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1

Bollero, Real Alberto. "Isotropic nanocrystalline (Nd,Pr)(Fe,Co)B permanent magnets." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2003. http://nbn-resolving.de/urn:nbn:de:swb:14-1069758225796-19366.

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Nanokristalline Permanentmagnete zeigen ungewöhnliche magnetische Eigenschaften aufgrund von Oberflächen- und Grenzflächeneffekten, die verschieden von denen massiver oder mikrokristalliner Materialien sind. Diese Arbeit zeigt Ergebnisse einer systematischen Untersuchung der Beziehung zwischen Mikrostruktur und magnetischen Eigenschaften von isotropen nanokristallinen (Nd,Pr)(Fe,Co)B-Permanentmagneten. Hochkoerzitive Magnete vom Typ (Nd,Pr)FeB wurden durch hochenergetisches Mahlen in der Kugelmühle oder Rascherstarrung hergestellt. Der Einfluss geringer Mengen von Zusätzen wie Dy und Zr und die Substitution von Nd durch Pr auf die magnetischen Eigenschaften wird dargestellt. Weiterhin wurde eine Einschätzung des Warmumformverhaltens dieser Materialien durchgeführt. Hochenergetisches Kugelmahlen einer Legierung mit der Anfangszusammensetzung Pr9Nd3Dy1Fe72Co8B6.9Zr0.1 führte, nach Glühbehandlung, zu fast einphasigem Magnetpulver mit einem maximalen Energieprodukt von (BH)max~140 kJm-3. Das hochenergetische Kugelmahlen wurde zu einer sehr vielseitigen Technik zur Herstellung hochleistungsfähiger Nanokompositmagnete weiterentwickelt. Das Zulegieren unterschiedlicher Anteile von weichmagnetischem alpha-Fe ist damit sehr effektiv möglich. Der Zusatz von 25 Gew.-% alpha-Fe führt zu einem hohen (BH)max=178kJm-3. Dies wird auf eine sehr effektive Austauschkopplung zwischen den hart- und weichmagnetischen Phasen zurückgeführt. Die Natur der intergranularen Wechselwirkungen kann durch die Wohlfarth´sche Remanenzanalyse (?deltaJ-plot¡§) beschrieben werden. Im speziellen wurden deltaJ-Diagramme für verschiedene (i) alpha-Fe Gehalte, (ii) Korngrößen und (iii) Austauschlängen erstellt. Es konnte gezeigt werden, dass in den Nanokompositmagneten auf Pr-Basis keine Spinumorientierung auftritt. Abschließend zeigt die Arbeit die Möglichkeit der Nutzung einer mechanisch aktivierten Gas-Festkörper-Reaktion auf, mit der eine sehr feinkörnige Mikrostruktur erhalten wird. Die Untersuchungen wurden mit stöchiometrischen Nd2(Fe1-xCox)14B-Legierungen begonnen (x=0-1). Die Verbindungen wurden unter höheren Wasserstoffdrücken und Temperaturen gemahlen, wodurch sie zu NdH2+delta und krz-(Fe,Co) (x=0-0.75) oder kfz-Co (x=1) entmischt wurden. Die Korngrößen des rekombinierten Nd2(Co,Fe)14B-Materials liegen im Bereich von 40-50 nm
Nanocrystalline permanent magnets present unusual magnetic properties because of surface/interface effects different from those of bulk or microcrystalline materials. This work presents results of a systematic investigation of the relationship between microstructure and magnetic properties in isotropic nanocrystalline (Nd,Pr)(Fe,Co)B permanent magnets. Highly coercive (Nd,Pr)FeB-type magnets have been produced using high energy ball milling and melt-spinning. The influence of small amounts of additives, Dy and Zr, and the substitution of Nd by Pr on the microstructural and magnetic properties are shown. An assessment of the hot deformation behaviour has been carried out. Intensive milling of an alloy with starting composition Pr9Nd3Dy1Fe72Co8B6.9Zr0.1 yields, after annealing treatment, nearly single-phase magnet powders with a maximum energy product (BH)max?î140kJm-3. Co has a beneficial effect on the intrinsic magnetic properties but also on the microstructure, with a mean grain size of 20nm. Intensive milling is used to produce high-performance nanocomposite magnets by blending this latter alloy with different fractions of soft magnetic alfa-Fe. Addition of 25wt.% alfa-Fe leads to a high (BH)max=178 kJm-3 due to an effective exchange-coupling between the hard and the soft magnetic phases. The intergrain interactions between the crystallites of the nanocomposite structure are analysed. Demagnetisation recoil loops of the nanocomposite magnets show relatively open minor loops due to the exchange-spring mechanism. Information about the intergrain interactions during demagnetisation are obtained by plotting the deviation of the demagnetising remanence from the Wohlfarth-model (¡§deltaJ-plot¡¨). Exchange-coupling phenomena are studied by analysing the evolution of the corresponding deltaJ values when varying (i) the alfa-Fe content, (ii) the annealing temperature, i.e. the grain size and (iii) the measurement temperature. Low temperature measurements do not reveal any sign of spin reorientation for these Pr-based nanocomposite magnets. The work concludes showing the possibility of using a mechanically activated gas-solid reaction to obtain an effective grain refined microstructure starting from stoichiometric Nd2(Fe1-xCox)14B alloys (x=0-1). These compounds were milled under enhanced hydrogen pressure and temperature leading to their disproportionation into NdH2+delta and bcc-(Fe,Co) (x=0-0.75) or fcc-Co (x=1). Grain sizes of recombined Nd2(Fe,Co)14B materials were found to be 40-50nm
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2

Figuera, Dilcia. "FACET Simulation in the Imataca Forest Reserve, Venezuela: Permanent Plot Data and Spatial Analysis." Thesis, University of North Texas, 2006. https://digital.library.unt.edu/ark:/67531/metadc5282/.

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Tree diameter data from 29 years of observations in six permanent plots was used to calculate the growth rate parameter of the FACET gap model for 39 species in the Imataca forests in Venezuela. The compound topographic index was used as a measure of differential soil water conditions and was calculated using geographic information systems. Growth rate values and topographic conditions typical of hill and valley were input to FACET to simulate dynamics at the species level and by ecological and functional groups. Species shade-tolerance led to expected successional patterns. Drought-tolerant/saturation-intolerant species grew in the hills whereas drought-intolerant/saturation-tolerant species occurred in the valleys. The results help to understand forest composition in the future and provide guidance to forest management practices.
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3

Pinter, Giselle de Souza Leite. "Estudos de padrões morfológicos de tronco, raízes e casca externa de árvores emergentes e de dossel da floresta ombrófila densa no parque estadual \'Carlos Botelho\', SP." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/41/41132/tde-02022009-154703/.

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Árvores emergentes e de dossel da Floresta Ombrófila Densa Sub-montana de uma Parcela Permanente (10,24ha) no Parque Estadual "Carlos Botelho", SP, foram estudadas e descritas morfologicamente considerando padrões de tronco, raízes e casca externa com a finalidade de auxiliar na identificação de campo. O critério de inclusão (DAP igual ou superior a 48cm) abrangeu 324 indivíduos de 64 espécies pertencentes a 36 famílias. São fornecidas descrições, ilustrações e chave de identificação para as espécies estudadas baseadas em características do tronco à altura do peito e da base; das raízes aparentes e rentes ao tronco; das raízes superficiais; e das texturas da casca externa nas regiões da árvore mencionadas. Considerando que não há uma terminologia padrão para descrição dos caracteres estudados, é proposta aqui uma nomenclatura, além de serem utilizados termos propostos por Torres et al. (1994) e Ribeiro et al. (1999), com adaptações para as variações observadas no local de estudo. O tronco foi diferenciado em cilíndrico ou acanalado, com base reta ou dilatada. As raízes variaram entre digitadas e sapopemas. Foram categorizados 13 padrões básicos de textura da casca externa: liso, áspero, sujo, rugoso, fissurado, fendido, lenticelado, reticulado, com placas, escamoso, laminado, variegado e com depressões. O uso de terminologia padronizada na descrição de características de tronco, raízes e casca permite sua aplicação e comparação com dados de estudos desenvolvidos em diferentes regiões, sendo importante ressaltar sua utilização aliada a outros caracteres da planta para uma identificação mais eficiente.
Emergent and canopy trees of lowmontane dense ombrophyllous forest in a permanent plot (10,24ha) in "Carlos Botelho" State Park, SP, were studied and morphologically described. Trunk, roots and outer bark patterns were considered in order to make field identification easier. A total of 324 trees, 64 species and 36 families were included (DAP ≥ 48cm) and analyzed. We provide descriptions, figures and an identification key based on the following features: trunk at breast high; trunk base; apparent roots; superficial roots; and texture of outer bark. Since there is not a standard morphological nomenclature for these patterns, we propose a nomenclature here, besides using those terms proposed by Torres et al. (1994) and Ribeiro et al. (1999) with some adaptations. Trunk are named terete or angular, straight or with an expanded base. Roots are named digitated or buttressed. Thirteen basic patterns of outer bark texture were named: entire, rough, messy, rugose, fissured, cracked, lenticellate, reticulate, flaky, scaly, laminate, variegated and dippled. Using this terminology allows its application and comparison with data from different areas. They should be used with other features, reproductive and vegetative ones, in order to allow a correct identification.
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4

Karfakis, Theodoros. "Amazonian forest functional composition and resilience to sellective logging : an enquiry using permanent sample plot data and computer simulation models." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/31410.

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This study set out to explore the hypothesis that previously undisturbed Amazonian terra firme (non-flooded) tropical forests show a gradient in resilience to selective logging as a function of tree species functional composition and in particular a positive relation with the presence of a specific ecological guild regarded as intermediate in the process of ecological succession known as the light hardwoods (LHW's). Field data came from the Manaus and Tapajos regions in Brazil and the Puerto Maldonado region in Peru. In response to drought stress induced canopy opening which is the natural disturbance analogue to selective logging, there was a significantly better performance in terms of turnover (diameter growth, mortality and recruitment) of the LHW's relative to climax species. Inresponse to selective logging trees growing within logging gaps showed a similar growth performance gradient 3 years after logging when species ecological guild was not taken under account. In series simulation experiments where conducted to determine actual stand levelcompositional and biomass responses to logging. Forest dynamics models in the SYMFORframework were used to conduct simulations of the most common logging practices. Results indicated that functional composition deviation from undisturbed forest showed a positive relation with resilience with LHW's proportions but only up to a certain threshold. Above this their proportion was positively related with deviation from primary forest conditions and therefore negatively related to resilience. A similar pattern was observed for stand basal area with intermediate sites showing the greatest resilience. For sites with low and medium proportions the opposite pattern was observed with sites of highest proportions showing the second greatest resilience followed by sites with lowest. This study indicates that there is a positive correlation between proportions of LHW trees in a forest stand and resilience to selective logging as currently practiced in the Brazilian Amazon but only up to a certain compositional threshold in functional composition.
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Kribel, Jacob Robert George. "Long Term Permanent Vegetation Plot Studies in the Matoaka Woods, Williamsburg, Virginia : Establishment and Initial Data Analysis of Plots Established with the North Carolina Vegetation Survey Protocol, Resampling of Single Circular Plots and a Comparison of Results from North Carolina Vegetation Survey Protocol and Single Circular Plot Methods." W&M ScholarWorks, 2003. https://scholarworks.wm.edu/etd/1539624378.

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6

Pardi, Mariana Meireles. "Espécies Arbustivo-arbóreas em clareiras e micro-sítios de luz em 5,12ha de Floresta de Restinga na Ilha do Cardoso, São Paulo." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-29082007-102348/.

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Estudos da dinâmica de florestas tropicais evidenciam a importância do conhecimento da relação existente entre a luz e a distribuição das espécies para o entendimento da regeneração e manutenção da diversidade dessas comunidades. Para contribuir com este conhecimento para as espécies que ocorrem nas Restingas o presente estudo descreveu a distribuição dos indivíduos arbustivo-arbóreos com DAP maior que 4,8cm em treze categorias indiretas de regime de luz em 5,12 hectares de uma Floresta de Restinga situada na Ilha do Cardoso, Município de Cananéia, SP. Estas categorias correspondem aos diferentes microsítios de luz do mosaico florestal, e são oriundas da combinação entre condições quanto ao tipo ou ausência de cobertura (cobertura decídua, cobertura perenifólia ou a pleno sol) e situações de localização dos indivíduos arbustivoarbóreos na floresta (clareira, sub-bosque, dossel). As espécies amostradas foram classificadas em grupos ecológicos de acordo com a literatura disponível em pioneiras, secundárias iniciais, sub-bosque, clímax e não classificadas para correlação com a distribuição de seus indivíduos nas categorias de luz. Foram amostrados 7.277 indivíduos arbustivo-arbóreos sendo 381 pioneiros distribuídos em 12 espécies, 4.138 secundários iniciais distribuídos em 24 espécies, 48 típicos de sub-bosque distribuídos em duas espécies, 2.133 climáxicos distribuídos em 48 espécies e 577 indivíduos distribuídos em 19 espécies permaneceram sem classificação. Das 105 espécies amostradas, 35 apresentaram uma distribuição preferencial por determinados microsítios de luz. Estes padrões de distribuição encontrados sugeriram que a quantidade de luz que chega ao subbosque das Florestas de Restinga não restringe a ocorrência de espécies pioneiras apenas às clareiras. Para algumas espécies a classificação em grupos ecológicos encontrada na literatura não foi coerente com a distribuição dos indivíduos, tendo sido sugerida uma classificação diferente de acordo com sua ocorrência nessa Floresta de Restinga, que só se confirmará através de repetições deste estudo ao longo do tempo. Foram delimitadas 77 clareiras na área de estudo durante a classificação dos indivíduos nas categorias indiretas de regime de luz, para as quais foram estimadas área, forma, composição de espécies e de indivíduos para análise da distribuição das espécies e grupos ecológicos em seu interior e favorecer futuras comparações com estudos recorrentes na área ou com estudos de regeneração natural. Repetições desse método numa mesma área, ao longo do tempo, e em diferentes áreas da mesma formação florestal proporcionarão o acúmulo de dados não só sobre a distribuição momentânea dos indivíduos, mas da dinâmica dessas florestas, promovendo o conhecimento sobre o comportamento ecológico das espécies e dos padrões de distribuição das mesmas em relação à luz.
Tropical Forest dynamics studies elucidate the importance of knowledge about the relationship between light and distribuition of species to understanding the regeneration and diversity mainteinence of these communities. To contribute with this knowledge to Restinga Forest species this study described the distribuition of trees with dbh (diameter at breast high) ≥4,8cm in thirteen (13) indirect light categories, in 5,12ha of a Restinga Forest in Ilha do Cardoso, Cananeia Municipal District, Sao Paulo State. These categories correspond to different light micro-sites within the forest mosaic and are derived of the combination of the type or absence of covery where the individuals can be under of (under decidual trees, under evergreen trees or under intense light) and the position which each individual can ocupy within the forest (gap, understory, canopy). All the species were classified in ecological groups according to available literature into pioneers, early secondary, understory, climax and non-classified to correlation with their individuals distribuition within the light categories. There were sampled 7.277 tree specimens represented by 381 pioneers of 12 different species, 4.138 early secondary of 24 species, 48 understory of 2 species, 2.133 climax of 48 species and 577 non-classified specimens of 19 different species. Among the 105 species sampled, 35 presented preferential distribuition for some light micro-sites. These distribuition patterns suggest that the light quantity reaching the understory doesn't restrict the occurence of pioneer species only to gaps. For some species the classification in ecological groups found in the literature were not coherent with the individuals distribuition and there were been suggested another classification according to its occurence in the Restinga Forest, which will be confirmed only through repetitions of this study among time. There were delimited 77 gaps in the study area during the classification in the indirect light categories, to which there were estimated area, shape, species and individuals compositions to assess the distribuition of species and ecological grups within these gaps and support comparisons with repeated studies in this area and with natural regeneration studies. Recurring studies using this method over the same spot during time or in different areas of the same Forest formation will provide data accumulation not only about the instantaneous distribuition of the specimens, but also about these forests dynamics, promoting the knowledge about the ecological bahaviour of species and about distribuition patterns of these species according to light regimes.
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Lamedica, Silvia. "FORESTE DI AREA TEMPERATA: STRUTTURE E DINAMICHE A CONFRONTO IN POPOLAMENTI VERGINI E LASCIATI A LIBERA EVOLUZIONE." Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3421643.

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A proper understanding of forest stands structure and dynamics is important in order to apply a sustainable forest management. Forest structure analysis studies the interactions between size classes of the trees, age classes, species, the role of natural and human disturbances etc. Those relationships emerge from the interpretation of different data (dbh, height, age, annual increments, deadwood, XY position of each tree in the stand…), which give information in order to assess the organization and functionality of the ecosystem. Time and space are the two main factors in the analysis of forest structure and dynamics. Concerning time, the order of magnitude should be consistent with the generation time of the ecosystems, so in forest analysis we need to carry out long-term research. In this context, permanent plots are essential instruments, since they permit the acquisition of database at regular intervals in long-term projects, which reflect the tendency of ecosystems to change slowly. The spatial scale of these plots should be set in order to catch the trends and dynamics of the vegetation. In particular, surfaces of 1-4 ha are considered large enough to capture the presence of groups and gradients, which are the expression of the ongoing dynamics in the population at a mesoscale level. This work focused on the study of forest spatial structures in some stands which are representative of different forest types with different exploitation regimes. The analyses were conducted in 4 ha permanent plots, located in the Eastern Carpathians (virgin forests) and the Alps (previously managed stands left to natural development). On the plots, all the trees taller than 1.3 m were mapped and for each tree dbh, height, height of lowest living branch, crown radii projection, increment cores, etc. were measured. The main objective was to compare virgin and managed forest, in order to assess the extent of human impact on the structure and dynamics of the latter stands. In general we found that natural areas, without major disturbances, present more complex spatial structures than the previously managed ones, even if sometimes they were left to natural development for some decades. The human impact lead towards a simplification in the stands structure and composition: signs of this impact are the unimodal diameter distributions, random spatial distribution of trees, spatial structures with almost monospecific groups. This homogeneous structure is still evident even after decades since the last human intervention. In the long term we will see if those stands will develop towards more natural structures or if they will tend to maintain their actual structure.
Un’appropriata comprensione della struttura e delle dinamiche dei popolamenti è basilare per una gestione forestale sostenibile. Lo studio della struttura dei popolamenti forestali passa attraverso la definizione delle relazioni tra classi dimensionali, età, specie, del ruolo dei disturbi naturali e antropici e così via. Queste relazioni emergono dall’interpretazione di dati di natura diversa (diametro, altezza, età, incrementi annuali, necromassa, posizione di ogni individuo…) che forniscono informazioni differenti ma tutte utili al fine di valutare in misura più o meno approfondita l’organizzazione e le funzionalità dell’ecosistema. Lo studio della struttura e delle dinamiche di un popolamento deve tenere in considerazione due fattori fondamentali: il tempo e lo spazio. Per quanto riguarda il primo, questo deve essere conforme con i tempi generazionali degli ecosistemi studiati e perciò nel nostro caso si parla necessariamente di lungo periodo. La predisposizione di aree di monitoraggio permanente quindi si rivela particolarmente utile ai nostri scopi, in quanto permette di disporre di database per l’acquisizione di dati a intervalli regolari nell’ambito di progetti di lunga durata, che riflettono la tendenza degli ecosistemi ad evolvere lentamente. La scala spaziale di queste aree si dovrebbe calibrare in modo tale da essere sufficiente per evidenziare le tendenze e dinamiche della vegetazione in esame. In particolare, superfici di 1-4 ha costituiscono un livello di mesoscala sufficiente a cogliere la presenza di gruppi e gradienti che sono molto spesso espressione delle dinamiche in atto nel popolamento. Il presente lavoro si è concentrato sullo studio delle strutture spaziali di popolamenti forestali scelti in base al diverso impatto antropico subito nel corso della loro vita. Le analisi sono state effettuate all’interno di aree di monitoraggio permanente di 4 ha poste in parte in foreste vergini dei Carpazi Orientali e in parte in popolamenti lasciati a libera evoluzione situati sulle Alpi. In ogni area sono state mappate e misurate tutte le piante con altezza superiore a 1.3 m, rilevando una serie di parametri biometrici (diametro a 1.3 m, altezza, altezza d’inserzione della chioma, proiezioni dei raggi di chioma, prelievo delle carotine legnose, ecc.) utili alla descrizione e al confronto delle strutture spaziali dei diversi popolamenti. In particolare, ci si è concentrati sul confronto tra popolamenti vergini e lasciati a libera evoluzione, per valutare in che misura l’impatto antropico abbia influito sulle strutture e le dinamiche di questi ultimi. In generale si è riscontrato che aree vergini, in assenza di disturbi naturali significativi, si esprimono in strutture spaziali più complesse e articolate rispetto ad analoghe formazioni precedentemente gestite. In quest'ultime, l’impatto antropico ha portato a una semplificazione nella composizione e nella struttura del bosco, che si manifesta, di volta in volta, in distribuzioni diametriche unimodali,distribuzioni spaziali casuali, strutture spaziali per gruppi dalla composizione omogenea. Questa struttura più omogenea è ancora evidente nonostante in alcuni casi siano passati più di quarant’anni dall’ultimo intervento. Sarà interessante approfondire queste dinamiche nel lungo periodo e verificare le traiettorie di sviluppo future, ovvero se tali popolamenti manterranno a lungo l'attuale tipologia o evolveranno verso strutture più naturaliformi.
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Štěpánová, Martina. "Restaurace a zázemí ČRS Lačnov." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-372134.

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The subject of this thesis is the process of building technical part of the design documentation for the realization of a newly-built restaurant and facilities for Czech fishing union in the village Lačnov. The building consists of two objects interconnected by a connecting neck. The ground floor of the building with a flat roof is used as a restaurant. The restaurant is wheelchair accessible. Public entrance is from the southern side. The entrance for the staff and the supply will be from the east side. Facilities for staff and technical facilities there is in the northern part of the building. On the second floor there is an office, a meeting room and a training room for the Czech fishing union. In the second object with a gabled roof is an apartment for a fishing man and a shop with small fishing equipment. There is also a showers and toilets for the disabled. The technical background is situated in the attic. The house is based on strips foudations. Vertical loadbearing structures above ground are made of Porotherm system, external walls of the basement are made of prefabricated concrete shuttering blocks. Horizontal structures are designed as a monolithic reinforced concrete slab. Building is insulated. Part of the external wall finish are made of silicone plaster and part of it consists of ventilated facade with timber cladding.
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Dölle, Michaela. "From arable field to forest: Long-term studies on permanent plots /." Göttingen, 2008. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000252253.

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10

Thérien, Guillaume. "Growth prediction of recent permanent sample plots for forest inventory projection." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/31159.

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Permanent sample plots have become the main source of information for estimating models which quantify the dynamic processes of a forest. Fitted models allow for projecting inventories, used to determine timber production and many forest management decisions. The quality of these models is largely dependent on the quality of the information provided by the permanent sample plots. However, the pool of information contained in recent permanent sample plots is limited. Efficient estimation techniques must use all the information available from such plots. Current estimation techniques can be improved. Existing techniques employed in forestry have failed to recognize the random nature of the individual model characterizing each plot. On the other hand, techniques designed for remeasured entities in other scientific fields do not address particular forestry situations such as the small number of remeasurements or the irregularity of remeasurements. A framework for estimating forestry growth models which recognizes the individuality of each plot and special forestry situations is presented in this dissertation. The proposed framework is a two-stage estimation technique, in which the growth rate of a permanent sample plot is considered analogous to the interest rate on a bank account. The first stage estimates the growth rate after removing the time effect. The second stage, based on Von Bertalanffy's growth curve, relates growth rate to site index and volume at the beginning of the growing season. The proposed predictor of future growth rates, the "weighted predictor," is a weighted average between the growth rate observed on a plot and the growth rate predicted from the second-stage model. The weighted predictor is then used to compound the current volume of a plot. An estimate of the variance of the prediction can also be computed.
Forestry, Faculty of
Graduate
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11

Vasconcelos, Neto Elias Lourenço. "Agrupamento ecológico e funcional de espécies florestais na Amazônia Sul Ocidental." Universidade Federal do Amazonas, 2012. http://tede.ufam.edu.br/handle/tede/3033.

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The Amazon forest is a mixture of hundreds of species, with different ages and growth rates, knowing them, both for researchers as to Amazonian populations, is a major challenge. The aim of this study was to perform species ecological and functional grouping of Acre state forests. This work was developed from data of 95 permanent plots, with one hectare each (100 x 100m), sub-divided into plots of 10 x 10 and installed on Projeto de Colonização (PC) Pedro Peixoto, State Forest of Antimary (FEA) and ST Management. In these sub-plots all individuals with diameter at breast height (DBH) greater than or equal to 10 cm were measured. The collect period was from 1996 to 2007, with measurements at non-regular intervals. The clustering process occurred in three stages: (1) cluster analysis to group the most populous species. For this process, the variables employed were Periodic Annual Increment in diameter - IPADAP Medium in High, Medium and Low competition and 95% percentile of cumulative frequency distribution of diameters using Ward hierarchical method; (2) discriminant analysis, to allocate the least populated species to the groups formed, using variables of the 95% percentile of the cumulative frequency distribution of diameters and the average annual periodic increments in diameter (IPADAP) and the Fisher method, (3) subjective stage, used to allocate species with few individuals to formed groups. Ward method used in cluster analysis and the Fisher method used for discriminant proved to be effective in creating and training groups. The use of these methods resulted in formation of ten groups of species with high growth rates of similarity between individuals of the same group and low similarity between groups. Variables: IPADAP for stand and IPADAP in low, medium and high competition and P95 of cumulative frequency distribution of diameters shown are variables useful for the purposes of grouping of species. Variations in the growth rates for the overall mean data were reduced when calculated for each group of species.
A floresta amazônica é uma mistura de centenas de espécies, com diferentes idades e taxas de crescimento, o seu conhecimento, tanto para pesquisadores quanto para as populações amazônicas, é um grande desafio. O objetivo deste estudo foi efetuar o agrupamento ecológico e funcional de espécies presentes na floresta do Estado do Acre. Este trabalho foi desenvolvido a partir de dados de 95 parcelas permanentes, com área de um hectare cada (100 x 100m), subdividida em subparcelas de 10 x 10 e instaladas no Projeto de Colonização (PC) Pedro Peixoto, Floresta Estadual do Antimary (FEA) e ST Manejo. Nestas sub-parcelas todos os indivíduos com diâmetro a altura do peito (DAP) maior ou igual a 10 cm foram medidos. O período de coleta foi de 1996 até 2007, com medições em intervalos de tempo não regulares. O processo de agrupamento ocorreu em três estágios: (1) análise de Cluster para fazer o agrupamento das espécies mais populosas. Para esse processo foram empregadas as variáveis Incremento Periódico Anual em diâmetro - IPADAP médio em Alta, Media e Baixa competição e percentil 95% da distribuição de frequência cumulativa dos diâmetros pelo método hierárquico Ward; (2) análise Discriminante, para alocar as espécies menos populosas aos grupos formados, utilizando-se as variáveis percentil 95% da distribuição de frequência cumulativa dos diâmetros e os incrementos periódicos médios anuais em diâmetro (IPADAP) e o método de Fisher; (3) estágio subjetivo, utilizado para alocar as espécies com poucos indivíduos aos grupos formados. O método Ward utilizado na análise de Cluster e o método de Fisher usado no discriminante demonstraram-se eficazes na criação e formação dos grupos. A utilização destes métodos resultou na formação de dez grupos de espécies com crescimentos de alta similaridade entre indivíduos do mesmo grupo e baixa similaridade entre grupos. As variáveis: IPADAP para o povoamento e IPADAP em baixa, média e alta competição e P95 da distribuição de frequência cumulativa dos diâmetros demonstraram-se variáveis úteis para a realização do agrupamento de espécies. As variações nas taxas de crescimento relativas à média total dos dados foram reduzidas quando calculada para cada grupo de espécies.
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12

Kouevidjin, Modobozi. "Evaluation des performances énergétiques d'une nouvelle génération d'éolienne off-shore." Thesis, Artois, 2015. http://www.theses.fr/2015ARTO0208/document.

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L’alternateur étudié dans cette thèse équipe une éolienne flottante à axe vertical. Il s’agit d’unemachine synchrone de 2MW, polyphasée, bobinée sur plots, à pas fractionnaire, à aimants et à prisedirecte. L’objectif majeur de la thèse est la caractérisation de cet alternateur afin d’en évaluer lesperformances. Une modélisation analytique de la perméance d'entrefer et de la force magnétomotriceont conduit à l'étude de l'induction d'entrefer dont le contenu harmonique s'est révélé êtreparticulièrement riche. La caractérisation a également porté sur la détermination des inductancespropres et mutuelles, avec un calage du modèle effectué en exploitant des mesures expérimentalesfaites à l’arrêt. La particularité de la machine étudiée nous a amené à considérer un enroulement fictiféquivalent dans le but de déterminer les inductances cycliques, nécessaires à l'établissement du schémamonophasé équivalent. De plus, le fonctionnement back to back de la machine a été étudié et simulé. Ilpermet de faire des tests de la machine elle-même mais aussi des éléments de la chaîne de conversion,sans l'utilisation d'une deuxième machine ou des pâles pour entraîner le rotor du prototype. Il offre enplus la possibilité de tester différents type de fonctionnements et d'évaluer la puissance que peutproduire la machine : différents scénario de fonctionnement ont été simulés et les paramètresnécessaires aux essais sur site ont été définis. Le fonctionnement back to back a fait l’objetd’investigation sur une machine synchrone classique. Les difficultés de fonctionnement ontnotamment pu être mises en évidence avec une modélisation analytique des phénomènesélectromagnétique qui s'y produisent et des essais expérimentaux
The studied alternator equips a vertical axis offshore wind turbine. It is a 2MW fractional slotconcentrated winding permanent magnet synchronous polyphase machine, directly connected to bladeturbine. The principal purpose of this thesis consists in characterizing the alternator in order toevaluate its performances. The air gap permeance and the magnemotive force analytical modelingleads to study the air gap flux density and its harmonic content, which is particularly rich. Thecharacterization has also concerned the self and mutual inductance determination, which has requiredstalling the model by exploiting experimental measurements done at standstill. The particularity of thestudied machine leads us to consider an equivalent fictitious winding in order to determine the cyclicalinductances, necessary for the single-phase equivalent scheme establishment. Moreover, the machineback to back functioning has been studied and simulated. This functioning allows testing the machineitself and the other conversion chain subsystems, without using a second machine or blades to drivethe prototype rotor. It offers the possibility to test different types of operating points and to estimatethe power that can produce the studied machine: different operating points scenarios have beensimulated and parameters for tests have been defined. The back to back functioning of a classicalsynchronous machine has been also investigated, with an analytical modeling of the electromagneticphenomena and experimental tests
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13

McDonald, Hannah Beth. "Tree Growth and Spatial Pattern in Two Forest Park Permanent Plots: A Look at Stand Composition and Condition." PDXScholar, 2011. https://pdxscholar.library.pdx.edu/open_access_etds/313.

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In June of 2010, two permanent research plots were established in Forest Park, based on their differing proximities to downtown Portland, Oregon. As part of a long-term ecological research project that seeks to explore the ecological status and human thumbprint on this 5,100 acre forested reserve, the 2010 tree data was investigated for emergent compositional and spatial patterns. Stand composition, tree size, growth rates, and spatial patterns were analyzed, along with ecological and land use histories. Results indicate that the Balch plot, more closely located to the urban center, has different stand composition, condition, and vegetation growth rates, compared to the more rural Miller site. This study supports findings from a study done by Broshot in 2009, where more urban plots demonstrate a different stand composition and recruitment pattern than rural sites. The study is an initial step for exploring questions regarding the ecological status of Forest Park and how land use and disturbance, past and present, shape Portland's forested reserve.
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14

Pessoa, José Felipe Salomão. "Estrutura e diversidade da comunidade arbórea do Parque Natural Municipal da Lajinha (Juiz de Fora, MG, Brasil)." Universidade Federal de Juiz de Fora (UFJF), 2016. https://repositorio.ufjf.br/jspui/handle/ufjf/3092.

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O objetivo do estudo foi fornecer informações sobre a estrutura, composição florística e o estado de conservação do Parque Natural Municipal da Lajinha, Juiz de Fora, MG. Foram alocadas, aleatoriamente e georreferenciadas 25 parcelas permanentes, de 20 x 20 m, totalizando 1393 indivíduos arbóreos vivos e 145 mortos em pé (CAP ≥ 15,7 cm), pertencentes a 155 espécies, 100 gêneros e 51 famílias. Nectandra nitidula, Eugenia hiemalis, Bathysa australis, Virola bicuhyba, Alchornea triplinervea são as cinco espécies com maior VI, enquanto Fabaceae (23), Myrtaceae (14), Lauraceae (11), Euphorbiaceae (8), Sapindaceae (7), Meliaceae (5), Monimiaceae (5) e Rubiaceae (5) são as famílias com maior riqueza de espécies. O índice de diversidade de Shannon (H’) foi um dos mais altos registrados para florestas da região (H’ = 4,36 nats.ind-1), contendo inclusive espécies ameaçadas (Ocotea odorifera, Virola bicuhyba, Dicksonia sellowiana), segundo critérios do Livro vermelho da flora do Brasil. Metade da comunidade e a maioria das mortas se enquadram na primeira classe diamétrica proposta (7,5 cm), o que reflete elevado grau de competição. A distribuição diamétrica da comunidade seguiu o modelo “J-reverso”, padrão para comunidades florestais tropicais. O elevado índice de equabilidade de Pielou (J’ = 0,866) mostra baixa dominância ecológica e alta heterogeneidade florística da comunidade, confirmadas pelas análises de agrupamento florístico (coeficiente de Morisita-Horn), inferior a 0,5, e DCA (Análise de Correspondência Distendida), que apresentou altos valores, superiores a 0,3 (Eixo 1 = 0,49 e Eixo 2 = 0,33). O resultado da análise de similaridade florística nas unidades amostrais, utilizando o coeficiente qualitativo de Jaccard, evidencia a importância das espécies de baixa densidade na amostra. Esses resultados expõem a complexidade da dinâmica de funcionamento dos processos bióticos presentes em uma comunidade florestal secundária. Estudos com medições posteriores poderão analisar aspectos e atributos funcionais dessas espécies e seu papel efetivo na comunidade. A presença de espécies raras para o Estado de Minas Gerais e o alto índice de diversidade encontrado evidencia o potencial biológico do Parque Natural da Lajinha e reforça a necessidade da adequação do mesmo para se tornar Unidade de Conservação.
The aim of this study is to provide information about the conservation status, structure and composition of the Parque Natural Municipal da Lajinha, Juiz de Fora, Minas Gerais State, Brazil. Randomly placed and georeferenced 25 permanent plots of 20 x 20 m, totaling 1393 individuals living arboreal and 145 dead in sampled (CAP ≥ 15,7 cm), belonging to 155 species, 100 genera and 51 families. Nectandra nitidula, Eugenia hiemalis, Bathysa australis, Virola bicuhyba, Alchornea triplinervea are the five species with higher IV as Fabaceae (23), Myrtaceae (14), Lauraceae (11), Euphorbiaceae (8), Sapindaceae (7), Meliaceae (5), Monimiaceae (5) and Rubiaceae (5) are families with the highest species richness. The Shannon diversity index (H’) was one of the highest recorded for the region's forests (H’ = 4,36 nats.ind-1), containing including endangered species (Ocotea odorifera, Virola bicuhyba, Dicksonia sellowiana), according to Red Book of Brazilian flora. Half community and most dead fall within the first class proposal diameter (7,5 cm), which reflects the high degree of competition. The community diametric distribution followed the model "J-reverse" standard for tropical forest communities. The high evenness index of evenness (J’ = 0.866) shows low ecological dominance and high floristic heterogeneity of the community, floristic confirmed by cluster analysis (Morisita-Horn coefficient) is less than 0,5, and DCA, which showed values greater than 0,3 (Axis 1 = 0,49 and Axis 2 = 0,33). The result of floristic similarity analysis using qualitative coefficient of Jaccard highlights the importance of species of low density in the sample. These results expose the complexity of the operating dynamics of biotic processes present in a secondary forest community. Further resampling studies may analyze functional aspects and attributes of these species and their effective role in community. The presence of rare species for the state of Minas Gerais, the availability of resources for the regional fauna and high diversity index shows the biological potential of the Natural Park of Lajinha and reinforces the need to adapt the same to become a Unit Conservation.
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15

Liao, De-Chih, and 廖德智. "Woody Floristic Composition of the Secondary Forest Permanent Plot of Nanjenshan Area." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/91729090097786321888.

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碩士
國立中山大學
生物科學系研究所
88
The purpose of this study is to understand the composition of the secondary forest of Nanjenshan area. A 5-ha plot was established at altitudes 200-264m on the north ridge of Nanjenshan. All free-standing woody plantsin the plot with DBH≧1cm were identified, measured, tagged and mapped. A total of 108 tree species belonging to 40 families and 77 genera was recorded. The dominant species are Acacia confusa, Lagerstroemia subcostata, Psychotria rubra, Ficus septica及Dendrocnide meyeniana. The dominant families are Fabaceae, Moraceae, Euphorbiaceae, Rubiaceae及Lythraceae. TWINSPAN analysis reveales four groups. Group 1 is dominanted by Acacia confusa, Glochidion philippicum and Psychotria rubra. Group 2 is dominanted by Acacia confusa, Psychotria rubra and Lagerstroemia subcostata. Group 3 is dominanted by Acacia confusa, Psychotria rubra and Glochidion rubrum. Group 4 is dominanted by Acacia confusa, Lagerstroemia subcostata and Dendrocnide meyeniana. There are four kind of distribution pattern in this plot. Machilus obovatifolia and Osmanthus marginatus occurred on the hilltop; Dendrocnide meyeniana and Ficus virgata occurred on the middle-woody site; Zanthoxylum ailanthoides and Wendlandia uvariifolia only occurred along the steamside; Acacia confusa and Psychotria rubra were commonly distributed over the plot.
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16

Wang, Jui-Chun, and 王瑞君. "Study on the relationship between Abies kawakamii population dynamic and environmental factors in the Abies kawakamii permanent plot at Mt. Hohuan, Taiwan." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/43368261541232202553.

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碩士
國立東華大學
自然資源與環境學系
101
Abies Kawakamii is endemic to Taiwan, which belongs to sect. Abies, distribution in the earth north latitude of most south boundary, and it has significance of ecological indicators. We used the Taroko National Park 0.2 ha permanent sample plots which establish in 1992, for observation Taiwan firs population structure dynamics of the study area. We had analyzed 17 years three times (1992, 1998, 2009) survey data, and to further explore environmental factors such as soil and climate effects. The results, we have found the population is still Taiwan firs of the dominant species, which mainly distribution of between in the Taiwan fir forest and Yushania niitakayamensis shrub passage of a belt. It population size structure based on sapling trees (ie 3
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17

Dölle, Michaela. "From arable field to forest: Long-term studies on permanent plots." Doctoral thesis, 2008. http://hdl.handle.net/11858/00-1735-0000-0006-B115-1.

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18

Lai, Tsung-Ming, and 賴聰明. "Monitoring the Vegetation on the Permanent Plots of Dan-da Resion." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/64252056672646096111.

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碩士
國立中興大學
森林學系
92
10 permanent plots were originally or newly set up for monitoring the vegetation dynamics at the representative forest stands in Dan-da area, central Taiwan. Based on matrix cluster analysis, overstory vegetation could be divided into: Quercus variabilies Type, Pinus taiwanensis Type, Chamaecyparis formosensis-Cyclobalanopsis stenophylloides Type, Machilus japonica Type, Tsuga chinensis Type and Abies kawakamii Type. For the understory, vegetation type recognized included Miscanthus transmorrisonensis Type, Chamaecyparis obtusa var. formosana-Senecio nemorensis-Polygonum cuspidatum Type, Yushania niitakayamensis Type and Yushania niitakayamensis-fern Type. Species diversity in overstory and understory shown that Q statistic value with more stable intermediate abundance species in species community were emphasized. This result revealed that Q statistic value had higher distinguishability with other diversity indices. Totally 504 conifer seedlings, including Taiwan juniper, Taiwan hinoki falsecypress, armand’s pine and Chinese hemlock were tagged and monitored. Average growth in stem-diameter was 1.10 mm/yr, and average height growth was 9.83 cm/yr. Survival rates of the seedlings of all conifer species were higher than 85%. The understory coverage was almost completely recovered in 2 years following burning. Based on the growth ring analysis of the fire-scared stems, it was estimated that the fire interval in Dan-da forest was 15-20 years.
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19

Kao, Yu-Min, and 高裕閔. "Forest Permanent Plots Survey and Analysis for CO2 Sequestration in Hepping Working Circle." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/45650757282301680063.

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碩士
國立宜蘭大學
森林暨自然資源學系碩士班
102
To understand the carbon storage at the Heping Working Circle, this study conducted an analysis with the data of the permanent plots established by Luodong Forest District Office of Taiwan Forestry Bureau. These plots were installed in 2001, and then reinvestigated in 2006 and 2011. This data set was analyzed for monitoring the forest dynamics on the total amount of volume, carbon and CO2 storage that can offer important information for making administrative policies in forest management.    This study analyzed a total of 101 permanent plots with three investigations and stratified the plots into 15 forest types. For better accuracy, we obtained a height-diameter curve using regression equation based on the measured tree heights recorded at the first reinvestigation, and estimated the tree heights at the other two investigations, and then acquired the volume stock. Regarding volume stock changed over the 10-year period, all forests had increasing volume stock, except for the camphor tree forest with decreasing volume stock(-0.26 m3/ha/yr). In particular, the man-made mixed-conifer forest had the best performance in the periodic annual increment (15.13 m3/ha/yr). Regarding the overall stand structure, the number of trees with smaller DBH decreased, and the number of tress with bigger DBH slightly increased. This indicates a trend of DBH getting bigger over 10 years. Based on the Weibull diameter distribution, there is an increase in both parameter b and parameter c over 10 years, which supports the result of the stand structure as well.    The result of the estimated carbon storage in 2011 based on the permanent plots data showed that the natural mixed conifer-hardwood forest had the largest amount of carbon and CO2 storage(i.e. 237.21 C ton/ha and 869.75 CO2 ton/ha). From 2001 to 2011, the man-made mixed conifer forest had the largest increase in carbon and CO2 storage (i.e. 48.78 C ton/ha and 178.88 CO2 ton/ha). In order to estimate the total carbon and CO2 storage of the Heping Working Circle, we combined the original 15 forest types into 10 types. Based on the second reinvestigation data and calculated through stratified random sampling, the total carbon storage of the working circle is between 6,602,000 and 10,411,184 tons, and the total CO2 storage is between 24.2 and 38.2 million tons.
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20

Dölle, Michaela [Verfasser]. "From arable field to forest : long-term studies on permanent plots / vorgelegt von Michaela Dölle." 2008. http://d-nb.info/99476619X/34.

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21

Smyth, Clint R., and William Kovach. "Long-term monitoring of permanent reclamation plots on high-elevation disturbances at the Line Creek Mine." 2002. http://hdl.handle.net/2429/9438.

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High-elevation exploration disturbances at the Line Creek Mine were revegetated in 1980. In 1982, permanent reclamation monitoring plots were established. In 1988, the monitoring program was expanded to compare vegetation dynamics with undisturbed natural reference areas. Mean total vegetation cover increased from 1982 to 1988, decreased during the period from 1988 to 1996 and increased between 1996 and 2000. Changes in mean total cover from 1982 to 1996 are attributed to the increase and subsequent die-back of agronomic grasses while the increase in total cover in later years is attributed to colonization and expansion of native forbs. Total cover in the undisturbed reference plots remained relatively constant over the monitoring period. Species richness increased over the monitoring period although structural diversity of the reclaimed areas remains lower than that for the undisturbed "reference" plots. The most important difference between the reclaimed and the native plots is the reclaimed plots exhibit relatively high grass species cover and low woody species cover.
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22

Tan, Yun-Tso, and 譚運籌. "The Effects of Forest Carbon Sequestration of Permanent Plots in Nanzhuang Working Circle of Hsinchu Forest District." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/80973295320159166577.

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碩士
國立屏東科技大學
森林系
95
Nanzhuang working circle of Hsinchu forest district is located in northern Taiwan which belongs to Taiwan Forest Bureau and about 8,711.87 hectares. In 1998 and 2003, the database of permanent plots were collected about the forest growth and dynamics of the eight main forest types. The aims of this study are to use the data from the plots to estimate the effects of carbon sequestration for each forest type. The results showed that only the plantation of mixed conifer and hardwood decreased in both stock and the average growth rate, but the other seven forest types increased gradually. Among all the stand structure of forests, it revealed that the changes of the diameter at breast height moved greatly into larger class of dbh from 1998 to 2003. The amounts of carbon sequestration in the hardwood forest types were higher than those of the conifer forest types except the plantation of Cryptomeria japonica. Within five years, the plantation of mixed conifer and hardwood decreased while the other seven forest types increased in the amounts of carbon sequestration. All of which, Taiwania cryptomerioides type increased the most, about 55.89 ton/ha. The second one that increased about 49.60 ton/ha is Cryptomeria japonica type. To obtain total carbon sequestration in Nanzhuang working circle, the forest type map was established. The amounts of carbon and CO2 sequestration of natural mixed hardwood are the highest. Among them, the sum of carbon is around 533,398.78 tons, and CO2 is around 1,957,573.51 tons. The mixed conifer was the second (carbon: 211,494.58 tons; CO2: 776,185.13 tons). The total carbon sequestration was around 752,765.65~1,089,397.50 tons, and total CO2 sequestration was around 2,762,649.924~3,998,088.812 tons in Nanzhuang working circle.
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23

BARTOŠOVÁ, Alena. "Dlouhodobé změny vegetace ve vápencových lomech Českého krasu." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-180583.

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Vegetation sampling was carried out to determine changes on the limestone quarries after 30 years. These semi-permanent plots are located in the Czech Karst Protected Landscape Area in the Czech Republic.
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24

Šimák, Martin. "Změny vegetace vlhkých luk ve Slavkovském lese." Master's thesis, 2018. http://www.nusl.cz/ntk/nusl-386901.

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This thesis focuses on the changes of vegetation of the wet meadows in Slavkovský Les during past decade. It uses data on vegetation gained from 100 permanent plots. By the analysis of the species composition and diversity it aims to elucidate the changes of the wet meadows over the last ten years. It aims to define, which are declining and which are becoming more common. Applied management should have a great impact on the observed vegetation changes so its effect is studied in the thesis as well. The knowledge of the suitable management should lead to conservation of the local biodiversity. The abiotic environmental factors are important as well as they can influence the species composition. These factors were studied by the application of Ellenberg indicator values on the species present in the study. These changes were compared in time and in a combination of time with a management type. Thus, we should be able to say how the environment has changed in the past decade and whether the type of management has any effect on the changes. Furthermore, the thesis explores whether changes in species composition over time may be explained by species traits. The results indicate that the species diversity and composition have indeed changed during the past decade. Apparently, the higher amount of...
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25

Prach, Jindřich. "Změny lesní vegetace Šumavy a jejího podhůří během druhé poloviny 20. století." Master's thesis, 2012. http://www.nusl.cz/ntk/nusl-306692.

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Long-term forest vegetation changes were studied in the Bohemian Forest and its foothills. New vegetation relevés were taken at sites of typological plots established by forest engineers between 1955 and 1980. Data from 158 semi-permanent plots were analysed using modern statistical methods. The data show significant changes and homogenization of the vegetation. Ellenberg indicator values indicate eutrofication. Repeated measurements of soil pH suggest acidification, but the interpretation of these data is complicated by methodological problems. The forests under study exhibit high spatial variability. No main prevailing trend in vegetation changes was found. The changes are considered to be related to sulphur and nitrogen deposition and forest management. The influence of increasing age of forest stands seems to be unimportant. Discussed are not only vegetation changes and their possible causes but also the possibilities and limitations of using such old forestry data in botanical and ecological studies.
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26

Pospíšková, Marie. "Lesní vegetace východního Polabí v polovině 20. století a dnes." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-337639.

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This thesis describes the shift in vegetation of broadleaf forests in eastern part of the Elbe River Basin between 1958-1968 and 2011-2013. It emphasizes the understorey vegetation. From lowland woodlands in other temperate regions in Europe and North America changes towards eutrophic and mesophytic vegetation are documented, specifically driven by changes in forest management and by atmospheric depositions; in some localities the game impact can be also important. The data were obtained by sampling 190 typological semi-permanent plots, which were precisely located - in 43% the original soil pit was found. The vegetation on study sites shifted towards nutrient-demanding, shade- adapted species, it was partly ruderalized. These changes can be seen on the level of species and communities as well as on phytosociological level. Increase of soil pH and moisture was discovered using Ellenberg indicator values. The number of seedlings and cover of shrubs also increased significantly. Homogenization of sites was significant as well although total number of species and alpha- diversity remained unchanged. These changes are probably caused by changes in forest management and by atmospheric depositions of nitrogen. On subset of plots in game-preserves the vegetation also demonstrated eutrophication but no increase in...
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Kopecký, Martin. "Vegetační změny českých nížinných lesů během posledních desetiletí." Doctoral thesis, 2015. http://www.nusl.cz/ntk/nusl-351674.

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Vegetation changes in Czech lowland forests over the past decades Martin Kopecký ABSTRACT To explore decadal changes in plant species diversity and composition of typical lowland forests in the Czech Republic, I compared vegetation on plots sampled decades ago with vegetation on the same plots sampled recently. First I evaluated the robustness of the approach used in my thesis. In Chapter 1, we provided the first direct test of the effect of uncertainty in original plot location on results from vegetation resurvey. We found that temporal trends in vegetation diversity and composition were comparable between exactly relocated permanent and only approximately relocated semi-permanent plots. Therefore, we conclude that the resurvey of semi-permanent plots is robust to the uncertainty in original plot location. Then, we showed that vegetation in lowland oak forest shifted from species-rich communities of thermophilous forest toward species poorer communities of mesic forest (Chapter 2). The species typical for thermophilous oak forests and nationally endangered species suffered the most significant decline. We identified as the main driver behind these changes shift from traditional coppicing toward high forest management after WWII. Further, we explored the processes behind temporal shifts in species diversity...
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