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Previous issue date: 2008-02-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Nematodes are possibly one of the oldest forms of existing life. They are microscopical animals
and respond to changes in the environment. This work has the objective to extend the referring
knowledge to the influences of the land use cover changes systems over the population of soil
nematodes. One gives credit that the different systems of agricultural management and land
cover act directly on the population of the nematodes. The study discussed in Chapter 1 was
lead from an experiment of long term duration in the experimental field of the Embrapa Gado de
Corte in Campo Grande MS. The evaluated treatments were: CD - original Cerrado forest, an
area without disturbance for agriculture; PL - permanent pasture of B. decumbens implanted in
December of 1993, joined with the mucunoides legumes with fertilization of biennial
maintenance; SCV - area under continuous farming of soybean since 1993, with conventional
management, without winter culture, SCS - area under continuous farming of soybean since
1993, conservacionist soil, with plantation of millet in the winter; SPD - area under continuous
farming of soybean since 1993, without soil preparation, with direct plantation of the soybean
with millet in the winter. Based on taxonomics characteristics and ecological parameters, the
nematodes communities were analyzed in function of the total abundance, trophic function,
standard of decomposition of the organic substance, diversity of Shannon, dominance of
Simpson, equitability of Pielou and degree of disturbance. It was observed that there had been
identified a total of 70 genus accumulated in the five studied. The genus most abundant was
Helicotylenchus, Acrobeles, Eucephalobus, Cephalobus and Tylenchus. The systems CD and
SCS presented the highest numbers of genus (S) of nematodes. The CD system showed the
highest diversity of nematodes followed by SCS. The systems PL and SCV presented the
highest values for the index of Simpson dominance, with the higher number of fitoparasitic
nematodes. The system CD presented greater equitabilility of the genus of nematodes. The
system CD had the highest index of maturity, followed by SCS and PL presented which showed
the lowest index of maturity. The ratio of the trophic groups, dominated by fitoparasitics and
bacterivores, was similar to the registered in the literature in pastures. The standard
decomposition of the organic substance was differentiated in accordance with the land use cover
change. The objective of the study in Chapter 2 was to evaluate the relation between the
environment variables over the genus diversity and abundance of nematodes in different
systems of soil management in Campo Grande - MS. This relation was evaluated with Canonic
Analysis of Correspondence (CCA) in two samplings. The CCA was used to show the
importance of the environmental variables in the explanation of the standard of occurrence of
nematodes in the present study. It was observed that the CCA made possible the separation
between the sampling systems and observed that system SPD presented greater correlations
with variables such as humidity, Corg and FLL. The environmental variable that had presented
greater correlation with the CD were P, FLL, FI and pH in 2004 winter samples. In 2005
summer, the diagram of the CCA presented a distinct configuration of the presented one in the
first collection. The CCA was useful to organize and to analyze two complex scenarios used in
this study. During both periods systems SCS and SPD had the biggest similarity with the
functional groups. In the multivaried PRC was observed that it had great seasonal fluctuation in
the composition of nematofauna in all the systems / Os nemat?ides s?o, possivelmente, uma das formas mais antigas de vida existente, s?o animais
microsc?picos e respondem com rapidez ?s mudan?as no ambiente. Esse trabalho objetivou
ampliar o conhecimento referente ?s influ?ncias dos sistemas de manejo e cobertura do solo na
popula??o de nemat?ides do solo. Acredita-se que os diferentes sistemas de manejo agr?cola e
coberturas vegetais atuem de forma vari?vel sobre a popula??o dos nemat?ides do solo. O
estudo apresentado no Cap?tulo 1 foi conduzido a partir de um experimento de longa dura??o no
campo experimental da Embrapa Gado de Corte em Campo Grande MS. Os tratamentos
avaliados foram: CD - Mata original de cerrados, PL - Pastagem permanente de B. decumbens
implantada em dezembro de 1993, consorciada com as leguminosas e mantida com aduba??o de
manuten??o bianual, SCV - ?rea sob lavoura cont?nua de soja desde 1993, com preparo do solo
convencional (uma ara??o e duas gradagens), sem cultura de inverno, SCS - ?rea sob lavoura
cont?nua de soja desde 1993, preparo de solo conservacionista (uma ara??o e uma gradagem),
com plantio de milheto no inverno, SPD - ?rea sob lavoura cont?nua de soja desde 1993, sem
preparo de solo, com plantio direto da soja onde foi cultivado milheto no inverno. Baseando-se
em caracter?sticas taxon?micas e par?metros ecol?gicos, as comunidades de nemat?ides foram
analisadas em fun??o da abund?ncia total, fun??o tr?fica, padr?o de decomposi??o da mat?ria
org?nica, ?ndices de diversidade de Shannon, domin?ncia de Simpson, equitabilidade de Pielou
e grau de dist?rbio. Analisando os resultados, observou-se que foi identificado um total de 70
g?neros acumulados nos cinco sistemas de manejo. Os g?neros mais abundantes foram
Helicotylenchus , Acrobeles, Eucephalobus, Cephalobus e Tylenchus. Os sistemas CD e SCS
apresentaram as maiores riquezas de g?neros (S) de nemat?ides. O sistema CD apresentou a
maior diversidade de nemat?ides seguido do sistema SCS. Os sistemas PL e SCV apresentaram
os maiores valores do ?ndice de domin?ncia de Simpson, com domin?ncia de nemat?ides
fitoparasitas. O sistema CD apresentou maior equitabilidade dos g?neros de nemat?ides. O
sistema CD apresentou o maior ?ndice de maturidade e o sistema PL apresentou o menor ?ndice
de maturidade. A propor??o dos grupos tr?ficos, dominado por fitoparasitas e bacteri?fagos, foi
semelhante ao registrado em literatura em sistemas de pastagens. O padr?o de decomposi??o da
mat?ria org?nica foi diferenciado de acordo com a cobertura do solo. O objetivo do estudo do
Cap?tulo 2 foi avaliar a rela??o entre a composi??o de g?neros de nemat?ides e vari?veis
ambientais em diferentes sistemas de manejo do. Para que esta rela??o fosse avaliada utilizou-se
a An?lise de Correspond?ncia Can?nica (CCA) em duas ?pocas de coleta. A CCA foi utilizada
para mostrar a import?ncia das vari?veis ambientais na explica??o do padr?o de ocorr?ncia de
nemat?ides no presente estudo. Observou-se que a CCA possibilitou a separa??o entre os
sistemas de manejo. O que o sistema SPD apresentou maiores correla??es com vari?veis ligadas
ao maior aporte de mat?ria org?nica. As vari?veis ambientais que apresentaram maior
correla??o com o sistema CD foram P, Fra??o Leve Livre, Fra??o Intra-agregado e pH na coleta
realizada no inverno de 2004. A CCA foi ?til para organizar e analisar dois complexos grupos
de dados utilizados neste estudo. Nas duas ?pocas avaliadas neste, os sistemas SCS e SPD
mantiveram a maior similaridade quanto ? distribui??o dos grupos funcionais. Na an?lise curva
de resposta principal (Principal Response Curves, PRC), observou-se que houve grande
flutua??o sazonal na composi??o da nematofauna em todos os sistemas.
| Identifer | oai:union.ndltd.org:IBICT/oai:localhost:tede/310 |
| Date | 15 February 2008 |
| Creators | Figueira, Adriana Fran?a |
| Contributors | Berbara, Ricardo Luiz Louro, Miranda, Cesar Heraclides Behling, Pimentel, Joao Pedro |
| Publisher | Universidade Federal Rural do Rio de Janeiro, Curso de P?s-Gradua??o em Agronomia - Ci?ncia do Solo, UFRRJ, Brasil, Ci?ncias Agr?rias |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFRRJ, instname:Universidade Federal Rural do Rio de Janeiro, instacron:UFRRJ |
| Rights | info:eu-repo/semantics/openAccess |
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