New Phytologist, 119(3):345–360.


·       Uddin, J., Smith, R., Hancock, N., and Foley, J. 2014. Evaluation of sap flow sensors to measure the transpiration rate of plants during canopy wetting and drying. Journal of Agricultural Studies, 2(2):105–119.


·       UNESCO 2014. People and nature — better together. Promotion video https://www.youtube.com/watch? v=5EhLKoAU5Vc.


·       UPRA 2015. Visible vegetation index (vvi) planetary habitability laboratory project. http://phl.upr.edu/projects/visible-vegetation-index-vvi by University of Puerto Rico at Arecibo.


·       van den Honert, T. H. 1948. Water transport in plants as a catenary process. Discuss. Faraday Soc., 3:146–153.


·       Vandegehuchte, M. W. and Steppe, K. 2012a. Improving sap flux density measurements by correctly determining thermal diffusivity, differentiating between bound and unbound water. Tree physiology, 32(7):930–942.


·       Vandegehuchte, M. W. and Steppe, K. 2012b. Interpreting the heat field deformation method: Erroneous use of thermal diffusivity and improved correlation between temperature ratio and sap flux density. Agricultural and Forest Meteorology, 162:91–97.


·       Vandegehuchte, M. W. and Steppe, K. 2012c. Sapflow+: a four-needle heat-pulse sap flow sensor enabling nonempirical sap flux density and water content measurements. New Phytologist, 196(1):306–317.


·       Vandegehuchte, M. W. and Steppe, K. 2013. Sap-flux density measurement methods: working principles and applicability. Functional Plant Biology, 40(3):213–223.


·       Vergeynst, L., Dierick, M., Bogaerts, J., Cnudde, V., and Steppe, K. 2015. Cavitation: a blessing in disguise? new method to establish vulnerability curves and assess hydraulic capacitance of woody tissues. Tree Physiology, 35:400–409.


·       Vicharnakorn, P., Shrestha, R. P., Nagai, M., Salam, A. P., and Kiratiprayoon, S. 2014. Carbon stock assessment using remote sensing and forest inventory data in Savannakhet, Lao PDR. Remote Sensing, 6(6):5452–5479.


·       Watson, R. T., Noble, I. R., Bolin, B., Ravindranath, N. H., Verardo, D. J., Dokken, D. J., et al. 2000. Land use, land-use change and forestry: a special report of the Intergovernmental Panel on Climate Change. Cambridge University Press.


·       Wouters, J., Quataert, P., Onkelinx, T., Bauwens, D., et al. 2008. Ontwerp en handleiding voor de tweede regionale bosinventarisatie van het vlaamse gewest. Report INBO.


·       Yang, J., Gong, P., Fu, R., Zhang, M., Chen, J., Liang, S., Xu, B., Shi, J., and Dickinson, R. 2013. The role of satellite remote sensing in climate change studies. Nature climate change, 3(10):875–883.

·       Zhang, H., Morison, J. I., and Simmonds, L. P. 1999. Transpiration and water relations of poplar trees growing close to the water table. Tree physiology, 19(9):563–573.

·       Zimmermann, M. H. 1983. Xylem structure and the ascent of sap. Springer-Verlag, Berlin.


·       Zweifel, R. 2012. Natkon point dendrometer ZN11-T-WP. Datasheet.


·       Zweifel, R., Eugster, W., Etzold, S., Dobbertin, M., Buchmann, N., and Häsler, R. 2010. Link between continuous stem radius changes and net ecosystem productivity of a subalpine norway spruce forest in the swiss alps. New Phytologist, 187(3):819–830.


·       Zweifel, R., Item, H., and Häsler, R. 2000. Stem radius changes and their relation to stored water in stems of young Norway spruce trees. Trees, 15(1):50–57.


·       Zweifel, R., Item, H., and Häsler, R. 2001. Link between diurnal stem radius changes and tree water relations. Tree Physiology, 21(12-13):869–877.

Universiteit of Hogeschool
Bio-ingenieurswetenschappen
Publicatiejaar
2015
Kernwoorden
Share this on: