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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Efeito de subst?ncias h?micas extra?das da mat?ria org?nica de turfeiras e de composto org?nico de res?duos da ind?stria t?xtil na reten??o de ?gua

Freire, Rafaela Dias de Arag?o 08 March 2013 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-23T14:01:55Z No. of bitstreams: 5 24.pdf: 1672619 bytes, checksum: 7cbd597a7354691931425838749b58c7 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2109 bytes, checksum: aa477231e840f304454a16eb85a9235f (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-10T13:03:11Z (GMT) No. of bitstreams: 5 24.pdf: 1672619 bytes, checksum: 7cbd597a7354691931425838749b58c7 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2109 bytes, checksum: aa477231e840f304454a16eb85a9235f (MD5) / Made available in DSpace on 2015-02-10T13:03:11Z (GMT). No. of bitstreams: 5 24.pdf: 1672619 bytes, checksum: 7cbd597a7354691931425838749b58c7 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2109 bytes, checksum: aa477231e840f304454a16eb85a9235f (MD5) Previous issue date: 2013 / A mat?ria org?nica do solo (MOS) relaciona-se intimamente com a capacidade de reten??o de ?gua pelo solo. As turfeiras e os compostos org?nicos s?o materiais ricos em MOS. O objetivo do trabalho foi quantificar a capacidade de reten??o de ?gua da humina (H) e dos ?cidos h?micos (AH) da mat?ria org?nica (MO) de turfeiras e de composto org?nico proveniente de res?duos da ind?stria t?xtil, puros e em mistura com areia. O fracionamento dos materiais seguiu uma adapta??o da metodologia da Internacional Humic Substances Society. Obtiveram-se os substratos advindos das seguintes propor??es de subst?ncias h?micas (SH), provenientes de turfeira e de composto, e areia (fina e m?dia): 0 % SH e 100 % de areia fina (AF) e m?dia (AM); 100 % SH e 0 % de areia AF ou AM; 75 % SH e 25 % AF ou AM; 50 % SH e 50 % AF ou AM; 25 % SH e 75 % AF ou AM. Com o aux?lio do extrator de Richards foram determinados os teores de ?gua retida nas tens?es de 0 (CMRA), 10, 100, 300, 500, 700 kPa, para todos os substratos. Foi feita a an?lise de vari?ncia. N?o se observou diferen?as estat?sticas entre substratos com 100 % de AF e AM. Analisando-se as diferen?as de reten??o de ?gua dos substratos com 100% de AH e da H, e as diferen?as de origem (composto e turfeira), encontrou-se as maiores reten??es para os substratos com AH e para os substratos com SH provenientes de turfeira. A humina ? a SH que predomina amplamente no composto de res?duos de industria t?xtil e de turfeira. A maior reten??o de ?gua, na CMRA e nas tens?es 10, 100, 300, 500 e 700 kPa, foi obtida pelo substrato com 100% de AH em rela??o aos substratos com 100% de H. Os substratos com diferentes propor??es de AH e areia apresentaram reten??o de ?gua semelhante aos substratos com diferentes propor??es de H e areia. O substrato que obteve as maiores reten??es de ?gua foi 75 % de SH e 25 % de AF. Os AH e a H apresentam hidrofilia e tem potencial para a fabrica??o do hidrorretentor org?nico sustent?vel. Pela modelagem de reten??o de ?gua, a perda de ?gua pelos substratos ? base de H ? bem mais evidente na CMRA. Para os substratos ? base de AH a perda de ?gua com o aumento da press?o aplicada se torna mais evidente nas propor??es de 75 % de SH e principalmente, na CMRA. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013.
2

Caracteriza??o qualiquantitativa dos recursos h?dricos e da din?mica do carbono de turfeiras das cabeceiras do Rio Ara?ua?

Bispo, Di?go Faustolo Alves 23 August 2013 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-23T13:04:51Z No. of bitstreams: 2 diego_faustolo_alves_bispo.pdf: 4358144 bytes, checksum: c31dd0a5e7a197ab14657a12c115ae66 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-23T13:05:17Z (GMT) No. of bitstreams: 2 diego_faustolo_alves_bispo.pdf: 4358144 bytes, checksum: c31dd0a5e7a197ab14657a12c115ae66 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2014-12-23T13:05:35Z (GMT) No. of bitstreams: 2 diego_faustolo_alves_bispo.pdf: 4358144 bytes, checksum: c31dd0a5e7a197ab14657a12c115ae66 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) / Made available in DSpace on 2014-12-23T13:05:35Z (GMT). No. of bitstreams: 2 diego_faustolo_alves_bispo.pdf: 4358144 bytes, checksum: c31dd0a5e7a197ab14657a12c115ae66 (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Previous issue date: 2013 / As turfeiras s?o importantes reguladores dos fluxos de ?gua e de elementos, principalmente do carbono, entre os compartimentos terrestres e aqu?ticos. O objetivo deste trabalho foi caracterizar qualiquantitativamente os Organossolos e os recursos h?dricos das turfeiras das cabeceiras do Rio Ara?ua? quanto ? disponibilidade h?drica e a din?mica do carbono no sistema solo-?gua. Coletou-se oito testemunhos representantes de quatro perfis de solo do Campo Limpo ?mido e Floresta Estacional Semidecidual de duas turfeiras nas cabeceiras de afluentes do Rio Ara?ua? (C?rrego Cachoeira dos Borges e Rio Preto), descritos e caracterizados f?sica, qu?mica, elementar e morfologicamente. Em tr?s pontos do curso d??gua de cada afluente e duas ?pocas (chuvosa e seca) foram coletadas amostras de ?gua e analisados os seus atributos f?sicos e qu?micos. Procedeu-se o mapeamento das turfeiras e o c?lculo dos volumes e fluxos de ?gua e de carbono. Empregou-se an?lise de vari?ncia para atestar o efeito das fitofisionomias, profundidades de amostragem e das intera??es destes fatores sobre as vari?veis do solo. Para os atributos da ?gua atestaram-se efeitos dos locais (afluentes), ?pocas de amostragem e das intera??es entre estes fatores. Boa parte dos atributos caracterizadores da mat?ria org?nica e a composi??o elementar do solo apresentaram diferen?as significativas entre os locais, fitofisionomias e profundidades de amostragem e variaram em fun??o da composi??o e grau de evolu??o do material org?nico. A maioria dos atributos f?sico-qu?micos das ?guas n?o diferenciou entre os locais e nem entre as ?pocas, mas foram influenciados pelos atributos dos Organossolos de onde se originam. A turfeira do Rio Preto estoca 4.299,39 t de C (206,70 t ha-1) e 227.258,15 m3 de ?gua (10.925,87 m3 ha-1) e a turfeira do C?rrego Cachoeira dos Borges estoca 14.781,09 t de C (184,10 t ha-1) e 745.950,30 m3 de ?gua (9.290,70 m3 ha-1). A vaz?o do Rio Preto foi de 0,023 m3 s-1 e do C?rrego Cachoeira dos Borges foi de 0,067 m3 s-1 no per?odo chuvoso. No per?odo seco estes cursos d??gua apresentaram vaz?o m?nima constante, demonstrando a capacidade das turfeiras de suas cabeceiras de perenizar a vaz?o. Estimou-se o lan?amento de uma carga m?dia de 360,84 t ano-1 de N e 6.812,73 t ano-1 de C e de 917,32 t ano-1 de N e 33.516,16 t ano-1 de C, respectivamente para o Rio Preto e C?rrego Cachoeira dos Borges. As turfeiras das cabeceiras dos afluentes do Rio Ara?ua? influenciam significativamente na vaz?o e na qualidade de suas ?guas, sendo urgente a necessidade de preserva??o destes pedoambientes. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2013. / ABSTRACT The peatlands are important regulators of water flows and elements between terrestrial and aquatic compartments, especially of the carbon. The objective of this study was to characterize qualitatively and quantitatively the Histosols and water resources of headwater from peatlands of the Rio Ara?ua? as to hydric availability and carbon dynamics in the soil-water system. Been collected eight testimonies representatives from four soil profiles of moist meadow and semi-deciduous seasonal forest in two peatlands in the headwaters of affluents of the Rio Ara?ua? (C?rrego Cachoeira dos Borges e Rio Preto), described and characterized physics, chemistry, elementary and morphologically. In three points of each watercourse affluent and two seasons (wet and dry) water samples were collected and analyzed their physical and chemical attributes. Been done the mapping of peatlands and the calculation of volumes and flows of water and carbon. It was used analysis of variance to attested effect of vegetation types, sampling depths and the interactions of these factors over soil variables. For the attributes of water attested effects of local (affluents), sampling periods and the interactions between these factors. Much of the attributes that characterize the organic matter and elemental composition of the soil, showed significant differences between the sites, vegetation types and depths of sampling and varied according to the composition and degree of evolution of the organic material. Most physical and chemical attributes of the water did not differ between the sites and between sampling periods, but were influenced by the attributes of the Histosols of where they originate. The peatland from Rio Preto stocks 4,299.39 tons of C (206.70 tons ha-1) and 227,258.15 m3 (10,925.87 m3 ha-1) of water and peatland from the C?rrego Cachoeira dos Borges stocks 14,781.09 tons of C (184.10 tons ha-1) and 745.950,30 m3 (9.290,70 m3 ha-1) of water. The flow of water of the Rio Preto was 0.023 m3 s-1 and of the C?rrego Cachoeira dos Borges was 0.067 m3 s-1 in the rainy season. These watercourses showed constant minimum flow in the dry season, demonstrating the capacity of peatlands its headwaters to maintain water flow. It has been estimated the launch of a load average of 360.84 tons year-1 of N and 6812.73 tons year-1 of C and of 917.32 tons year-1 of N and 33516.16 tons year-1 of C respectively for the Rio Preto and C?rrego Cachoeira dos Borges. The peatlands from the headwaters of the affluents of the Rio Ara?ua? have a significant influence the flow and quality of its waters, and the urgent need to preservation these pedological environments.
3

Efeito de fontes e doses de ?cidos h?micos na produ??o do feij?o (Phaseolus vulgaris L.) / Effects of sources and doses of humic acids in bean production (Phaseolus vulgaris L.)

Barral, Uidemar Morais January 2015 (has links)
Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2016-01-05T13:42:22Z No. of bitstreams: 2 uidemar_morais_barral.pdf: 1274629 bytes, checksum: d89bbca6115310a0b5ad8323167ba551 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2016-01-05T18:01:03Z (GMT) No. of bitstreams: 2 uidemar_morais_barral.pdf: 1274629 bytes, checksum: d89bbca6115310a0b5ad8323167ba551 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) / Made available in DSpace on 2016-01-05T18:01:03Z (GMT). No. of bitstreams: 2 uidemar_morais_barral.pdf: 1274629 bytes, checksum: d89bbca6115310a0b5ad8323167ba551 (MD5) license_rdf: 22974 bytes, checksum: 99c771d9f0b9c46790009b9874d49253 (MD5) Previous issue date: 2015 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / A mat?ria org?nica (MOS) do solo consiste de uma mistura de compostos em v?rios est?gios de decomposi??o, resultante da degrada??o biol?gica de res?duos de plantas e animais, e da atividade de microrganismos, denominados subst?ncias h?micas (SHs). Essas subst?ncias fracionadas em ?cidos f?lvicos (AF), ?cidos h?micos (AH) e humina (H), de acordo com sua solubilidade em meio ?cido ou b?sico. Os AH t?m sido usados como fertilizantes aplicados diretamente no solo ou via foliar, principalmente por influenciarem o metabolismo das plantas. Objetivou-se com este trabalho avaliar em feijoeiro (Phaseolus vulgaris L.), a influ?ncia de fontes e doses diferentes de AH, na produ??o, crescimento radicular e absor??o de nutrientes e biodisponibilidade de nutrientes no solo. O experimento foi conduzido utilizando o delineamento em blocos casualizados com 15 tratamentos, sendo estes as fontes de AH (turfa - 1, composto - 2 e produto comercial - 3) e as doses de AH (0, 2, 8, 16 e 32 kg ha-1), com quatro repeti??es. Foram avaliadas: altura das plantas (cm), di?metro do caule (cm), teor de clorofila (?g cm-2) e teor de macro e micronutrientes nas folhas no florescimento do feijoeiro e ao fim do experimento, peso de sementes (g), massa seca da parte a?rea e de ra?zes (g), n?mero de vagem por planta e de sementes por vagem e no solo: pH em ?gua e teores de mat?ria org?nica, P, K, Ca, Mg, Al e H+Al. A aplica??o de AH reduziu o crescimento e produ??o de gr?o, com aumento das doses em cada fonte, seguindo a ordem fonte 3 > fonte 1 > fonte 2. Os teores de P, K, Cu, Fe, Mn e Zn nas folhas foram influenciados pelas doses de todas as fontes de AH. Houve redu??o para maioria dos nutrientes quantificados nas folhas com aumento das doses de AH. Os teores de P e K se elevaram no solo, com a aplica??o de AH. Para condi??es testadas, n?o se recomenda utiliza??o de AH para cultura do feijoeiro. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Produ??o Vegetal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2015. / ABSTRACT The soil organic matter (SOM) consists of a mixture of compounds in many decomposition stages, the result of biological degradation of residues of plants and animals, and microorganisms activity, called humic substances (HS). These substances are fractionated into fulvic acids (FA), humic acids (HA) and humin (H), according to their solubility in acidic or basic medium. HA have been used as fertilizers directly applied to the soil or via foliar, mainly because they influence plants metabolism. The main goal of this study was evaluating, in bean plant (Phaseolus vulgaris L.), the influence of sources and different doses of HA in production, root growth, nutrients absorption and bioavailability of nutrients in the soil. The experiment was conducted using randomized block design with 15 treatments, which are the sources of HA (peat ? 1, compound ? 2 and commercial product ? 3) and doses of HA (0, 2, 8, 16 e 32 kg ha-1), with four repetitions. Evaluations were made on: plants height (cm), stem diameter (cm), chlorophyll content (?g cm-2) and content of macro and micronutrients in the leaves in the flowering stages and in the end of the experiment, seeds weight (g), dry matter of the aerial part and roots (g), number of pods per plant and seeds per pod, and in the soil: pH in water and contents of organic matter, P, K, Ca, Mg, Al and H+Al. Application of HA reduced bean growth and production, with increase of doses in each source, following order: source 3 > source 1 > source 2. Contents of P, K, Cu, Fe, Mn and Zn in the leaves were influenced by the doses of all HA sources. Most of the nutrients quantified in the leaves were reduced with increasing HA doses. Contents of P and K were increased in the soil with application of HA. For tested conditions, the use of HA for bean culture is not recommended.
4

Crescimento inicial e morfologia foliar em plantas de Mimosa caesalpiniaefolia Benth. Em fun??o do manejo microbiano, sob estresse salino

Menezes, Virginia Cl?udia de Lima 19 December 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-03T20:33:06Z No. of bitstreams: 1 VirginiaClaudiaDeLimaMenezes_DISSERT.pdf: 1208323 bytes, checksum: b1e6f942167139cbb5930b457a0c271a (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-03-08T23:06:45Z (GMT) No. of bitstreams: 1 VirginiaClaudiaDeLimaMenezes_DISSERT.pdf: 1208323 bytes, checksum: b1e6f942167139cbb5930b457a0c271a (MD5) / Made available in DSpace on 2016-03-08T23:06:45Z (GMT). No. of bitstreams: 1 VirginiaClaudiaDeLimaMenezes_DISSERT.pdf: 1208323 bytes, checksum: b1e6f942167139cbb5930b457a0c271a (MD5) Previous issue date: 2014-12-19 / O sabi? (Mimosa caesalpiniaefolia Benth.) ? uma esp?cie end?mica do bioma Caatinga, sendo considerada tolerante aos estresses salino e h?drico. O processo de saliniza??o dos solos e das ?guas subterr?neas e superficiais ? um dos mais importantes problemas de degrada??o ambiental, com seus efeitos prejudiciais sendo mais pronunciados nas ?reas de regi?es ?ridas e semi?ridas, e que vem crescendo rapidamente em diversas partes do globo, causando problemas de grandes propor??es na produtividade das culturas agr?colas. Condicionadores org?nicos como esterco de curral e casca de arroz podem contribuir para redu??o da PST, possivelmente em virtude da libera??o de CO2 e produ??o de ?cidos org?nicos, durante a decomposi??o da mat?ria org?nica, al?m de atuarem como fontes de c?lcio e magn?sio e inibirem a disponibilidade do s?dio. A associa??o ?ntima e ben?fica das micorrizas com as plantas resulta no aumento da absor??o de ?gua e nutrientes pelos vegetais, principalmente o f?sforo, devido sua baixa mobilidade no solo. O objetivo deste trabalho foi a avalia??o do crescimento inicial de mudas de sabi? sob inocula??o com fungos micorr?zicos arbusculares, adubadas com esterco de curral e irrigadas com ?gua de diferentes n?veis de salinidade. O experimento foi instalado em condi??es de casa de vegeta??o nas depend?ncias da Escola Agr?cola de Jundia? - UFRN, Campus Maca?ba. O delineamento estat?stico adotado foi o inteiramente casualizado composto de doze tratamentos ? tr?s substratos (solo est?ril, esterco e FMA), quatro n?veis de salinidade (0,2; 1,5; 3,0 e 4,5 dS m-1 ) e cinco repeti??es, totalizando sessenta unidades experimentais. Os resultados indicam que a inocula??o de fungos micorr?zicos possui contribui??es para o crescimento das plantas, sobretudo em ra?zes e parte a?rea, o que sugere que sua aplica??o seja ben?fica no estabelecimento de plantas de sabi? em condi??es naturais, com solo pobre em P. Os n?veis de salinidade n?o causaram efeitos com relev?ncia estat?stica no desenvolvimento das plantas, indicando a resist?ncia do sabi? ? mesma. / The sabi? (Mimosa caesalpiniaefolia Benth.) is an endemic species of the Caatinga biome, considered tolerant to salt and water stress. The process of salinization of soil and groundwater and surface water is one of the most important problems of environmental degradation, with its harmful effects being more pronounced in the areas of arid and semiarid regions, and rapidly growing in many parts of the globe, causing problems of the major crop yield. Organic conditioners as barnyard manure, and rice hulls can contribute to reducing the PST, possibly due to the release of CO2 and the production of organic acids during the decomposition of organic matter, and act as sources of calcium and magnesium and inhibit the availability sodium. The intimate association of mycorrhizae and beneficial to plants results in increased uptake of water and nutrients by plants, especially phosphorus, due to their low mobility in soil. The objective of this study was to evaluate the initial growth of thrush seedlings under inoculation with mycorrhizal fungi and fertilized with manure corral and irrigated with water of different salinity levels. The experiment was conducted in greenhouse conditions of vegetation on the premises of the Agricultural School of Jundia? - UFRN, Campus Maca?ba. The adopted statistical design was randomized composed of twelve treatments - three substrates (sterile soil, manure and FMA), four salinity levels (0.2, 1.5, 3.0 and 4.5 dS m-1 ) and five repetitions, totaling sixty experimental units. The results indicate that inoculation with mycorrhizal fungi own contributions to the growth of plants, especially in roots and shoots, which suggests that its application is beneficial in establishing thrush plants in natural conditions, with poor soil in P. Levels salinity caused no effects with statistical significance in plant development, indicating Sabia resistance to it.
5

Influ?ncia do manejo da palhada de aveia-preta e tremo?o-branco sobre a fauna invertebrada do solo em ambiente de montanha / Influence of the management of black oats and lupines albus straw on the invertebrate fauna of the soil in mountain environment

Antunes, Tayana Galv?o Sceiffer de Paula 31 May 2016 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-07-26T16:23:58Z No. of bitstreams: 1 2016 - Tayana Galv?o Scheiffer de Paula Antunes.pdf: 886909 bytes, checksum: 3d81bdb995e369056c9a96e210803d4c (MD5) / Made available in DSpace on 2017-07-26T16:23:58Z (GMT). No. of bitstreams: 1 2016 - Tayana Galv?o Scheiffer de Paula Antunes.pdf: 886909 bytes, checksum: 3d81bdb995e369056c9a96e210803d4c (MD5) Previous issue date: 2016-05-31 / Aiming to obtain information to support the biodiversity management that enable sustainable production systems and ensure the quality of natural resources, this study contribute to increasing agricultural productivity based on the use of green manure in a sustainable manner, aiming to evaluate the behavior of winter green manures lupines albus, black oats and the consortium between those two in mountain environment, and the influence of the herbicide decomposition rate of straws from these plants and diversity and abundance of soil fauna. The experiment was conducted in the area of EscolaT?cnicaAgr?colaEstadualRei Alberto I, located in the Watershed Barrac?o dos Mendes, Municipality of NovaFriburgo, mountainous region on the state of Rio de Janeiro at an altitude of 1,065m. The experimental design was a randomized complete block design with four treatments: black oat, lupines albus, consortium and weeds, with four replications each, totaling 16 plots in the first stage of work, experiment 1. On the experiment 2, the plots were subdivided into two management systems, mechanical, where the plants were mowed and chemical, which occurred application of glyphosate herbicide, for the deposition of the straws on the ground. On the first part, productivity of green manure was evaluated, as well as the accumulation of nutrients and the epigaeous fauna associated to vegetation. The second part, after the management of the green manure, aimed the evaluation of mass loss of plant residues, epigaeous fauna and associated soil macrofauna. The main results showed that the lupine, single or consortium obtained satisfactory productivity, both in terms of biomass and the amount of accumulated nutrients, presenting potential for use in the mountainous region of Rio de Janeiro. The loss of mass of the residues was affected by the use of herbicide. The community of epigaeous fauna was not a good indicator because it didn?t suffer significant changes before or after the green manure management. The colembolas population was negatively afected by the herbicide. The soil macrofauna was more sensitive to the diferent forms of management, and the reduction of the density soil organisms could be observed up to 10 times when the plants were sprayed with herbicide. It was also noted the reduction on the macrofauna diversity. There was no difference in the chemical composition of the soil due to different covers and forms of management / Visando obter informa??es que ap?iem a proposi??o de manejos de gest?o da biodiversidade, que viabilizem sistemas de produ??o sustent?veis e garantam a qualidade dos recursos naturais, este estudo pretende colaborar com o aumento da produtividade agr?cola com base no uso da aduba??o verde, de forma sustent?vel. Nesse sentido, o presente trabalho teve como objetivo avaliar o comportamento dos adubos verdes de inverno tremo?o-branco, aveia-preta e do cons?rcio entre os dois, em ambiente de montanha, e a influ?ncia do herbicida na taxa de decomposi??o das palhadas dessas plantas e na diversidade e abund?ncia da fauna do solo. O experimento de campo foi conduzido na ?rea da Escola T?cnica Agr?cola Estadual Rei Alberto I, localizada na Microbacia do Barrac?o dos Mendes, Munic?pio de Nova Friburgo, Regi?o Serrana do Estado do Rio de Janeiro, a uma altitude de 1.065 m. O Delineamento experimental adotado foi o de blocos casualizados, com quatro tratamentos: aveia-preta, tremo?o-branco, cons?rcio e plantas espont?neas, com quatro repeti??es cada, totalizando 16 parcelas na primeira etapa do trabalho, etapa I. Na etapa II, as parcelas foram subdivididas em duas formas de manejo, mec?nico, onde as plantas foram ro?adas, e qu?mico, onde ocorreu aplica??o do herbicida glifosato, para a deposi??o das palhadas sobre o solo. Na etapa I, estudou-se a produtividade das plantas de cobertura, bem como o ac?mulo de nutrientes e a fauna ep?gea associada ?vegeta??o. Na segunda etapa, ap?s o manejo das plantas de cobertura, foi realizada a avalia??o da perda de massa dos res?duos vegetais, fauna ep?gea e macrofauna ed?fica associadas a esses res?duos. Como principais resultados, observou-se que o tremo?o, solteiro ou consorciado, obteve produtividade satisfat?ria, tanto em termos de fitomassa, quanto de quantidades de nutrientes acumulados, apresentando potencial para o uso na Regi?o Serrana do Rio de Janeiro. A perda de massa dos res?duos vegetais foi afetada com o uso de herbicida. A comunidade da fauna ep?gea n?o foi um bom indicador, pois n?o sofreu significativas modifica??es antes ou ap?s o manejo das plantas de cobertura. No entanto, as popula??es de col?mbolos foram afetadas negativamente pelo herbicida. J? a comunidade da macrofauna ed?fica se mostrou mais sens?vel ?s formas de manejo, sendo observada a redu??o da densidade dos organismos do solo ? metade e em at? 10 vezes, quando as plantas foram manejadas com herbicida. Observou-se tamb?m redu??o da diversidade da macrofauna. N?o houve diferen?a na composi??o qu?mica do solo em fun??o das diferentes coberturas e formas de manejo
6

Organossolos: fun??es de pedotransfer?ncia para densidade do solo, avalia??o do grau de subsid?ncia, e estoques de carbono / Histosols: bulk density pedotransfer functions, evaluation of subsidence rate, and carbon stocks

BEUTLER, Sidinei Julio 25 February 2016 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-08-22T19:26:53Z No. of bitstreams: 1 2016 - Sidinei Julio Beutler.pdf: 3474278 bytes, checksum: 1adaf2ecd1077cf6ca3fa70c64954a43 (MD5) / Made available in DSpace on 2017-08-22T19:26:53Z (GMT). No. of bitstreams: 1 2016 - Sidinei Julio Beutler.pdf: 3474278 bytes, checksum: 1adaf2ecd1077cf6ca3fa70c64954a43 (MD5) Previous issue date: 2016-02-25 / CAPES / The Histosols are a major source of carbon storage in terrestrial environments and have high susceptibility to carbon losses when disturbed. The objective of this study was to generate pedotransfer functions (FPT) to assess the accuracy of previously published equations, applying them to predict soil bulk density (Bd) in organic soils from Brazil; to evaluate subsidence rate, and the variation of Bd and carbon of humic substances in Histosols over a period of one year; and to estimate stock and potential loss of carbon in Histosols from Rio de Janeiro State. For the first part of the study, there were used organic horizons, i.e., soil materials with total organic carbon (TOC) equal to or greater than 80 g kg-1 soil, totaling 280 horizons from different regions of Brazil. It was used the multiple linear regression technique and the equations were validated on independent data. There were tested 9 equations already published in the literature. The equations with better performance were the Hollis and FPT2, with R2 validation parameters of 0.48 and 0.49. When the clay fraction data is availlable, it is recommended to use the FPT1 equation; if there is no data on clay it is recommended the FPT2 and Hollis equations, which have only the TOC as a predictor variable. For the second part, a greenhouse experiment was carried out. For that, undisturbed samples were collected using PVC pipes, of two profiles of Organossolos Tiom?rficos, one in the neighborhood of Santa Cruz (SC Profile), city of Rio de Janeiro, and one in Mag? (Profile MG) municipality. There were evaluated 3 drainage levels, at 30, 60, and 100 cm deep, with 5 measuremts over time, being 0, 90, 180, 270, and 360 days (4 replicates). The MG profile presented the highest rates of subsidence, reaching 1.30 cm year-1 for the 100 cm drainage. Bd increased over time for both profiles, and the deeper drainage increased values in the SC profile. The deeper drainage favored the reduction of pH for both profiles. The TOC showed a decreasing trend over time. The values of carbon in the fulvic acid fraction (FAF), humic acid fraction (HAF), and humin fraction (HUM) showed no differences according to drainage levels. However, over time they showed high sensitivity to temperature changes, showing high levels of FAF and HAF at the end period and a consequent reduction in humin fraction. For the third and final section, there were used 43 soil profiles, where 18 of them did not have bulk density data, which were estimated by the FPTs. Comparisons between measured and estimated data groups was performed using the Wilcoxon test. The spatial distribution of the variables was performed using the IDW interpolation method. The average values of TOC was 228.0 g kg-1, Bd was 0.48 Mg m-3, the thickness of the profiles was 86 cm, the depth was 90 cm and the average stock TOC was 73.51 kg m-2. The spatialization showed qualitative differences for the variables in the different profile locations. The estimated TOC stock for the profiles form RJ State was 27,178,631.8 Mg. The estimated rates of loss were 10.87 kg m-2 for Histosols more recently drained and high TOC; of 7.16 kg m-2 for intermediate drained Histosols; and 1.46 kg m-2 for Histosols with longer time after drainage and low TOC. Soils with high TOC levels are more likely to have high losses TOC when disturbed. / Os Organossolos s?o uma importante fonte de estoque de carbono nos ambientes terrestres e possuem alta suscetibilidade ?s perdas de carbono quando perturbados. O objetivo do presente trabalho foi gerar equa??es, avaliar a acur?cia de equa??es j? publicadas, aplicando-as para a predi??o da densidade do solo (Ds) em solos org?nicos do Brasil; avaliar a taxa de subsid?ncia, a varia??o da Ds, e o carbono das subst?ncias h?micas em Organossolos ao longo do per?odo de um ano; e estimar o estoque e as potenciais perdas de carbono nos Organossolos do Estado do Rio de Janeiro. Para a primeira parte, trabalhou-se com horizontes org?nicos, i.e., materais de solo com teores de carbono org?nico total (COT) iguais ou maiores que 80 g kg-1 de solo, totalizando 280 horizontes em diferentes regi?es do Brasil. Foi empregada a t?cnica de regress?o linear m?ltipla e as equa??es foram validadas sobre dados independentes. Foram testadas 9 equa??es j? publicadas na literatura. As equa??es com melhor desempenho foram FPT2 e Hollis, com par?metros de valida??o R2 de 0,48 e 0,49. Em casos onde os teores de argila estejam quantificados, recomenda-se a equa??o FPT1, e na sua aus?ncia recomenda-se as equa??es FPT2 e Hollis, que possuem somente o COT como vari?vel preditora. Para a segunda parte, realizou-se um experimento em casa de vegeta??o. Foram coletadas amostras indeformadas em tubos de PVC, de dois perfis de Organossolo Tiom?rfico, sendo um no bairro Santa Cruz (Perfil SC), munic?pio de Rio de Janeiro, e outro no munic?pio de Mag? (Perfil MG). Foram avaliados 3 n?veis de drenagem, sendo de 30, 60, e 100 cm de profundidade, 5 avalia??es ao longo do tempo, sendo de 0, 90, 180, 270, e 360 dias (com 4 repeti??es). O perfil MG apresentou as maiores taxas de subsid?ncia, chegando a 1,30 cm ano-1 para a drenagem de 100 cm. A Ds aumentou ao longo do tempo para os dois perfis, e a drenagem mais profunda aumentou os valores no perfil SC. A drenagem mais profunda favoreceu a redu??o do pH para os dois perfis. Os teores de COT apresentaram tend?ncia de redu??o ao longo do tempo. Os valores de carbono da fra??o ?cido f?lvico (FAF), fra??o ?cido h?mico (FAH), e fra??o humina (HUM), n?o mostraram diferen?as de acordo com os n?veis de drenagem. No entanto, ao longo do tempo, apresentaram alta sensibilidade ?s varia??es de temperatura, mostrando elevados teores de FAF e FAH no per?odo final, e a consequente redu??o dos teores de HUM. Para a terceira e ?ltima parte do estudo, foram usados 43 perfis de Organossolos, sendo que 18 deles n?o apresentavam os dados de densidade do solo (Ds), os quais foram estimados por meio de FPTs. As compara??es entre os grupos de dados medidos e estimados foi feita pelo teste de Wilcoxon. A espacializa??o das vari?veis foi realizado atrav?s do m?todo de interpola??o IDW. Os valores m?dios de COT foi de 228,0 g kg-1, a Ds foi de 0,48 Mg m-3, a espessura dos perfis foi de 86 cm, a profundidade foi de 90 cm, e o estoque m?dio de COT foi de 73,51 kg m-2. A espacializa??o mostrou diferen?as qualitativas para as vari?veis nos diferentes locais. Foi estimado um estoque de COT de 27.178.631,8 Mg para os Organossolos do Estado do RJ. As taxas estimadas de perdas foram de 10,87 kg m-2 para Organossolos com drenagem mais recente e altos teores de COT; de 7,16 kg m-2 para Organossolos intermedi?rios; e 1,46 kg m-2 para Organossolos com menores teores de COT e longo tempo de drenagem. Solos com altos teores de COT est?o mais propensos a terem altas perdas de COT quando perturbados.
7

Caracteriza??o dos solos e avalia??o da aptid?o agr?cola das regi?es produtoras de vinhos finos de altitude de Santa Catarina / Soil characterization and evaluation of agricultural potential of the regions producing fine wines in Santa Catarina altitude

DORTZBACH, Denilson 02 June 2016 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-10-03T17:25:33Z No. of bitstreams: 1 2016 - Denilson Dortzbach.pdf: 2628494 bytes, checksum: 615986b2b9f4992ad6bc0756d35c6669 (MD5) / Made available in DSpace on 2017-10-03T17:25:33Z (GMT). No. of bitstreams: 1 2016 - Denilson Dortzbach.pdf: 2628494 bytes, checksum: 615986b2b9f4992ad6bc0756d35c6669 (MD5) Previous issue date: 2016-06-02 / CAPES / The soils of fine wines producing regions of Santa Catarina State, has particular altitude characteristics resulting from its lithology and high levels of organic matter. That differentiate the soil of the major producing regions of the world wine. The study was conducted in the regions of west and mountain through Santa Catarina, covering over 80 % of the properties where descriptions and collections of 38 modal profiles and vineyards spread over 45 farms were carried out. The objectives were: a) To characterize the distribution and interaction of soil formation factors and chemical weathering rates; b) evaluate and quantify the carbon, humic fractions in the profiles and ?13C in surface horizons of Cambisols; c) To characterize physical and chemically soils of the vineyards; d) To evaluate the agricultural potential through different methods, with subsequent adaptation of the System for Agricultural Assessment of land for the grape culture in addition to formulating a proposal for zoning for the wine industry of the state. The results indicate that pedogenetic soil was strongly influenced by the source material, weather and terrain. Cluster analysis separated by the similarity the soil profiles in three different groups. Predominate classes Cambisols and Nitossols. Humic substances allowed to discriminate the taxonomic orders of soil and showed ?13C in soil with the humic, little change in isotopic signature, and soils with moderate. The observed changes were derived from C3 and C4 plants crops. The vineyards have similar chemical properties, and thus can be grouped in a single region for a determination of Geographical Indication. As for agricultural suitability evaluating different methods indicated that the evaluated profiles have low agricultural aptitude for annual crops. Therefore, it was proposed an adaptation of the evaluation system of agricultural suitability of the land for the growing of vines, taking into account specific conditions of altitude in the SC state. Allied to this, the drafting of the zoning proposal is an important tool for the implementation of new vineyards. / Os solos das regi?es produtoras de vinhos finos de altitude do estado de Santa Catarina apresentam caracter?sticas particulares decorrentes da sua litologia e dos elevados teores de mat?ria org?nica, que os diferenciam dos solos das grandes regi?es produtoras de vinho do mundo. O estudo foi realizado nas regi?es do meio oeste e serrana de Santa Catarina, abrangendo mais de 80 % das propriedades, onde foram realizadas descri??es e coletas de 38 perfis modais e em vinhedos espalhados em 45 propriedades rurais. Os objetivos foram: a) caracterizar a distribui??o e a intera??o dos fatores de forma??o dos solos e a taxa de intemperismo qu?mico; b) avaliar e quantificar os teores de carbono, fra??es h?micas nos perfis e o ?13C em horizontes superficiais de Cambissolos; c) caracterizar f?sica e quimicamente os solos dos vinhedos; e d) avaliar a aptid?o agr?cola atrav?s dos diferentes m?todos, com posterior adapta??o do Sistema de Avalia??o Agr?cola das Terras, para a cultura da videira, al?m de formular proposta de zoneamento para a vitivinicultura do estado. Os resultados indicam que a pedog?nese dos solos foi fortemente influenciada pelos fatores material de origem, clima e relevo. A an?lise do agrupamento separou pela similaridade os perfis de solo em tr?s grupos distintos. Predominam as classes de Cambissolos e Nitossolos. As subst?ncias h?micas permitiram discriminar as ordens taxon?micas de solos e o ?13C revelando pouca altera??o na assinatura isot?pica nos solos com horizonte A h?mico. Nos solos com A moderado foram observadas altera??es decorrentes de mudan?as nas coberturas (plantas C3 ou C4). As ?reas dos vinhedos apresentam atributos qu?micos similares, podendo ser agrupadas em uma regi?o ?nica para eventual determina??o de Indica??o Geogr?fica. Quanto ? aptid?o agr?cola, ? avalia??o atrav?s de m?todos usuais na literatura resultou em classes que indicam baixa aptid?o para culturas anuais. Diante disto, foi proposta adapta??o do sistema de avalia??o da aptid?o agr?cola das terras, para a cultura da videira, considerando condi??es especificas de altitude no estado de SC e associada ? elabora??o de uma proposta de zoneamento para a implanta??o de novos vinhedos.
8

Bioss?lido de lodo de esgoto na restaura??o florestal: produ??o de mudas e aduba??o de plantio / Sewage sludge biosolids in forest restoration: seedlings production and planting fertilization

Cabreira, Gerhard Valkinir 17 February 2017 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2018-08-16T14:12:02Z No. of bitstreams: 1 2017 - Gerhard Valkinir Cabreira.pdf: 1076645 bytes, checksum: 61bdbca123cd46ef5ee16794ef55fd17 (MD5) / Made available in DSpace on 2018-08-16T14:12:02Z (GMT). No. of bitstreams: 1 2017 - Gerhard Valkinir Cabreira.pdf: 1076645 bytes, checksum: 61bdbca123cd46ef5ee16794ef55fd17 (MD5) Previous issue date: 2017-02-17 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / One of the ways to promote forest restoration is through the planting of shrub and tree species for the formation of forest stands. For this, it is necessary to obtain quality seedlings, as it will provide greater capacity to withstand the adverse conditions found in the field; and this quality is closely related to the choice of container type and substrate. Among the products with potential of use as substrate for the production of the forest seedlings is the stabilized sewage sludge (biosolid). A solid waste from Sewage Treatment Plants, rich in organic matter and nutrients, which allows an increase in nursery production, cost reduction and an adequate form of solid waste recycling. In this context, the first part of this study had the objective of evaluating the growth of seedlings of three forest species produced in tubes of 110 and 280 cm3, with increasing doses of controlled release fertilizer applied to biosolids as substrate base. Also, the survival and initial growth of these seedlings after planting were evaluated. In this analysis, the results showed that the seedlings of the three species responded positively to the addition of controlled release fertilizer to the biosolids. Field planting showed good survival and seedling growth, indicating that it was better to produce seedlings of the three species in 280 cm3 tubes with 3 kg of controlled release fertilizer N-P-K (15-09-12) per m3 of biosolids, applied at the time of filling of the tubes. From the results of the biosolids in the nursery, the objective was to evaluate the use of biosolids as fertilizer in field conditions, comparing them to the use of mineral fertilization, using two forest species with controlled growth and response. In the first months after planting, there was basically no significant difference between the use of biosolids and mineral fertilization / Uma das maneiras de impulsionar a restaura??o florestal ? com o plantio de esp?cies arbustivas e arb?reas para a forma??o dos povoamentos florestais. Para isso, faz-se necess?rio a obten??o de mudas de qualidade, pois ir? proporcionar maior capacidade de resistirem ?s condi??es adversas encontradas no campo; e essa qualidade est? intimamente relacionada ? escolha do tipo de recipiente e do substrato. Dentre os produtos com potencial de uso como substrato para produ??o das mudas florestais tem-se o lodo de esgoto estabilizado (bioss?lido). Um res?duo s?lido oriundo das Esta??es de Tratamento de Esgoto (ETEs), rico em mat?ria org?nica e nutrientes e que possibilita aumento na produ??o dos viveiros, diminui??o de custos, al?m de constituir uma forma adequada de reciclagem de res?duos s?lidos. Nesse contexto, a primeira parte desse estudo teve por objetivo avaliar o crescimento de mudas de tr?s esp?cies florestais produzidas em tubetes de 110 e de 280 cm3, com doses crescentes de fertilizante de libera??o controlada N-P-K (15-09-12) aplicados ao bioss?lido como substrato base. Tamb?m, foi avaliado a sobreviv?ncia e crescimento inicial destas mudas ap?s plantio. Nessa an?lise, os resultados mostraram que as mudas das tr?s esp?cies responderam positivamente ao acr?scimo de fertilizante de libera??o controlada junto ao bioss?lido. O plantio em campo apresentou boa sobreviv?ncia e crescimento das mudas, indicando ser melhor produzir mudas das tr?s esp?cies, em tubetes de 280 cm3 com 3 kg de fetilizante de libera??o controla N-P-K (15-09-12) por m3 de bioss?lido, aplicados na ?poca de enchimento dos tubetes. A partir dos resultados que o bioss?lido apresentava no viveiro, buscou-se avaliar o uso do bioss?lido como aduba??o de plantio em condi??es de campo, comparando ao uso de fertiliza??o mineral, utilizando duas esp?cies florestais de crescimento e resposta controlada. Nos primeiros meses ap?s o plantio, basicamente n?o houve diferen?a significativa entre o uso de bioss?lido e fertiliza??o mineral
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Avalia??o de processo de lodos ativos por batelada seguido de tratamento terci?rio com ?nfase na remo??o de mat?ria org?nica e na sedimentabilidade do lodo

Costa Neto, Alfredo 22 February 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-22T15:58:11Z No. of bitstreams: 1 AlfredoCostaNeto_DISSERT.pdf: 2022328 bytes, checksum: 2983ffa40c26116372d25ff1ff172621 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-28T00:26:43Z (GMT) No. of bitstreams: 1 AlfredoCostaNeto_DISSERT.pdf: 2022328 bytes, checksum: 2983ffa40c26116372d25ff1ff172621 (MD5) / Made available in DSpace on 2016-07-28T00:26:43Z (GMT). No. of bitstreams: 1 AlfredoCostaNeto_DISSERT.pdf: 2022328 bytes, checksum: 2983ffa40c26116372d25ff1ff172621 (MD5) Previous issue date: 2016-02-22 / Este trabalho avalia o desempenho de uma Esta??o de Tratamento de Esgotos na modalidade lodos ativados em batelada sequencial, localizada em regi?o de temperatura alta. Tamb?m apresenta a analise da degrada??o da mat?ria org?nica e a avalia??o das condi??es de sedimentabilidade do lodo, atrav?s de reatores em escala de bancada, alimentados com licor misto proveniente da ETE em estudo, com diferentes concentra??es de substrato e biomassa. Os resultados mostraram, a alta efici?ncia e estabilidade do processo de tratamento utilizando RSB para esgotos dom?sticos, mesmo com bruscas oscila??es de carga org?nica e hidr?ulicas. A an?lise dos reatores em bancada, com rela??es A/M pr?-definidas, apresentou o comportamento da sedimenta??o e da biodegradabilidade da mat?ria org?nica para essas concentra??es, situando a rela??o A/M nas condi??es de opera??o atual da ETE e a rela??o A/M ?tima (Concentra??o do Substrato por Concentra??o da Biomassa), cujo tempo de sedimenta??o e de biodegradabilidade da mat?ria org?nica obt?m a m?xima efici?ncia operacional. / This paper evaluate the performance of a Wastewater Treatment Plant (WWTP) in sequential batch activated sludge modality with tertiary treatment step, located in high temperature region. It also presents the analysis of organic matter?s removal and the evaluation of sludge sedimentation conditions through reactors in bench scale, fed with different substrate?s and biomass? concentrations, from the WWTP in study. The results showed high efficiency and stability of the treatment process using Sequential Batch Reactors for domestic sewage, even with sudden changes of organic and hydraulic load, reaching more than 90% of efficiency in the removal of biodegradable organic matter. The removal of organic matter and sedimentation tests in bench reactors showed the good performance in respect of the organic matter?s removal, however, the high concentration of micro-organism results in a lower sludge sedimentation rate, which can compromise the quality of the final effluent. The relation Food/Microorganism in the conditions of the WWTP?s current operation showed a value of 0.06 gCOD/gVSS.d. and zonal sedimentation velocity of 0.59 m/h, the great ratio of the concentration of the substrate by biomass concentration, which obtained the maximum operational efficiency, showed a value of 0.09 gCOD/gVSS.d. and zonal sedimentation velocity of 1.4 m/h.
10

Efeitos da precipita??o e da exposi??o ? radia??o solar na decomposi??o da serrapilheira em um ecossistema no semi?rido brasileiro

Costa, Uirand? Oliveira 31 August 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-03-09T22:53:49Z No. of bitstreams: 1 UirandeOliveiraCosta_TESE.pdf: 1500113 bytes, checksum: 95e5da4af45f2aeb4a8d35e6ece2795b (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-03-13T23:15:53Z (GMT) No. of bitstreams: 1 UirandeOliveiraCosta_TESE.pdf: 1500113 bytes, checksum: 95e5da4af45f2aeb4a8d35e6ece2795b (MD5) / Made available in DSpace on 2017-03-13T23:15:53Z (GMT). No. of bitstreams: 1 UirandeOliveiraCosta_TESE.pdf: 1500113 bytes, checksum: 95e5da4af45f2aeb4a8d35e6ece2795b (MD5) Previous issue date: 2016-08-31 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / O objetivo dessa tese ? compreender o papel da radia??o solar e da precipita??o, bem como o efeito da redu??o desta, sobre a decomposi??o da serrapilheira em um ecossistema no semi?rido brasileiro. O estudo foi desenvolvido, entre os anos de 2013 e 2015, em um fragmento da Caatinga situado no munic?pio de Jo?o C?mara, Rio Grande do Norte, Brasil, atrav?s de um conjunto de tr?s experimentos manipulativos em campo. Evidenciou-se que, no ecossistema estudado, a fotodegrada??o e seus efeitos indiretos afetaram o processo de decomposi??o, proporcionando, isoladamente, 24% da perda de massa e desempenhando papel similar ?quele da precipita??o (26%). Observou-se um papel aditivo da radia??o solar e da precipita??o no controle das taxas de decomposi??o anual da serrapilheira. As redu??es nos n?veis de precipita??o mostraram-se respons?veis por gerar impactos negativos nas taxas de decomposi??o da serrapilheira de at? 41,2%, nos cen?rios testados. Resta comprovado que, na ?rea de estudo, o processo de decomposi??o da serrapilheira n?o est? estruturado apenas por um processo biol?gico, mas, tamb?m, pelo processo abi?tico da fotodegrada??o. Por fim, os resultados desta tese alertam para poss?vel colapso no processo de decomposi??o da serrapilheira decorrente de eventuais redu??es de chuvas, e que esse efeito pode comprometer o funcionamento desse ecossistema. / The aim of this thesis is to understand the role of solar radiation and precipitation, as well as the effect of reducing this, on the decomposition of litter in an ecosystem in the Brazilian semiarid region. The study was conducted between the years 2013 and 2015 in a fragment of the Caatinga in the municipality of Jo?o C?mara, Rio Grande do Norte, Brazil, through a set of three manipulative field experiments. It had demonstrated that the photodegradation and its indirect effects affected the decomposition process, providing alone, 24% of the weight loss and plays a similar role to that of precipitation (26%). We observed an additive role of solar radiation and the precipitation in the control of annual litter decomposition rates. Reductions in the levels of rainfall proved to be responsible for generating negative impacts on litter decomposition rates of up to 41.2% in the tested scenarios. It remains proven that, in the study area, the process of decomposition of leaf litter is not structured only by a biological process, but also by abiotic photodegradation. Finally, the results of this thesis warn of possible collapse of the litter decomposition process due to possible reductions in rainfall which may undermine the functioning of this ecosystem.

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