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 (2020). - ISSN 1466-822X
    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.

    Salt equilibria in nutritional formulae for infants and young children
    Huppertz, Thom ; Timmer, Christel - \ 2020
    International Dairy Journal 110 (2020). - ISSN 0958-6946

    The distribution of Ca, Mg, K and Na between the sedimentable (200×g), protein-associated and soluble phase of infant formula (IF; n = 46), follow-on formula (FOF; n = 8), junior growing up milk (jGUM; n = 22) and senior GUM (sGUM; n = 16) were studied. For all product classes, virtually all Na and K was in the soluble phase and small amounts were found as protein-associated, i.e., as counterions. Most Mg was also found in the soluble phase, but a notable proportion (20–30%) was found to be protein-associated. Sedimentable Mg was only found in a few samples. Particularly in IF and FOF products, notable amounts of sedimentable Ca were observed; the proportion of protein-associated Ca increased with increasing casein content of samples, but even after correction for casein content, large differences (>2-fold) remained between products. These differences in casein mineralisation can affect physicochemical properties and colloidal stability.

    Biased-corrected richness estimates for the Amazonian tree flora
    Steege, Hans ter; Prado, Paulo I. ; Lima, Renato A.F. de; Pos, Edwin ; Souza Coelho, Luiz de; Andrade Lima Filho, Diogenes de; Salomão, Rafael P. ; Amaral, Iêda Leão ; Almeida Matos, Francisca Dionízia de; Castilho, Carolina V. ; Phillips, Oliver L. ; Guevara, Juan Ernesto ; Jesus Veiga Carim, Marcelo de; Cárdenas López, Dairon ; Magnusson, William E. ; Wittmann, Florian ; Martins, Maria Pires ; Sabatier, Daniel ; Irume, Mariana Victória ; Silva Guimarães, José Renan da; Molino, Jean François ; Bánki, Olaf S. ; Piedade, Maria Teresa Fernandez ; Pitman, Nigel C.A. ; Ramos, José Ferreira ; Monteagudo Mendoza, Abel ; Venticinque, Eduardo Martins ; Luize, Bruno Garcia ; Núñez Vargas, Percy ; Silva, Thiago Sanna Freire ; Leão Novo, Evlyn Márcia Moraes de; Reis, Neidiane Farias Costa ; Terborgh, John ; Manzatto, Angelo Gilberto ; Casula, Katia Regina ; Honorio Coronado, Euridice N. ; Montero, Juan Carlos ; Duque, Alvaro ; Costa, Flávia R.C. ; Castaño Arboleda, Nicolás ; Schöngart, Jochen ; Zartman, Charles Eugene ; Killeen, Timothy J. ; Marimon, Beatriz S. ; Marimon-Junior, Ben Hur ; Vasquez, Rodolfo ; Mostacedo, Bonifacio ; Demarchi, Layon O. ; Feldpausch, Ted R. ; Engel, Julien ; Petronelli, Pascal ; Baraloto, Chris ; Assis, Rafael L. ; Castellanos, Hernán ; Simon, Marcelo Fragomeni ; Medeiros, Marcelo Brilhante de; Quaresma, Adriano ; Laurance, Susan G.W. ; Rincón, Lorena M. ; Andrade, Ana ; Sousa, Thaiane R. ; Camargo, José Luís ; Schietti, Juliana ; Laurance, William F. ; Queiroz, Helder Lima de; Nascimento, Henrique Eduardo Mendonça ; Lopes, Maria Aparecida ; Sousa Farias, Emanuelle de; Magalhães, José Leonardo Lima ; Brienen, Roel ; Aymard C, Gerardo A. ; Revilla, Juan David Cardenas ; Vieira, Ima Célia Guimarães ; Cintra, Bruno Barçante Ladvocat ; Stevenson, Pablo R. ; Feitosa, Yuri Oliveira ; Duivenvoorden, Joost F. ; Mogollón, Hugo F. ; Araujo-Murakami, Alejandro ; Ferreira, Leandro Valle ; Lozada, José Rafael ; Comiskey, James A. ; Toledo, José Julio de; Damasco, Gabriel ; Dávila, Nállarett ; Lopes, Aline ; García-Villacorta, Roosevelt ; Draper, Freddie ; Vicentini, Alberto ; Cornejo Valverde, Fernando ; Lloyd, Jon ; Gomes, Vitor H.F. ; Neill, David ; Alonso, Alfonso ; Dallmeier, Francisco ; Souza, Fernanda Coelho de; Maas, Paul ; Baker, Tim R. ; Andel, Tinde R. van; Noronha, Janaína Costa ; Barbosa, Edelcilio Marques ; Malhi, Yadvinder ; Tirado, Milton ; Wang, Ophelia ; Nascimento, Marcelo Trindade ; Flores, Bernardo Monteiro - \ 2020
    Scientific Reports 10 (2020)1. - ISSN 2045-2322

    Amazonian forests are extraordinarily diverse, but the estimated species richness is very much debated. Here, we apply an ensemble of parametric estimators and a novel technique that includes conspecific spatial aggregation to an extended database of forest plots with up-to-date taxonomy. We show that the species abundance distribution of Amazonia is best approximated by a logseries with aggregated individuals, where aggregation increases with rarity. By averaging several methods to estimate total richness, we confirm that over 15,000 tree species are expected to occur in Amazonia. We also show that using ten times the number of plots would result in an increase to just ~50% of those 15,000 estimated species. To get a more complete sample of all tree species, rigorous field campaigns may be needed but the number of trees in Amazonia will remain an estimate for years to come.

    Competition influences tree growth, but not mortality, across environmental gradients in Amazonia and tropical Africa
    Rozendaal, Danaë M.A. ; Phillips, Oliver L. ; Lewis, Simon L. ; Affum-Baffoe, Kofi ; Alvarez-Davila, Esteban ; Andrade, Ana ; Aragão, Luiz E.O.C. ; Araujo-Murakami, Alejandro ; Baker, Timothy R. ; Bánki, Olaf ; Brienen, Roel J.W. ; Camargo, José Luis C. ; Comiskey, James A. ; Djuikouo Kamdem, Marie Noël ; Fauset, Sophie ; Feldpausch, Ted R. ; Killeen, Timothy J. ; Laurance, William F. ; Laurance, Susan G.W. ; Lovejoy, Thomas ; Malhi, Yadvinder ; Marimon, Beatriz S. ; Marimon Junior, Ben Hur ; Marshall, Andrew R. ; Neill, David A. ; Núñez Vargas, Percy ; Pitman, Nigel C.A. ; Poorter, Lourens ; Reitsma, Jan ; Silveira, Marcos ; Sonké, Bonaventure ; Sunderland, Terry ; Taedoumg, Hermann ; Steege, Hans ter; Terborgh, John W. ; Umetsu, Ricardo K. ; Heijden, Geertje M.F. van der; Vilanova, Emilio ; Vos, Vincent ; White, Lee J.T. ; Willcock, Simon ; Zemagho, Lise ; Vanderwel, Mark C. - \ 2020
    Ecology 101 (2020)7. - ISSN 0012-9658
    climatic water deficit - competition - forest dynamics - mortality - neighborhood effects - soil fertility - trait-based models - tree growth - tropical forest - wood density

    Competition among trees is an important driver of community structure and dynamics in tropical forests. Neighboring trees may impact an individual tree’s growth rate and probability of mortality, but large-scale geographic and environmental variation in these competitive effects has yet to be evaluated across the tropical forest biome. We quantified effects of competition on tree-level basal area growth and mortality for trees ≥10-cm diameter across 151 ~1-ha plots in mature tropical forests in Amazonia and tropical Africa by developing nonlinear models that accounted for wood density, tree size, and neighborhood crowding. Using these models, we assessed how water availability (i.e., climatic water deficit) and soil fertility influenced the predicted plot-level strength of competition (i.e., the extent to which growth is reduced, or mortality is increased, by competition across all individual trees). On both continents, tree basal area growth decreased with wood density and increased with tree size. Growth decreased with neighborhood crowding, which suggests that competition is important. Tree mortality decreased with wood density and generally increased with tree size, but was apparently unaffected by neighborhood crowding. Across plots, variation in the plot-level strength of competition was most strongly related to plot basal area (i.e., the sum of the basal area of all trees in a plot), with greater reductions in growth occurring in forests with high basal area, but in Amazonia, the strength of competition also varied with plot-level wood density. In Amazonia, the strength of competition increased with water availability because of the greater basal area of wetter forests, but was only weakly related to soil fertility. In Africa, competition was weakly related to soil fertility and invariant across the shorter water availability gradient. Overall, our results suggest that competition influences the structure and dynamics of tropical forests primarily through effects on individual tree growth rather than mortality and that the strength of competition largely depends on environment-mediated variation in basal area.

    Må hjelpe insektene få barn
    Oonincx, Dennis - \ 2019
    Evolutionary diversity is associated with wood productivity in Amazonian forests
    Coelho de Souza, Fernanda ; Dexter, Kyle G. ; Phillips, Oliver L. ; Pennington, Toby R. ; Neves, Danilo ; Sullivan, Martin J.P. ; Alvarez-Davila, Esteban ; Alves, Átila ; Amaral, Ieda ; Andrade, Ana ; Aragao, Luis E.O.C. ; Araujo-Murakami, Alejandro ; Arets, Eric J.M.M. ; Arroyo, Luzmilla ; Aymard C, Gerardo A. ; Bánki, Olaf ; Baraloto, Christopher ; Barroso, Jorcely G. ; Boot, Rene G.A. ; Brienen, Roel J.W. ; Brown, Foster ; Camargo, José Luís C. ; Castro, Wendeson ; Chave, Jerome ; Cogollo, Alvaro ; Comiskey, James A. ; Cornejo-Valverde, Fernando ; Costa, Antonio Lola da; Camargo, Plínio B. de; Fiore, Anthony Di; Feldpausch, Ted R. ; Galbraith, David R. ; Gloor, Emanuel ; Goodman, Rosa C. ; Gilpin, Martin ; Herrera, Rafael ; Higuchi, Niro ; Honorio Coronado, Eurídice N. ; Jimenez-Rojas, Eliana ; Killeen, Timothy J. ; Laurance, Susan ; Laurance, William F. ; Lopez-Gonzalez, Gabriela ; Lovejoy, Thomas E. ; Malhi, Yadvinder ; Marimon, Beatriz S. ; Marimon-Junior, Ben Hur ; Mendoza, Casimiro ; Monteagudo-Mendoza, Abel ; Neill, David A. ; Vargas, Percy Núñez ; Peñuela Mora, Maria C. ; Pickavance, Georgia C. ; Pipoly, John J. ; Pitman, Nigel C.A. ; Poorter, Lourens ; Prieto, Adriana ; Ramirez, Freddy ; Roopsind, Anand ; Rudas, Agustin ; Salomão, Rafael P. ; Silva, Natalino ; Silveira, Marcos ; Singh, James ; Stropp, Juliana ; Steege, Hans ter; Terborgh, John ; Thomas-Caesar, Raquel ; Umetsu, Ricardo K. ; Vasquez, Rodolfo V. ; Célia-Vieira, Ima ; Vieira, Simone A. ; Vos, Vincent A. ; Zagt, Roderick J. ; Baker, Timothy R. - \ 2019
    Nature Ecology & Evolution 3 (2019). - ISSN 2397-334X - p. 1754 - 1761.

    Higher levels of taxonomic and evolutionary diversity are expected to maximize ecosystem function, yet their relative importance in driving variation in ecosystem function at large scales in diverse forests is unknown. Using 90 inventory plots across intact, lowland, terra firme, Amazonian forests and a new phylogeny including 526 angiosperm genera, we investigated the association between taxonomic and evolutionary metrics of diversity and two key measures of ecosystem function: aboveground wood productivity and biomass storage. While taxonomic and phylogenetic diversity were not important predictors of variation in biomass, both emerged as independent predictors of wood productivity. Amazon forests that contain greater evolutionary diversity and a higher proportion of rare species have higher productivity. While climatic and edaphic variables are together the strongest predictors of productivity, our results show that the evolutionary diversity of tree species in diverse forest stands also influences productivity. As our models accounted for wood density and tree size, they also suggest that additional, unstudied, evolutionarily correlated traits have significant effects on ecosystem function in tropical forests. Overall, our pan-Amazonian analysis shows that greater phylogenetic diversity translates into higher levels of ecosystem function: tropical forest communities with more distantly related taxa have greater wood productivity.

    Rarity of monodominance in hyperdiverse Amazonian forests
    Steege, Hans Ter; Henkel, Terry W. ; Helal, Nora ; Marimon, Beatriz S. ; Marimon-Junior, Ben Hur ; Huth, Andreas ; Groeneveld, Jürgen ; Sabatier, Daniel ; Souza Coelho, Luiz de; Andrade Lima Filho, Diogenes de; Salomão, Rafael P. ; Amaral, Iêda Leão ; Almeida Matos, Francisca Dionízia de; Castilho, Carolina V. ; Phillips, Oliver L. ; Guevara, Juan Ernesto ; Jesus Veiga Carim, Marcelo de; Cárdenas López, Dairon ; Magnusson, William E. ; Wittmann, Florian ; Irume, Mariana Victória ; Martins, Maria Pires ; Silva Guimarães, José Renan da; Molino, Jean François ; Bánki, Olaf S. ; Piedade, Maria Teresa Fernandez ; Pitman, Nigel C.A. ; Mendoza, Abel Monteagudo ; Ramos, José Ferreira ; Luize, Bruno Garcia ; Moraes de Leão Novo, Evlyn Márcia ; Núñez Vargas, Percy ; Silva, Thiago Sanna Freire ; Venticinque, Eduardo Martins ; Manzatto, Angelo Gilberto ; Reis, Neidiane Farias Costa ; Terborgh, John ; Casula, Katia Regina ; Honorio Coronado, Euridice N. ; Montero, Juan Carlos ; Feldpausch, Ted R. ; Duque, Alvaro ; Costa, Flávia R.C. ; Arboleda, Nicolás Castaño ; Schöngart, Jochen ; Killeen, Timothy J. ; Vasquez, Rodolfo ; Mostacedo, Bonifacio ; Demarchi, Layon O. ; Assis, Rafael L. ; Baraloto, Chris ; Engel, Julien ; Petronelli, Pascal ; Castellanos, Hernán ; Medeiros, Marcelo Brilhante de; Quaresma, Adriano ; Simon, Marcelo Fragomeni ; Andrade, Ana ; Camargo, José Luís ; Laurance, Susan G.W. ; Laurance, William F. ; Rincón, Lorena M. ; Schietti, Juliana ; Sousa, Thaiane R. ; Sousa Farias, Emanuelle de; Lopes, Maria Aparecida ; Magalhães, José Leonardo Lima ; Mendonça Nascimento, Henrique Eduardo ; Lima de Queiroz, Helder ; Aymard C, Gerardo A. ; Brienen, Roel ; Revilla, Juan David Cardenas ; Vieira, Ima Célia Guimarães ; Cintra, Bruno Barçante Ladvocat ; Stevenson, Pablo R. ; Feitosa, Yuri Oliveira ; Duivenvoorden, Joost F. ; Mogollón, Hugo F. ; Araujo-Murakami, Alejandro ; Ferreira, Leandro Valle ; Lozada, José Rafael ; Comiskey, James A. ; Toledo, José Julio de; Damasco, Gabriel ; Dávila, Nállarett ; Draper, Freddie ; García-Villacorta, Roosevelt ; Lopes, Aline ; Vicentini, Alberto ; Alonso, Alfonso ; Dallmeier, Francisco ; Gomes, Vitor H.F. ; Lloyd, Jon ; Neill, David ; Aguiar, Daniel Praia Portela de; Arroyo, Luzmila ; Carvalho, Fernanda Antunes ; Souza, Fernanda Coelho de; Amaral, Dário Dantas do; Feeley, Kenneth J. ; Gribel, Rogerio ; Pansonato, Marcelo Petratti ; Barlow, Jos ; Berenguer, Erika ; Ferreira, Joice ; Fine, Paul V.A. ; Guedes, Marcelino Carneiro ; Jimenez, Eliana M. ; Licona, Juan Carlos ; Peñuela Mora, Maria Cristina ; Villa, Boris ; Cerón, Carlos ; Maas, Paul ; Silveira, Marcos ; Stropp, Juliana ; Thomas, Raquel ; Baker, Tim R. ; Daly, Doug ; Dexter, Kyle G. ; Huamantupa-Chuquimaco, Isau ; Milliken, William ; Pennington, Toby ; Ríos Paredes, Marcos ; Fuentes, Alfredo ; Klitgaard, Bente ; Pena, José Luis Marcelo ; Peres, Carlos A. ; Silman, Miles R. ; Tello, J.S. ; Chave, Jerome ; Cornejo Valverde, Fernando ; Fiore, Anthony Di; Hilário, Renato Richard ; Phillips, Juan Fernando ; Rivas-Torres, Gonzalo ; Andel, Tinde R. van; Hildebrand, Patricio von; Noronha, Janaína Costa ; Barbosa, Edelcilio Marques ; Barbosa, Flávia Rodrigues ; Matos Bonates, Luiz Carlos de; Sá Carpanedo, Rainiellen de; Dávila Doza, Hilda Paulette ; Fonty, Émile ; GómeZárate Z, Ricardo ; Gonzales, Therany ; Gallardo Gonzales, George Pepe ; Hoffman, Bruce ; Junqueira, André Braga ; Malhi, Yadvinder ; Andrade Miranda, Ires Paula de; Pinto, Linder Felipe Mozombite ; Prieto, Adriana ; Jesus Rodrigues, Domingos de; Rudas, Agustín ; Ruschel, Ademir R. ; Silva, Natalino ; Vela, César I.A. ; Vos, Vincent Antoine ; Zent, Egleé L. ; Zent, Stanford ; Weiss Albuquerque, Bianca ; Cano, Angela ; Carrero Márquez, Yrma Andreina ; Correa, Diego F. ; Costa, Janaina Barbosa Pedrosa ; Flores, Bernardo Monteiro ; Galbraith, David ; Holmgren, Milena ; Kalamandeen, Michelle ; Nascimento, Marcelo Trindade ; Oliveira, Alexandre A. ; Ramirez-Angulo, Hirma ; Rocha, Maira ; Scudeller, Veridiana Vizoni ; Sierra, Rodrigo ; Tirado, Milton ; Umaña Medina, Maria Natalia ; Heijden, Geertje van der; Vilanova Torre, Emilio ; Vriesendorp, Corine ; Wang, Ophelia ; Young, Kenneth R. ; Ahuite Reategui, Manuel Augusto ; Baider, Cláudia ; Balslev, Henrik ; Cárdenas, Sasha ; Casas, Luisa Fernanda ; Farfan-Rios, William ; Ferreira, Cid ; Linares-Palomino, Reynaldo ; Mendoza, Casimiro ; Mesones, Italo ; Torres-Lezama, Armando ; Giraldo, Ligia Estela Urrego ; Villarroel, Daniel ; Zagt, Roderick ; Alexiades, Miguel N. ; Oliveira, Edmar Almeida de; Garcia-Cabrera, Karina ; Hernandez, Lionel ; Palacios Cuenca, Walter ; Pansini, Susamar ; Pauletto, Daniela ; Ramirez Arevalo, Freddy ; Sampaio, Adeilza Felipe ; Valderrama Sandoval, Elvis H. ; Valenzuela Gamarra, Luis ; Levesley, Aurora ; Pickavance, Georgia ; Melgaço, Karina - \ 2019
    Scientific Reports 9 (2019). - ISSN 2045-2322

    Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors.

    A 7000-year history of changing plant trait composition in an Amazonian landscape; the role of humans and climate
    Sande, M.T. van der; Gosling, W. ; Correa-Metrio, A. ; Prado-Junior, Jamir A. ; Poorter, L. ; Oliveira, R.S. ; Mazzei, Luca ; Bush, M.B. - \ 2019
    Ecology Letters 22 (2019)6. - ISSN 1461-023X - p. 925 - 935.
    Tropical forests are shifting in species and trait composition, but the main underlying causes remain unclear because of the short temporal scales of most studies. Here, we develop a novel approach by linking functional trait data with 7000 years of forest dynamics from a fossil pollen record of Lake Sauce in the Peruvian Amazon. We evaluate how climate and human disturbances affect community trait composition. We found weak relationships between environmental conditions and traits at the taxon level, but strong effects for community‐mean traits. Overall, community‐mean traits were more responsive to human disturbances than to climate change; human‐induced erosion increased the dominance of dense‐wooded, non‐zoochorous species with compound leaves, and human‐induced fire increased the dominance of tall, zoochorous taxa with large seeds and simple leaves. This information can help to enhance our understanding of forest responses to past environmental changes, and improve predictions of future changes in tropical forest composition.
    Data from: A 7000-year history of changing plant trait composition in an Amazonian landscape; the role of humans and climate
    Sande, M.T. van der; Gosling, W. ; Correa-Metrio, A. ; Prado-Junior, J. ; Poorter, L. ; Oliveira, R.S. ; Mazzei, L. ; Bush, M. - \ 2019
    Wageningen University & Research
    Amazon - charcoal - climate change - erosion - fire - fossil pollen - functional traits - human disturbance - Peru - tropical forest
    Tropical forests are shifting in species and trait composition, but the main underlying causes remain unclear because of the short temporal scales of most studies. Here, we develop a novel approach by linking functional trait data with 7000 years of forest dynamics from a fossil pollen record of Lake Sauce in the Peruvian Amazon. We evaluate how climate and human disturbances affect community trait composition. We found weak relationships between environmental conditions and traits at the taxon level, but strong effects for community-mean traits. Overall, community-mean traits were more responsive to human disturbances than to climate change; human-induced erosion increased the dominance of dense-wooded, non-zoochorous species with compound leaves, and human-induced fire increased the dominance of tall, zoochorous taxa with large seeds and simple leaves. This information can help to enhance our understanding of forest responses to past environmental changes, and improve predictions of future changes in tropical forest composition.
    Colonization of siliques and seeds of rapid cycling Brassica oleracea plants by Xanthomonas campestris pv. campestris after spray-inoculation of flower clusters.
    Wolf, J.M. van der; Kastelein, P. ; Antônio Fernandes da Silva Júnior, Tadeu ; Vieira Lelis, Flavia ; Zouwen, P.S. van der - \ 2019
    European Journal of Plant Pathology 154 (2019)2. - ISSN 0929-1873 - p. 445 - 461.
    Glasshouse experiments were conducted to study the colonization of seedpods (siliques) and seeds of rapid cycling Brassica oleracea plants after spraying
    inoculum on clusters of recently opened flowers with Xanthomonas campestris pv. campestris (Xcc) at densities of 107–108 cfu ml−1. A green fluorescent protein (GFP) tagged Xcc strain was used to allow visualization of the bacteria by epifluorescence stereo microscopy (ESM) and confocal laser scanning microscopy (CLSM). The GFP-tagged strain showed reduced virulence compared to the untagged parental strain, but was still able to cause black rot symptoms. Two to three days after sprayinoculation, sepals, stamen and petals were colonized by
    Xcc, as observed by ESM. In green siliques a GFP-signal was observed on valves, septa and seeds, despite the fact that a high percentage of Xcc cells had lost their ability to express GFP as found by dilution-plating. Densities of Xcc in infected silique tissues were up to 109 cfu g−1. A fluorescent signal using ESM was found in seeds harvested from symptomatic siliques after incubation of
    seeds on blotting paper wetted with broth to enhance the multiplication of Xcc. Xcc was found in association with the seed coat and in a single seed, also in the
    endosperm and embryo, indicating deep-seated seed infection. The estimated incidence of contaminated seeds in both years was ca. 7%. The estimated incidence of deep-seated infections, still detectable after warm water treatment of seeds, was also high (2–3.8%). It is concluded that spray-inoculation of flower clusters with Xcc can result in the infection of sepals and reproductive organs,
    and in deep-seated seed infections.
    Teachers’ multicultural attitudes and perceptions of school policy, and school climate, in relation to burnout
    Dubbeld, Anneke ; Hoog, N. de; Brok, Perry den; Martens, R. - \ 2019
    Intercultural Education 30 (2019)6. - ISSN 1467-5986 - p. 599 - 617.
    There is a growing number of ethnically and culturally diverse students in Dutch junior vocational high schools. This article examines teachers’ multicultural attitudes, their perceptions of cultural diversity related to school policy and school climate, and the chance of general and diversity-related burnout. The present research also characterizes teachers in terms of their multicultural attitudes and perceptions of school policy and climate through cluster analysis. Results are based on questionnaire data of 120 teachers, working at five locations of a multicultural junior vocational high school in a highly urbanized part of the Netherlands. Correlational, regression and variance analyses indicated that the highest levels of general and diversity-related burnout were found among teachers categorized as assimilationist in attitude and who perceived their school as pluralistic. Teachers could be divided into three types of profiles: (1) relative assimilative attitude, (2) no pronounced assimilative attitude, and (3) moderate assimilative attitude. Teachers with the second profile showed the highest chance for burnout.
    Compositional response of Amazon forests to climate change
    Esquivel-Muelbert, Adriane ; Baker, Timothy R. ; Dexter, Kyle G. ; Lewis, Simon L. ; Brienen, Roel J.W. ; Feldpausch, Ted R. ; Lloyd, Jon ; Monteagudo-Mendoza, Abel ; Arroyo, Luzmila ; Álvarez-Dávila, Esteban ; Higuchi, Niro ; Marimon, Beatriz S. ; Marimon-Junior, Ben Hur ; Silveira, Marcos ; Vilanova, Emilio ; Gloor, Emanuel ; Malhi, Yadvinder ; Chave, Jerôme ; Barlow, Jos ; Bonal, Damien ; Davila Cardozo, Nallaret ; Erwin, Terry ; Fauset, Sophie ; Hérault, Bruno ; Laurance, Susan ; Poorter, Lourens ; Qie, Lan ; Stahl, Clement ; Sullivan, Martin J.P. ; Steege, Hans ter; Vos, Vincent Antoine ; Zuidema, Pieter A. ; Almeida, Everton ; Almeida de Oliveira, Edmar ; Andrade, Ana ; Vieira, Simone Aparecida ; Aragão, Luiz ; Araujo-Murakami, Alejandro ; Arets, Eric ; Aymard C, Gerardo A. ; Baraloto, Christopher ; Camargo, Plínio Barbosa ; Barroso, Jorcely G. ; Bongers, Frans ; Boot, Rene ; Camargo, José Luís ; Castro, Wendeson ; Chama Moscoso, Victor ; Comiskey, James ; Peña-Claros, Marielos - \ 2019
    Global Change Biology 25 (2019)1. - ISSN 1354-1013 - p. 39 - 56.
    bioclimatic niches - climate change - compositional shifts - functional traits - temporal trends - tropical forests

    Most of the planet's diversity is concentrated in the tropics, which includes many regions undergoing rapid climate change. Yet, while climate-induced biodiversity changes are widely documented elsewhere, few studies have addressed this issue for lowland tropical ecosystems. Here we investigate whether the floristic and functional composition of intact lowland Amazonian forests have been changing by evaluating records from 106 long-term inventory plots spanning 30 years. We analyse three traits that have been hypothesized to respond to different environmental drivers (increase in moisture stress and atmospheric CO2 concentrations): maximum tree size, biogeographic water-deficit affiliation and wood density. Tree communities have become increasingly dominated by large-statured taxa, but to date there has been no detectable change in mean wood density or water deficit affiliation at the community level, despite most forest plots having experienced an intensification of the dry season. However, among newly recruited trees, dry-affiliated genera have become more abundant, while the mortality of wet-affiliated genera has increased in those plots where the dry season has intensified most. Thus, a slow shift to a more dry-affiliated Amazonia is underway, with changes in compositional dynamics (recruits and mortality) consistent with climate-change drivers, but yet to significantly impact whole-community composition. The Amazon observational record suggests that the increase in atmospheric CO2 is driving a shift within tree communities to large-statured species and that climate changes to date will impact forest composition, but long generation times of tropical trees mean that biodiversity change is lagging behind climate change.

    Teachers’ Attitudes Toward Multiculturalism in Relation to General and Diversity-Related Burnout
    Dubbeld, Anneke ; Hoog, Natascha de; Brok, Perry den; Laat, Maarten de - \ 2019
    European Education 51 (2019)1. - ISSN 1056-4934 - p. 16 - 31.
    This study focuses on teachers’ general and diversity-related burnout in relation to teachers’ attitudes toward multiculturalism. Results are based on the responses of 120 teachers working at five different urban, ethnically diverse junior vocational high schools in the Netherlands. Analyses indicated that teachers with assimilative attitudes exhibited higher levels of general and diversity-related burnout, whereas there was no relationship between pluralistic attitudes and burnout. In addition, there were no relationships between teacher background variables and attitude and burnout, besides the finding that native teachers experienced less general burnout, and had less pluralistic attitudes, than nonnative teachers.
    Unravelling the moons : Review of the genera paratetilla and cinachyrella in the indo-pacific (demospongiae, tetractinellida, tetillidae)
    Santodomingo, Nadiezhda ; Becking, Leontine E. - \ 2018
    ZooKeys 2018 (2018)791. - ISSN 1313-2989 - p. 1 - 46.
    Anchialine systems - Coral reef - Mangrove - Marine lake - Porifera

    Paratetilla bacca (Selenka, 1867) and Cinachyrella australiensis (Carter, 1886) occur in a broad range of marine environments and are allegedly widely distributed species in the Indo-Pacific. We coin the term ‘moon sponges’ for these species as they are spherical in shape with numerous porocalices resembling the lunar surface. Both species have a complex taxonomic history with high synonymization, in particular by Burton (1934, 1959). An examination of the junior synonyms proposed by Burton (1934, 1959) was conducted to establish the validity of the names. More than 230 specimens from Naturalis Biodiversity Center were reviewed that belong to the genera Paratetilla and Cinachyrella from marine lakes, coral reefs, and mangroves in Indonesia. The aim of the current study was to untangle the taxonomic history, describe the collection of moon sponges from Indonesia, and develop a key. We extensively reviewed the taxonomic literature as well as holotypes of most of the species synonymized by Burton. The taxonomic history of Paratetilla spp. and Cinachyrella australiensis showed some cases of misinterpreted synonyms, misidentifications, and lack of detailed descriptions for some species. The conclusion of the revision is that there are three valid species of Paratetilla (P. arcifera, P. bacca, and P. corrugata) and four valid species of Cinachyrella (C. australiensis, C. porosa, C. paterifera, and C. schulzei) in Indonesia. This is furthermore corroborated by molecular work from previous studies. Paratetilla arcifera Wilson 1925 and C. porosa (Lendenfeld, 1888) are resurrected. A full review of taxonomic history is provided as well as a key for identification of moon sponges from Indonesia. All species are sympatric and we expect that there are undescribed species remaining within the Tetillidae from the Indo-Pacific. Our current review provides the framework from which to describe new species in the genera Paratetilla and Cinachyrella from the Indo-Pacific.

    An acidic model pro-peptide affects the secondary structure, membrane interactions and antimicrobial activity of a crotalicidin fragment
    Júnior, Nelson G.O. ; Cardoso, Marlon H. ; Cândido, Elizabete S. ; Broek, Danielle van den; Lange, Niek de; Velikova, Nadya ; Kleijn, J.M. ; Wells, Jerry M. ; Rezende, Taia M.B. ; Franco, Octávio Luiz ; Vries, Renko de - \ 2018
    Scientific Reports 8 (2018)1. - ISSN 2045-2322

    In order to study how acidic pro-peptides inhibit the antimicrobial activity of antimicrobial peptides, we introduce a simple model system, consisting of a 19 amino-acid long antimicrobial peptide, and an N-terminally attached, 10 amino-acid long acidic model pro-peptide. The antimicrobial peptide is a fragment of the crotalicidin peptide, a member of the cathelidin family, from rattlesnake venom. The model pro-peptide is a deca (glutamic acid). Attachment of the model pro-peptide only leads to a moderately large reduction in the binding to- and induced leakage of model liposomes, while the antimicrobial activity of the crotalicidin fragment is completely inhibited by attaching the model pro-peptide. Attaching the pro-peptide induces a conformational change to a more helical conformation, while there are no signs of intra- or intermolecular peptide complexation. We conclude that inhibition of antimicrobial activity by the model pro-peptide might be related to a conformational change induced by the pro-peptide domain, and that additional effects beyond induced changes in membrane activity must also be involved.

    Field methods for sampling tree height for tropical forest biomass estimation
    Sullivan, Martin J.P. ; Lewis, Simon L. ; Hubau, Wannes ; Qie, Lan ; Baker, Timothy R. ; Banin, Lindsay F. ; Chave, Jerôme ; Cuni-Sanchez, Aida ; Feldpausch, Ted R. ; Lopez-Gonzalez, Gabriela ; Arets, Eric ; Ashton, Peter ; Bastin, Jean François ; Berry, Nicholas J. ; Bogaert, Jan ; Boot, Rene ; Brearley, Francis Q. ; Brienen, Roel ; Burslem, David F.R.P. ; Canniere, Charles de; Chudomelová, Markéta ; Dančák, Martin ; Ewango, Corneille ; Hédl, Radim ; Lloyd, Jon ; Makana, Jean Remy ; Malhi, Yadvinder ; Marimon, Beatriz S. ; Junior, Ben Hur Marimon ; Metali, Faizah ; Moore, Sam ; Nagy, Laszlo ; Vargas, Percy Nuñez ; Pendry, Colin A. ; Ramírez-Angulo, Hirma ; Reitsma, Jan ; Rutishauser, Ervan ; Salim, Kamariah Abu ; Sonké, Bonaventure ; Sukri, Rahayu S. ; Sunderland, Terry ; Svátek, Martin ; Umunay, Peter M. ; Martinez, Rodolfo Vasquez ; Vernimmen, Ronald R.E. ; Torre, Emilio Vilanova ; Vleminckx, Jason ; Vos, Vincent ; Phillips, Oliver L. - \ 2018
    Methods in Ecology and Evolution 9 (2018)5. - ISSN 2041-210X - p. 1179 - 1189.
    Above-ground biomass estimation - Allometry - Carbon stocks - Forest inventory - Forest structure - Sample size
    Quantifying the relationship between tree diameter and height is a key component of efforts to estimate biomass and carbon stocks in tropical forests. Although substantial site-to-site variation in height-diameter allometries has been documented, the time consuming nature of measuring all tree heights in an inventory plot means that most studies do not include height, or else use generic pan-tropical or regional allometric equations to estimate height. Using a pan-tropical dataset of 73 plots where at least 150 trees had in-field ground-based height measurements, we examined how the number of trees sampled affects the performance of locally derived height-diameter allometries, and evaluated the performance of different methods for sampling trees for height measurement. Using cross-validation, we found that allometries constructed with just 20 locally measured values could often predict tree height with lower error than regional or climate-based allometries (mean reduction in prediction error = 0.46 m). The predictive performance of locally derived allometries improved with sample size, but with diminishing returns in performance gains when more than 40 trees were sampled. Estimates of stand-level biomass produced using local allometries to estimate tree height show no over- or under-estimation bias when compared with biomass estimates using field measured heights. We evaluated five strategies to sample trees for height measurement, and found that sampling strategies that included measuring the heights of the ten largest diameter trees in a plot outperformed (in terms of resulting in local height-diameter models with low height prediction error) entirely random or diameter size-class stratified approaches. Our results indicate that even limited sampling of heights can be used to refine height-diameter allometries. We recommend aiming for a conservative threshold of sampling 50 trees per location for height measurement, and including the ten trees with the largest diameter in this sample.
    Concurrentie, concentratie en rentabiliteit in de glastuinbouw in Nederland
    Veerman, Kees - \ 2018
    Wageningen University. Promotor(en): O. van Kooten. - Wageningen : Wageningen University - ISBN 9789463438865 - 331

    Introduction

    The expansion of the market area of the European Union has caused a strong increase of supply and demand of fresh horticulture products of the Dutch glasshouse sector on the European market. Consequently there is increased competition with companies from new European member states, producing against lower prices, as well as changes in production and sales structure. In the Dutch food horticulture sector this led to a large horizontal and vertical merger between most of the auctions and a number of large exporters. From 1996 to 1998 VTN/The Greenery changed from a co-operative auction into a co-operative trade organisation. In the floriculture sector only horizontal mergers took place between co-operative auctions. The wholesalers/exporters remained independent. At present there are two Flower Auctions, FloraHolland te Naaldwijk (market share 98%) and Plantion in Ede (2%).

    Central research question

    This thesis explores the development of market structure, market strategy and market results in the horticulture glasshouse sector over the last thirty-five years. The central research question is whether the difference in market structure and market strategy in the Dutch sectors of glasshouse vegetables and glasshouse cut flowers and pot plants is a significant cause to explain the difference in market results for the growers and their co-operative organisations.

    The conceptual model

    A number of theories and models have been studied derived from the Industrial Organisation Theory. This theory focuses on the analysis of branches of industries, industry chains and markets involved. It examines the relation between market structure (S), market conduct (C) and market performance (P) through the SCP-model (in Dutch: SGR-model). A description and explanation is given of the static SCP-model of Bain, the dynamic SGR-model of De Jong and the branch-analysing models of Porter and Daems. The conceptual model of competition, concentration and performance (figure 1.1) has been constructed from these models to analyse the Dutch horticulture glasshouse sectors.

    Research of producers, sector research and research of auctions/sales organisations

    From 2006-2008 three research projects on producers were conducted amongst 40 growers of vegetables, 40 growers of cut flowers and 40 growers of pot plants, all under glass. Data and opinions of growers about their company, market strategy and performance were gathered. In the same period sector research of the development of total production, imports and exports took place in the three sectors of the glasshouse industry on sector level, on the level of sales organisations and the wholesalers/ exporters. The gathered data have been analysed and tested on selected variables. In three different chapters temporary conclusions have been drawn. The most important business and market characteristics and research outcomes are discussed in three separate tables at the end of these three chapters and the associated appendices. The research of producers was expanded in 2015/2016 on the basis of the data of the research 2006-2008 with econometric research and multiple analysis of a number of the most important variables of market structure and market conduct to explain the market results (Lerner Index).

    Results of sector research

    The three horticulture sectors under glass show a positive development in yearly production and export value over a period of thirty-five years, besides a small decrease in 2009 and 2011, as a result of the banking and EHEC crisis. In the Dutch floriculture sector the average growing figures are a bit higher than in the food horticulture sector because of a stronger yearly increase in the production of pot plants. In all three sectors the production and export values are increased almost every year until the banking crisis in 2009. After 2010/2011 the sectors have been recovering.

    Development of variables in Dutch horticulture glasshouse sector 1980-2016

    The sector cut flowers under glass show a decrease of area and production (m2 glass) in The Netherlands. However, there is an increase of import and direct supply of cut flowers from foreign growers and Dutch companies from the southern part of Africa (roses, chrysanthemums etc.). All sectors profit from the growing import/re-export function of vegetables and fruit, cut flowers and pot plants from The Netherlands to neighbouring countries and trade partners in Europe. The high share of the sector variables domestic share and export share in all three sectors stimulate the development of production value, export value and prices.

    Results of research into auctions/sales organisations

    In the food horticulture and floriculture sectors there has been quite a difference in market strategy and market structure since 1998. In the sector vegetables under glass the degree of concentration of the four largest sales organisations (C4) has decreased to the level of before the merger (60%). In 1997 this figure was 96%. Also the share of growers of VTN/The Greenery in the area of Dutch vegetables under glass has decreased. VTN/The Greenery did not reach her target of 1996 with their strategy of horizontal and vertical concentration: organizing a larger bundling of the turnover of the Dutch auctions and wholesalers/exporters.

    The search for a good working integration of horticultural production and trade in one company with an efficient and effective structure has not been completed yet and started in 2016 with a new sales organisation. The financial position of VTN/The Greenery on the European market is not strong. Since 1996 the annual turnover has strongly fluctuated between 0.9 and 1.5 billion euros, with a variation range of 25 to 30 %. The supply of their own members halved, just like the income out of commission. The position on the Dutch market is stable, on the most important European markets difficult. The return on investment is low. In 2015 and 2016 a careful recovery started after the difficult years of crisis 2009, 2011 and 2013.

    Flower auctions FloraHolland and VBA showed a clear strategy and good results around the merger of 2007. The merger was a good example of a carefully implemented strategy of horizontal concentration, bringing together the interests of the flower auctions and their members. For FloraHolland the period of the crisis 2009-2011 was a test with success.

    There was an expansion of horizontal concentration across the borders: a new joint venture auction Rhein-Maas, founded together with the German organisation Landgard and there was an integration with the import auction TFA in Aalsmeer. Both organisations are important for the market position of FloraHolland. In the Dutch floriculture sector under glass there are hardly any examples of vertical concentration of producers or sales organisations with wholesalers/exporters. There are examples, though, of vertical co-operation between these organisations and international retail, especially with the larger growers of pot plants.

    The auction clock, physical and digital, is the most important sales method the flower auctions use daily. For most products there is a public pricing system. It provides a transparent process of supply and demand against sharp tariffs of the auction. For cut flowers as well as for pot and garden plants a large part of the product groups are sold by way of the auction clock, which mostly ensures a reliable reference price for mediation and personal selling and provides a good match of supply and demand and a ‘clean’ market. Attention to strengthen the position of the auction clock, especially with the selling of pot and garden plants, is important. The turnover of FloraHolland decreased in 2009 (bank crisis) and increased in 2010 and 2011 just above the level of 2008. Incomes out of services dropped. As costs decreased more than incomes, profits and solvency improved in this period.

    In 2012 FloraHolland realised a turnover increase of 3% compared to 2011. However, the incomes out of services decreased. In 2013 the sector performed reasonably. The turnover of FloraHolland increased slightly but costs were higher than incomes and FloraHolland had an exploitation loss. 2014 was a year of slight recovery, 2015 and 2016 ended with an increasing turnover of 3 and 4%. Profit after tax in these years are 12 and 3 million euros. For most of the growers and customers the results in 2015 and 2016 were positive. The decision of the wholesale/export (VGB) to contribute again in the promotion costs of Bloemenbureau Holland was welcomed very positively. Along with the new strategy of 2020 FloraHolland is working on the strengthening and expansion of the physical and digital market places.

    Research results of producers

    On producers level there is also quite a difference in market strategy, structure and results between growers in the sectors of glasshouse vegetables and glasshouse cut flowers and pot plants. At present there is a fierce struggle to survive in each sector. It seems that the small grower of cut flowers and pot plants stands a better chance than the small grower in vegetables. The most striking single relations between structure, conduct and result will be mentioned.

    Most striking single relations glasshouse vegetables

    - The small company has relatively higher costs than the larger types. If the sales organisation uses the principle of ‘the user pays the total costs made’ this burden is rather heavy for the smallest companies.

    - Auction growers mainly deliver round or grape tomatoes, the majority of independent growers choose for the special varieties. This influences the pricing process.

    - Small and large auction growers differ significantly in business size from independent growers, but realise comparable margins. Large-scale production does not always lead to lower average costs and a better margin, but it does entail a greater risk of too much supply and low prices. Growers with a larger business size are faced with larger financial problems in difficult years than smaller ones.

    - Horizontal concentration of the four largest growers of vegetables lies at a low level and their sales power is low. The concentration of the four largest sales organisations is about 60%.

    - Vertically integrated auction growers are smaller in business size and invest less than non- integrated independent growers. They realise comparable margins.

    - The importance of the sales organisation to realise good prices and margins for the members’ products seems rather small. Sharp purchase prices are of equal importance for the trade organisation and influence the margin of the members.

    - Higher investments don’t produce higher results (directly). More innovative investments are needed to improve prices and margins.

    Most striking single relations glasshouse cut flowers

    - The small auction grower realises an expected smaller turnover and pays higher commission than the larger auction grower, member of a growers organisation. Although there is no significant relation between grower type and realised margin, higher commission can lead to higher prices and margins. Besides the higher price level, smaller growers realise a higher solvency than larger growers.

    - Growers of roses under glass realise a higher margin than growers of chrysanthemums because of a wide and deep assortment.

    - Small growers of cut flowers show comparable or better results than the larger ones.

    - Horizontal concentration of the four largest growers of cut flowers lies, just like the sectors of vegetables and pot plants under glass, at a low level. The small auction grower has little market power and needs the sales organisation for reasonable prices and successful sales.

    - There are no significant relations between the organisation of sales and growers’ turnover, realised margin and the height of commission. It looks as if every grower uses his own mix of marketing and sales activities in a way that no significant differences in results arise.

    - Selling of cut flowers by means of the auction clock gives good results.

    Most striking single relations glasshouse pot plants

    - The smaller auction grower, with or without personal selling, realises an expected smaller turnover but a higher margin than the larger auction grower, member of a growers organisation.

    - Smaller growers (in m2 glass) get higher results or results comparable to those of the larger ones. Old and new companies get comparable margins.

    - Growers of green plants get a significant lower yearly turnover than growers of blooming pot plants. Green plants are often more unique than blooming plants. That is why growers of green plants get higher prices and margins.

    - Horizontal concentration of the growers of pot plants lies, just like in the other sectors, at a low level. The small auction grower has little market power and needs the sales organisation for realising reasonable prices and successful sales.

    - Like in the other sectors the small grower invests less in his business than the larger ones. Higher investments do not directly produce higher results. More innovative investments are needed to improve prices and margins.

    - There is a significant relation between the organisation of sales and the yearly realised turnover: larger growers use more personal selling besides the sales services of the auction, as their own business activity or as an activity of the growers organisation.

    Boarding out all sales activities to FloraHolland is effective especially for the small grower and enlarges the chance of realising a higher margin. Although he pays a higher commission, he realises a higher margin because of the positive relation between commission and margin.

    Producers results through econometric research

    Most striking multiple relations glasshouse vegetables

    The results of the econometric analysis show that in the sector glasshouse vegetables membership of a growers association produces better results on average than membership of a traditional marketing corporation. Especially young producers with new ideas about the organisation of the company and vertical co-operation with on average large and modern companies are booking the best results.

    Most striking multiple relations glasshouse cut flowers

    Auction growers using the auction clock exclusively to sell their products realise a higher margin on average than growers using other selling methods. The membership of a growers association produces higher results on average than no membership and smaller companies get higher margins than large ones. Senior growers get higher results than junior growers. The auction clock is the best guarantee for realising higher margins. It seems that in the sector cut flowers a larger scale has less effect on the margin than producing ‘niche’ product types. For the latter the selling method via the auction clock plays an important role. Companies with ‘niche’ products have higher fixed costs although a higher margin gives fewer problems when it comes to finance the production.

    Final conclusion

    The answer to the central question confirms the following: the difference in market structure and market strategy in the Dutch sectors of glasshouse vegetables and glasshouse cut flowers is a significant cause to explain the difference in market results. If we follow the position and the results of the small grower in the sector glasshouse vegetables, we are looking at a producer in a tight spot with lower average results for the grower and his co-operation in comparison with the independent grower and his grower association. In the sector glasshouse cut flowers the position and results of the small auction clock grower is better in comparison with the grower who sells on his own or via a growers association.

    The results of this research indicate that in the sector glasshouse vegetables the highest margins are obtained by the independent growers associations, working either cooperativly with the classical co-operations or independent there from but in any case with their own marketing strategy. In the sector glasshouse cut flowers it is the grower selling through the auction clock who gets the highest margins. In the sector glasshouse pot plants, where the type of the product clearly differs from the perishable vegetables and cut flowers, there are too few data to draw conclusions.

    The impact of water hyacinth (Eichhornia crassipes) on greenhouse gas emission and nutrient mobilization depends on rooting and plant coverage
    Oliveira-Junior, Ernandes Sobreira ; Tang, Yingying ; Berg, Sanne J.P. van den; Cardoso, Simone J. ; Lamers, Leon P.M. ; Kosten, Sarian - \ 2018
    Aquatic Botany 145 (2018). - ISSN 0304-3770 - p. 1 - 9.
    Carbon dioxide - Eutrophication - Floating plant - Invasive species - Methane - Nutrient dynamics
    Water hyacinth stands are known to affect both nutrient concentrations in the water and carbon exchange with the atmosphere. However, both enhanced and reduced greenhouse gas (GHG) emissions have been reported in relation to water hyacinth presence. This controversy may be explained by variation in plant density and rooting. High growth rates indicate its capacity to mobilize and store nutrients in the tissues, and assimilate large amounts of carbon dioxide (CO2). Simultaneously the plant can stimulate methane (CH4) emission. This may occur when plants are rooting in the sediment due to CH4 shuttling from the sediment, through the plant, into the atmosphere. To unravel the potential influences of water hyacinth on nutrient dynamics and GHG fluxes, we performed an experiment in which plant coverage and root access to the sediment were manipulated. Plants reduced phosphorus concentrations in water and pore-water, independent of coverage and rooting, also rooting plants grown at high coverage showed higher plant N:P ratios. CH4 emissions were highest at high coverage and were further increased by rooting, indicating that plant-mediated transport indeed takes place. However, the overall GHG budget in terms of CO2 equivalents still resulted in the water hyacinth vegetation being near neutral, or even a net sink with respect to GHG exchange. The plant-induced enhancement of CH4 emissions suggests that the plant can be an effective CO2-to-biomass-to-CH4 converter. Our results show that plant coverage and water depth – regulating sediment-root contact – should be taken into account when estimating water hyacinth's effect on GHG emissions.
    Biodiversity and climate determine the functioning of Neotropical forests
    Poorter, L. ; Sande, M.T. van der; Arets, E.J.M.M. ; Ascarrunz, N. ; Enquist, B.J. ; Finegan, B. ; Licona, J.C. ; Martinez-Ramos, M. ; Mazzei, L. ; Meave, J. ; Munoz, R. ; Nytch, C.J. ; Oliveira, A.A. de; Perez-Garcia, E.A. ; Prado-Junior, J.A. ; Rodriguez-Velazquez, J. ; Ruschel, A.R. ; Salgado Negret, B. ; Schiavini, I. ; Swenson, N.G. ; Tenorio, E.A. ; Thompson, J. ; Toledo, M. ; Uriarte, M. ; Hout, P. van der; Zimmerman, J.K. ; Pena Claros, M. - \ 2017
    Wageningen University & Research
    biodiversity - biomass - carbon - ecosystem functioning - forest dynamics - productivity - soil fertility - tropical forest - water
    Tropical forests account for a quarter of the global carbon storage and a third of the terrestrial productivity. Few studies have teased apart the relative importance of environmental factors and forest attributes for ecosystem functioning, especially for the tropics. This study aims to relate aboveground biomass (AGB), biomass dynamics (i.e., net biomass productivity and its underlying demographic drivers: biomass recruitment, growth and mortality) to forest attributes (tree diversity, community-mean traits, and stand basal area) and environmental conditions (water availability, soil fertility and disturbance). We used data from 26 sites, 201 one-ha plots and >92,000 trees distributed across the Neotropics. We quantified for each site water availability and soil total exchangeable bases and for each plot three key community-weighted mean functional traits that are important for biomass stocks and productivity. We used structural equation models to test the hypothesis that all drivers have independent, positive effects on biomass stocks and dynamics. Of the relationships analysed, vegetation attributes were more frequently significantly associated with biomass stocks and dynamics than environmental conditions (in 67% versus 33% of the relationships). High climatic water availability increased biomass growth and stocks, light disturbance increased biomass growth, and soil bases had no effect. Rarefied tree species richness had consistent positive relationships with biomass stocks and dynamics, probably because of niche complementarity, but was not related to net biomass productivity. Community-mean traits were good predictors of biomass stocks and dynamics. Water availability has a strong positive effect on biomass stocks and growth, and a future predicted increase in (atmospheric) drought might, therefore, potentially reduce carbon storage. Forest attributes – including species diversity and community-weighted mean traits – have independent and important relationships with AGB stocks, dynamics, and ecosystem functioning, not only in relatively simple temperate systems, but also in structurally complex hyper-diverse tropical forests.
    Biodiversity and climate determine the functioning of Neotropical forests
    Poorter, Lourens ; Sande, Masha T. van der; Arets, Eric J.M.M. ; Ascarrunz, Nataly ; Enquist, Brian ; Finegan, Bryan ; Licona, Juan Carlos ; Martínez-Ramos, Miguel ; Mazzei, Lucas ; Meave, Jorge A. ; Muñoz, Rodrigo ; Nytch, Christopher J. ; Oliveira, Alexandre A. de; Pérez-García, Eduardo A. ; Prado-junior, Jamir ; Rodríguez-Velázques, Jorge ; Ruschel, Ademir Roberto ; Salgado-Negret, Beatriz ; Schiavini, Ivan ; Swenson, Nathan G. ; Tenorio, Elkin A. ; Thompson, Jill ; Toledo, Marisol ; Uriarte, Maria ; Hout, Peter van der; Zimmerman, Jess K. ; Peña-Claros, Marielos - \ 2017
    Global Ecology and Biogeography 26 (2017)12. - ISSN 1466-822X - p. 1423 - 1434.
    Aim: Tropical forests account for a quarter of the global carbon storage and a third of the terrestrial productivity. Few studies have teased apart the relative importance of environmental factors and forest attributes for ecosystem functioning, especially for the tropics. This study aims to relate aboveground biomass (AGB) and biomass dynamics (i.e., net biomass productivity and its underlying demographic drivers: biomass recruitment, growth and mortality) to forest attributes (tree diversity, community-mean traits and stand basal area) and environmental conditions (water availability, soil fertility and disturbance). Location: Neotropics. Methods: We used data from 26 sites, 201 1-ha plots and >92,000 trees distributed across the Neotropics. We quantified for each site water availability and soil total exchangeable bases and for each plot three key community-weighted mean functional traits that are important for biomass stocks and productivity. We used structural equation models to test the hypothesis that all drivers have independent, positive effects on biomass stocks and dynamics. Results: Of the relationships analysed, vegetation attributes were more frequently associated significantly with biomass stocks and dynamics than environmental conditions (in 67 vs. 33% of the relationships). High climatic water availability increased biomass growth and stocks, light disturbance increased biomass growth, and soil bases had no effect. Rarefied tree species richness had consistent positive relationships with biomass stocks and dynamics, probably because of niche complementarity, but was not related to net biomass productivity. Community-mean traits were good predictors of biomass stocks and dynamics. Main conclusions: Water availability has a strong positive effect on biomass stocks and growth, and a future predicted increase in (atmospheric) drought might, therefore, potentially reduce carbon storage. Forest attributes, including species diversity and community-weighted mean traits, have independent and important relationships with AGB stocks, dynamics and ecosystem functioning, not only in relatively simple temperate systems, but also in structurally complex hyper-diverse tropical forests.
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