957 resultados para ALBO, ALBERTO


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Esta pesquisa aborda em primeiro momento os conceitos de crimes de perigo abstrato e concreto. Estendeu a ideia de crime e as funções do Direito Penal na sociedade contemporânea, como ainda evidencia esta área do Direito no sistema e/ou estrutura do mundo da vida. Os dois casos de crimes de perigo abstrato e concreto foram propostos nos estudos acerca do artigo 306 do Código de Trânsito Brasileiro CTB no tratado à embriaguez ao volante e a constitucionalidade ou não da aplicação do crime de perigo abstrato ao caso em específico. Nesta perspectiva as análises se configuraram nos relatos dos Tribunais de Justiça dos Estados do Rio de Janeiro e de Rondônia a fim de significar as tipificações em tela, bem como às relações intersubjetivas dos desembargadores e à própria organização de cada órgão judiciário. Dessas análises foi possível chegar à interpretação das diferenças entre o crime de perigo abstrato e concreto presentes nas incidências e/ou ocorrências de acidentes de trânsito nos dois Estados respectivamente. Em um terceiro momento centrou-se as análises nos estudos socioeconômicos e culturais que tratam de entender o fenômeno do trânsito nos municípios de Porto Velho-RO e Rio de Janeiro-RJ, cujos acidentes nas vias públicas modificam os modos de ser e de viver nos locais. Do ponto de vista metodológico a ideia é conceituar os crimes de perigo concreto e abstrato; os riscos da sociedade atual, se utilizando muitas vezes de Niklas Luhmann e Raffaele De Giorgi; Leonel S. Rocha; Renato de Mello Jorge Silveira; Jorge Luis Fortes Pinheiro da Câmara; Aparecida Luzia Alzira Zuin, Jürgen Habermas, Juarez Estevam Xavier Tavares; Eduardo Sanz de Oliveira Silva; Winfried Hassemer; Antônio Carlos Wolkmer e José Rubens Morato Leite; Diego Romero, entre outros. A fim de entender o que é perigo no escopo abrangido pelo Direito Penal, tomamos como embasamentos teóricos Luiz H. Merlin; Sánchez Silva, Luís Greco, Claus Roxin, Nilo Batista etc. Além desses autores, a tese se apoia nos teóricos: Juarez Tavares, Luiz Alberto Machado; E. Raúl Zaffaroni; Alexandre de Moraes. Ainda, complementamos as referências com Luiz Regis Prado; Nilo Batista. Estende-se à ideia aos crimes de perigo abstrato e direito penal brasileiro; aqui, encontramos subsídios em: Celso Delmanto; Luiz Flávio Gomes, dentre outros. Vale mencionar que neste diapasão, a proposta é conceituar e exemplificar os princípios legitimadores do Direito Penal frente à proposta fundamental da Constituição Federal de 1988. Ainda, conceituar e descrever os objetivos do CTB; as aplicações legais ou não do Art. 306 do CTB; e a definição e/ou classificação de embriaguez nesta linha de pensamento.

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Modelos de evolução populacional são há muito tempo assunto de grande relevância, principalmente quando a população de estudo é composta por vetores de doenças. Tal importância se deve ao fato de existirem milhares de doenças que são propagadas por espécies específicas e conhecer como tais populações se comportam é vital quando pretende-se criar políticas públicas para controlar a sua proliferação. Este trabalho descreve um problema de evolução populacional difusivo com armadilhas locais e tempo de reprodução atrasado, o problema direto descreve a densidade de uma população uma vez conhecidos os parâmetros do modelo onde sua solução é obtida por meio da técnica de transformada integral generalizada, uma técnica numérico-analítica. Porém a solução do problema direto, por si só, não permite a simulação computacional de uma população em uma aplicação prática, uma vez que os parâmetros do modelo variam de população para população e precisam, portanto, ter seus valores conhecidos. Com o objetivo de possibilitar esta caracterização, o presente trabalho propõe a formulação e solução do problema inverso, estimando os parâmetros do modelo a partir de dados da população utilizando para tal tarefa dois métodos Bayesianos.

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A vitamina D, atualmente, é relacionada também ao metabolismo da glicose e o desenvolvimento de órgãos. Fêmeas de camundongos suíços (F0) foram alimentadas por uma das dietas experimentais: SC (dieta padrão) ou VitD- (dieta sem vitamina D). A prole de machos foi estudada nas idades: nascimento, 10 dias, desmame e seis meses, nas gerações F1 e F2. Avaliou-se a biometria [Massa Corporal (MC), Comprimento nasoanal (CNA) e Pressão Arterial (PA)], urina de 24 horas, glicemia e Teste Oral de Tolerância à Glicose (TOTG). Durante a eutanásia, o sangue foi coletado para análise bioquímica e os tecidos foram removidos para análise estereológica, morfométrica e Western blotting (WB). Não houve diferença de MC ao nascimento. Ao desmame, o grupo F2-VitD- teve maior MC que F2-SC (P=0,03) e aos seis meses, os grupos F1 e F2-VitD- tiveram MC mais elevada (P<0,05 vs SC). A PA foi crescente na prole VitD-, sendo maior em F1-VitD- (P=0,001). A glicemia e TOTG foram alterados somente na F1-VitD-, seguida de esteatose hepática (+99%), hipertrofia da ilhota pancreática (+40%) e elevação do triglicerídeo sanguíneo (P<0,01). O WB de fígado mostrou elevação de FAS (+18%, P<0,01), no grupo com esteatose. Curiosamente, embora a F2-VitD- tenha apresentado elevação de MC, somente o colesterol total fora alterado (P<0,05). Quanto à nefrogênese, houve 50% mais glomérulos imaturos em F1-VitD- que F1-SC (P<0,0001). Porém, na F2 houve aumento somente de 20% (P<0,001). Aos 10 dias, F1-VitD- teve 150% mais glomérulos imaturos e 25% mais glomérulos maduros que SC-F1 (P<0,0001). O WB de rim mostrou que a prole F1-VitD- apresentou maior expressão de renina, ao desmame e aos seis meses, enquanto que a expressão de podocina foi reduzida (P=0,0004). Não houve diferença na análise de WT1. A restrição materna em vitamina D altera a morfologia do pâncreas e fígado, com resistência à insulina, altera a expressão renal de importantes fatores, assim como retarda a maturação glomerular estendendo o período da nefrogênese, principalmente na geração F1.

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Los censos de la fauna de un país o región cualquiera, constituyen una suerte de codificación de la Naturaleza, como paso previo e indispensable para un ensayo racional de aprovechamiento de las riquezas naturales y de su adecuada conservación. Desde fines del siglo XVIII se ha dicho, y lo han repetido en nuestro medio, Cosme Argerich, Alberto Palcos y otros estudiosos y cientistas, que un Código de la Naturaleza es indispensable para la libertad de una nación” (Ringuelet y Arámburu, 1957).

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Recruitment, defined and measured as the incorporation of new individuals (i.e. coral juveniles) into a population, is a fundamental process for ecologists, evolutionists and conservationists due to its direct effect on population structure and function. Because most coral populations are self-feeding, a breakdown in recruitment would lead to local extinction. Recruitment indirectly affects both renewal and maintenance of existing and future coral communities, coral reef biodiversity (bottom-up effect) and therefore coral reef resilience. This process has been used as an indirect measure of individual reproductive success (fitness) and is the final stage of larval dispersal leading to population connectivity. As a result, recruitment has been proposed as an indicator of coral-reef health in marine protected areas, as well as a central aspect of the decision-making process concerning management and conservation. The creation of management plans to promote impact mitigation,rehabilitation and conservation of the Colombian coral reefs is a necessity that requires firstly, a review and integration of existing literature on scleractinian coral recruitment in Colombia and secondly, larger scale field studies. This motivated us to summarize and analyze all existing information on coral recruitment to determine the state of knowledge, isolate patterns, identify gaps, and suggest future lines of research.

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The domestication of livestock represented a crucial step in human history. By using endogenous retroviruses as genetic markers, we found that sheep differentiated on the basis of their "retrotype" and morphological traits dispersed across Eurasia and Afr

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随着工业化的发展,大气中二氧化碳的浓度(CO2)预测从现在的平均350μmol·mol-1升高到2030年的570μmol·mol-1,其增温作用将持续多个世纪。植被在大气二氧化碳减排以及调控区域水热状况过程中起重要作用,而其机理过程目前十分不清楚。本实验应用自控、封闭、独立生长室,研究了CO2浓度和温度升高对红桦根、茎、叶和枝可溶性蛋白含量和分配的影响,从蛋白水平上来解释川西亚地区的建群种-红桦对CO2升高和温度升高及其交互作用的响应规律,为全球气候变暖川西亚高山的植被保护和恢复提供理论依据。研究结果表明: 1. CO2浓度升高增加了可溶性蛋白的总量,改变了可溶性蛋白分配模式,即,可溶性蛋白分配到根的比例增加,分配到茎、枝、叶的比例减少。可能意味:在CO2浓度升高条件下,红桦根系的生长和营养物质吸收功能将会增强。 2. CO2浓度升高增加了根和茎的清蛋白含量,降低了叶片的清蛋白含量,叶片的球蛋白含量、醇溶蛋白含量和谷蛋白含量均增加。表明CO2浓度升高增加了清蛋白在根中积累,球蛋白、醇溶蛋白和谷蛋白大量在叶片中积累;前人研究所指出的CO2浓度升高使植物叶片可溶性蛋白的含量降低可能仅仅是由于清蛋白含量的降低造成的。 3. 温度升高使红桦幼苗整株所含可溶性蛋白总量增加,但可溶性蛋白总量的分配因红桦幼苗器官的不同而异。温度升高下根、茎、叶和枝的分配量分别占总可溶性蛋白的27.74%、35.57%、23.00%、13.68%,即茎>根>叶>枝。对照的根茎叶枝的分配量分别占总可溶性蛋白的21.01%、41.41%、23.08%、14.50%,即茎>叶>根>枝。表明温度升高使可溶性蛋白分配到根的比例增加,有利于根的可溶性蛋白的积累,增强了根吸收水分和矿质营养的能力,从而有利于根系的生长。 4. 温度升高处理下清蛋白和球蛋白在根中含量升高,在茎、叶和枝中含量下降,但没有达到显著水平;醇溶蛋白在根和叶中含量显著增加;谷蛋白在茎中的含量显著降低。表明温度升高增加清蛋白和球蛋白在红桦幼苗根部的积累,也有利于根和叶醇溶蛋白的积累,但不利于谷蛋白在茎的积累;温度升高条件下叶片可溶性蛋白升高是醇溶蛋白在叶片中积累的结果。 5. CO2浓度和温度同时升高条件下红桦幼苗的可溶性蛋白总量增加很少,只有分配到茎的可溶性蛋白比例增加,并且对可溶性蛋白分配规律没有影响。CO2和温度同时升高下红桦幼苗枝的可溶性蛋白含量的降低是可溶性蛋白总量的降低而不是碳水化合物稀释的结果,并且CO2和温度同时升高对红桦幼苗的生长没有明显的促进作用。 6. CO2和温度同时升高处理对可溶性蛋白含量有显著影响。清蛋白含量在根、茎、叶和枝中均降低,球蛋白含量在根中显著降低,醇溶蛋白含量在根、茎、叶和枝中均降低,谷蛋白含量在根中显著降低。表明CO2浓度和温度同时升高对根的影响显著,即降低了根的可溶性蛋白含量,可能导致根的吸收能力下降。 7. 因此,CO2和温度同时升高对可溶性蛋白影响不能简单地通过CO2和温度单因子影响机理来解释。 It is well known that atmospheric CO2 concentration and temperature are increasing as a consequence of human activities. Atmospheric CO2 concentration are predicted to increase from 350μmol·mol-1 now to 570μmol·mol-1 2030. And temperature will continue to increase for several centuries as a result of CO2 enrichment. Vegetation play a key role in reducing atmospheric CO2 and adapting and controlling warter and energy process in a certain region, while the underlying mechanism are not clear, yet. Betula albo-sinensis, as the dominating tree species of subalpine dark coniferous forest in west Sichuan province, play an important role in determing structure and function of forest ecosystem. In our study, effects of elevated atmospheric CO2 concentration (ambient±350±25μmol·mol-1), increased temperature (ambient±2.0±0.5℃) and their combination on contents and allocation of soluble protein were studied in independent and enclosed-top chamber system under high-frigid conditions. Chambers with ambient CO2 concentration and temperature are taken as control. The results are as the following, 1) Elevated atmospheric CO2 increased the accumulation of total weight of soluble protein in whole plant and changed allocation of soluble protein in red birch by increasing its allocation to roots and reducing its allocation to stem. This caused much more accumulation of soluble protein in roots which might help to prompt growth, development and nutrient absorption ability of roots. 2) Treatment EC increased content of albumin in roots and stems, reduced the content of albumin in leaves, and increased the content of globulin, promalin and glutenin in leaves. That is to say EC increased the accumulation of albumin in roots and accumulation of globulin, promalin and glutenin in leaves. The reduced soluble protein contents in plant leaves by EC, as reported by former researchers, are mainly resulted from the reduced content of albumin in leaves. 3) Elevated temperature increased the total of soluble proteins, but its allocation was dependent on organs. In treatment ET, roots, stems, leaves and branches take 27.74%, 35.57%, 23.00% and 13.68% of total weight of soluble protein. In treatment CK, roots, stems, leaves and branches take 21.01%, 41.41%, 23.08% and 14.50%. Elevated temperature changed allocation of soluble proteins in that it stimulated soluble proteins accumulation in roots and improved the uptake of water in roots. 4) Treatment ET increased the content of albumin and globulin in roots, and reduced the content of albumin and globulin in stems, leaves and branches. The content of promalin in roots and leaves was increased significantly, and the content of glutenin in stems was reduced significant. This suggested that ET stimulated the accumulation of albumin and globulin in roots and accumulation of promalin in leaves and roots; that treatment ET increased content of soluble protein in leaves was mainly resulted from the increased promalin content in leaves. 5) Regarding treatment ETC, the total of weight of soluble proteins increased, but not significantly; but increased in stems. So the combination of elevated atmospheric CO2 and temperature had not changed the allocation of soluble proteins in red birch seedling and reduced soluble proteins in branches were not the result of increased carbohydrate. 6) Treatment ETC reduced the content of albumin and promalin in roots, stems, leaves and branches, reduced the content of globulin and glutenin in roots significantly. That is to say elevated atmospheric CO2 and temperature reduced the content of soluble proteins in roots significantly which might help to prompt growth, development and nutrient absorption ability of roots. 7) The effects of elevated atmospheric CO2 and temperature on soluble protein cannot be simply interpreted through their mechanism that obtained when they were imposed on plant separately.

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土壤微生物(Soil microbes)是生态系统的重要组成部分,它参与土壤中复杂有机物质的分解和再合成,也参与C、N、S、P等的循环。土壤酶(Soil enzyme)是土壤中具有生物活性的蛋白质,它与微生物一起推动着土壤的生物化学过程,并在树木营养物质的转化中起着重要的作用。鉴于土壤微生物和土壤酶对环境变化的敏感性,它们在CO2浓度和温度升高时的反应将在很大程度上影响森林生态系统的结构和功能。因此,要全面评价大气CO2浓度和温度升高对整个生态系统的影响,有必要对CO2浓度和温度升高条件下的土壤微生物的反应进行深入的研究与探讨。本文应用自控、封闭、独立的生长室系统,研究了川西亚高山岷江冷杉(Abies faxoniana)根际、非根际土壤微生物数量,红桦(Betula albosinensis)根际微生物数量以及根际、非根际土壤酶活性对大气CO2浓度(环境CO2浓度+350±25μmol·mol-1,EC)和温度(环境温度+2.0±0.5℃,ET)升高及两者同时升高(ECT)的响应。结果表明: 1) EC和ET显著增加岷江冷杉根际微生物数量,但不同微生物种类对EC和ET的反应有所差异。6、8和10月,岷江冷杉根际微生物数量与对照(CK)相比,EC处理的根际细菌数量分别增加了35%、164%和312%,ET处理增加了30%、115%和209%;EC和ET处理对根际放线菌和根际真菌数量影响不显著。ECT处理的根际放线菌数量分别增加了49%、50%和96%,根际真菌数量增加了151%、57%和48%;而ECT对根际细菌数量影响不显著。EC、ET和ECT处理对岷江冷杉土壤微生物总数的根际效应明显,其R/S值分别为1.93、1.37和1.46(CK的R/S值为0.81)。 2) 红桦根际微生物数量对EC、ET和ECT的响应不同。生长季节(5~10月),高密度的红桦根际细菌数量与CK 相比,EC的根际细菌数量分别增加28%、33%、423%、65%、43%和79%,而低密度的红桦根际细菌数量增加不显著。ET能显著增加根际细菌数量(7~10月),其中高密度的根际细菌数量分别增加了377%、107%、35%、22%,而低密度的根际细菌数量分别增加了27%、27%、64%、48%;ECT对两个密度水平下根际细菌数量均未产生有显著的影响。高、低密度的红桦根际放线菌和根际真菌数量与 CK 相比,EC显著增加了低密度的红桦根际放线菌数量,而对高密度的根际放线菌数量无显著影响;ET和ECT对高低密度的红桦根际放线菌数量均未产生显著影响。EC和ET对高低密度的根际真菌数量也无显著影响,而ECT却显著增加了高低密度的根际真菌数量。 3) EC、ET和ECT处理的低密度红桦根际微生物(细菌、放线菌和真菌)数量没有显著高于或低于高密度根际微生物数量,表明短期内密度对红桦根际微生物数量不产生影响。 4) 不同种类的氧化还原酶对EC、ET和ECT的响应不同。5~10月,EC的红桦根际过氧化氢酶活性是CK 的1.44、1.06、1.11、1.10、1.12和1.24倍,差异显著(6月除外);ET和ECT处理根际过氧化氢酶活性无显著增加。EC的红桦根际多酚氧化酶活性比CK显著增加;ET的根际多酚氧化酶活性显著高于CK(8月除外)。ECT的根际多酚氧化酶活性高于CK,差异不显著。EC的根际脱氢酶活性分别增加了46%、40%、133%、48%、17%和26%,差异显著。5~7月,ET和ECT的根际脱氢酶活性高于CK的脱氢酶活性,而8~9月则相反,差异性均不显著。 5) EC、ET和ECT对不同种类的水解酶的影响不同。EC能显著增加红桦根际脲酶活性,5~10月分别增加了29%、42%,、70%、67%、59%和57%。ET和ECT 对根际脲酶活性未产生显著影响。EC显著提高根际转化酶活性,5、6和9月EC的根际转化酶活性分别比CK高51%、42%和40%。5和10月,ET的根际转化酶活性低于CK,而其余月份却高于CK,但均具有显著性差异。ECT的根际转化酶活性与CK的根际转化酶活性有显著性差异(9月除外),5、6和7月的根际转化酶活性分别提高了94%、198%和67%。 6) 与CK相比,EC、ET和ECT的非根际土壤微生物数量以及非根际土壤酶活性均无显著提高。EC、ET和ECT的过氧化氢酶、脲酶的根际效应明显,而多酚氧化酶和脱氢酶根际效应不明显。EC和ECT的转化酶根际效应明显,而ET的转化酶根际效应不明显。 It is well known that atmospheric CO2 concentration and temperature are increasing as a consequence of human activities. In past decades, considerable efforts had been put into investigating the effects of climate change on processes of forest ecological system. In general, studies had been mainly focused on the effects of elevated atmospheric CO2 on plant physiology and development, litter quality, and soil microorganisms. Studies showed that there was variation in the responses of root development and below-ground processes to climate between different plant communities. Since the concentration of CO2 in soil was much higher (10~50 times) than in the atmosphere, increasing levels of atmospheric CO2 may not directly in fluence below ground processes. Betula albosinensis and Abies faxoniana, as the dominated tree species of subalpine dark coniferous forest in the western Sichuan province, which play an important role in the structure and function of this kind of forest ecosystem. In our study, effects of elevated atmospheric CO2 concentration (350±25μmol·mol-1), increased temperature (2.0±0.5℃) and both of the two on the number of rhizospheric microbe and rhizospheric enzyme activity were studied by the independent and enclosed-top chamber’ system under high-frigid conditions. Responses of rhizospheric bacteria, actinomycetes and fungi number of Betula albosinensis and Abies faxoniana under different densities(high density with 84 stems·m-2, low density with 28 stems·m-2 ), and rhizospheric enzyme activity of Betula albo-sinensis to elevated CO2 concentration and increased temperature were analyzed and discussed. The results are as the following, 1) In comparion with the control, the numbers of rhizospheric bacteria of Abies faxoniana were increased by 35%, 164% and 312% significantly in June, August and October respectively of EC, and were increased by 30%, 115% and 209% respectively of ET.However the effect of EC and ET on rhizospheric actinomycetes and fungi was not significant. The number of rhizospheric actinomycetes of ECT were increased significantly by 49%, 50% and 96% respectively, and the increment of rhizospheric fungi were 151%, 57% and 48% respectively .The effect of ECT on rhizospheric bacteria was not significant. Rhizospheric effect of soil microbe for all treatments was significant, with the R/S of 1.93, 1.27 and 1.46 for EC, ET and ECT, respectively. 2) Treatment EC improved the number of rhizospheric bacteria of Betula albosinensis under high density significantly in comparison with the control, over the growing season, the greatest increment of rhizospheric bacteria was from July. However, EC had no effect on the number of rhizospheric bacteria under low density. Except May and June, treatment ET improved the number of rhizospheric signifcantly. The effect of treatment ECT on the number of rhizospheric bacteria under different densities was not significant. Of treatment EC, the number of rhizospheric actinomycetes of Betula albosinensis under low density were increased significantly, however, treatment EC did not stimulate the number of rhizospheric actinomycetes under high density. Simultaneously, treatment ET and ECT did not stimulate the number of rhizospheric actinomycetes. Finally, in treatment ECT, the number of rhizospheric fungi under high density were increased significantly, however treatment EC and ET did not stimulate the number of rhizospheric fungi under different densities. 3) Of treatment EC, ET and ECT, the number of rhizospheric microbe of Betula albosinensis under low density were not more or fewer than that of microbe under hign density along the growing season, which showed that plant density had no effect on the nmber of microbe. 4) From May to October, 2004,rhizospheric catalase activity of Betula albosinensis of treatment EC was 1.44, 1.06, 1.11, 1.10, 1.12 and 1.24 times as treatment CK respectively, and the difference was statistically significant(except June). Treatment ET and ECT did not increase rhizospheric catalase activity significantly. In treatment EC, the rhizospheric pohyphenol oxidase activity was higher than treatment CK significantly. The rhizospheric pohyphenol oxidase activity of treatment ET was higher than CK significantly (except August). The rhizospheric pohyphenol oxidase activity of treatment ECT was higher than CK, but the difference was not statistically significant. Over the growing period, the rhizospheric dehydrogenase activity were increased 46%, 40%, 133%, 48%, 17% and 26% respectively by treatment EC, and the difference was statistically significant. From May to July, the rhizospheric dehydrogenase activity in treatment ET and ECT was higher than CK, but from August to October, the rhizospheric dehydrogenase activity was lower than CK, the difference was not significant. 5) Treatment EC increased rhizospheric urease activity significantly, from May to October, rhizospheric urease activity were increased 29%, 42%, 70%, 67%, 59% and 57% respectively by EC. Treatment ET and ECT had no effect on rhizospheric urease activity. Treatment EC improved rhizospheric invertase activity significantly, in May, June and September, the rhizospheric invertase activity of treatment EC were increased 51%, 42% and 40% in comparison with the control. Except May and October, the rhizospheric invertase activity of treatment ET was markly higher than CK. The rhizospheric invertase activity of treatment ECT was significantly different from CK (except September), in May, June and July treatment ECT increased rhizospheric invertase activity by 94%, 198% and 67% respectively. 6) In comparison with the control, treatment EC, ET, and ECT had no effect on the number of non-rhizospheric microbe and non-rhizospheric enzyme activity. Rhizospheric effect of catalase and urease for all treatments was significant, but rhizospheric effect of pohyphenol oxidase and dehydrogenase was not significant. Rhizospheric effect of invertase of EC and ECT was significant, but rhizospheric effect of invertase of ET was not significant.

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在青藏高原东部的亚高山针叶林区,如何尽快恢复这一生态脆弱地区的植被,改变生态环境恶化的趋势,是一个十分重要的课题。光一直被认为是植物种间相互替代,尤其是森林演替过程中植物相互替代或植被恢复中的关键环境要素之一。植物能否适应林冠下或林窗中异质的、或多变的光照条件,对其在林中的生存、分布、更新以及森林动态都是非常重要的。 本文以青藏高原东部亚高山针叶林的主要森林类型——岷江冷杉林群落的几种树苗为研究对象,采用实验生态学、生理及生物化学等方法,通过模拟针叶林不同大小林窗内光照强度的变化,在中国科学院茂县生态站内采用遮荫处理设置6个光照梯度(100、55、40、25、15与7%全光照),来研究具有不同喜光特性的植物对光强的响应与适应机制,其研究结果可为揭示亚高山针叶林的演替规律、以及人工林下幼苗的存活与定居提供科学依据,也能为苗木的生产与管理提供科学指导,尤其是对针阔树种在不同光强下的响应与适应的比较研究,能为如何将阔叶树种整合到人工针叶林中提供新的思路。 光强对植物生长的影响 光强对植物的生长具有重要作用,不同植物在各自适宜的光强梯度下才能生长良好。通过一个野外盆栽实验,来研究不同光强对植物生长的影响(第三章)。主要研究结果如下,低光强下植物株高/茎生物量增加,说明植物会将生物量更多用于高生长,以便有效地拦截光资源;在强光下,植物将生物量更多地向根部分配,使得植物在强光下能够吸收更多的水分,而避免干旱胁迫。 在第一个生长季节,以相对生长速率(RGR)表示,红桦和青榨槭在100%全光照下RGR最大,粗枝云杉在55%最大,岷江冷杉在25-40%下较好;然而,在第二个生长季节,2种阔叶树的相对生长速率(RGR)的适宜光强则变为25-55%,云杉为55-100%,而冷杉为25-100%。可见,从第一年到第二年,2种阔叶树苗更适宜在部分荫蔽的条件下生长;而2种针叶树苗对光的需求则逐渐增加,这可能是增加对根生物量相对投资的结果,因为以这种方式,强光下生长的针叶树幼苗更能保持其内部水分平衡,其生长不会因干旱胁迫而受到严重影响。另外,严重遮荫会引起冷杉幼苗死亡。 植物对光强的生理适应 植物可以通过自身形态和生理特征的调整,来发展不同的光能利用策略从而能够在林中共存。通过一个野外盆栽实验,研究了不同光强下生长的几种树苗的生理特征(第四章)对不同光强的响应与适应。结果显示:强光下,粗枝云杉和红桦的光合能力增加,而岷江冷杉和青榨槭在中度遮荫(25-55%)的条件下光合能力最大。植物叶氮和叶绿素含量增高,而光补偿点和暗呼吸速率降低,这些都是植物对低光环境的适应性反应;而强光下植物叶片和栅栏组织变厚,是对强光的一种保护性反应。 植物对光的可塑性反应 不同植物会表现出对光适应有利的生理和形态可塑性反应。本文对第三章、第四章的实验数据进行可塑性指数分析,来研究植物对光强的表型可塑性反应(第五章)。结果显示,生理特征调整是植物对不同光环境的主要适应途径。红桦和青榨槭的可塑性指数平均值要大于粗枝云杉和岷江冷杉,充分表明这2种阔叶树在生理和形态上较强的可塑性更有利于对光环境的适应,而具有比耐荫树种更强的适应能力。另外,2种针叶树相比,云杉的适应性更强。本研究结果支持树种的生理生态特性决定了其演替状况和生境选择的假说。 植物的光抑制与防御 当植物叶片吸收了过多光能,会发生光抑制现象。植物对光抑制的敏感性及防御能力对其生长具有重要意义。本文通过两个野外盆栽实验,研究了生长在强光下(第六章)和变化光强下(第八章)植物的光抑制现象及其防御策略。结果表明,在强光下或从遮荫状态转入强光下,植物都会发生光抑制,其对光抑制的敏感性与植物的耐荫性(或喜光)和演替状态有密切联系。长期生长在强光下的植物受到光抑制是可恢复的,而当处于荫蔽环境的植物突然暴露于强光下时,受到的光抑制不能完全恢复,可能是(部分)光合机构受到破坏的缘故。粗枝云杉和青榨槭防御光抑制伤害的能力较强,热耗散是其防御光抑制的主要途径。长期的强光作用能使岷江冷杉和红桦发生严重光抑制,甚至光伤害,而红桦能够通过“凋落老叶,萌发新叶”的途径来适应新的强光环境。 How to restore the vegetation of subalpine coniferous forest in eastern Qinghai-Tibet Plateau, and change the trend of ecological deterioration is a very important issue. Acclimation of tree seedlings to different and varing light environment affects to a great extent the successful regeneration and establishment of subalpine coniferous forests in southwestern China’s montane forest areas, because the ability to respond to such changing resource are commonly assumed to be critical to plant success, and have a growth advantage than others. In this paper, several species seedlings in Abies faxoniana community were chosed to study the response and adaptation to light intensity and the interspecific differences of adaptability in six shaded sheds (100, 55, 40, 25, 15 and 7% of full sunlight) in the Maoxian Ecological Station of Chinese Academy of Sciences. Our results could provide a strong theoretical evidence for understanding the forest succession laws of subalpine coniferous forests, and the survival and settlement of seedlings under plantations, and provide scientific direction for the production and management of seedlings, especially the comparative studies of the acclimation to light between the conifer and broadleaf trees could provide new ideas for how to integrate the broad-leaved trees into the artificial coniferous forest. Growth under different light intensity Light intensity plays an important role on plant growth. One field experiments was conducted to study the growth of tree seedlings of Picea asperata, Abies faxoniana, Betula albo-sinensis and Acer davidii under different light intensities. The results showed that plants under low light environment could increase the specific stem length (stem length/ stem dry mass), in order to effectively intercept light resources, while biomass greater allocation to the roots, could make plants under high light environment absorb more water, and avoid drought stress. During the first growing season, the relative growth rates (RGRs) of Betula albo-sinensis and Acer davidii had the greatest values under the 100% of full light, for 55% of Picea asperata, and for 25-40% of Abies faxoniana. However, in the second growing season the the relative growth rates of the two broad-leaved trees changed and were appropriate for 25-55% of full light, for 55-100% of spruce, and for 25-100% of fir. Thus, from the first year to the second year, two broad-leaved seedlings maybe more suitable to partly shading environment, and two coniferous seedlings would have an increase in light demand, which may be an increased root biomass investment. Because in this way, seedlings grown under high light could better maintain their internal water balance, and thus its growth would not be seriously affected by drought stress. In addition, serious shading would cause fir seedlings to die. Acclimation of physiology to light Plants could coexist in forest ecosystem by forming different strategies of light use. One field experiments was conducted to study the acclimation of tree seedlings to different light intensity of Picea asperata, Abies faxoniana, Betula albo-sinensis and Acer davidii. The results showed that the photosynthetic capacity of Picea asperata and Betula albo-sinensis exhibited a general tendency of increase with more light availability; but for Abies faxoniana and Acer davidii seedlings, their highest values of the same parameters were found under intermediate light regime (i.e. 25-55% of PFD relative to full sunlight). Plants under low light environment could increase the specific stem length (stem length/ stem dry mass), in order to effectively intercept light resources. Leaf nitrogen and chlorophyll content increased, while dark respiration rate and light compensation points decreased, all of which were adaptive response to the low light environment. On the contrary, plants under high light environment had the thicken leaves and palisade tissue, which was a protective response to high light. Phenotypic plasticity to light Phenotypic plasticity can be exhibited in morphological and physiological processes. Physiological characteristical adjustment is the main for plant adaptation to different light environment.The means of plasticity indexes for Betula albo-sinensis and Acer davidii seelings were greater than Picea asperata and Abies faxoniana, amplied that the two broad-leaved trees were much more adaptable to the environment. In addition, spruce had the higher adaptablity than fir. The findings supported the hypothesis that the ecological characteristics of the species determined the biological status and its biological habitat selection. Photoinhibition and photoprotection to light Compared with conifer, broad-leaved trees could better change leaf morphology and adjust biomass allocation to adapt to changing light environment. However, excess light can photoinhibit photosynthesis and may lead to photooxidative destruction of the photosynthetic appatus. Two field experiments were conducted to study the photoinhibition of photosynthesis. The results showed that when plants grown under high light environment or plants transferred from low to high irradiance, the four tree seedlings would undergo a period of photoinhibition. In four species, photoinhibited leaves could recover to initial photosynthetic rates when they were long-term planted under high light environment. However, when plants were suddenly exposed to high irradiance, this photoinhibition could not be reversible, may be the photosynthesis apparatus were (or partly) photooxidatively destructed.