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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    The global abundance of tree palms
    Muscarella, Robert ; Emilio, Thaise ; Phillips, Oliver L. ; Lewis, Simon L. ; Slik, Ferry ; Baker, William J. ; Couvreur, Thomas L.P. ; Eiserhardt, Wolf L. ; Svenning, Jens Christian ; Affum-Baffoe, Kofi ; Aiba, Shin Ichiro ; Almeida, Everton C. de; Almeida, Samuel S. de; Oliveira, Edmar Almeida de; Álvarez-Dávila, Esteban ; Alves, Luciana F. ; Alvez-Valles, Carlos Mariano ; Carvalho, Fabrício Alvim ; Guarin, Fernando Alzate ; Andrade, Ana ; Aragão, Luis E.O.C. ; Murakami, Alejandro Araujo ; Arroyo, Luzmila ; Ashton, Peter S. ; Corredor, Gerardo A.A. ; Baker, Timothy R. ; Camargo, Plinio Barbosa de; Barlow, Jos ; Bastin, Jean François ; Bengone, Natacha Nssi ; Berenguer, Erika ; Berry, Nicholas ; Blanc, Lilian ; Böhning-Gaese, Katrin ; Bonal, Damien ; Bongers, Frans ; Bradford, Matt ; Brambach, Fabian ; Brearley, Francis Q. ; Brewer, Steven W. ; Camargo, Jose L.C. ; Campbell, David G. ; Castilho, Carolina V. ; Castro, Wendeson ; Catchpole, Damien ; Cerón Martínez, Carlos E. ; Chen, Shengbin ; Chhang, Phourin ; Cho, Percival ; Chutipong, Wanlop ; Clark, Connie ; Collins, Murray ; Comiskey, James A. ; Medina, Massiel Nataly Corrales ; Costa, Flávia R.C. ; Culmsee, Heike ; David-Higuita, Heriberto ; Davidar, Priya ; Aguila-Pasquel, Jhon del; Derroire, Géraldine ; Fiore, Anthony Di; Do, Tran Van; Doucet, Jean Louis ; Dourdain, Aurélie ; Drake, Donald R. ; Ensslin, Andreas ; Erwin, Terry ; Ewango, Corneille E.N. ; Ewers, Robert M. ; Fauset, Sophie ; Feldpausch, Ted R. ; Ferreira, Joice ; Ferreira, Leandro Valle ; Fischer, Markus ; Franklin, Janet ; Fredriksson, Gabriella M. ; Gillespie, Thomas W. ; Gilpin, Martin ; Gonmadje, Christelle ; Gunatilleke, Arachchige Upali Nimal ; Hakeem, Khalid Rehman ; Hall, Jefferson S. ; Hamer, Keith C. ; Harris, David J. ; Harrison, Rhett D. ; Hector, Andrew ; Hemp, Andreas ; Herault, Bruno ; Pizango, Carlos Gabriel Hidalgo ; Honorio Coronado, Eurídice N. ; Hubau, Wannes ; Hussain, Mohammad Shah ; Ibrahim, Faridah Hanum ; Imai, Nobuo ; Joly, Carlos A. ; Joseph, Shijo ; Anitha, K. ; Kartawinata, Kuswata ; Kassi, Justin ; Killeen, Timothy J. ; Kitayama, Kanehiro ; Klitgård, Bente Bang ; Kooyman, Robert ; Labrière, Nicolas ; Larney, Eileen ; Laumonier, Yves ; Laurance, Susan G. ; Laurance, William F. ; Lawes, Michael J. ; Levesley, Aurora ; Lisingo, Janvier ; Lovejoy, Thomas ; Lovett, Jon C. ; Lu, Xinghui ; Lykke, Anne Mette ; Magnusson, William E. ; Mahayani, Ni Putu Diana ; Malhi, Yadvinder ; Mansor, Asyraf ; Peña, Jose Luis Marcelo ; Marimon-Junior, Ben H. ; Marshall, Andrew R. ; Melgaco, Karina ; Bautista, Casimiro Mendoza ; Mihindou, Vianet ; Millet, Jérôme ; Milliken, William ; Mohandass, D. ; Mendoza, Abel Lorenzo Monteagudo ; Mugerwa, Badru ; Nagamasu, Hidetoshi ; Nagy, Laszlo ; Seuaturien, Naret ; Nascimento, Marcelo T. ; Neill, David A. ; Neto, Luiz Menini ; Nilus, Rueben ; Vargas, Mario Percy Núñez ; Nurtjahya, Eddy ; Araújo, R.N.O. de; Onrizal, Onrizal ; Palacios, Walter A. ; Palacios-Ramos, Sonia ; Parren, Marc ; Paudel, Ekananda ; Morandi, Paulo S. ; Pennington, R.T. ; Pickavance, Georgia ; Pipoly, John J. ; Pitman, Nigel C.A. ; Poedjirahajoe, Erny ; Poorter, Lourens ; Poulsen, John R. ; Prasad, P.R.C. ; Prieto, Adriana ; Puyravaud, Jean Philippe ; Qie, Lan ; Quesada, Carlos A. ; Ramírez-Angulo, Hirma ; Razafimahaimodison, Jean Claude ; Reitsma, Jan Meindert ; Requena-Rojas, Edilson J. ; Correa, Zorayda Restrepo ; Rodriguez, Carlos Reynel ; Roopsind, Anand ; Rovero, Francesco ; Rozak, Andes ; Lleras, Agustín Rudas ; Rutishauser, Ervan ; Rutten, Gemma ; Punchi-Manage, Ruwan ; Salomão, Rafael P. ; Sam, Hoang Van; Sarker, Swapan Kumar ; Satdichanh, Manichanh ; Schietti, Juliana ; Schmitt, Christine B. ; Marimon, Beatriz Schwantes ; Senbeta, Feyera ; Nath Sharma, Lila ; Sheil, Douglas ; Sierra, Rodrigo ; Silva-Espejo, Javier E. ; Silveira, Marcos ; Sonké, Bonaventure ; Steininger, Marc K. ; Steinmetz, Robert ; Stévart, Tariq ; Sukumar, Raman ; Sultana, Aisha ; Sunderland, Terry C.H. ; Suresh, Hebbalalu Satyanarayana ; Tang, Jianwei ; Tanner, Edmund ; Steege, Hans ter; Terborgh, John W. ; Theilade, Ida ; Timberlake, Jonathan ; Torres-Lezama, Armando ; Umunay, Peter ; Uriarte, María ; Gamarra, Luis Valenzuela ; Bult, Martin van de; Hout, Peter van der; Martinez, Rodolfo Vasquez ; Vieira, Ima Célia Guimarães ; Vieira, Simone A. ; Vilanova, Emilio ; Cayo, Jeanneth Villalobos ; Wang, Ophelia ; Webb, Campbell O. ; Webb, Edward L. ; White, Lee ; Whitfeld, Timothy J.S. ; Wich, Serge ; Willcock, Simon ; Wiser, Susan K. ; Young, Kenneth R. ; Zakaria, Rahmad ; Zang, Runguo ; Zartman, Charles E. ; Zo-Bi, Irié Casimir ; Balslev, Henrik - \ 2020
    Global Ecology and Biogeography 29 (2020)9. - ISSN 1466-822X - p. 1495 - 1514.
    above-ground biomass - abundance patterns - Arecaceae - local abiotic conditions - Neotropics - pantropical biogeography - tropical rainforest - wood density

    Aim: Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change. Location: Tropical and subtropical moist forests. Time period: Current. Major taxa studied: Palms (Arecaceae). Methods: We assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ≥10 cm diameter at breast height) abundance relative to co-occurring non-palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure. Results: On average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long-term climate stability. Life-form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non-tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above-ground biomass, but the magnitude and direction of the effect require additional work. Conclusions: Tree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests.

    Seasonal drought limits tree species across the Neotropics
    Esquivel-Muelbert, Adriane ; Baker, Timothy R. ; Dexter, Kyle G. ; Lewis, Simon L. ; Steege, Hans ter; Lopez-Gonzalez, Gabriela ; Monteagudo Mendoza, Abel ; Brienen, Roel ; Feldpausch, Ted R. ; Pitman, Nigel ; Alonso, Alfonso ; Heijden, Geertje van der; Peña-Claros, Marielos ; Ahuite, Manuel ; Alexiaides, Miguel ; Álvarez Dávila, Esteban ; Murakami, Alejandro Araujo ; Arroyo, Luzmila ; Aulestia, Milton ; Balslev, Henrik ; Barroso, Jorcely ; Boot, Rene ; Cano, Angela ; Chama Moscoso, Victor ; Comiskey, James A. ; Cornejo, Fernando ; Dallmeier, Francisco ; Daly, Douglas C. ; Dávila, Nallarett ; Duivenvoorden, Joost F. ; Duque Montoya, Alvaro Javier ; Erwin, Terry ; Fiore, Anthony Di; Fredericksen, Todd ; Fuentes, Alfredo ; García-Villacorta, Roosevelt ; Gonzales, Therany ; Guevara Andino, Juan Ernesto ; Honorio Coronado, Euridice N. ; Huamantupa-Chuquimaco, Isau ; Killeen, Timothy J. ; Malhi, Yadvinder ; Mendoza, Casimiro ; Mogollón, Hugo ; Jørgensen, Peter Møller ; Montero, Juan Carlos ; Mostacedo, Bonifacio ; Nauray, William ; Neill, David ; Vargas, Percy Núñez ; Palacios, Sonia ; Palacios Cuenca, Walter ; Pallqui Camacho, Nadir Carolina ; Peacock, Julie ; Phillips, Juan Fernando ; Pickavance, Georgia ; Quesada, Carlos Alberto ; Ramírez-Angulo, Hirma ; Restrepo, Zorayda ; Reynel Rodriguez, Carlos ; Paredes, Marcos Ríos ; Sierra, Rodrigo ; Silveira, Marcos ; Stevenson, Pablo ; Stropp, Juliana ; Terborgh, John ; Tirado, Milton ; Toledo, Marisol ; Torres-Lezama, Armando ; Umaña, María Natalia ; Urrego, Ligia Estela ; Vasquez Martinez, Rodolfo ; Gamarra, Luis Valenzuela ; Vela, César I.A. ; Vilanova Torre, Emilio ; Vos, Vincent ; Hildebrand, Patricio von; Vriesendorp, Corine ; Wang, Ophelia ; Young, Kenneth R. ; Zartman, Charles Eugene ; Phillips, Oliver L. - \ 2017
    Ecography 40 (2017)5. - ISSN 0906-7590 - p. 618 - 629.
    Within the tropics, the species richness of tree communities is strongly and positively associated with precipitation. Previous research has suggested that this macroecological pattern is driven by the negative effect of water-stress on the physiological processes of most tree species. This implies that the range limits of inventory plots of closed canopy forest distributed across the western Neotropics taxa are defined by their ability to occur under dry conditions, and thus in terms of species distributions predicts a nested pattern of taxa distribution from wet to dry areas. However, this 'dry-tolerance' hypothesis has yet to be adequately tested at large spatial and taxonomic scales. Here, using a dataset of 531 we investigated how precipitation, evaluated both as mean annual precipitation and as the maximum climatological water deficit, influences the distribution of tropical tree species, genera and families. We find that the distributions of tree taxa are indeed nested along precipitation gradients in the western Neotropics. Taxa tolerant to seasonal drought are disproportionally widespread across the precipitation gradient, with most reaching even the wettest climates sampled; however, most taxa analysed are restricted to wet areas. Our results suggest that the 'dry tolerance' hypothesis has broad applicability in the world's most species-rich forests. In addition, the large number of species restricted to wetter conditions strongly indicates that an increased frequency of drought could severely threaten biodiversity in this region. Overall, this study establishes a baseline for exploring how tropical forest tree composition may change in response to current and future environmental changes in this region.
    Efectos ecológicos del cambio de uso del suelo en el espacio natural de la Sierra de Ancares (León). Análisis de cambios mediante sig y teledetección; Efectos ecológicos del uso del paisaje en la comarca de Ancares
    Alvarez Martinez, J.M. ; Suarez-Seoane, S. ; Stoorvogel, J.J. ; Luis Calabuig, E. de - \ 2011
    In: La evolución del paisaje vegetal y el uso del fuego en la Cordillera Cantábrica / Ezquerra Boticario, F.J., van den Bercken, E.R., Valladolid : Fundacíon Patrimonio Natural de Castilla y León - ISBN 9788469435434 - p. 265 - 282.
    Agronomic, economic and ecological aspects of the papaya (Carica papaya) production in Tabasco, Mexico
    Guzmán-Ramón, E. ; Gómez-Alvarez, R. ; Pat-Fernández, J.M. ; Pohlan, H.A.J. ; Álvarez-Rivero, J.C. ; Geissen, V. - \ 2010
    African Journal of Plant Science 4 (2010)4. - ISSN 1996-0824 - p. 99 - 106.
    The cultivation of papaya is important in the tropic because it provides source of income to the farmer within a short time. Statistical data were obtained from farmers located in the Chontalpa, Rios and Centro-Sierra regions; the size of the survey was 67 farmers. The study shows the results of the farmers’ problem in a drastic reduction of their productivity because of the virosis and low prices in commercialization. The farmers were classified into three levels of technology, “low”, “middle” and “high”. The first one covers 88% of the farmers in seasonal conditions in contrast with the high technology that concentrates 4.5% in irrigation conditions. According to the technology used, the fertilizer shows more yields. Economically, the high technology had an internal tax return of 0.43 in comparison with the low technology of 0.25, which means that the investment is recovered with different yields. However, the use of high technology makes the system more competitive. Key words:
    Uncertainty analysis as a tool for refining land dynamics modelling on changing landscapes: a case study in a Spanish Natural Park
    Álvarez-Martínez, J.M. ; Stoorvogel, J.J. ; Suárez-Seoane, S. ; Luis Calabuig, E. de - \ 2010
    Landscape Ecology 25 (2010)9. - ISSN 0921-2973 - p. 1385 - 1404.
    thematic classification accuracy - remote-sensing imagery - cover change - fuzzy classification - vegetation change - driving forces - satellite data - sensed data - tm data - fire
    In this study we developed a methodology aimed at improving the assessment of inter-annual land cover dynamics from hard classified remotely sensed data in heterogeneous and resilient landscapes. The methodology is implemented for the Spanish Natural Park of Sierra de Ancares, where human interference during the last century has resulted in the destruction and fragmentation of the original land cover. We ran supervised classifications, with a maximum likelihood algorithm (Maxlike), on a temporal series of Landsat images (1991–2005), followed by an uncertainty assessment using fuzzy classifications and confusion indices (CIs). This allowed us to show how much (and where) of the resulting maps contained a substantial amount of error, distinguishing data that might be useful to measure land change from data that are not particularly useful when applying a post-classification comparison methodology. In this way, we can detect true changes not skewed by the effects of uncertainty. Even if patterns of change were always coherent amongst years, they were more realistic after reducing uncertainty, in spite of a substantial decrease in the number of available pixels (i.e. unmasked by the method). We then computed land cover dynamics by means of a model specifically designed to determine the frequency of disturbances (mainly fire events) and the vegetation recovery time during the study period. Model outputs showed correlated landscape patterns at a broad scale and provided useful results to explore land cover change from pattern to process
    Transgenes in Mexican maize: molecular evidence and methodological considerations for GMO detection in landrace populations
    Pineyro-Nelson, A. ; Heerwaarden, J. van; Perales, H.R. ; Serratos-Hernandez, J.A. ; Rangel, A. ; Hufford, M.B. ; Gepts, P. ; Garay-Arroyo, A. ; Rivera-Bustamante, R. ; Alvarez-Buylla, E.R. - \ 2009
    Molecular Ecology 18 (2009)4. - ISSN 0962-1083 - p. 750 - 761.
    bentgrass agrostis-stolonifera - biodiversity communications - (trans)gene flow - crop origin - gene flow - diversity - pollen - establishment - evolution - centers
    A possible consequence of planting genetically modified organisms (GMOs) in centres of crop origin is unintended gene flow into traditional landraces. In 2001, a study reported the presence of the transgenic 35S promoter in maize landraces sampled in 2000 from the Sierra Juarez of Oaxaca, Mexico. Analysis of a large sample taken from the same region in 2003 and 2004 could not confirm the existence of transgenes, thereby casting doubt on the earlier results. These two studies were based on different sampling and analytical procedures and are thus hard to compare. Here, we present new molecular data for this region that confirm the presence of transgenes in three of 23 localities sampled in 2001. Transgene sequences were not detected in samples taken in 2002 from nine localities, while directed samples taken in 2004 from two of the positive 2001 localities were again found to contain transgenic sequences. These findings suggest the persistence or re-introduction of transgenes up until 2004 in this area. We address variability in recombinant sequence detection by analyzing the consistency of current molecular assays. We also present theoretical results on the limitations of estimating the probability of transgene detection in samples taken from landraces. The inclusion of a limited number of female gametes and, more importantly, aggregated transgene distributions may significantly lower detection probabilities. Our analytical and sampling considerations help explain discrepancies among different detection efforts, including the one presented here, and provide considerations for the establishment of monitoring protocols to detect the presence of transgenes among structured populations of landraces
    Molecular characterization of mesophilic and thermophilic sulfate reducing microbial communities in expanded granular sludge bed (EGSB) reactors
    Freeman, S.A. ; Sierra-Alvarez, R. ; Altinbas, M. ; Hollingsworth, J. ; Stams, A.J.M. ; Smidt, H. - \ 2008
    Biodegradation 19 (2008)2. - ISSN 0923-9820 - p. 161 - 177.
    16s ribosomal-rna - gradient gel-electrophoresis - sp-nov. - gen.-nov. - polyethylene-glycol - fatty-acid - methylotrophic methanogen - fermentative degradation - desulfococcus-biacutus - pelobacter-venetianus
    The microbial communities established in mesophilic and thermophilic expanded granular sludge bed reactors operated with sulfate as the electron acceptor were analyzed using 16S rRNA targeted molecular methods, including denaturing gradient gel electrophoresis, cloning, and phylogenetic analysis. Bacterial and archaeal communities were examined over 450 days of operation treating ethanol (thermophilic reactor) or ethanol and later a simulated semiconductor manufacturing wastewater containing citrate, isopropanol, and polyethylene glycol 300 (mesophilic reactor), with and without the addition of copper(II). Analysis, of PCR-amplified 16S rRNA gene fragments using denaturing gradient gel electrophoresis revealed a defined shift in microbial diversity in both reactors following a change in substrate composition (mesophilic reactor) and in temperature of operation from 30 degrees C to 55 degrees C (thermophilic reactor). The addition of copper(II) to the influent of both reactors did not noticeably affect the composition of the bacterial or archaeal communities, which is in agreement with the very low soluble copper concentrations (3-310 microg l(-1)) present in the reactor contents as a consequence of extensive precipitation of copper with biogenic sulfides. Furthermore, clone library analysis confirmed the phylogenetic diversity of sulfate-reducing consortia in mesophilic and thermophilic sulfidogenic reactors operated with simple substrates
    Fungal Biotransormation Products of Dehydroabietic Acid
    Beek, T.A. van; Claassen, F.W. ; Dorado, J. ; Godejohann, M. ; Sierra-Alvarez, R. ; Wijnberg, J.B.P.A. - \ 2007
    Journal of Natural Products 70 (2007)2. - ISSN 0163-3864 - p. 154 - 159.
    pseudomonas-abietaniphila bkme-9 - mill effluent - kraft pulp - mortierella-isabellina - bacterial degradation - resin acids - paper-mill - hydroxylation - diterpenoids - constituents
    Dehydroabietic acid (DHA) (1) is one of the main compounds in Scots pine wood responsible for aquatic and microbial toxicity. The degradation of 1 by Trametes versicolor and Phlebiopsis gigantea in liquid stationary cultures was followed by HPLC-DAD-ELSD. Both fungi rapidly degraded DHA relative to a control. More breakdown products were observed for T. versicolor than for P. gigantea. After 13 days, four compounds were identified by means of spectroscopic methods in P. gigantea cultures: 1 beta-hydroxy-DHA (2), 1 beta,7 alpha-dihydroxy-DHA (3), 1 beta,16-dihydroxy-DHA (5), and tentatively 1 beta-hydroxy-7-oxo-DHA (4). In T. versicolor cultures, 1 beta,16-dihydroxy-DHA (5), 7 beta,16-dihydroxy-DHA (6), 1 beta,7 beta,16-trihydroxy-DHA (7), 1 beta,16-dihydroxy-7-oxo-DHA (8), 1 beta,15-dihydroxy-DHA (9), and 1 beta,7 alpha,16-trihydroxy-DHA (10) were identified after 9 days of incubation. Thus the biotransformation of 1 by the two fungi was different, with only 5 being produced by both strains. Compounds 3, 7, 8, and 10 are reported for the first time as natural products.
    Fungal bio-treatment of spruce wood with Trametes versicolor for pitch control: Influence on extractive contents, pulping process parameters, paper quality and effluent toxicity
    Beek, T.A. van; Kuster, B. ; Claassen, F.W. ; Tienvieri, T. ; Bertaud, F. ; Lennon, G. ; Petit-Concil, M. ; Sierra-Alvarez, R. - \ 2007
    Bioresource Technology 98 (2007)2. - ISSN 0960-8524 - p. 302 - 311.
    white-rot fungi - mills - detoxification - chromatography - degradation
    Lipophilic low molar-mass constituents in wood chips for the paper industry result in low quality pulp, pitch deposition, and effluent toxicity. New biotechnological solutions such as fungal pre-treatment of wood chips can reduce pitch problems. This laboratory-scale study focuses on the potential and limitations of a fungal bio-treatment of Norway spruce chips with the white-rot fungus Trametes versicolor. Different fungal treatment conditions were compared. A 4-week fungal treatment reduced the concentration of resin acids and triglycerides by 40% and 100%, respectively, but neither lowered the energy requirements of the TMP process nor significantly affected the morphological fiber characteristics and the physical pulp properties. The pre-treatment led to slightly poorer optical properties. The Trametes versicolor fungal treatment contributed to a less toxic effluent and improved the biodegradability. A treatment of 2-3 weeks appears optimal
    A non-destructive approach for assessing decay in preservative treated wood
    Machek, L. ; Edlund, M.L. ; Sierra-Alvarez, R. ; Militz, H. - \ 2004
    Wood Science and Technology 37 (2004)5. - ISSN 0043-7719 - p. 411 - 417.
    This study investigated the suitability of the non-destructive vibration-impulse excitation technique to assess the attack of preservative-treated wood in contact with the ground. Small stakes (10×5×100 mm3) of treated and untreated Scots pine sapwood were exposed to decay in laboratory-scale terrestrial ecosystems. Different soils were used to prove the influence of different types of wood destroying micro-organisms. Wood decay was monitored periodically for one year by determining mass losses and changes in dynamic modulus of elasticity. The results show a large variability in resistance against attacking fungi, depending on wood preservative and soil type. The non-destructive approach using the dynamic modulus of elasticity proved to be a good and sensitive tool for assessing the attack of stakes in laboratory soil testing
    Biological durability of wood in relation to end-use - Part 1. Towards a European standard for laboratory testing of the biological durability of wood
    Acker, J. Van; Stevens, M. ; Carey, J. ; Sierra-Alvarez, R. ; Militz, H. ; Bayon, I. Le; Kleist, G. ; Peek, R.D. - \ 2003
    Holz als Roh- und Werkstoff 61 (2003)1. - ISSN 0018-3768 - p. 35 - 45.
    The determination of biological durability of wood is an issue requiring sufficient reliability regarding end-use related prediction of performance. Five test institutes joined efforts to check standard test methods and to improve methodology and data interpretation for assessment of natural durability of timber species. A range of softwood and hardwood species was tested using both basidiomycete and soil soft rot testing. Based on combined processing of all data collected, an improved and simplified durability classification system was established. The test methods and the interpretation of results are proposed to be used to assess suitability and service life for applications under European hazard class 3 and 4. The methodology for basidiomycete testing only requires two test fungi and allows direct classification based on median mass loss, while for soil bed testing, which is only required when hazard class 4 applications are envisaged, a slightly more complicated approach proved to be necessary mainly due to variation in test soil parameters. Since service life can be based on natural durability classes, it is evident that these are identified differently for uses in or out of ground contact and for softwoods or hardwoods
    The influence of wood moisture content on dynamic modulus of elasticity measurements in durability testing
    Machek, L. ; Militz, H. ; Sierra-Alvarez, R. - \ 2001
    Holzforschung und Holzverwertung 2001 (2001)5. - ISSN 0018-3849 - p. 97 - 100.
    Natural decay resistance of Teak wood from Brazilian origin against soft-rot fungi and soil-inhabiting micro-organisms
    Laming, P.B. ; Sierra-Alvarez, R. - \ 2001
    Journal of tropical forest products 7 (2001)2. - ISSN 1394-2204 - p. 207 - 211.
    The use of an acoustic technique to assess wood decay in laboratory soil-bed tests
    Machek, L. ; Militz, H. ; Sierra-Alvarez, R. - \ 2001
    Wood Science and Technology 34 (2001). - ISSN 0043-7719 - p. 467 - 472.
    This study assesses the changes in elastic behaviour (i.e. modulus of elasticity - MOE) and mass loss of different hardwood and softwood species exposed to decay in laboratory soil-bed tests. Elasticity moduli were determined using conventional static methods as well as a dynamic method based on flexural vibration. The results obtained show a high correlation between dynamic and static bending measurements for all the timber species tested at different stages of fungal decay. Furthermore, the non-destructive MOE assessment proved to be a good tool for the early detection of wood decay.
    Utilización de hongos ligninoliticos para el control del pitch en la indústria papelera
    Dorado, J. ; Sierra-Alvarez, R. ; Claassen, F.W. ; Beek, T.A. van - \ 2001
    Afinidad 493 (2001). - ISSN 0001-9704 - p. 175 - 180.
    Degradation of lipophilic wood extractive constituents in Pinus sylvestris by the white-rot fungi Bjerkandera sp. and Trametes versicolor
    Dorado, J. ; Beek, T.A. van; Claassen, F.W. ; Sierra-Alvarez, R. - \ 2001
    Wood Science and Technology 35 (2001). - ISSN 0043-7719 - p. 117 - 125.
    The white-rot fungi Trametes versicolor and Bjerkandera spp. are among the most frequent decomposers of angiosperm wood in forest ecosystems and in wood products in service. Wood extractives have a major impact on wood properties and wood utilization. This work evaluated the ability of two white-rot fungal strains (Bjerkandera sp. strain BOS55 and T. versicolor strain LaVec94-6) to degrade the main lipophilic extractive constituents in Scots pine (Pinus sylvestris L.). The time course of wood decay and wood extractive degradation was monitored in stationary batch assays incubated for eight weeks. The strains tested eliminated high levels of total resin, 34 to 51␒n two weeks. Wood triglycerides were the most readily degraded extractive components (over 93␎limination in only two weeks). Free fatty acids and resin acids, which are potential fungal inhibitors, were also rapidly decomposed by the fungal strains. Sterols were used more slowly, nonetheless, the fungal degradation of this extractive fraction ranged from 50 to 88 after four weeks.
    Removal and transformation of toxic resin acids by wood-inhabiting fungi
    Sierra-Alvarez, R. ; Dorado, J. ; Lenon, G. ; Claassen, F.W. ; Beek, T.A. van; Wijnberg, H.B.P.A. - \ 2000
    In: tappi.org/00pulping.asp : Pulping./Process & Product Quality Conference, Shereton Boston, Boston, Ma USA, 5-8 November 2000
    Evaluation of fungal capacity for detoxification of extractives in Scots pine sapwood
    Martinez-Inigo, M.J. ; Claassen, F.W. ; Joseleau, B. ; Beek, T.A. van; Lenon, G. ; Sierra-Alvarez, R. - \ 2000
    Environmental Technology 21 (2000). - ISSN 0959-3330 - p. 569 - 575.
    Ninety wood-inhabiting fungi were screened for their ability to degrade and detoxify acetone extractives in Scots pine (Pinus sylvestris L.) sapwood under solid-state fermentation conditions. Fungal degradation of resin acids and long-chain fatty acids was investigated by high pressure liquid chromatography with evaporative light scattering detection (HPLC-ELSD) and the toxicity of the acetone soluble fraction of wood measured by Microtox assay. Discriminant analysis of data showed different patterns of extractive detoxification for white-rot basidiomycetes and sapstain fungi. The major detoxification skills of basidiomycetes appeared to be related to the highest degradation of resin acids, and particularly dehydroabietic acid. Among them, Ischnoderma benzoinum, Stereum sanguinolentum and Trametes versicolor greatly reduced the sapwood toxicity due to acetone extractives from the EC50 value of 0.08 mg wood ml-1 to levels between 5-10 mg wood ml-1.
    Degradation and detoxification of softwood extractives by sapstain fungi
    Dorado, J. ; Claassen, F.W. ; Lenon, G. ; Beek, T.A. van; Wijnberg, J.B.P.A. ; Sierra-Alvarez, R. - \ 2000
    Bioresource Technology 71 (2000). - ISSN 0960-8524 - p. 13 - 20.
    Wood extractives (resin) cause pitch deposition problems and effluent toxicity in pulp and papermaking. The ability of six sapstaining fungi to degrade and detoxify extractive constituents in Scots pine sapwood was examined, and the results were compared with those obtained with the commercial depitching fungus Cartapip (Ophiostoma piliferum). Pestalotiopsis crassiuscula and O. piliferum were the best strains and they provided high reductions of total resin (50–60␒n 6 weeks). Both strains were highly effective in the degradation of individual extractive components including triglycerides, diglycerides and free fatty acids. Although all strains displayed moderate to high pitch degradation, their detoxifying capacity was limited. Two important exceptions were Ceratocystis deltoideospora and O. piliferum that caused a 11–14-fold decrease in toxicity (Microtox bioassay). These results indicate the potential of wood pretreatment with the selected sapstain fungi for minimizing pitch problems and decreasing effluent toxicity in pulping.
    Elimination and detoxification of softwood extractives by white-rot fungi
    Dorado, J. ; Claassen, F.W. ; Beek, T.A. van; Lenon, G. ; Wijnberg, J.B.P.A. ; Sierra-Alvarez, R. - \ 2000
    Journal of Biotechnology 80 (2000). - ISSN 0168-1656 - p. 231 - 240.
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