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Registro Completo |
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Biblioteca(s): |
Embrapa Pantanal. |
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Data corrente: |
24/05/1996 |
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Data da última atualização: |
23/04/2013 |
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Autoria: |
GREIG-SMITH, P. |
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Título: |
The development of numerical classification and ordination. |
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Ano de publicação: |
1980 |
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Fonte/Imprenta: |
Vegetatio, v.42, n.1/3, p.1-9, 1980. |
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Idioma: |
Inglês |
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Conteúdo: |
The paper reviews the constraints and influences which have affected the developmental of numerical classification and ordination of vegetation. Initial development of ordination techniques and their reception by ecologists was hindered by the mistaken idea that ordination involved acceptance of variation in vegetation as a continuum, as well as by a general suspicion of mathematical approaches. Three distinct approaches to ordination, largely unrecognised at the time, are apparent in earlier work: direct gradient analysis, reduction in dimensionality and pathseeking (catenation) (Dale 1975). Modifications of simple initial techniques made them more efficient at the cost of increased computation. Acceptance of heavier computation as computers increased in capacity and speed turned attention to principal component analysis and the superficially similar factor analysis. These have been widely misunderstood largely because they were initially applied in the same way as in the analysis of psychological data, in which different constraints and objectives ap- ply. The initial failure to recognise that principal component analysis involves a preliminary data transformation, the form o which depends on answers to biological, not mathematical questions, was particularly unifortunate. Principal component analysis has limitations as a techique of ordination resulting from its assumtions of linearity and additivity of plant res- ponses. Attempts to devise more effective techniques raise questions about the practical importance of non-linearity if the objective is data-exploration rather than elucidating the nature of species-response curves and about the adequacy of using simulated data as test data when we do not know how to simulate realistic data. Data exploration has been more prominent in practical uses of ordination but many methodological developments ha- ve concentrated rather on species responses curves. Numerical classification also met obstacles to its acceptance additional to a general aversion to numerical techniques. The first numerical techniques were presented in the context of the relationships of a particular set of data, rather than of a generally valid system, which was the more familiar concept in non-numerical classification. Both numerical and non-numerical classification aim to produce as homogeneous groups as possible. The distinctive contribution of numerical methods is to allow the data to indicate the most efficient criteria of classification; this was an unfamiliar idea. Thew strategy of classification may be either divisive or agglomerative and either monothetic or polythetic. Choice of strategy in earlier work was not only constrained by computational limitation but may also have been influenced by an author's previous experience of non numerical classification. As with ordination, the distinction between preliminary data transformation and subsequent analysis was at first not appreciated. Numerical classification has been influenced by parallel numerical development in formal taxonomy. Because objectives and assumptions are not always the same, this influence has not been altogether helpful. The limitation of real data suggest that developments of technique are at risk of becoming too concerned with refinements of methodology. Increa singly complex methods and increasing availability of programmes for such methods carry the risk that they may be used without adequate understanding of what they do. MenosThe paper reviews the constraints and influences which have affected the developmental of numerical classification and ordination of vegetation. Initial development of ordination techniques and their reception by ecologists was hindered by the mistaken idea that ordination involved acceptance of variation in vegetation as a continuum, as well as by a general suspicion of mathematical approaches. Three distinct approaches to ordination, largely unrecognised at the time, are apparent in earlier work: direct gradient analysis, reduction in dimensionality and pathseeking (catenation) (Dale 1975). Modifications of simple initial techniques made them more efficient at the cost of increased computation. Acceptance of heavier computation as computers increased in capacity and speed turned attention to principal component analysis and the superficially similar factor analysis. These have been widely misunderstood largely because they were initially applied in the same way as in the analysis of psychological data, in which different constraints and objectives ap- ply. The initial failure to recognise that principal component analysis involves a preliminary data transformation, the form o which depends on answers to biological, not mathematical questions, was particularly unifortunate. Principal component analysis has limitations as a techique of ordination resulting from its assumtions of linearity and additivity of plant res- ponses. Attempts to devise more effective techniques rais... Mostrar Tudo |
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Palavras-Chave: |
Classificacao numerical; Desenvolvimento; Numerical classification; Ordenacao; Ordination. |
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Thesagro: |
Vegetação. |
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Thesaurus Nal: |
vegetation. |
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Categoria do assunto: |
-- |
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Marc: |
LEADER 04023naa a2200205 a 4500
001 1788620
005 2013-04-23
008 1980 bl --- 0-- u #d
100 1 $aGREIG-SMITH, P.
245 $aThe development of numerical classification and ordination.
260 $c1980
520 $aThe paper reviews the constraints and influences which have affected the developmental of numerical classification and ordination of vegetation. Initial development of ordination techniques and their reception by ecologists was hindered by the mistaken idea that ordination involved acceptance of variation in vegetation as a continuum, as well as by a general suspicion of mathematical approaches. Three distinct approaches to ordination, largely unrecognised at the time, are apparent in earlier work: direct gradient analysis, reduction in dimensionality and pathseeking (catenation) (Dale 1975). Modifications of simple initial techniques made them more efficient at the cost of increased computation. Acceptance of heavier computation as computers increased in capacity and speed turned attention to principal component analysis and the superficially similar factor analysis. These have been widely misunderstood largely because they were initially applied in the same way as in the analysis of psychological data, in which different constraints and objectives ap- ply. The initial failure to recognise that principal component analysis involves a preliminary data transformation, the form o which depends on answers to biological, not mathematical questions, was particularly unifortunate. Principal component analysis has limitations as a techique of ordination resulting from its assumtions of linearity and additivity of plant res- ponses. Attempts to devise more effective techniques raise questions about the practical importance of non-linearity if the objective is data-exploration rather than elucidating the nature of species-response curves and about the adequacy of using simulated data as test data when we do not know how to simulate realistic data. Data exploration has been more prominent in practical uses of ordination but many methodological developments ha- ve concentrated rather on species responses curves. Numerical classification also met obstacles to its acceptance additional to a general aversion to numerical techniques. The first numerical techniques were presented in the context of the relationships of a particular set of data, rather than of a generally valid system, which was the more familiar concept in non-numerical classification. Both numerical and non-numerical classification aim to produce as homogeneous groups as possible. The distinctive contribution of numerical methods is to allow the data to indicate the most efficient criteria of classification; this was an unfamiliar idea. Thew strategy of classification may be either divisive or agglomerative and either monothetic or polythetic. Choice of strategy in earlier work was not only constrained by computational limitation but may also have been influenced by an author's previous experience of non numerical classification. As with ordination, the distinction between preliminary data transformation and subsequent analysis was at first not appreciated. Numerical classification has been influenced by parallel numerical development in formal taxonomy. Because objectives and assumptions are not always the same, this influence has not been altogether helpful. The limitation of real data suggest that developments of technique are at risk of becoming too concerned with refinements of methodology. Increa singly complex methods and increasing availability of programmes for such methods carry the risk that they may be used without adequate understanding of what they do.
650 $avegetation
650 $aVegetação
653 $aClassificacao numerical
653 $aDesenvolvimento
653 $aNumerical classification
653 $aOrdenacao
653 $aOrdination
773 $tVegetatio$gv.42, n.1/3, p.1-9, 1980.
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Registro original: |
Embrapa Pantanal (CPAP) |
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Biblioteca |
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| Registros recuperados : 11 | |
| 2. |  | DAVIS, S. C.; BODDEY, R. M.; ALVES, B. J. R.; COWIE, A. L.; GEORGE, B. H.; OGLE, S. M.; SMITH, P.; von NOORDWIJK, M.; van WIJK, M. T. Management swing potential for bioenergy crops. Global Change Bioenergy, v. 5, n. 6, p. 623-638, 2013.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: A - 1 |
| Biblioteca(s): Embrapa Agrobiologia. |
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| 3. | | RUMPEL, C.; AMIRASLANI, F.; CHENU, C.; GARCIA CARDENAS, M.; KAONGA, M.; KOUTIKA, L-S.; LADHA, J.; MADARI, B.; SHIRATO, Y.; SMITH, P.; SOUDI, B.; SOUSSANA, J-F.; WHITEHEAD, D.; WOLLENBERG, E. The 4p1000 initiative: opportunities, limitations and challenges for implementing soil organic carbon sequestration as a sustainable development strategy. Ambio, v. 49, n. 1, p. 350-360, Jan. 2020.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: A - 1 |
| Biblioteca(s): Embrapa Arroz e Feijão. |
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| 4. | | CHENU, C.; AMIRASLANI, F.; GARCIA CARDENAS, M.; KAONGA, M.; KOUTIKA, L-S.; LADHA, J.; MADARI, B. E.; RUMPEL, C.; SHIRATO, Y.; SMITH, P.; SOUDI, B.; SOUSSANA, J-F; WHITEHEAD, D.; WOLLENBERG, L. The 4 per 1000 initiative. In: WORLD CONGRESS OF SOIL SCIENCE, 21., 2018, Rio de Janeiro. Soil science: beyond food and fuel: proceedings. Rio de Janeiro: SBCS, 2018.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Arroz e Feijão. |
|  |
| 5. | | RUMPEL, C.; AMIRASLANI, F.; CHENU, C.; GARCIA CARDENAS, M.; KAONGA, M.; KOUTIKA, L-S; LADHA, J.; MADARI, B. E.; SHIRATO, Y.; SMITH, P.; SOUDI, B.; SOUSSANA, J-F.; WHITEHEAD, D.; WOLLENBERG, L. The 4 per mille initiative is promoting the implementation of sustainable development goals through science-policy-practice interactions. In: TERRAenVISION18, 2018, Barcelona. Conference: proceedings. Barcelona: University of Barcelona, 2018.| Tipo: Resumo em Anais de Congresso |
| Biblioteca(s): Embrapa Arroz e Feijão. |
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| 6. | | SMITH, P.; DAVIES, C. A.; OGLE, S.; ZANCHI, G.; BELLARBY, J.; BIRD, N.; BODDEY, R. M.; NcNAMARA, N. P.; POLWSON, D.; COWIE, A.; VAN NOORDWIJK, M.; DAVIS, S. C.; RICHTER, D.; KRYZANOWSKI, L.; VAN WIJK, M.; STUART, J.; KIRTON, A.; EGGAR, D.; NEWTON-CROSS, G.; ADHYA, T.; BRAIMOH, A. K. Towards an integrated global framework to assess the impacts of land use and management change on soil carbon: current capability and future vision. Global Change Biology, v. 18, n. 7, p. 2089-2101, 2012.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: A - 1 |
| Biblioteca(s): Embrapa Agrobiologia. |
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| 7. | | SOUSSANA, J-F.; ARIAS-NAVARRO, C.; BISPO, A.; CHENU, C.; SMITH, P.; KUHNERT, M.; FRELIH-LARSEN, A.; HERB, I.; KUIKMAN, P.; KEESSTRA, S.; VERHAGEN, J.; CLAESSENS, L.; MADARI, B. E.; DEMENOIS, J.; ALBRECHT, A.; VERCHOT, L.; MONTANARELLA, L.; HIEDERER, R.; GRUNDY, M.; BALDOCK, J.; CHOTTE, J-L.; KIM, J. Strategic research agenda on soil carbon in agricultural soils. Wageningen: CIRCASA, 2020. European Union's Horizon 2020 research and innovation programme grant agreement No 774378. Coordination of International Research Cooperation on soil Carbon Sequestration in Agriculture.| Tipo: Nota Técnica/Nota Científica |
| Biblioteca(s): Embrapa Arroz e Feijão. |
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| 8. | | BRAY, A. W.; KIM, J. H.; SCHRUMPF, M.; PEACOCK, C.; BANWART, S.; SCHIPPER, L.; ANGERS, D.; CHIRINDA, N.; ZINN, Y. L.; ALBRECHT, A.; KUIKMAN, P.; JOUQUET, P.; DEMENOIS, J.; FARRELL, M.; SOUSSANA, J.-F.; KUHNERT, M.; MILNE, E.; FONTAINE, S.; TAGHIZADEH-TOOSI, A.; CERRI, C. E. P.; CORBEELS, M.; CARDINAEL, R.; CERVANTES, V. A.; OLESEN, J. E.; BATJES, N.; HEUVELINK, G.; MAIA, S. M. F.; KEESSTRA, S.; CLAESSEN, L.; MADARI, B. E.; VERCHOT, L.; NIE, W.; BRUNELLE, T.; MORAN, D.; FRANK, S.; BODLE, R.; FRELIH-LARSEN, A.; DOUGILL, A.; MONTANARELLA, L.; STRINGER, L.; CHENU, C.; HIEDERER, R.; SMITH, P.; ARIAS-NAVARRO, C. The science base of a strategic research agenda: executive summary. Wageningen: CIRCASA, 2019. 15 p. European Union's Horizon 2020 Research and Innovation Programme Grant Agreement No 774378. Coordination of International Research Cooperation on Soil Carbon Sequestration in Agriculture.| Tipo: Nota Técnica/Nota Científica |
| Biblioteca(s): Embrapa Arroz e Feijão. |
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| 9. | | HERRERO, M.; THORNTON, P. K.; MASON-D'CROZ, D.; PALMER, J.; BENTON, T. G.; BODIRSKY, B. L.; BOGARD, J. R.; HALL, A.; LEE, B.; NYBORG, K.; PRADHAN, P.; BONNETT, G. D.; BRYAN, B. A.; CAMPBELL, B. M.; CHRISTENSEN, S.; CLARK, M.; COOK, M. T.; BOER, I. J. M. de; DOWNS, C.; DIZYEE, K.; FOLBERTH, C.; GODDE, C. M.; GERBER, J. S.; GRUNDY, M.; HAVLIK, P.; JARVIS, A.; KING, R.; LOBOGUERRERO, A. M.; LOPES, M. A.; MCLNTYRE, C. L.; NAYLOR, R.; NAVARRO, J.; OBERSTEINER, M.; PARODI, A.; PEOPLES, M. B.; PIKAAR, I.; POPP, A.; ROCKSTROM, J.; ROBERTSON, M. J.; SMITH, P.; STEHFEST, E.; SWAIN, S. M.; VALIN, H.; VAN WIJK, M.; VAN ZANTEN, H. H. E.; VERMEULEN, S.; VERVOORT, J.; WEST, P. C. Innovation can accelerate the transition towards a sustainable food system. Nature Food, v. 1, p. 266-272, May 2020. Perspective.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: B - 5 |
| Biblioteca(s): Embrapa Agroenergia. |
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| 10. | | EASTWOOD, R. J.; TAMBAM, B. B.; ABOAGYE, L. M.; AKPAROV, Z. I.; ALADELE, S. E.; ALLEN, R.; AMRI, A.; ANGLIN, N.; ARAYA, R.; ARRIETA-ESPINOZA, G.; ASGEROV, A.; AWANG, K.; AWAS, T.; BARATA, A. M.; BOATENG, S. K.; BREHM, J. M.; BREIDY, J.; BREMAN, E.; ANGULO, A. B.; BURLE, M. L.; CASTAÑEDA-ÁLVAREZ, N. P.; CASIMIRO, P.; CHAVES, N. F.; CLEMENTE, A. S.; COCKEL, C. P.; DAVEY, A.; LA ROSA, L. de; DEBOUCK, D. G.; DEMPEWOLF, H.; DOKMAK, H.; ELLIS, D.; FARUK, A.; FREITAS, C.; GALSTYAN, S.; GARCÍA, R. M.; GHIMIRE, K. H.; GUARINO, L.; HARKER, R.; HOPE, R.; HUMPHRIES, A.; JAMORA, N.; JATOI, S. A.; KHUTSISHVILI, M.; KIKODZE, D.; KYRATZIS, A. C.; LEÓN-LOBOS, P.; LIU, U.; MAINALI, R. P.; MAMMADOV, A. T.; MANRIQUE-CARPINTERO, N. C.; MANZELLA, D.; ALI, M. S. M.; MEDEIROS, M. B. de; GUZMÁN, M. A. M.; MIKATADZE-PANTSULAIA, T.; MOHAMED, E. T. I.; MONTEROS-ALTAMIRANO, A.; MORALES, A.; MÜLLER, J. V.; MULUMBA, J. W.; NERSESYAN, A.; NÓBREGA, H.; NYAMONGO, D. O; OBREZA, M.; OKERE, A. U.; ORSENIGO, S.; ORTEGA-KLOSE, F.; PAPIKYAN, A.; PEARCE, T. R.; CARVALHO, M. A. A. P. de; PROHENS, J.; ROSSI, G.; SALAS, A.; SHRESTHA, D. S.; SIDDIQUI, S. U.; SMITH, P. P.; SOTOMAYOR, D. A.; TACÁN, M.; TAPIA, C.; TOLEDO, A.; TOLL, J.; VU, D. T.; VU, T. D.; WAY, M. J.; YAZBEK, M.; ZORRILLA, C.; KILIAN, B. Adapting agriculture to climate change: a synopsis of Coordinated National Crop Wild Relative Seed Collecting Programs across five continents. Plants, v. 11, 2022. 1840. Na publicação: Marcelo B. Medeiros.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: A - 4 |
| Biblioteca(s): Embrapa Recursos Genéticos e Biotecnologia. |
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| 11. | | MILNE, E.; BANWART, S. A.; NOELLEMEYER, E.; ABSON, D. J.; BALLABIO, C.; BAMPA, F.; BATIONO, A.; BATJES, N. H.; BERNOUX, M.; BHATTACHARYYA, T.; BLACK, H.; BUSCHIAZZO, D. E.; CAI, Z.; CERRI, C. E.; KUN, C.; COMPAGNONE, C.; CONANT, R.; COUTINHO, H. L. C.; BROGNIEZ, D. de; BALIEIRO, F. de C.; DUFFY, C.; FELLER, C.; FIDALGO, E. C. C.; SILVA, C. F. da; FUNK, R.; GAUDIG, G.; GICHERU, P. T.; GOLDHABER, M.; GOTTSCHALK, P.; GOULET, F.; GOVERSE, T.; GRATHWOHL, P.; JOOSTEN, H.; KAMONI, P. T.; KIHARA, J.; KRAWCZYNSKI, R.; SCALA JUNIOR, N. la; LEMANCEAU, P.; LI, L.; LI, Z.; LUGATO, E.; MARON, P. A.; MARTIUS, C.; MELILLO, J.; MONTANARELLA, L.; NIKOLAIDIS, N.; NZIGUHEBA, G.; PAN, G.; PASCUAL, U.; PAUSTIAN, K.; PIÑEIRO, G.; POWLSON, D.; QUIROGA, A.; RICHTER, D.; SIGWALT, A.; SIX, J.; SMITH, J.; SMITH, P.; STOCKING, M.; TANNEBERGER, F.; TERMANSEN, M.; NOORDWIJK, M. van; WESEMAEL, B. van; VARGAS, R.; VICTORIA, R. L.; WASWA, B.; WERNER, D.; WICHMANN, S.; WICHTMANN, W.; ZHANG, X.; ZHAO, Y.; ZHENG, J.; ZHENG, J. Soil carbon, multiple benefits. Environmental Development, v. 13, p. 33-38, Jan. 2015.| Tipo: Artigo em Periódico Indexado | Circulação/Nível: B - 1 |
| Biblioteca(s): Embrapa Solos. |
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| Registros recuperados : 11 | |
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| Nenhum registro encontrado para a expressão de busca informada. |
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