No presente trabalho, estudamos uma área de vegetação natural, composta principalmente por cerrado, com 1269 ha, situada no munícipio de Santa Rita do Passa Quatro, estado de São Paulo (21 36-44 S e 47 34-41 W). O levantamento florístico da área foi efetuado em 18 excursões de coleta mensais, com duração de 3 ou 4 dias cada, entre setembro de 1995 e fevereiro de 1997. Em cada uma das formações e fisionomias de cerrado existentes (cerradão, cerrado sensu stricto, campo cerrado, campo úmido, mata ciliar, floresta estacional semidecídua), o material em fase florífera ou frutífera ou de formação de esporos foi coletado e, posteriormente, prensado e identificado em nível específico. Coletamos 1944 exsicatas, representando 499 espécies, 317 gêneros e 107 famílias. As famílias que se destacaram foram: Asteraceae, Fabaceae, Poaceae e Rubiaceae. A comparação das formações e fisionomias de cerrado através de índice de similaridade ressaltou a unidade florística do cerrado. Para auxiliar a identificação das espécies coletadas, construimos chaves baseadas em caracteres vegetativos para as formações de cerrado sensu lato, campo úmido, mata ciliar e floresta estacional semidecídua. Para estudar a estrutura da comunidade vegetal, lançamos aleatoriamente parcelas nas fisionomias de cerrado e na floresta estacional semidecídua, cujos tamanhos e critérios de inclusão foram diferentes em função de variações no componente lenhoso. A biomassa, estimada pelo volume cilíndrico total, aumentou do campo cerrado à floresta estacional semidecídua, com valores intermediários no cerrado sensu stricto e no cerradão. O cerrado, em suas três fisionomias, apresentou não só grande diversidade alfa, como também altas diversidades beta e gama. A partir dos dados do levantamento florístico, estudamos as variações fenológicas das espécies, procurando analisá-las como estratégias adaptativas. A proporção de espécies anemo e autocóricas foi maior no componente herbáceo-subarbustivo, ao contrário das zoocóricas, mais freqüentes no componente arbustivo-arbóreo. As espécies arbustivo-arbóreas floresceram principalmente no início da estação chuvosa, enquanto que as herbáceo-subarbustivas produziram flores, de modo geral, apenas no final da estação úmida, após período de acúmulo de carboidratos. A proporção de espécies anemo e autocóricas em frutificação foi maior na estação seca, quando sua dispersão é mais eficiente. Já as espécies zoocóricas frutificaram principalmente durante toda a estação quente e chuvosa, quando seus frutos carnosos podem se manter atraentes por mais tempo. / We studied a natural vegetation area, composed mainly by cerrado, with 1269 ha, located at Santa Rita do Passa Quatro municipality, São Paulo State, southeastern Brazil (21 36-44 S e 47 34-41 W). We carried out a floristic survey in 18 field trips, each one with 3 or 4 days, from September 1995 to February 1997. On each existing vegetation types (three cerrado physiognomies, floodplain grassland, gallery forest, and seasonal semidecidous forest), all vascular plants in reproductive stage were collected and then pressed and identified in species level. A total of 499 species, representing 317 genera and 107 families, was found. The most important families were: Asteraceae, Fabaceae, Poaceae and Rubiaceae. The comparison of all vegetation types and cerrado physiognomies through similarity index emphasized the cerrado floristic unity. To help the species identification, we constructed four indented keys based on vegetative characters, one for each vegetation type (cerrado, floodplain grassland, gallery forest, and seasonal semidecidous forest). To study the plant community structure, we placed randomly quadrats in the cerrado physiognomies and in the seasonal semidecidous forest, with different sizes and inclusion criteria according to its woody component. Biomass, estimated by total cylindric volume, increased from campo cerrado to seasonal semidecidous forest, with intermediate values in cerrado sensu stricto and cerradão. Cerrado, on its three physiognomies, showed high alpha diversity as well as beta and gamma ones. Based on the data collected during the floristic survey, we studied the phenological variations, analysing them as adaptive strategies. The ratio of anemo and autochorous species was greater in the herbaceous component. The zoochorous ones, on the other hand, were more frequent in the woody component. The woody species flowered mainly at the beginning of the rainy season, while the herbaceous ones produced flowers generally at the end of that season, after a period of carbohydrate accumulation. The anemo and autochorous species produced fruits principally at the dry season, when its dispersion is more efficient. The zoochorous ones fruited along the whole rainy and warm season, when its fruits become attractive for longer time.

Orientador: Fernando Roberto Martins / Tese (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-06T16:39:18Z (GMT). No. of bitstreams: 1 Sfair_JuliaCaram_M.pdf: 493785 bytes, checksum: ebef9315b1a0c2f01f38726b8e89c7b4 (MD5) Previous issue date: 2006 / Resumo: Diferentes formas de vida de plantas, por possuírem diferentes estratégias de alocação de recursos, podem apresentar aspectos fenológicos diferentes. Além disso, interações bióticas e abióticas e perturbações antrópicas podem influenciar a fenologia. Os objetivos deste trabalho foram (a) invetigar a fenologia em árvores com (forófito) e sem (controle) liana na borda e no interior de um fragmento de cerrado denso em Itirapina, SP; e (b) investigar a sobreposição das fenofases reprodutivas e vegetativas entre lianas e forófitos para o mesmo fragmento de vegetação. Durante um ano, semanalmente foram coletados dados referentes às atividades e às intensidades de lianas e árvores com e sem lianas na borda e no interior do fragmento de cerrado. As espécies analisadas foram: Anadenanthera falcata, Dalbergia miscolobium, Miconia rubiginosa, Qualea grandiflora, Vochysia tucanorum e Xylopia aromatica. Foram usadas análises envolvendo estatística circular. A. falcata, D. miscolobium e X. Aromatica com lianas investiram mais na produção de folhas e menos na reprodução que as mesmas espécies sem lianas. M. rubiginosa, V. tucanorum, Q. grandiflora e X. Aromatica na borda alocaram mais recursos para a reprodução e menos para a troca de folhas que as mesmas espécies no interior, uma vez que a borda possui mais luz disponível. M. rubiginosa em ambiente estressante (lianas no interior do fragmento) investiu na reprodução como forma de escapar do estresse. A perda e o ganho de folhas de A. falcata, M. rubiginosa e V. tucanorum e suas lianas associadas ocorreu na transição das estações secas e chuvosas, indicando que a água está disponível por meio de raízes profundas para ambas as formas de vida. A competição por polinizador promoveu diferentes padrões de floração entre A. falcata e V. tucanorum e suas lianas associadas. M. rubinosa e X. aromatica produziram diásporos carnosos no final da estação chuvosa, provendo recursos para animais e aumento a eficiência na sua dispersão / Abstract: Different life-forms with different resources allocation strategies can show different phenologies. Biotic and abiotic interactions and anthropogenic disturbance may additionally influence the phenology. The aims of this study were (a) to test the phenology between trees with and without lianas at the edge and in the interior of a dense cerrado fragment in Itirapina, São Paulo state; and (b) investigate the reproductive and vegetative phenophases overlap between lianas and their support trees. Phenological data were taken weekly, during a year, activity and intensity of trees with and without lianas at the edge and in the interior of the fragment were collected. Anadenanthera falcata, Dalbergia miscolobium, Miconia rubiginosa, Qualea grandiflora, Vochysia tucanorum and Xylopia aromatica were the analyzed species. The data were analyzed with circular statistics. A. falcata, D. miscolobium and X. aromatica with lianas invested more on leaf production e less on reproduction than the same species without lianas. M. rubiginosa, V. tucanorum, Q. grandiflora and X. Aromatica at the edge allocated more resources for reproduction and less to leaf change than these species in the interior, since at the edge more light is available. M. rubiginosa in stressful environment (lianas in the interior of the fragment) invested on reproduction as a way to escape from stress. Leaf flushing and fall of A. falcata, M. rubiginosa and V. tucanorum e their associated lianas occurred on dry-wet seasons transitions, indicating that the water is available by deep root system for both life-forms. Pollinators competition promotes different flowering patterns among A. falcata and V. tucanorum and their associated lianas. M. rubinosa and X. aromatica produced fleshy diaspores in the end of dry season, providing resources for animals and increasing diaspore dispersal efficiency / Mestrado / Mestre em Ecologia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Agriculture modernization, which stimulated the development of agricultural in countries like Brazil, influenced coconut palms move to unusual areas. Consequently, in order to find more adaptive crops and to reduce negative impacts on the environment, the need for awareness of the environmental influence in this plantation growth became real. With this view, this paper aimed to study the reproductive and vegetative behavior of four cultivars of dwarf coconut palms: the Malayan Yellow Dwarf (MYD), the Malayan Red Dwarf (MRD), the Cameroon Red Dwarf (CRD) and the 'Green Dwarf of Jiqui' (BGDJ) of Agreste, located in Neópolis, Sergipe. It was established a randomized block design with four treatments and four replications usind eight plants per plot. Concerning growth, flowering, fructification and fruit characterization, the following characters were analyzed: the number of alive leaves (NAL), number of emitted leaves (NEL) and the number of dead leaves (NDL); height (HS) and circumference of stipe (CS); leaf length (LL), leaflet length (LLe) and width (LW), leaflet area (LA); number of emitted inflorescences (NEI), female flowers per inflorescence (NFFI), fruits at three (NFr3) and six (NrF6) months old, fruit weight (FW) and fruit water volume (FWV). The data were submitted to analysis of variance, which was made by Sisvar program. This program compared the averages of each character and each cultivar; and GENES program estimated the heritability (h2) and genotypic (rge) and phenotypic (rfe) correlations. The cultivars have shown different vegetative and reproductive behaviors, being the BGDJ, the most adaptive cultivar for this area. Heritability was high ranging from 89,16% to 98,66%, which means that there is a high correlation between phenotypic and genotypic values. High positive phenotypic and genotypic correlations were observed for the pairs of characters NAL x NEL, NAL x NEI, NEL x NDL, NEL x NEI, NFFI x NFr3, NFFI x NFr6, NFFI x FW, NFr3 x NFr6, NFr6 x FWV, FW x FWV, expressing that the selection of a character will indirectly be selecting another; and high negative phenotypic and genotypic correlations for NEL x NFr6, NEL x FWV, SH x NFFI, SH x NFr3, SH x NFr6 e SH x FWV showing that a selection of a character may cause undesirable changes in another. / A modernização da agricultura, que impulsionou o desenvolvimento de nações agrícolas como o Brasil, influenciou na interiorização do coqueiro para áreas não habituais, onde é necessário conhecer a influência do ambiente no desenvolvimento dessa cultura com a finalidade de encontrar as cultivares mais adaptadas, de modo que diminua os impactos negativos no ambiente. Nesse sentido, o trabalho objetivou estudar o comportamento vegetativo e reprodutivo de quatro cultivares de coqueiro anão: anão amarelo da Malásia (AAM), anão vermelho da Malásia (AVM), anão vermelho de Camarões (AVC) e anão verde do Brasil de Jiqui (AVeBrJ), da empresa Agreste, localizada no município de Neópolis, Sergipe. O delineamento experimental foi em blocos ao acaso com quatro tratamentos e quatro repetições utilizando-se oito plantas úteis por parcela. Foram avaliados caracteres referentes a crescimento, floração, frutificação e fruto tais como: número de folhas vivas (NFV), emitidas (NFE) e mortas (NFM), altura (AE) e circunferência do estipe (CE), comprimento da folha (CFol), comprimento (CF) e largura do folíolo (LF), área foliar (AF), número de inflorescências emitidas (NIE), flores femininas por inflorescência (NFFI), frutos com três (NFr3) e seis meses (NFr6), peso do fruto (PF) e volume de água do fruto (VAF). Nas análises de variância foram utilizandos os programa Sisvar, para comparar as médias de cada caráter e de cada cultivar e o programa Genes, para estimar a herdabilidade (h2) e as correlações fenotípicas (rfe) e genotípicas (rge). As cultivares apresentaram comportamentos vegetativo e reprodutivo diferenciados, sendo que o AVeBrJ foi o que se mostrou mais adaptado a esse ambiente. A herdabilidade foi alta variando de 89,16% a 98,66%, o que indica a alta correlação entre os valores genético e fenotípico. Foram constatadas correlações fenotípicas e genéticas altas e positivas para os pares de caracteres NFV x NFE, NFV x NIE, NFE x NFM, NFE x NIE, NFFI x NFr3, NFFI x NFr6, NFFI x PF, NFr3 x NFr6, NFr6 x VAF, PF x VAF indicando que a seleção de um caráter indiretamente estará selecionando outro; e correlações fenotípicas e genéticas negativas e altas para NFE x NFr6, NFE x VF, AE x NFFI, AE x NFr3, AE x NFr6 e AE x VAF indicando que a seleção de um caráter pode provocar alterações indesejáveis em outro.

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2015-03-04T12:01:13Z No. of bitstreams: 2 Dissertação - Ana Paula Marquez Belo - 2014.pdf: 792588 bytes, checksum: 137adbb028109dde710c82a639c91180 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-03-04T12:35:07Z (GMT) No. of bitstreams: 2 Dissertação - Ana Paula Marquez Belo - 2014.pdf: 792588 bytes, checksum: 137adbb028109dde710c82a639c91180 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-03-04T12:35:07Z (GMT). No. of bitstreams: 2 Dissertação - Ana Paula Marquez Belo - 2014.pdf: 792588 bytes, checksum: 137adbb028109dde710c82a639c91180 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-02-27 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The objective of this work is to study the phenological development of the arboreal cashew fruit from Cerrado (Anacardium othonianum Rizz) to collect biometrics data related to the growth of cashew trees, selecting early plants, both analyse the progress of the antracnosis disease (Colletotrichum gloeosporioides) and the severity caused in the plants, with the intention of contributing to the domestication of the species, in order that the extrativism can be avoided and to preserve it into its natural habitat. The initial material of this research is present in an specific area in where there are exclusively plants from arborous cashew fruit, that belong to a germoplasm collection in the area of the Agronomy School of the Federal University of Goiás - EA/UFG, in Goiânia, GO, in the geographical coordinates 16º35'12” of South latitude, 49º21'14” of longitude the West of Greenwich, and 730 m of altitude, which the cultivation was carried out in January of 2011, totalizing 546 plants originating from 182 plants-mothers. There were monthly obtained results related to the total height, and to the stem circumference to 10,0 cm of height of all the plants. The meteorological data was obtained in the Evaporimetric Station of First Class in operation at EA/UFG. The phenophasis were studied of foliage, blooming and fructification of A othonianum, in the period between March of 2012 to September of 2013, and the observations are done monthly. The evaluations referring to the antracnosis were also done monthly, based on a notes scale of the disease severity, in 65 cashew trees selected in the experimental area. The plants, with 32 months after being planted, presented height varying from 4,0 cm to 380,0 cm and diameter of 1,5 mm stem to 94 mm. The leaves emission showed up with intensity in the months of March, April and May. The blooming did not present correlation with any connected climatic data, and had its peak in June. Only three plants had fruits during the study period. Progenies from UFG and from the city of São Miguel do Passa Quatro region showed precociousness and fruits production, being able to be indicated for a future genetic improvement. The antracnosis manifested itself in several levels along the study period, demonstrating it hardest in the months of February, March and April. The phenofasis of new leaves emission and flowers contribute significantly to the disease progress. / Este trabalho teve como objetivo estudar o desenvolvimento fenológico do caju arbóreo do Cerrado (Anacardium othonianum Rizz.), avaliar os dados biométricos referentes ao crescimento dos cajueiros, selecionar plantas precoces em relação a produção, além de analisar o progresso da antracnose (Colletotrichum gloeosporioides) e a severidade causada nas plantas, com o intuito de contribuir para a domesticação da espécie, a fim de se evitar o extrativismo e conservar a espécie em seu habitat natural. O material inicial desta pesquisa está presente em uma área constituída exclusivamente por plantas de caju arbóreo, pertencentes a uma coleção de germoplasma na área da Escola de Agronomia da Universidade Federal de Goiás - EA/UFG, em Goiânia, GO, nas coordenadas geográficas 16º35’12” de latitude Sul, 49º21’14” de longitude a Oeste de Greenwich, e 730 m de altitude, cujo plantio foi realizado em janeiro de 2011, totalizando 546 plantas provenientes de 182 plantas-mães. Mensalmente foram obtidos dados relativos à altura total, e à circunferência do caule a 10,0 cm de altura de todas as plantas. Os dados meteorológicos foram obtidos na Estação Evaporimétrica de Primeira Classe em operação na EA/UFG. Foram estudadas as fenofases de folhação, floração e frutificação do A. othonianum, no período de março de 2012 a setembro de 2013, sendo as observações realizadas mensalmente. As avaliações referentes à antracnose foram realizadas mensalmente, com base em uma escala de notas de severidade da doença, em 65 cajueiros selecionados na área experimental. As plantas, com 32 meses após o plantio apresentaram altura variando de 4,0 cm a 380,0 cm e diâmetro de caule de 1,5 mm a 94 mm. A emissão de folhas apresentou-se com intensidade nos meses de março, abril e maio. A floração não apresentou correlação com nenhum dos dados climáticos relacionados, e teve seu pico no mês de junho. Apenas três plantas produziram frutos durante o período de estudo. Progênies da UFG e da região de São Miguel do Passa Quatro se destacaram quando a precocidade e produção de frutos, podendo ser indicadas para um futuro melhoramento genético. A antracnose se manifestou em níveis variados de severidade ao longo do período de estudo, se demonstrando mais severa nos meses de fevereiro, março e abril. As fenofases de emissão de folhas novas e flores contribuem significativamente para o progresso da doença.

O presente trabalho teve como objetivos: 1) estudar a fenologia, o crescimento e desenvolvimento de quatro híbridos de milho AG9010, DAS CO32, Exceler e DKB 333B semeados no período da "safrinha" na região de Piracicaba, Estado de São Paulo; 2) calibrar e testar o desempenho do modelo CERES-Maize para simular o desenvolvimento e a produtividade do milho "safrinha" para a mencionada região; 3) aplicar o modelo calibrado e testado para a determinação das épocas de semeadura com menores riscos, para as condições de sequeiro e irrigada, para os quatro híbridos mencionados; 4) aplicar o modelo CERES-Maize para simulações de longo período visando a estimativa da previsão de safra do milho "safrinha" na região de Piracicaba, Estado de São Paulo; 5) verificar a existência de associação entre parâmetros climáticos e o fenômeno do ENOS (El Niño Oscilação Sul) na região de Piracicaba, Estado de São Paulo; 6) analisar a influencia do fenômeno do ENOS na produtividade da cultura do milho “safrinha”. Para tanto, três experimentos de campo com quatro híbridos de milho foram conduzidos na Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, em Piracicaba, Estado de São Paulo, Brasil, durante os anos de 2001 e 2002. Um experimento foi conduzido no ano 2001 sob condições irrigadas e os outros dois no ano 2002: um sob condições de sequeiro e outro sob irrigação. Todos os experimentos tiveram delineamento de blocos completos ao acaso. Os híbridos de milho utilizados neste estudo foram: AG9010 (ciclo super precoce), DAS CO32 e Exceler (ciclo precoce) e DKB 333B (ciclo normal). As datas de semeadura foram 15 de março para o experimento de 2001 e 13 de março para os experimentos conduzidos em 2002. Os resultados obtidos neste estudo indicaram que o milho “safrinha”, sob condições de sequeiro, apresentou em geral, menores valores de IAF, altura de planta e acúmulo de matéria seca do que sob condições de irrigação. A cultura submetida a limitação de água no solo teve uma atividade radicular intensa nas camadas mais profundas do solo, sugerindo que um incremento no comprimento das raízes foi a resposta às deficiências hídricas. O modelo CERES-Maize simulou com adequada precisão a fenologia e o rendimento do milho “safrinha” para as condições de Piracicaba. Em geral, para os dois sistemas de cultivo, sob irrigação e sob sequeiro, quanto mais tardia a semeadura, menor o rendimento do milho “safrinha” simulado para os quatro híbridos. O modelo CERES-Maize mostrou ser uma excelente ferramenta para a previsão do rendimento do milho “safrinha”, utilizando-se dados climatológicos combinados aos dados meteorológicos do ano em questão. Com esse procedimento foi possível se obter adequada estimativa do rendimento com 45 dias de antecedência à colheita nos quatro híbridos de milho semeados na “safrinha” em Piracicaba. Os fenômenos “El Niño” e “La Niña” tiveram influência sobre o rendimento do milho “safrinha” em Piracicaba, em decorrência de mudanças nos padrões de precipitação durante os meses de abril e maio. Os rendimentos foram maiores durante os anos de “El Niño” do que em anos de “La Niña”, que por sua vez foram superiores aos rendimentos obtidos para os anos neutros. / The objectives of the present work were: 1) to study the phenology and development of four maize hybrids: AG9010, DAS CO32, Exceler and DKB 333B sown off-season in Piracicaba region, State of São Paulo, Brazil; 2) to calibrate and test the CERES-Maize model to estimate the productivity and development for the four maize hybrids sown off-season for the mentioned region; 3) to apply the model for determination of sowing dates with less risk, for irrigated and rainfed conditions, for the four maize studied hybrids; 4) to apply the CERES-Maize model for long term climatic conditions aiming yield forecast; 5) to verify the association between climatic parameter and ENSO phases (El Niño Southern Oscillation) for Piracicaba region; 6) to analyze the influence of ENSO phases in maize productivity. Three field experiments that included four hybrids with different maturity durations were conducted during the autumn and winter growing seasons of 2001 and 2002 at the Escola Superior de Agricultura “Luiz de Queiroz”, University of São Paulo, in Piracicaba, SP, Brazil. One experiment was conducted in 2001 under irrigated conditions, and two experiments were conducted in 2002, one under rainfed and another under irrigated conditions. All experiments had a randomized complete block design. The maize hybrids used in this study were: AG9010 (very short season), DAS CO32 and Exceler (short season) and DKB 333B (normal season). The sowing dates were March 15th, for the 2001 experiment, and March 13th, for the 2002 experiments. CERES-Maize model was calibrated and tested with data obtained in these experiments. The results suggested that maize sown off-season under rainfed conditions, presented in general, lower values of LAI, plant height and less dry matter accumulation than under irrigated conditions. An increase in root water uptake on deep layers of the soil was evident on maize crop under soil water limitations conditions. The CERES-Maize model simulated with accuracy the maize phenology and yield for off-season conditions. In general, for the two cropping systems, irrigated and rainfed, as more delayed the planting date is, less simulate yield for the four hybrids. The CERES-Maize was an excellent tool for maize off-season yield forecast using climatic historic data combined with data from the year of study. This procedure permitted to obtain a good estimation of yield 45 days before harvest for the hybrids sown off-season in Piracicaba. The ENSO phases had influence on maize sown off-season yield, as result of the precipitation patterns during April and May months. The highest yields were simulated for “El Niño” years, being higher than yields for “La Niña” years, which were higher than for neutral years.

A perda de área foliar, em sua maior parte resultante da ação de herbívoros, é um dos fatores que regulam o sucesso reprodutivo de uma planta e indiretamente de todos os consumidores relacionados na comunidade. A maior parte dos estudos feitos com perda foliar e herbivoria são pontuais, ou seja, referem-se a uma ou poucas espécies vegetais. Para os cerrados, a savana tropical brasileira, a maior savana em extensão e diversidade no mundo, não há nenhum estudo que investigue a dinâmica de perda de área foliar ao longo do tempo na comunidade, considerando os fatores climáticos e fenológicos que podem influenciar este processo, além da presença dos principais predadores de herbívoros atrópodes na vegetação de cerrado, as formigas, sendo este o principal objetivo do presente estudo. O estudo foi desenvolvido em uma área de reserva de Cerrado de 628 ha, situada em Uberlândia, MG (18º59S, 48º18O), tendo os dados sido coletados de janeiro a dezembro de 2007 (bimestralmente) e de 2008 (mensalmente). Foram estabelecidos aleatoriamente na área de cerrado sensu stricto da reserva, 15 quadrantes de 10m x 10m onde todos os indivíduos com diâmetro à altura do peito igual ou superior a três centímetros foram marcados e incluídos na amostra. Em cada quadrante observou-se (sem remoção), seis folhas (escolhidas aleatoriamente duas da parte alta, duas da parte mediana e duas de ramos mais baixos), por planta de cada espécie, sendo registrada a porcentagem de área foliar perdida. Foram amostrados um total de 1006 indivíduos distribuídos em 82 espécies e 34 famílias. A espécie Ouratea spectabilis (137 indivíduos) foi a mais abundante na área de estudo, seguida de Banisteriopsis malifolia (122), Machaerium acutifolium (59) e Tabebuia ochracea (41). A perda de área foliar variou significativamente ao longo do tempo (meses) e entre as famílias e espécies de plantas. Os meses mais secos do ano apresentaram a maior perda de área foliar tanto em 2007 (abril, junho e agosto) quanto em 2008 (de maio a agosto). Os fatores climáticos influenciaram significativamente a perda de área foliar, pois ela variou ao longo do tempo. Portanto, os resultados do presente estudo indicaram que a perda de área foliar da comunidade de plantas de cerrado varia sazonalmente e ocorre com maior intensidade na estação seca. Fatores abióticos como temperatura e precipitação influenciam a fenologia das espécies de plantas, que buscam o melhor momento para maximizar seu desenvolvimento e evitar que inimigos naturais causem perdas significativas para sua sobrevivência e sucesso reprodutivo. As características de cada espécie promovem diferenças na perda de área foliar, devido às defesas e/ou associações mutualísticas que possuem. A presença de nectários extraflorais associados às formigas desempenha um papel significativo para as plantas. Dentre os fatores bióticos, a presença de ninhos de formigas Ectatomma teve um impacto positivo para as plantas reduzindo a perda de área foliar. / The loss of leaf area, mostly resulting from the action of herbivores is one of the factors that regulate the reproductive success of a plant and indirectly to all consumers connected to the community. Most studies of herbivory and leaf loss are punctual, i.e., refer to one or a few plant species. In the cerrado, a tropical savanna in Brazil, the largest savanna in scope and diversity in the world, there are no studies to investigate the dynamics of loss of leaf area over time in the community, considering the climatic factors, phenology and carnivorous ants that can influence this process, which is the main objective of this study. The study was conducted in a closed area of 628 ha of Cerrado, located in Uberlandia, Brazil (18 º 59\'S, 48 18\'W) and the data were collected from January to December 2007 (bimonthly) and 2008 (monthly). Were established randomly in the area of cerrado of the reserve, 15 quarters of 10m x 10m where all trees with diameter at breast height greater than or equal to three centimeters were marked with numbered label and sampled. In each quadrant was observed (without removal), six leaves (randomly chosen two of high part, two of the middle, and two of the lower branches), in plant species, and recorded the percentage of leaf area lost. We sampled a total of 1006 individuals belonging to 82 species and 34 families. The species Ouratea spectabilis (137 individuals) was the most abundant in the study area, followed by Banisteriopsis malifolia (122), Machaerium acutifolium (59) and Tabebuia ochracea (41). The loss of leaf area varied significantly over time (months) and between families and species of plants. The driest months of the year showed the greatest loss of leaf area in both 2007 (April, June and August) and in 2008 (May-August). Climatic factors also significantly influenced the loss of leaf area, as it varied over time, depending on the rainfall and temperature variation. Therefore, the results of this study indicated that the loss of leaf area community of cerrado plants varies seasonally and occurs mostly in the dry season. Abiotic factors like temperature and rainfall influence the phenology of species of plants, seeking the best time to maximize their development and prevent natural enemies result in significant losses for their survival and reproductive success. The characteristics of each species promote differences in leaf area loss due to defenses and / or mutualistic associations they have. The presence of extrafloral nectaries associated with ants play a significant role for plants. For this reason, among the biotic factors, the presence of Ectatomma nests had a significant positive impact on reducing the loss of leaf area, since these ants are predators of herbivores.

The phenology of plants in northern ecosystems is currently changing. Roots have a key role in these ecosystems, though the phenology of roots is still poorly understood. The aim of this report was to investigate if above- and belowground phenology of the circumpolar sedge Eriophorum vaginatum was synchronized in a subarctic peatland underlain by permafrost, and to investigate which abiotic factors are limiting root growth. Additionally, the length of the belowground growing season was examined. The study was performed with a non-destructive in situ method (minirhizotrons and NDVI measurements) in the northernmost part of Sweden. Both above- and belowground phenology was measured biweekly during the whole growing season in 2016. The depth of the active layer, air temperature, soil temperature and soil moisture were measured to investigate the determinants of root growth. Root growth and aboveground activity was asynchronous, as peak in root growth occurred on average 21 days before maximum NDVI was reached. Soil temperature and thaw depth seem to be important factors regulating root growth in this peatland. The result highlight that solely studying the aboveground parts of plants can give a misleading interpretation about the phenology of the entire plant and thus during which time periods important ecosystem processes take place. Hence, to more accurate forecast ecosystem responses to global warming, both aboveground and belowground phenology should be considered.

Climate models have projected that arid and semiarid lands will experience warmer and drier conditions for the next 100 years. For the last twenty years, the Southwestern US has been experiencing one of the worst droughts over the last century, not only threatening ecological systems but also the water security of its population. Understanding the environmental processes that affect arid and semiarid forests are essential to better understand the water and carbon cycles, and tree-ring research has contributed valuable knowledge in this regard. There is a common understanding that moisture-stress has significant impacts on forested ecosystems and thereby on the global carbon and water cycles. Under persistent moisture deficit, a decline in growth, an increased proportion of wildfires, insect outbreaks, and mass-tree-mortality are often observed in arid and semi-arid forests, having large impacts on their carbon budgets and their capacity to act as a carbon sink. This study addresses the seasonal and regional climatic influences on the water-carbon relations in the ponderosa pine forests of the southwestern US (SW). This region is characterized by a complex climatology related to the North American Monsoon system (NAMS). A topic of interest in this dissertation is the role of the summer rainfall after the early-summer hyper-arid period in the region, providing a unique seasonal condition for these ecosystems to thrive. While these forests clearly rely on winter snowpack to drive much of their annual net primary productivity, the temporal and regional extent to which they supplement winter moisture with summer monsoon moisture needs to be clarified. The core of this dissertation is a study of the spatial and temporal variability of the stable carbon and oxygen isotopes in the cellulose of subsections of the tree rings (e.g., earlywood and latewood) collected from a network of thirteen sites along a latitudinal gradient extending from southern Arizona and New Mexico, through southwest Colorado, and up to northern Utah. The analysis is based on biological and physical processes and their close relationships with isotope effects to infer eco-physiological responses to climate variations over the last century. The stable carbon isotopes are used to derive intrinsic Water-Use Efficiency (iWUE) defined by the molar ratio of carbon gain to water loss. The stable oxygen isotope ratio is used to infer the variations on evaporative flux at the leaf level, which depend on stomatal conductance, atmospheric vapour pressure deficit at the leaf surface, and variations in the isotopic ratio of the source water. Both isotopic ratios are used to document variations in tree productivity and hydrologic vulnerability within the context of climate change impacts on this region. During the study, it was found that climate change in the SW has impacted the carbon and water cycles of these forests for at least the past twenty years. Additionally, seasonality influence the eco-physiology of ponderosa pine change along the latitudinal gradient, as shown by significant differences between EW and LW. These differences are explained by the large shifts in seasonal VPD, which are more evident in the southern part of our study region due to the mid-summer arrival of monsoon rains. These findings will be useful for regional natural resource managers and improves our understanding of seasonal influences on forest water–carbon relationships. This approach will also be useful to develop seasonally resolved paleoclimate and paleo-ecophysiological reconstructions to characterize the long-term influence of winter versus summer moisture on carbon-water relations in forested ecosystems.

Climate change is expected to impact species by altering infectious disease outcomes, modifying community composition, and causing species to shift their phenology, body sizes and range distributions. However, the outcomes of these impacts are often controversial; for example, scientists have debated whether climate change will exacerbate emerging infectious disease and which species are at greatest risk to advance their phenology. There reason for these controversies may be that climate change is impacting diverse processes across a wide range of ecological scales, as the interplay between fine-scale processes and broad-scale dynamics can often cause unpredictable changes to the biosphere. Therefore, it is important to consider how ecological processes change across spatial, temporal and allometric scales in order to understand the impacts of climate change. For example, if community composition controls disease distributions at small spatial scales while abiotic factors do so at large, regional scales, studies conducted at a single spatial scale may misestimate the impacts of climate change on biodiversity. Because small organisms acclimate quickly, they may track their phenology to climatic factors over shorter temporal scales than large organisms. In addition, small organisms have wider thermal breadths, or temperature ranges where performance is relatively strong, than large organisms. This may cause cold-adapted hosts to face performance gaps with parasites at warmer temperatures than those where host or parasite performance peaks, putting them at risk when the climate warms. I began my dissertation work by examining how spatial scale modulates the observed effects of human modifications to ecological processes. Humans are altering the distribution of species by changing the climate and disrupting biotic interactions and dispersal. A fundamental hypothesis in spatial ecology suggests that these effects are scale-dependent; biotic interactions should shape distributions at local scales while climate should control them at regional scales. Thus, common single-scale analyses might be unable to accurately estimate the impacts of anthropogenic modifications on biodiversity and the environment because they may miss effects at other scales. However, the large-scale datasets and computing power necessary to test scale hypotheses have not been available until recently. I conducted a cross-continental, cross-scale (almost five orders of magnitude) analysis of the influence of biotic, abiotic, and dispersal processes on the distribution of three emerging pathogens: the amphibian chytrid fungus implicated in worldwide amphibian declines, and West Nile virus and the bacterium that causes Lyme disease (Borrelia burgdorferi), which are responsible for ongoing human health crises. For all three pathogens, biotic factors were only significant predictors of distributions at local scales (~102-103 km2), whereas climate factors and a proxy for dispersal limitations were almost always only significant at relatively larger, regional scales (>104 km2). Spatial autocorrelation analyses revealed that biotic factors were relatively more variable at smaller scales whereas climatic factors were more variable at larger scales, consistent with the prediction that factors should be important at the scales they vary the most. Finally, no single scale could detect the importance of all three categories of processes. My results highlight that common, single-scale analyses can misrepresent the true impact of anthropogenic modifications on biodiversity and the environment. Although it is important to understand how ecological processes affect patterns across scales, a critical step towards understanding the ecological impacts of climate change is to develop cross-scale frameworks that can predict these patterns. Thus, I proceeded to develop a framework to help understand how species are altering their phenology, or the timing of seasonal activities, using data collected across spatial and temporal scales. Phenological shifts are concerning because they can cause species declines by creating asynchronies or “mismatches” in plant–pollinator, plant–herbivore, and host–parasite interactions. Although advancements in the phenology of plants and animals have been widely reported and synthesized, several open knowledge gaps of critical concern have persisted. First, although many phenological studies and syntheses assume climate change as an important driver of phenological shifts, many do so without explicitly testing for any effect of climate, and among those that have, standardized climate data are rarely used. As a consequence, it remains unclear which climatic variables are driving shifts in phenology and whether geographical heterogeneity in these variables across regional scales has impacted their predictive power to detect ecological trends. Second, one of the chief concerns about species shifting the timing of their phenologies is the possibly of ecological mismatches, or asynchrony in the timing of species interactions, especially in mutualisms. I hypothesized that across regional scales, factors driving seasonality would also drive phenological shifts. I also hypothesized that small species might shift their phenology faster than large organisms because they acclimate to new conditions more easily. I addressed these questions by synthesizing 1,011 published time series of animal phenology and historic global climate data using a meta-analytical framework. I found that while temperature drives phenological responses at high latitudes, low-latitude shifts are driven by precipitation. Small body size and ectothermy were associated with strong phenological shifts, suggesting emerging asynchrony between hosts and parasites and predators and prey. Finally, I looked at how variation across allometric scales might impact host-parasite interactions in the context of changing temperatures. Small organisms have larger performance breadths, or temperature ranges where performance is relatively high, than large organisms, and thus pathogens should typically have broader performance breadths than hosts. Therefore, the performance gap between pathogens and cold- and warm-adapted hosts should occur at relatively warm and cold temperatures, respectively. To test this hypothesis, which I coin the thermal mismatch hypothesis, we quantified the temperature-dependent susceptibility of “cold-“ and “warm-adapted” amphibian species (Atelopus zeteki, Osteopilus septentrionalis, and Anaxyrus terrestris) to the fungal pathogen Batrachochytrium dendrobatidis (Bd) using laboratory experiments and field prevalence estimates from 4,775 host populations. In both the laboratory and field, I found that peak susceptibility for cold- and warm-adapted hosts occurred at relatively warm and cool temperatures, respectively, providing support for the thermal mismatch hypothesis. Finally, I found that the temperature-dependent A. zeteki mortality patterns observed in our experiment accurately predicted historic extinctions of Atelopus spp., suggesting that climate change contributed to the extinctions. My results suggest that as climate change shifts hosts away from their optimal temperatures, the probability of infectious disease outbreaks may increase, but the effect will depend on the host species and the direction of the climate shift. My findings partly explain the tremendous variation in species’ responses to climate change. Based on the results of my dissertation, I conclude that climate change has diverse effects on ecology across scales. Biotic interactions control disease distributions at small, local spatial scales while abiotic factors do at large scales, suggesting that climate change may impact species distributions differently at different scales. Across temporal scales, differences in acclimation rates could be affecting which species are more likely to shift their phenology. Finally, across allometric scales, differences in thermal breadths between individuals of different body sizes could alter host-parasite interactions by causing hosts to be susceptible to disease even at conditions far from where parasites perform best. Thus, I believe that my dissertation has contributed to what we understand about how scale relates to disease and biodiversity declines in the context of climate change.

Pollinator sharing in mixed species communities is expected to significantly contribute to mating patterns in contemporary populations but may also affect the evolutionary trajectory of traits associated with plant mating. In this thesis, I considered how the spring environment and pollinator sharing may contribute to the widespread convergence in traits among spring flowering species using comparative biology. The proposed correlation between a spring flowering phenology and white or light floral colour, fleshy fruits, woody growth forms and understory occupation is confirmed. In addition, I examined the effects of pollinator responses to community and population traits to determine the relative importance of inter- and intraspecific interactions in pollinator mediated reproductive success of a spring flowering species, Trillium grandiflorum. In this study, the reproductive success of T. grandiflorum was pollen limited. However, the magnitude of pollen limitation was influenced only by intraspecific density and varied independently of community diversity. The results of this thesis contribute significantly to our understanding of pollinator-mediated interactions in spring flowering communities but also highlight future avenues of investigation.