Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

Budongo Forest Reserve (BFR) is a flagship reserve for primate conservation due to its abundant chimpanzee (Pan troglodytes) population, and its current management policy for multiple economic, conservation and environmental benefits. The identification and better understanding of the structure and dynamics of the forest/plant community types, patterns of species distribution and quantitative properties of their diversity is important to the conservation and sustainable management of tropical rainforests. This study seeks to contribute to a better understanding of the BFR forest community types, species diversity patterns and environmental correlates, as well as natural regeneration processes (i.e. seedling establishment and sprouting). Data on vegetation and environmental variables were collected using rectangular 50 x 100m (0.5 ha) plots, sub-divided into five equal contiguous (20 x 50 m) 0.1 ha sub-plots. Data on land-use/cover changes, and relevant associated socio-economic parameters were collected through the analysis of multi-temporal satellite imagery and field observations, as well as interviews of local households and key informants. The study revealed significant land-use/cover changes, with the area under sugarcane cultivation increasing over 17-fold, from 690 ha in 1988 to 12729 ha in 2002, with a concomitant loss of about 4680 ha (8.2% loss) of forest/woodland, mainly in the southern part of BFR. These changes are attributed to agricultural expansion, a rapidly increasing human population, exacerbated by large influxes of refugees, lack of alternative sources of income, conflicts of interest and political interference in the management of BFR, and an unclear land tenure system. The need for more land for agricultural expansion and the loss of woodlands (a source of building materials and fuelwood for the local communities) is leading to the invasion of and encroachment on BFR, which threatens plant and wild animal conservation. The study revealed that the vegetation of BFR is formed by a mosaic of plant communities, with the major forest types being; Pseudospondias microcarpa Swamp Forest, Funtumia elastica - Pouteria altissima, Lasiodiscus mildbraedi - Khaya anthotheca and Cynometra alexandri - Rinorea ilicifolia forest communities. Canonical correspondence analysis (CCA) indicated that soil nutrients (Si, Ca, N, Fe and Li) and anthropogenic disturbances are the main factors controlling forest community patterns. The variances explained as a proportion of total inertia were relatively high (0.53 and 0.56 for basal area and abundance, respectively), showing how well the measured variables explained species composition. These plant communities differed significantly in terms of woody species diversity and richness; being highest in the Pseudospondias microcarpa swamp and lowest in the Cynometra alexandri-Rinorea ilicifolia forest. However, about 48 species were shared between the forest community types. A total of 269 species representing 171 genera and 51 families was recorded. Fisher’s alpha-diversity ranged 4.45-30.59 and 3.07-29.7 for stem diameters ≥2.0 cm and ≥10 cm, respectively, being significantly higher for stem diameters ≥2.0 cm. The use of stem diameters ≥2.0 cm unveiled 53 more species (19.7%), with only 216 species recorded for the standard ≥10 cm dbh minimum size usually applied in tropical forests. A SHE analysis also showed greater richness (ln(S)) and H diversity for the >2.0 cm than the ≥10cm stem diameters. Hence, the study reaffirmed that the use of 10 cm as a minimum dbh in woody plant diversity studies in forests, where many tree species rarely exceed 10 cm stem diameter, is highly likely to underestimate diversity and richness, potentially biasing the understanding of diversity patterns. The most speciose families were Euphorbiaceae, Fabaceae, Rubiaceae, Moraceae, Meliaceae, Rutaceae, Annonaceae, and Flacourtiaceae, accounting for 147 species. Families with the highest Familial Importance values (FIV) were; Fabaceae (17.5), followed by Euphorbiaceae (16.3), and Ulmaceae (8.35). The BFR exhibits characteristics intermediate between log-normal and log-series species-abundance distributions, indicating a community with a small number of abundant species and a relatively large proportion of rare species. Both Whittaker’s (βw) and the Morisita-Horn Index measures of β-diversity consistently showed higher β-diversity for logged and arboricide treated areas, followed by logged only, and then nature reserve historical management practice types. β-diversity was relatively high at the total forest community scale, but lower for stem diameter ≥2.0 cm than ≥10.0 cm data. Environmental variables significantly explained 66.5% and 61.9% of the variance in species composition for stem diameter ≥2.0 cm and ≥10.0 cm data, respectively. Hence, the variation in species composition of BFR is characterised by significant spatial patterns, and the patterns in β-diversity are to a great extent associated with environmental heterogeneity (i.e. soil nutrients, topographic and light gradients) and anthropogenic disturbances. Investigation of natural regeneration showed that sprouting is generally common among the woody species, with both canopy and sub-canopy trees sprouting prolifically. Of the 122 species affected by ii harvesting, and tree and branch fall disturbances, 199 (97.5%) from 31 families sprouted from the cut stumps, with only Caloncoba crepiniana (De Wild. & Th.Dur.) Gilg exhibiting both stem and root sprouting. Stump basal diameter, height, bark-thickness, and height of stump above the ground at which the first sprout emerged, were significant predictors of sprouting ability among individuals. Number of sprouts/stump differed significantly among families, species, and stump size-classes. Of the 241 seedling species, representing 46 families, about 30.3% were rare (only 2-10 individuals); while 12% were very rare (only 1 individual each). Cynometra alexandri C.H. Wright and Lasiodiscus mildbraedii Engl. were the most abundant seedlings and also among the most widely distributed species in the forest. Analysis of similarity (ANOSIM) revealed significant differences in seedling composition between transects, but not between topographic positions or historical management practice types. Canonical Correspondence Analysis (CCA) showed that the measured environmental variables significantly explained 59.4% of the variance in seedling species distributions, with the three most important variables being organic matter, titanium and leaf area index (LAI; an indicator of light availability below the canopy). Hence, the important mechanisms influencing regeneration via seedlings in BFR operate through the soil system, and the ground and canopy vegetation characteristics. Nine of the 15 intensively studied multiple-use species, namely L. mildbraedii, Celtis Mildbraedii Engl., Pouteria altissima (A. Chiev.) Aubrev. & Pellegr., Chrysophyllum albidum G. Don., C. alexandri, Diospyros abyssinica (Hiern) F. White, Funtumia elastica (Preuss) Stapf., Chrysophyllum perpulchrum Hutch. & Dalz, and Antiaris toxicaria (Pers.) Lesch. had highly negative size-class distribution (SCD) slopes and substantial seedling regeneration. While Alstonia boonei De Wild. and Cordia millenii Bak. had weakly negative SCD slopes and pulsed or sporadic regeneration patterns. The wide distribution of seedlings for a variety of species, and with most of the intensively studied species having population structures showing healthy regeneration patterns, suggests that BFR is currently experiencing a continuous regeneration phase. In conclusion, the gradients in the vegetation of BFR are a reflection not only of site conditions as shown by the edaphic and abiotic factors, but also the history of human interventions.

A produção de mudas via propagação vegetativa é fundamental para se obter os ganhos desejados nos programas de melhoramento genético, bem como garantir o sucesso da implantação florestal. No entanto, existem muitos fatores que impedem a sua utilização de forma abrangente na produção de mudas para algumas espécies florestais, principalmente em relação à baixa taxa de enraizamento. Para atender a essa necessidade, pesquisas com o uso de substâncias que promovam maior taxa de enraizamento de miniestacas e crescimento de mudas vem sendo desenvolvidas, como o uso de reguladores de crescimento e de bioestimulantes à base de substâncias húmicas. Dessa forma o objetivo do presente trabalho é avaliar o efeito de adubos foliares e condicionadores de solo na produção de mudas clonais de híbridos de Pinus caribaea var. hondurensis vs. elliottii var. elliottii e de Pinus tecunumanii vs. caribaea var. hondurensis. Os experimentos foram desenvolvidos em viveiro florestal na cidade de Paranapanema-SP, com delineamento de blocos ao acaso, em arranjo fatorial 4x2, com duração de seis meses. Foram utilizados dois condicionadores de solo, sendo o C1 à base de pescados marinhos e o C2 à base de ácidos húmicos e quatro adubos foliares, sendo AF1 à base de quitosana, AF2 à base de pescados marinhos, AF3 à base de ácido húmico e AF4 extrato da alga Ascoplhyllum nodosum, além da mistura dos adubos M1AF (AF2+AF3+AF4) e o M2AF (AF1+AF3+AF4). Foram instalados dois experimentos: 1) híbrido de P. caribaea var. hondurensis vs. elliottii var. elliottii, testando a combinação dos dois condicionadores de solo e os adubos AF2, AF3, AF4 e M1AF e 2) híbrido de P. tecunumanii vs. carearia var. hondurensis em que a única alteração nos tratamentos foi o AF2 por AF1 e o M1AF por M2AF. As mudas foram avaliadas nas três fases da seguinte forma: 1) casa de vegetação: taxa de enraizamento; 2) casa de sombra: altura, massa seca e verde da parte aérea e radicial e a relação entre elas; e 3) rustificação: avaliadas as mesmas variáveis da casa de sombra, além do estado nutricional das acículas. Para o experimento 1, a taxa de enraizamento com C2 + AF3 foi 46,67% maior quando comparada à testemunha, comprovando o efeito positivo das substâncias húmicas no enraizamento. Já na fase de rustificação, a interação C1 + AF3 promoveu maior crescimento das mudas. Para o experimento 2, não houve diferença nas taxas de enraizamento na casa de vegetação, devido a característica de rápido crescimento do P. tecunumanii. E, na fase de rustificação, o adubo foliar AF4 promoveu maior crescimento somente em altura. Na casa de sombra, os tratamentos testados não promoveram crescimento significativo para ambos os híbridos. Os teores nutricionais analisados nas acículas estão dentro dos níveis adequados para ambos os experimentos. Somente o Mn apresentou baixo teor, mas sem sintomas de deficiência no experimento 2. Os híbridos obtiveram respostas diferentes quando submetidos a tratamentos semelhantes e a determinação do tratamento adequado vai depender do gargalo na produção de mudas, podendo este ser o enraizamento ou o crescimento. / The production of cuttings by vegetative propagation is essential to obtain the desired accomplishment in genetic improvement programs and ensure the success of forest establishment. However there are many factors that prevent their use in a comprehensive manner considering the production of cuttings for some forest species especially in low rooting rate. In order to meet this need research on the use of substances that promote greater rooting rates of minicuttings and growth of cuttings have been developed with the use of growth regulators and biostimulants based on humic substances. Thus the purpose of this study is to evaluate the effect of foliar fertilizers and soil conditioners in the production of Pinus caribaea var. hondurensis vs. elliottii var. elliottii and Pinus tecunumanii vs. caribaea var. hondurensis hybrids cuttings. The experiment was conducted in the city of Paranapanema-SP using cutting nursery with delineation of randomized blocks in a factorial arrangement 4x2, lasting six months. It used two soil conditioners, the C1 based on marine fish and C2 based on humic acids and 4 foliar fertilizers, the AF1 chitosan base, AF2 based on marine fish, AF3 based on humic acid and AF4 by Ascoplhyllum nodosum seaweed extract, besides the mixture of fertilizers M1AF (AF2;AF3;AF4) and M2AF (AF1;AF3;AF4). Two experiments were implemented: 1) hybrid of P. caribaea var. hondurensis vs. elliottii var. elliottii, testing the combination of two soil conditioners as well as fertilizers AF2, AF3, AF4 and M1AF and 2) hybrid of P. tecunumanii vs. caribaea var. hondurensis in which the only change in treatment was the AF2 by AF1 and M1AF by M2AF. Cuttings were evaluated in three phases as follows: 1) greenhouse: rooting rate; 2) shade house: higher, aerial drywet mass and radicial part as well as the relationship between them; 3) hardening: the shade house had the same variables evaluated, in addition with the nutritional status of needles. For the experiment 1, the rooting rate with C2 + AF3 were 46.67% higher compared with the control, this stated the positive effect of humic substances on rooting. Considering the hardening phase C1 + AF3 interaction promoted greater seedling growth. For the experiment 2 there was no difference in rooting rates at greenhouse, because the characteristic of fast growth of P. tecunumanii. In hardening phase, the foliar fertilizer AF4 promoted greater growth only in height. In the shade house treatments did not promote significant growth for both hybrids. Nutritional contents analyzed the needles leaves are within appropriate levels for both experiments. Mn showed only low level, but without deficiency symptoms in the experiment 2. Different answers were obtained on hybrids when subjected to similar treatment and to determine the appropriate treatment will depend on the obstaclecuttings production, which may either rooting or growth.

Interações interespecíficas são consideradas importantes forças estruturadoras da vegetação. Enquanto a competição aparentemente prevalece em ambientes com menor estresse abiótico, a facilitação tende a aumentar em importância em ambientes de maior estresse. Consequentemente, é esperado que a facilitação desempenhe um papel importante em áreas tropicais degradadas, nas quais as condições abióticas, envolvendo altos níveis de irradiação, temperatura e evapotranspiração, são muito distintas das condições ótimas para a maioria das espécies florestais. Além disso, face à complexidade dos processos estruturadores de comunidades florestais tropicais altamente diversas, os ecólogos têm percebido a necessidade de simplificação. Um caminho promissor para isso é por meio do uso de características funcionais, que podem ser medidas para qualquer espécie e comparadas em diferentes sistemas e locais. No entanto, em áreas degradadas ainda é incerta a relação entre as características funcionais e o desempenho das espécies. Neste contexto, planejamos um projeto de restauração na planície costeira do sudeste brasileiro para comparar o crescimento e a sobrevivência de mudas de árvores plantadas em diferentes densidades (sistema isolado ou sistema agregado) em um experimento fatorial com adição de nutrientes. No primeiro capítulo analisamos a sobrevivência, altura, diâmetro ao nível do solo e projeção da copa de 4.132 mudas de 19 espécies de diferentes classificações sucessionais, durante um período de 18 meses. Usamos modelos de efeitos mistos para analisar a relação entre o desempenho de espécies e os tratamentos e selecionamos os melhores modelos utilizando o critério de informação de Akaike (AIC). Verificamos uma maior sobrevivência nos sistemas agregados para as espécies não-pioneiras, indicando o predomínio do processo de facilitação. Em contrapartida, constatamos um menor crescimento em diâmetro nos sistema de plantio agregado, indicando o predomínio de competição. A adição de nutrientes não afetou a sobrevivência nos sistemas agregados, mas, surpreendentemente, teve um efeito negativo sobre as plantas isoladas. Além disso, a adição de nutrientes teve um efeito positivo sobre crescimento, diâmetro e projeção da copa nos sistemas de plantio agregado (indicando a redução da competição), especialmente para espécies pioneiras. Uma vez que o estabelecimento de espécies não-pioneiras em áreas degradadas pode ser bastante difícil, a facilitação para a sobrevivência dessas espécies em sistemas agregados pode ser utilizada como instrumento para melhorar os modelos de restauração. No segundo capítulo utilizamos algumas características funcionais que são facilmente mensuráveis para investigar sua relação com o crescimento e sobrevivência das mudas. Além disso, testamos o efeito das interações interespecíficas na relação das características funcionais com o desempenho das plantas. Para espécies pioneiras, uma maior área foliar específica (SLA - Specific leaf area), foi relacionada com uma maior taxa de sobrevivência. Entretanto, ao considerarmos as relações interespecíficas (sistemas agregados), maior SLA foi relacionada com uma menor taxa de sobrevivência. Em geral, as características funcionais explicaram apenas parcialmente o desempenho de mudas no contexto de restauração de áreas degradadas. Nosso trabalho contribuiu para a discussão sobre o potencial da aplicação prática da abordagem funcional na escolha das espécies para a recuperação de áreas degradadas. O caráter manipulativo da restauração ecológica baseada no plantio de mudas amplia as perspectivas para implementar experimentos que visem testar novas hipóteses em ecologia e refinar modelos de restauração / Interspecific interactions are considered to be important structuring forces in early successional vegetation. Whereas competition seems to prevail in less severe environments, facilitation tends to increase in importance in harsh environments. Hence, facilitation is expected to play an important role in degraded tropical areas with high irradiance, heat loads, and evapotranspiration, where conditions are far from optimum for most forest species. Moreover, in order to understand complex structuring process of high diverse tropical forests, ecologists have realized the need for simplification. A promising way to do that is through the use of functional traits, which can be measured for any species and compared in different systems and different locations around the world. However, in these conditions, little is known about the role of species interaction on the relation of functional traits and species performance. In this scenario, we planned a restoration project on the southeastern Brazilian coastal plain to compare growth and survival of tree seedlings planted at two densities (isolated or aggregated) in a factorial experiment with nutrient addition. In the first chapter we analyzed survival, height, ground level diameter, and crown projection of 4,132 saplings from 19 species that ranged along a successional gradient, over an 18-month period. We used mixed-effect models to analyze the relationship between species performance and treatments, and Akaike\'s information criterion (AIC) to select the models. The best model showed higher survival in aggregated plantations (indicating facilitation) for non-pioneer species. In contrast, we found lower diameter growth in aggregated plantation (indicating competition). Fertilizer addition did not affect survival in clusters, but, surprisingly, it had a negative effect on isolated plants of both pioneer and non-pioneer species. On the other hand, fertilizer addition had a positive effect on diameter and crown projection growth in aggregated plantations (reducing competition), especially for pioneer species. Thus, whether facilitation or competition was the predominant interaction depended on the response analyzed. We concluded that, as establishment of non-pioneer species in disturbed sites can be challenging, restoration designs could take advantage of higher survival rates in clusters and use resource addition to ameliorate growth and decrease competition for limited resources. In the second chapter we used the core simple-measurable traits to investigate whether functional traits were related to growth and survival and whether there was a difference in the effect of the functional traits on plant performance of isolated individuals or of individuals subjected to interaction with neighbors. Our main findings were that for pioneer species, the greater the specific leaf areas (SLA), the greater the survival rates, but, under aggregated conditions, the greater the SLA the lower the survival rates. However, functional traits only partially explained saplings performance in a restoration context and more research is needed to understand its role in predicting seedlings outcomes, especially considering the potential applicability of this methodological approach. The manipulative character of ecological restoration broadens perspectives to use experiments to generate and test new hypotheses in ecology and to refine restoration models

A restauração florestal em matas ciliares é de suma importância para os processos de recuperação de áreas degradadas e conectividade da flora e fauna. O presente experimento foi instalado às margens do reservatório de Borborema - SP, com o objetivo de averiguar o acúmulo de biomassa de trinta espécies arbóreas nativas frente a dois sistemas silviculturais e dois tipos de recipientes de produção de mudas. O ensaio foi instalado em duas áreas com umidade de solo distintas, sendo uma mais seca, sem encharcamento mesmo em períodos chuvosos, outra mais úmida, com encharcamento. Os sistemas de manejo testados foram: i) convencional e operacionalmente utilizado pela empresa AES-Tietê; e ii) potencial, com maior nutrição e maior controle de mato-competição. Os recipientes de produção de mudas testados foram o tubete pequeno, com 56 cm3; e tubete grande com 290 cm3. O estudo foi instalado em fatorial 2x2, com os fatores Manejo e Tubete e dois níveis de cada fator (potencial e convencional, e tubete pequeno e grande) com quatro repetições na área seca. Não ocorreu interação entre os fatores estudados. Na área seca, o tratamento que utilizou tubete grande e manejo potencial apresentou diâmetro e altura 30% superiores que o tratamento que utilizou tubete pequeno e manejo convencional, e uma superioridade em 70% no Índice de Área Foliar e 62% no acúmulo de biomassa aos dois anos. O tubete grande apresentou sobrevivência de plantio 13% superior ao tubete pequeno e ganho em biomassa média das mudas de 43%. O manejo potencial apresentou área basal superior ao manejo convencional (6,23 versus 4,09m2ha-1) e IAF superior (1,28 versus 0,58 m2m- 2). Na área úmida, as zonas de alagamento baixo, médio e total apresentaram área basal decrescentes de 4,4 m2 ha-1, 2,6 m2 ha-1 e 0,9 m2 ha-1. Com esses resultados é possível concluir que as espécies nativas possuem capacidade de melhor desempenho quando produzidas em tubetes maiores e sob sistema silvicultural mais intensivo e que o alagamento (falta de aeração da raiz) é um estresse ambiental que requer melhor compreensão por ser altamente limitante à restauração com as espécies tradicionais. / Riparian forest restoration is extremely important for the processes of degraded areas restoration and connectivity of flora and fauna. This study was established on the Reservoirs of the Borborema Lake - SP, with the purpose to determine the biomass accumulation of thirty tree species native to two silvicultural systems and two sizes of hard plastic tubes for seedling production. This trial was conducted in two areas with different soil moisture, a more drought, without flooding even during rainy periods, and another more humid, with frequent flooding. The following silvicultural systems were tested: i) traditional, one who is operationally used by the AES Tiete company; ii) potential, with greater nutrition and greater weed control. The containers for seedlings production tested were small hard plastic tubes with 56 cm3, and large hard plastic tubes with 290 cm3. The study was carried out in a factorial 22, with factors such as silvicultural systems and sizes of recipients, being two levels of each factor (potential, traditional, small and large hard plastic tubes) and four replications in a dry area. There was no interaction between the factors studied. In dry area the treatment that used large hard plastic tubes and potential silvicultural system showed diameter and height 30% higher than the treatment that used small hard plastic tubes and traditional silvicultural system, and also a superiority of 70% for the Leaf Area Index and 62% for biomass to two years. The seedlings produced in large hard plastic tubes showed survival at planting 13% higher than those grown in small hard plastic tubes. Was also observed that the mean biomass of seedlings was 43% higher for treatment of large tubes. Potential silvicultural system showed basal area greater than the traditional silvicultural system (6.23 vs. 4.09 m2 ha-1) and higher LAI (1.28 vs. 0.58 m2 m-2). In the wetlands, the zones of low, medium and high flooding frequency showed decreasing basal area of 4.4 m2 ha-1, 2.6 m2 ha-1 and 0.9 m2 ha-1. With these results we can conclude that native species have a higher performance when produced in large hard plastic tubes and under more intensive silvicultural system and flooding (lack of aeration of the root) is an environmental stress that requires better understanding because it is factor highly limiting for the restoration with the traditional species.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2014-09-29T12:27:26Z No. of bitstreams: 2 Oliveira , Augusto Pedroso de-2012-Dissertação.pdf: 1221394 bytes, checksum: 3f53224e0b239d497b0f70bbf3b0393e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2014-09-29T15:07:22Z (GMT) No. of bitstreams: 2 Oliveira , Augusto Pedroso de-2012-Dissertação.pdf: 1221394 bytes, checksum: 3f53224e0b239d497b0f70bbf3b0393e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-09-29T15:07:22Z (GMT). No. of bitstreams: 2 Oliveira , Augusto Pedroso de-2012-Dissertação.pdf: 1221394 bytes, checksum: 3f53224e0b239d497b0f70bbf3b0393e (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2012-06-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / To produce rubber tree (Hevea brasiliensis) seedlings in nursery, the collection is limited by the short fall of seeds, which have a rapid loss of their germinal power and no guarantee their viability. This forces the nurseryman to acquire a much larger seeds than really necessary. With the adoption of standards for the quality of seed, the minimum parameters established 70% viability being suggested for such confirmation the tetrazolium test, according Rules for Seed Analysis (RSA) and/or a practical test done from the visual analysis of the seed endosperm color named in this work of "visual test". Despite tetrazolium test be scientifically based, its realization is made improbable by many financial and temporal reasons. Thus, the visual test points as a low-cost alternative, high reliability and immediate result, since both tests are considered trusted, but only the test tetrazolium test is recognized. The subject proposed to verify the credibility of the "visual test" legitimizing or not its use in the field. The field is composed of rubber seed, formed with the adult clone GT1. The seeds were homogenised and stored on two conditions: braided polypropylene bags and transparent plastic bags with minimum thickness of 0.02 mm microdrill at top. In each bag, in three treatments were placed ten kilograms of seed and these were stored in natural conditions of temperature and humidity (25° C ± 5 °C). Was pulled randomly a bag of seeds of rubber tree of each storage type, to zero and fourteen days of storing lots. The tests: visual, sprouting in sand and tetrazolium, besides the determination of the degree of moisture. Tetrazolium and visual tests were highly correlated, and the visual test results before had as the best way to analyze the seeds, for its significant correlation in General with the tetrazolium test, and simplicity in its execution and instant result, which gives good lot projection nurseryman to be acquired by him. / A produção de mudas de seringueira (Hevea brasiliensis) em viveiro, é limitada pelo curto período de produção, queda e coleta das sementes, que possuem uma rápida perda do seu poder germinativo e nenhuma garantia da sua viabilidade. Isto obriga o viveirista a adquirir uma quantidade de sementes maior do que aquela realmente necessária. Com a aprovação de normas para o padrão de qualidade de semente, se estabeleceram parâmetros mínimos de 70% de viabilidade sendo sugerido para tal confirmação o teste de tetrazólio, segundo as Regras para Análise de Sementes (RAS) e, ou, um teste prático feito a partir da análise visual da cor do endosperma da semente nomeado no presente trabalho de “teste visual”. Apesar do teste de tetrazólio ser embasado cientificamente, sua realização é inviabilizada por diversos motivos de ordem financeira e temporal. Sendo assim, o teste visual aponta como uma alternativa de baixo custo, alta confiabilidade e resultado imediato, já que ambos os testes são considerados confiáveis, mas apenas o teste de tetrazólio é reconhecido. Nesta pesquisa objetivou-se verificar a credibilidade do “teste visual” legitimando ou não seu uso no campo. As sementes de seringueira foram coletadas no município de Goianésia, estado de Goiás. O campo de sementes é constituido de seringal adulto, formado com o clone GT1. As sementes foram homogeneizadas e armazenadas em duas condições: sacos de polipropileno trançado e sacos plásticos transparentes com espessura mínima de 0,02 mm, microperfurados na parte superior. Em cada saco, nos dois tratamentos, foram colocados dez quilogramas de sementes e estes foram armazenados em condições naturais de temperatura e umidade (25° C ± 5 °C). Foi retirado aleatoriamente um saco de sementes de seringueira de cada tipo de armazenamento, no tempo zero e aos quatorze dias de armazenamento dos lotes de sementes coletados. Foram realizados os testes: visual, de germinação em areia e de tetrazólio, além da determinação do grau de umidade. Os testes visual e de tetrazolio foram altamente correlatos. O teste visual apresentou a melhor forma de análise das sementes, por sua significativa correlação no geral com o teste de tetrazólio, além da simplicidade em sua execução e resultado instantâneo, o que confere ao viveirista uma boa projeção do lote de sementes a serem adquiridas para a produção de mudas de seringueiras

Interações interespecíficas são consideradas importantes forças estruturadoras da vegetação. Enquanto a competição aparentemente prevalece em ambientes com menor estresse abiótico, a facilitação tende a aumentar em importância em ambientes de maior estresse. Consequentemente, é esperado que a facilitação desempenhe um papel importante em áreas tropicais degradadas, nas quais as condições abióticas, envolvendo altos níveis de irradiação, temperatura e evapotranspiração, são muito distintas das condições ótimas para a maioria das espécies florestais. Além disso, face à complexidade dos processos estruturadores de comunidades florestais tropicais altamente diversas, os ecólogos têm percebido a necessidade de simplificação. Um caminho promissor para isso é por meio do uso de características funcionais, que podem ser medidas para qualquer espécie e comparadas em diferentes sistemas e locais. No entanto, em áreas degradadas ainda é incerta a relação entre as características funcionais e o desempenho das espécies. Neste contexto, planejamos um projeto de restauração na planície costeira do sudeste brasileiro para comparar o crescimento e a sobrevivência de mudas de árvores plantadas em diferentes densidades (sistema isolado ou sistema agregado) em um experimento fatorial com adição de nutrientes. No primeiro capítulo analisamos a sobrevivência, altura, diâmetro ao nível do solo e projeção da copa de 4.132 mudas de 19 espécies de diferentes classificações sucessionais, durante um período de 18 meses. Usamos modelos de efeitos mistos para analisar a relação entre o desempenho de espécies e os tratamentos e selecionamos os melhores modelos utilizando o critério de informação de Akaike (AIC). Verificamos uma maior sobrevivência nos sistemas agregados para as espécies não-pioneiras, indicando o predomínio do processo de facilitação. Em contrapartida, constatamos um menor crescimento em diâmetro nos sistema de plantio agregado, indicando o predomínio de competição. A adição de nutrientes não afetou a sobrevivência nos sistemas agregados, mas, surpreendentemente, teve um efeito negativo sobre as plantas isoladas. Além disso, a adição de nutrientes teve um efeito positivo sobre crescimento, diâmetro e projeção da copa nos sistemas de plantio agregado (indicando a redução da competição), especialmente para espécies pioneiras. Uma vez que o estabelecimento de espécies não-pioneiras em áreas degradadas pode ser bastante difícil, a facilitação para a sobrevivência dessas espécies em sistemas agregados pode ser utilizada como instrumento para melhorar os modelos de restauração. No segundo capítulo utilizamos algumas características funcionais que são facilmente mensuráveis para investigar sua relação com o crescimento e sobrevivência das mudas. Além disso, testamos o efeito das interações interespecíficas na relação das características funcionais com o desempenho das plantas. Para espécies pioneiras, uma maior área foliar específica (SLA - Specific leaf area), foi relacionada com uma maior taxa de sobrevivência. Entretanto, ao considerarmos as relações interespecíficas (sistemas agregados), maior SLA foi relacionada com uma menor taxa de sobrevivência. Em geral, as características funcionais explicaram apenas parcialmente o desempenho de mudas no contexto de restauração de áreas degradadas. Nosso trabalho contribuiu para a discussão sobre o potencial da aplicação prática da abordagem funcional na escolha das espécies para a recuperação de áreas degradadas. O caráter manipulativo da restauração ecológica baseada no plantio de mudas amplia as perspectivas para implementar experimentos que visem testar novas hipóteses em ecologia e refinar modelos de restauração / Interspecific interactions are considered to be important structuring forces in early successional vegetation. Whereas competition seems to prevail in less severe environments, facilitation tends to increase in importance in harsh environments. Hence, facilitation is expected to play an important role in degraded tropical areas with high irradiance, heat loads, and evapotranspiration, where conditions are far from optimum for most forest species. Moreover, in order to understand complex structuring process of high diverse tropical forests, ecologists have realized the need for simplification. A promising way to do that is through the use of functional traits, which can be measured for any species and compared in different systems and different locations around the world. However, in these conditions, little is known about the role of species interaction on the relation of functional traits and species performance. In this scenario, we planned a restoration project on the southeastern Brazilian coastal plain to compare growth and survival of tree seedlings planted at two densities (isolated or aggregated) in a factorial experiment with nutrient addition. In the first chapter we analyzed survival, height, ground level diameter, and crown projection of 4,132 saplings from 19 species that ranged along a successional gradient, over an 18-month period. We used mixed-effect models to analyze the relationship between species performance and treatments, and Akaike\'s information criterion (AIC) to select the models. The best model showed higher survival in aggregated plantations (indicating facilitation) for non-pioneer species. In contrast, we found lower diameter growth in aggregated plantation (indicating competition). Fertilizer addition did not affect survival in clusters, but, surprisingly, it had a negative effect on isolated plants of both pioneer and non-pioneer species. On the other hand, fertilizer addition had a positive effect on diameter and crown projection growth in aggregated plantations (reducing competition), especially for pioneer species. Thus, whether facilitation or competition was the predominant interaction depended on the response analyzed. We concluded that, as establishment of non-pioneer species in disturbed sites can be challenging, restoration designs could take advantage of higher survival rates in clusters and use resource addition to ameliorate growth and decrease competition for limited resources. In the second chapter we used the core simple-measurable traits to investigate whether functional traits were related to growth and survival and whether there was a difference in the effect of the functional traits on plant performance of isolated individuals or of individuals subjected to interaction with neighbors. Our main findings were that for pioneer species, the greater the specific leaf areas (SLA), the greater the survival rates, but, under aggregated conditions, the greater the SLA the lower the survival rates. However, functional traits only partially explained saplings performance in a restoration context and more research is needed to understand its role in predicting seedlings outcomes, especially considering the potential applicability of this methodological approach. The manipulative character of ecological restoration broadens perspectives to use experiments to generate and test new hypotheses in ecology and to refine restoration models

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2017-01-09T11:54:46Z No. of bitstreams: 1 2016 - David da Cunha Valen?a.pdf: 2653024 bytes, checksum: d2b4461225be75ec25872fbc06de8bdb (MD5) / Made available in DSpace on 2017-01-09T11:54:46Z (GMT). No. of bitstreams: 1 2016 - David da Cunha Valen?a.pdf: 2653024 bytes, checksum: d2b4461225be75ec25872fbc06de8bdb (MD5) Previous issue date: 2016-02-24 / Funda??o Carlos Chagas Filho de Amparo ? Pesquisa do Estado do RJ - FAPERJ / The concern with the intensive use of natural resources has become increasingly justifying the development of new technologies aiming their rational use such as automated irrigation systems. The automation of irrigation could to allow water saving increasing efficiency of its use in agricultural production. The first chapter of this study was to evaluate five different volumes (130, 100, 80, 60 and 33% of volume of Simplified Irrigation Controller - SIC) in the production of lettuce in pots in a production system called "Organic Potponics". It was used the SIC, whose operation is based on tension in the soil solution. The different volumes were achieved by drippers association of different flow rates in the same pipe. It was evaluated fresh and dry weight, number of leaves and diameter of lettuce plants (production variables); stomatal conductance, chlorophyll content, relative water content in leaves and chlorophyll fluorescence (physiological variables); and the water use efficiency (WUE). The corresponding volume 126% specified by the SIC installed to a tension soil of 6 kPa was that provided the best results production of dry weight, whereas the maximal WUE was obtained for the corresponding slide 80%. It indicates the volume of 83%, because it provided the best economy of water and a satisfactory production to sale. In the second chapter aimed to evaluate the use of the SIC under four different tensions to the substrate for the production of lettuce seedlings in trays under greenhouse conditions. It was evaluated fresh and dry weight of shoots, number of leaves, shoot height, leaf length and leaf area (production variables); chlorophyll content (physiological variable); and WUE. Higher water stress in the substrate decreased irrigation events, harming the growth of linearly seedlings and causing large percentage of deaths. The tension of 4 kPa was the one that provided the highest values in all production variables. The tension of 6.5 kPa despite having a percentage of death, can be used to produce more resistant seedlings / A preocupa??o com o uso intensivo dos recursos naturais tem se tornado cada vez maior, justificando o desenvolvimento de novas tecnologias que buscam sua aplica??o racional, como dispositivos autom?ticos de irriga??o. A automa??o da irriga??o pode permitir a economia da ?gua aumentando a efici?ncia de seu uso na produ??o agr?cola. O primeiro cap?tulo desse estudo teve como objetivo avaliar cinco diferentes volumes de irriga??o (130, 100, 80, 60 e 33% do volume do Acionador Simplificado de Irriga??o - ASI) na produ??o de alface em vasos em um sistema de produ??o denominado ?Vasoponia Org?nica?. Foi utilizado o ASI, cujo funcionamento baseia-se na tens?o da solu??o do solo. Os diferentes volumes foram conseguidos pela associa??o de gotejadores de vaz?es distintas em uma mesma tubula??o. Foram avaliados pesos fresco e seco, n?mero de folhas e di?metro das plantas de alface (vari?veis de produ??o); condut?ncia estom?tica, Teor de clorofila, conte?do relativo de ?gua nas folhas e fluoresc?ncia da clorofila (vari?veis fisiol?gicas); al?m da efici?ncia de uso da ?gua (EUA). O volume correspondente a 126% do indicado pelo ASI, instalado para tens?o de 6 kPa no solo, foi a que proporcionou os melhores resultados de produ??o de massa seca, enquanto que a m?xima EUA foi obtido para a l?mina correspondente a 83%. Indica-se o volume de 83%, pois proporcionou a melhor economia de ?gua e uma produ??o satisfat?ria ? comercializa??o. No segundo cap?tulo, objetivou-se avaliar a utiliza??o do ASI sob quatro diferentes tens?es no substrato para a produ??o de mudas de alface em bandejas de isopor em ambiente protegido. Foram avaliados peso fresco e da parte a?rea, n?mero de folhas, altura da parte a?rea, comprimento de folhas e ?rea foliar (vari?veis de produ??o); teor de clorofila (vari?vel fisiol?gica); al?m da EUA. Maiores tens?es de ?gua no substrato diminu?ram o n?mero de eventos de irriga??o, prejudicando o crescimento das mudas de forma linear e ocasionando grande percentual de mortes. A tens?o de 4 kPa foi a que proporcionou os maiores valores em todas as vari?veis de produ??o. A tens?o de 6,5 kPa apesar de apresentar um percentual de morte, pode ser utilizada para a produ??o de mudas mais resistentes.

Despite extensive international acceptance of the critical role of mammalian post-dispersal seed predation in many plant communities, in New Zealand we have limited knowledge of these predators’ influence on plant recruitment in our forests. The principle objective of my thesis was to determine the importance of exotic mammals as post-dispersal seed predators in a New Zealand conifer-broadleaf forest remnant. To address this goal, I used a series of field-based experiments where the actions of different post-dispersal seed predators were separated by wire-mesh exclosures. My study was conducted at Mount Peel Forest Park Scenic Reserve, South Canterbury, New Zealand. Being a human modified conifer forest currently dominated by broadleaf species, it is typical of forest remnants in New Zealand. This presented an opportunity to study a wide range of both potential post-dispersal seed predators and broadleaf tree species. My findings indicate that exotic mammals are not only post-dispersal seed predators at Peel Forest, but are responsible for the majority of post-dispersal predation events observed. Ship rats (Rattus rattus) were the dominant post-dispersal seed predators, while brushtail possums (Trichosurus vulpecula), house mice (Mus musculus) and native invertebrates were also important post-dispersal seed predators for several tree species. Through use of time-lapse video and cafeteria experiments I found that exotic mammalian seed predators, when compared to native invertebrate seed predators, preyed upon larger-seeded plant species and were responsible for considerable seed losses of several tree species. However, exotic mammalian seed predators do share several foraging characteristics with native invertebrate seed predators, as predators foraged in similar habitats and responded in a similar way to changes in seed density. In investigating if post-dispersal seed predation by mammals had a flow-on effect to plant recruitment, I observed natural seedling densities at Peel Forest were significantly higher in the absence of mammalian seed predators, but I found no evidence that the presence of mammals significantly altered the overall species richness. At the community level, I did not find an interaction between habitat and exotic mammals, however I present evidence that for individual plant species a significant mammal : habitat interaction occurred. Consequently, even though my cafeteria experiment implied there was no significant difference in the overall amount of seed preyed upon within different habitats, the less favourable microsite conditions for germination under an intact continuous canopy allows mammals to exacerbate habitat-related patterns of seed mortality and have a noticeable effect on seedling establishment. In an effort to validate the use of manipulative experiments to predict the long-term effect of post-dispersal seed predation on plant dynamics, I attempted to link results of my cafeteria experiment with observed seedling abundance at Peel Forest. Seven tree species were used in this comparison and a strong correlation was observed. This result shows that the level of post-dispersal seed predation determined in the cafeteria experiment provided a good predictor of the effect of mammalian post-dispersal seed predation on seedling establishment. To fully gauge the impact of mammalian post-dispersal seed predators on seedling establishment, the relationship between these seed predators and the type of recruitment limitation experienced by a plant species was also investigated. By using a combination of seed addition, plot manipulations and seed predator exclusion I was able to investigate this relationship. I found evidence that seed limitation at Peel Forest is positively correlated with seed size, and that while mammalian post-dispersal seed predators can further reduce plant recruitment of plant species experiencing seed limitation, the influence of mammals in determining plant recruitment was limited for plant species experiencing microsite limitation. My study has proven that exotic mammals are now the dominant post-dispersal seed predators at Peel Forest, the amount of seed preyed upon varies among plant species, and post-dispersal seed predation by mammalian species can lead to differences in seedling richness and abundance. I proved that the influence of exotic mammals on seedling establishment is also linked to habitat structure and recruitment limitations. When combined these observations suggest that exotic mammalian post-dispersal seed predators may play an important role in determining landscape abundance and distribution of plants at Peel Forest.

Some aspects of the presence of systemic endophytic fungi in agriculturally important New Zealand grasses were studied in relation to plant breeding. Seedling resistance to adult Argentine stem weevil feeding in perennial ryegrass, Italian ryegrass and tall fescue was found to be related to the presence of their respective Acremonium endophytes in the seed rather than to plant genetic resistance. In addition a study of perennial ryegrass revealed that this resistance was independent of endophyte viability. The seedling resistance conferred by the endophyte of Italian ryegrass was found to be beneficial for field establishment. This endophyte differs from that in perennial ryegrass and tall fescue in that it does not confer resistance to Argentine stem weevil on mature plants, but only on seedlings. The extent of plant genetic seedling tolerance to adult Argentine stem weevil feeding was limited to broad inter-specific differences, with tall fescue more tolerant than perennial ryegrass and both of these more tolerant than Italian ryegrass. This ranking corresponds with previous observations on feeding preference on mature plants. A study of factors affecting the concentration of endophyte mycelia in infected seed of perennial ryegrass revealed that plant genetic factors had little effect. The major factors studied were: 1) the endophyte concentration in the maternal parent plant directly influenced the endophyte concentration in the seed. 2) nitrogen fertilizer applications to a seed crop reduced the concentration of mycelia in the seed, with earlier applications having a greater effect. 3) application of the fungicide propiconazole (Tilt) to a seed crop reduced the endophyte concentration in the seed. 4) the endophyte concentration in the seed was found to directly influence the endophyte concentration in seedlings, six month old plants and that of seed harvested from a first year seed crop. As there have been no previous reports of tetraploid perennial ryegrass cultivars with endophyte an experiment was conducted to determine if these could be developed by the standard procedure of colchicine treatment. The results revealed that endophyte was retained following colchicine treatment.