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1
Nelson, Robert Nicholas. "Connecting Ireland and America: Early English Colonial Theory 1560-1620". Thesis, University of North Texas, 2005. https://digital.library.unt.edu/ark:/67531/metadc4756/.
Testo completoAbstract (sommario):
This work demonstrates the connections that exist in rhetoric and planning between the Irish plantation projects in the Ards, Munster , Ulster and the Jamestown colony in Virginia . The planners of these projects focused on the creation of internal stability rather than the mission to 'civilize' the natives. The continuity between these projects is examined on several points: the rhetoric the English used to describe the native peoples and the lands to be colonized, who initiated each project, funding and financial terms, the manner of establishing title, the manner of granting the lands to settlers, and the status the natives were expected to hold in the plantation. Comparison of these points highlights the early English colonial idea and the variance between rhetoric and planning.
2
Baak, Paul Erik. "Plantation production and political power : plantation development in South-west India in a long-term historical perspective, 1743-1963". Delhi ; Calcutta ; Chennai [etc.] : Oxford university press, 1997. http://catalogue.bnf.fr/ark:/12148/cb375300224.
Testo completo
3
Stipriaan, Alex van. "Surinaams contrast : roofbouw en overleven in een Caraïbische plantagekolonie 1750-1863 /". Leiden : KITLV Uitg. [Koninklijk Instituut voor Taal-, Land- en Volkenkunde], 1993. http://catalogue.bnf.fr/ark:/12148/cb35573192v.
Testo completo
4
Ozanne, Claire Margaret Philippa. "The arthropod fauna of coniferous plantations". Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303621.
Testo completo
5
Thapa, Ram. "Modeling Mortality of Loblolly Pine Plantations". Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/46726.
Testo completoAbstract (sommario):
Accurate prediction of mortality is an important component of forest growth and yield prediction systems, yet mortality remains one of the least understood components of the system. Whole-stand and individual-tree mortality models were developed for loblolly pine plantations throughout its geographic range in the United States. The model for predicting stand mortality were developed using stand characteristics and biophysical variables. The models were constructed using two modeling approaches. In the first approach, mortality functions for directly predicting tree number reduction were developed using algebraic difference equation method. In the second approach, a two-step modeling strategy was used where a model predicting the probability of tree death occurring over a period was developed in the first step and a function that estimates the reduction in tree number was developed in the second step. Individual-tree mortality models were developed using multilevel logistic regression and survival analysis techniques. Multilevel data structure inherent in permanent sample plots data i.e. measurement occasions nested within trees (e.g., repeated measurements) and trees nested within plots, is often ignored in modeling tree mortality in forestry applications. Multilevel mixed-effects logistic regression takes into account the full hierarchical structure of the data. Multilevel mixed-effects models gave better predictions than the fixed effects model; however, the model fits and predictions were further improved by taking into account the full hierarchical structure of the data. Semiparametric proportional hazards regression was also used to develop model for individual-tree mortality. Shared frailty model, mixed model extension of Cox proportional hazards model, was used to account for unobserved heterogeneity not explained by the observed covariates in the Cox model.Ph. D.
6
Lynch, Alana Aileen. "Faunal procurement practice on antebellum plantations". [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0004893.
Testo completo
7
Ramírez, Bacca Renzo. "History of labour on a coffee plantation : La Aurora plantation, Tolima-Colombia, 1882-1982 /". Göteborg : University of Göteborg, 2002. http://catalogue.bnf.fr/ark:/12148/cb389558621.
Testo completo
8
Carson, Karen Michelle. "The function and failure of plantation government: interpreting spaces of power and discipline in representations of slave plantations". FIU Digital Commons, 2000. http://digitalcommons.fiu.edu/etd/2060.
Testo completoAbstract (sommario):
This investigation focuses on representations of the physical construction and landscape of Southern slave plantations in order to explore the power relationships among inhabitants of those plantations and how those power relationships attempted to function and failed to establish a system of discipline and governance. While every plantation functioned violently in some form, many plantations appear to have attempted to instill a sense of place and permanence of status in slaves with more than just physical violence or obvious and overt forms of mental coercion and abuse. As a supplement to the strategic (and oftentimes random) physical violence inflicted on slaves in the attempts to control their behaviors, owners seem to have also attempted to discipline their slaves through strategic constructions of the plantation landscapes. While concluding that this strategy ultimately failed, this thesis examines attempts by owners to implement particular strategies in regulating and disciplining the behavior of slaves which can be compared with the strategies implemented in a panoptic system as described by Michel Foucault.
9
Thaung, Tint Lwin. "Effect of nitrogen fertiliser additions on nitrogen fluxes and plantation productivity in young eucalyptus cloeziana (F. Muell) plantations /". [St. Lucia, Qld.], 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16847.pdf.
Testo completo
10
Oostindie, Gert J. "Roosenburg en Mon Bijou : twee Surinaamse plantages, 1720-1870 /". Dordrecht : Providence : Holland ; U.S.A. : Foris Publications, 1989. http://catalogue.bnf.fr/ark:/12148/cb37148244f.
Testo completo
11
Brown, Lauren Adele. "Reading resistance on the plantation writing new strategies in francophone Caribbean fiction /". Diss., Restricted to subscribing institutions, 2007. http://proquest.umi.com/pqdweb?did=1568134621&sid=1&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Testo completo
12
Simmons, Eunice Angela. "The ground flora of conifer-broadleaf plantations". Thesis, Imperial College London, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.338149.
Testo completo
13
Boucheret, Marianne. "Les plantations d'hévéas en Indochine (1897-1954)". Paris 1, 2008. http://www.theses.fr/2008PA010583.
Testo completoAbstract (sommario):
L'introduction de l'hevea en Indochine fut un succès, tant du point de vue des profits dégagés que de celui des exportations de caoutchouc réalisées par la colonie durant la première moitie du XXe siècle. Ces performances s' expliquent par la dynamique du marche mondial du caoutchouc, la politique des entreprises hévéicoles et Ie soutien de l'Etat colonial. La politique de « mise en valeur» menée par les pouvoirs publics fut particulièrement décisive. Les autorités françaises permirent aux planteurs de disposer à bas prix de la terre et de la main d'oeuvre. Aussi l'arbre àt caoutchouc devint-il précocement Ie symbole d'une double exploitation, celle du capitalisme et du colonialisme; il fut combattu à ce titre par Ie Vietminh. Prompts à réclamer Ie soutien de l'Etat colonial, les planteurs anticipèrent cependant l'échec de ce dernier. Ils préparèrent activement Ie redéploiement de leurs investissements et de leurs activités, avant que le signal officiel du départ ne fût donné.
14
Tran, Xuan Tri. "Les plantations d'hévéa en Cochinchine (1897-1940)". Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0016/document.
Testo completoAbstract (sommario):
Dès la conquête de la Cochinchine en 1862, l’Administration coloniale et des particuliers français exploitèrent l’agriculture locale et y développèrent l’économie. Ils tentèrent de faire l’essai et d’introduire diverses cultures, en particulier des arbres à caoutchouc. L’année 1897 marqua le début de l’hévéaculture de Cochinchine, lorsqu’on planta avec succès près de deux mille hévéas brasiliensis. La superficie de l’hévéaculture en Cochinchine se développait prodigieusement, allant de cent hectares à la fin du XIXème siècle à près de cent mille hectares au début des années trente, grâce d’une part à des capitaux provenant de la Métropole et, d’autre part à des mesures d’encouragement du Gouvernement colonial. Les plantations d’hévéa attirèrent les travailleurs locaux, surtout en provenance du Tonkin et de l’Annam, à raison d’une dizaine de mille, parfois une vingtaine de mille par an.Parallèlement à l’extension des superficies plantées, la production du caoutchouc de la colonie s’accrut rapidement, allant d’un peu plus d’une tonne en 1908 à plus de soixante mille tonnes en 1939. Les plantations d’hévéa devinrent l’une des cultures les plus importantes de Cochinchine à l’époque coloniale française. Non seulement elles apportèrent la fortune aux planteurs de la colonie, mais elles assurèrent une partie, et depuis 1938, la totalité des besoins de caoutchouc de l’industrie métropolitaine. Les plantations d’hévéa de Cochinchine représentaient un symbole de la colonisation agricole française, mais aussi hélas l’une des pages noires de l’histoire du colonialisme français au Vietnam par l’exploitation brutale des planteurs envers les travailleurs vietnamiensAs early as the conquest of Cochinchina in 1862, the colonial administration and French individuals exploited the local agriculture and developed the economy there. They tried to experiment and introduce various crops, especially rubber trees. The year of 1897 marked the beginning of the rubber plantation of Cochinchina, when two thousand rubber trees brasiliensis were successfully planted. The area of rubber tree plantation in Cochinchina grew tremendously, ranging from one hundred hectares at the end of the 19th century to nearly one hundred thousand hectares in the early 1930s, because of, on the one hand, the capital invested from the metropolis, and, on the other hand, the measures of encouragement taken by the colonial Government. The rubber plantations attracted local workers, mainly from Tonkin and Annam, at a rate of about 10.000, sometimes 20.000 persons a year. In parallel with the extension of the area of rubber plantation, the colonial rubber production rapidly increased from just over one tonne in 1908 to more than 60.000 tons in 1939.The rubber tree plantation became one of the most important crops of Cochinchina during the French colonial era. Not only they brought fortune to the planters of the colony, but they secured a part, and since 1938, the whole of the rubber demands of the metropolitan industries. The Cochinchina rubber plantations represented a symbol of French agricultural colonization and, unfortunately, one of the black pages of the history of French colonialism in Vietnam by the brutal exploitation of Vietnamese workers by rubber planters
15
Underhill, Ian David. "The Development and Assessment of Engineered Wood Products Manufactured from Low Grade Eucalyptus Plantation Thinnings". Thesis, Griffith University, 2017. http://hdl.handle.net/10072/366340.
Testo completoAbstract (sommario):
Over the last 10 to 15 years forestry plantation estates in Australia have increased in area by almost 50%. Much of this expansion can be attributed to new private-sector investment in sub-tropical and tropical Eucalypt plantations driven in part by favourable changes in taxation law and an increasing national and global demand for high quality sawn timber. While Australia has historically been a key exporter of hardwoods sourced from native forests, the development of a sub-tropical hardwood plantation industry has proven problematic. An array of factors, including long crop rotations that are sometimes in excess of 20 - 35 years, considerable production risks such as fires, cyclones, endemic and exotic pests and diseases, limited land availability and high establishment cost, have collectively undermined the economic viability of the sector. Producing high quality logs also comes with high-cost silvicultural practices that necessitate early plantation estate thinning to remove low quality trees, and pruning to improve log quality by minimising knots and defects. As a result, the profitability of the sub-tropical and tropical plantation hardwood sector in Australia is questionable. In the first 15 years of production up to three quarters (700 trees per hectare) of the hardwood plantation is removed through pruning and thinning processes. Currently, there are few if any identified viable markets for these small diameter low-grade trees termed ‘thinnings’. If new products that make use of thinnings could be identified, it could provide important early financial returns to the industry. Turning current commercial forest wastage into potential high-value alternative wood products would potentially ensure the economic viability of the sub-tropical and tropical hardwood plantation sector in Queensland.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Queensland College of Art
Arts, Education and Law
Full Text
16
Hamrouni, Ridha. "Le Processus d'intégration de la main d'oeuvre agricole dans les plantations agro-industrielles et dans les plantations villageoises satellites le cas de la SOCAPALM au Cameroun". Lille 3 : ANRT, 1985. http://catalogue.bnf.fr/ark:/12148/cb37594805z.
Testo completo
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DIABANGOUAYA, MAURICE. "Entomofaune des plantations industrielles d'eucalyptus des savanes cotieres du congo : cas d'helopeltis schoutedeni reuter (heteroptera miridae) depredateur des jeunes plantations". Paris 11, 1994. http://www.theses.fr/1994PA112269.
Testo completoAbstract (sommario):
Des plantations industrielles d'eucalyptus sont installees regulierement au congo depuis 1978, dans les savanes cotieres autour de pointe-noire, dans un but de production papetiere. Les arbres plantes sont des clones selectionnes a partir d'hybrides a forte productivite. Ces plantations sont sujettes a de nombreuses attaques d'insectes autochtones dont le ravageur principal actuel est une punaise: helopeltis schoutedeni reuter (heteroptera, miridae). Une etude detaillee de la biologie et de la dynamique des populations de ce depredateur est presentee. L'efficacite et les modalites optimales des methodes de lutte chimique, contre cette punaise ont ete evaluees. Toutefois c'est la lutte par variete resistante qui parait etre la mieux adaptee. En effet diverses experimentations en plantation et au laboratoire ont revele que les clones issus de l'hybride 12abl saligna sont plus resistants, alors que ceux issus des hybrides pf1 et urophylla sont plus sensibles. Ceci conduit a emettre l'hypothese d'un determinisme genetique de la sensibilite qui orientera les futurs programmes de selection. Les autres ravageurs comprennent plusieurs especes: augosoma. Centaurus, phoracantha semipunctata (introduit), ascotis selenaria, etc. Ils demeurent pour l'instant secondaires en frequence et en degats. Mais cette situation est susceptible d'evoluer en fonction de variations climatiques, de l'emploi des nouveaux clones et de l'evolution des techniques sylvicoles. Aussi le maintien d'une surveillance entomologique constante parait recommandable
18
Abdy, Evelyn. "Ground vegetation in conifer plantations in upland Wales". Thesis, Bangor University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.314679.
Testo completo
19
Avila, Olga B. "Modeling growth dynamics of juvenile loblolly pine plantations". Diss., Virginia Tech, 1993. http://hdl.handle.net/10919/39476.
Testo completoAbstract (sommario):
Modeling growth dynamics of juvenile loblolly pine plantations can help to address important management decisions that have to be made in young stands. The present study addressed diameter and height prediction as well as crown development analysis as functions of independent variables such as site index, relative spacing and age for trees younger than ten years old. It was found that height prediction for trees one and two years old was a function of the products of the variables site index and age (or square root of age) and relative spacing and age (or square root of age). For trees three years old and older these were also the independent variables used to explain height prediction but in this case age (or square root of age) was another significant independent variable. In regard to diameter prediction it was observed that groundline diameter was a function of age for trees one and two years old; while this variable was also a function of site index and relative spacing for trees three, four and five years old. For trees older than five years old diameter at breast height was a function of age, site index and relative spacing. The analysis of crown development showed that for trees five years old and older variables like diameter at breast height, total height, age, site index and relative spacing were significant when crown ratio was the dependent variable. For trees younger than five years old, groundline diameter and the other same independent variables (i.e. total height, age, index and relative spacing) were again found significant when crown ratio was the dependent variable.Ph. D.
20
Avila, Olga. "Modeling growth dynamics of juvenile loblolly pine plantations /". This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-10022007-144523/.
Testo completo
21
Langi, Martina Agustina. "Nutrient cycling in tropical plantations and secondary rainforests /". St. Lucia, Qld, 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16357.pdf.
Testo completo
22
Kien, Nguyen Duc. "Improvement of Eucalyptus plantations grown for pulp production". Uppsala : Dept. of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, 2009. http://epsilon.slu.se/200953.pdf.
Testo completo
23
Alley, Joseph L. "Forage legumes as living mulches in tree plantations /". free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p1421108.
Testo completo
24
Kessler, Lawrence Helfgott. "Planter's Paradise: Nature, Culture, and Hawaiʻi’s Sugarcane Plantations". Diss., Temple University Libraries, 2016. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/374197.
Testo completoAbstract (sommario):
HistoryPh.D.
Over the course of the nineteenth century, the Hawaiian sugar industry rose from economic insignificance to become one of the world’s most efficient and productive sugarcane plantation systems. "Planter's Paradise" traces the transnational environmental history of cane planting in Hawaiʻi, from Polynesian settlement to the early twentieth century, to explore how an export-based mono-culture plantation system eclipsed diversified farming, how cultural encounters between indigenous and Euro-American groups influenced agriculture and natural resource use, and how the politics of planting contributed to the rise of American hegemony over the islands. With research grounded in plantation records, agricultural association publications, popular media, and personal correspondence, I address sugarcane planting as a point where ideas about nature, methods of converting nature into commodities for consumption in distant markets, and nature itself influenced each other within the context of U.S. imperial expansion. I argue that the ascendance of Hawaiʻi’s sugar industry was the result of cultural encounters, economic relations, and environmental conditions at the local level, but cane planting also connected the archipelago to particular transnational networks of economic, ecological, and cultural exchange. Sugarcane planting introduced to Hawaiʻi foreign ways of relating to the natural world, a host of alien organisms, and advances in agricultural science and technology that impacted all of Hawaiian society. These introductions contributed to planters' power. By the early twentieth century, Hawaiʻi had become a planter's paradise: a society and environment transformed for the industrial cultivation of sugarcane.
Temple University--Theses
25
Ibell, Paula Therese. "Edaphic and Ecophysiological Responses to Early Establishment Weed Control and Fertilisation in F1 Hybrid Pine Plantations of Southeast Queensland". Thesis, Griffith University, 2014. http://hdl.handle.net/10072/367975.
Testo completoAbstract (sommario):
Post-planting silviculture in the exotic pine plantations of Southeast Queensland focuses on fertilisation and weed control at early plantation establishment. Early establishment silviculture in pine plantations aims to reduce the competition for light, nutrients and water in the short term, while maximising resource conversion for growth in the long term. However, silviculture can be applied in a systematic way without necessarily considering the limitations to maximum tree growth at each site. Accordingly, silvicultural treatments could be applied in a site specific manner to better reflect the limitations to tree growth at each site (e.g. nutrition and/or water), or for maximum effectiveness based on seasonal limitations (e.g. weed competition, water availability). This research aimed to investigate the effects of early establishment weed control and fertilisation practices on soil carbon (C) and nitrogen (N) cycling (as an indicator of soil fertility), tree nutrition (particularly N nutrition), growth and eco-physiological responses, in the F1 hybrid exotic pine plantations (Pinus elliottii Engelm var. elliottii x Pinus caribaea Morelet var. hondurensis (Sènècl.) W.H.G. Barett & Golfari.) in the subtropics of Southeast Queensland.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
Full Text
26
Teelock, Vijayalakshmi. "Bitter sugar : slavery and emancipation in nineteenth century Mauritius". Thesis, SOAS, University of London, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241817.
Testo completo
27
Spriggs, AC, e FD Dakora. "Field assessment of symbiotic N2 fixation in wild and cultivated Cyclopia species in the South African fynbos by 15N natural abundance". Oxford University Press, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000376.
Testo completoAbstract (sommario):
Nitrogen (N) derived from symbiotic fixation
of atmospheric N2 in wild and cultivated populations of
Cyclopia, a woody endemic genus used to make honeybush
tea in the Western Cape of South Africa, was quantified by
the 15N natural abundance method. Because Cyclopia
species are naturally mycorrhizal, non-N2-fixing arbuscular
mycorrhizal shrubs of similar phenology to Cyclopia
were chosen as reference plants to provide the d15Nvalue of
soil-derived N. Isotopic analysis showed that wild populations
of Cyclopia were highly dependent on N2 fixation
for theirNnutrition, ranging from 70 ± 4%to 100 ± 7%
(mean ± SE) at all sites, except for one. Further evidence
of the high dependency of wild Cyclopia populations on
symbiotic N was provided by their significantly higher
foliar N concentrations compared with the non-legume
reference plants. However, cultivated Cyclopia exhibited
variable amounts of N2 fixation, with Cyclopia genistoides
(L.) R. Br., for example, showing low amounts of N2
fixation at Sites P2 and P3 (0 ± 51% and 8 ± 46%,
respectively) as a result of low D values (D is defined as the
difference between the mean d15N value of the reference
plants and the B value of the test Cyclopia species, where B
is the d15N of an inoculated test legume grown in an N-free
growth medium), whereas at Sites P1, P2, P5 and P6, up to
89 ± 2%, 94 ± 13%, 85 ± 13% and 100 ± 18%,
respectively, plant N was derived from atmospheric fixation.
The high symbiotic N nutrition observed for wild
populations of Cyclopia suggests that these populations
are major contributors to the N economy of the nutrientpoor
soils of the South African fynbos. These data
indicate that by breeding for high N2 fixation rates in
Cyclopia cultivars and selecting more efficient rhizobial
strains, this legume has the potential to achieve higher N2
fixation rates under cultivation. The low variability in
Cyclopia d15N values within sites, however, suggests that
genetic variability is not a major factor influencing N2
fixation rates in cultivated Cyclopia, and thatmore benefit
may be gained from soil amelioration and the selection of improved rhizobial strains
28
Colin, Jean-Philippe. "La mutation d'une économie de plantation en basse Côte d'Ivoire /". Paris : Éd. de l'ORSTOM, 1990. http://catalogue.bnf.fr/ark:/12148/cb35456173q.
Testo completo
29
Brown, Peter Leonard. "Stand structure, canopy architecture and thinning response in mature Queensland maple (Flindersia brayleyana F. Muell.) plantations /". St. Lucia, Qld, 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16432.pdf.
Testo completo
30
Sioh, Maureen Kim Lian. "Fractured reflections : rainforests, plantations and the Malaysian nation-state". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0018/NQ48715.pdf.
Testo completo
31
Paz, Manuel Barcia. "Domination and slave resistance on Cuban plantations, 1808-1848". Thesis, University of Essex, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.418418.
Testo completo
32
McCurdy, Wyatt Conner. "Characterizing spatiotemporal variation in LAI of Virginia Pine Plantations". Thesis, Virginia Tech, 2020. http://hdl.handle.net/10919/96595.
Testo completoAbstract (sommario):
Loblolly pine is an important managed tree species within the southeastern United States, and better understanding spatial patterns in its productivity has potential to contribute to both modeling and management of the species. Using recently-created pine management maps specific to Virginia and empirical relationships predicting pine LAI from the Landsat satellite, we conducted a statewide analysis of temporal patterns in stand-level southern pine leaf area index (LAI) following clear-cut and planting. Here, using 28 years of Landsat time-series data for 13,140 stands that were clear-cut between 2014-2017, we examined 1) when LAI peaked over the rotation, and 2) how LAI in each stand compared to a recommended fertilization threshold of 3.5 LAI. We found that, on average, winter LAI reached a maximum of 2.02., which can be approximately doubled to give a summer LAI of 4.04, and within stand peak occurred between years 13 and 15. We also found that around 45.8% of stands achieved an LAI value higher than 3.5: a fertilization threshold recommended for managed stands in Virginia. The dataset produced by our analysis will bolster information required for modeling loblolly pines as a plant functional type in regional land simulations, and the finding that most stands are below the recommended LAI fertilization threshold will fuel further management-motivated research.Master of Science
Management of pines in the southeastern U.S. contributes to the region's economy and carbon sequestration potential. In this study, we used Virginia forest harvest maps to identify individual patches (stands) of pine forest which had each gone through a full harvest life cycle (rotation). With unique managed pine stands identified, we used satellite imagery to estimate growth of canopy leaf area over time within each stand, using a metric called leaf area index (LAI). We identified 13,140 separate stands, each with up to 28 years of available data. We took the first full-state census of areas of managed pines in Virginia, and their leaf area development. We acquired one LAI measurement from February of each year, for each stand in Virginia. Using February LAI for each of our stands, we found that an average stand in VA has a maximum winter LAI of 2.02 (meaning an approximate maximum summer LAI of 4.04), and that stands generally reached their peak LAI after around 14 years of growth. It is recommended, in VA, that a landowner fertilize their stand in the middle of a harvest rotation if summer peak LAI is under 3.5, at stand closure. We found that at ten years of stand age, 45.8% of stands were estimated to reach above this threshold. Since this study's dataset is the most comprehensive LAI dataset for managed pines in VA, it may be used to improve management outcomes as well as understand pine productivity for land surface modeling purposes.
33
Yamashita, Tamon. "Nitrogen cycling in soil ecosystems of temperate coniferous plantations". Kyoto University, 2005. http://hdl.handle.net/2433/145441.
Testo completoAbstract (sommario):
Kyoto University (京都大学)0048
新制・論文博士
博士(農学)
乙第11586号
論農博第2546号
新制||農||902(附属図書館)
学位論文||H17||N3990(農学部図書室)
22885
UT51-2004-U483
京都大学大学院農学研究科熱帯農学専攻
(主査)教授 武田 博清, 教授 東 順一, 教授 谷 誠
学位規則第4条第2項該当
34
Thomas, Anaïs. "Interactions entre espèces en plantations mélangées forestières et agroforestières". Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0079.
Testo completoAbstract (sommario):
Les plantations d'espèces à croissance rapide (par exemple les peupliers, les saules, les eucalyptus) sont largement utilisées pour l'approvisionnement en biomasse. Cependant, ces plantations sont souvent des systèmes monospécifiques et sont généralement très consommatrices en ressources. C'est notamment le cas des plantations des espèces appartenant au genre Populus, pouvant être cultivées en conditions de culture intensive, qui utilisent des quantités importantes d'eau et d'azote pour produire de grands volumes de biomasse. Dans ce contexte, les plantations mélangées, forestières ou agroforestières, apparaissent comme une alternative intéressante aux monocultures. En effet, elles peuvent produire plus en utilisant plus efficacement les ressources indispensables à la croissance des différentes composantes du mélange en jouant sur la complémentarité entre les espèces. L'introduction d'espèces fixatrices d'azote dans ces mélanges peut également être un atout supplémentaire pour réduire les besoins en intrants azotés de synthèse.Dans toute plantation, forestière ou agroforestière, les interactions intraspécifiques (individus d'une même espèce) ou interspécifiques (entre individus de deux espèces différentes) peuvent être négatives, positives, ou neutres. À ce jour, les interactions entre espèces qui déterminent si un mélange donné sera plus productif que les monocultures correspondantes sont encore mal comprises et les études de leur impact sur l'efficacité d'utilisation des ressources sont rares. L'objectif général des travaux de thèse a consisté à évaluer l'impact de plusieurs mélanges d'espèces, forestiers et agroforestiers, sur les performances de croissance des arbres à travers les effets sur les déterminants fonctionnels (efficiences d'utilisation des ressources), structuraux (architecture des houppiers) et phénologiques (phénologie printanière et automnale des bourgeons et des feuilles). L'hypothèse principale était que grâce à la fixation symbiotique de l'azote et à une complémentarité entre espèces, les arbres dans les mélanges seraient plus productifs et utiliseraient plus efficacement les ressources qu'en monoculture.Cet objectif a été poursuivi sur une plantation instrumentée sur le site de La Bouzule (54), installée au printemps 2014, composée de mélanges d'espèces ligneuses (peupliers et aulnes) et herbacées (légumineuses, graminées), ainsi que les monocultures correspondantes. Le fonctionnement de trois types de mélanges comprenant des espèces fixatrices d'azote (peupliers/succession luzerne - trèfle ; peupliers/aulnes ; aulnes/succession céréales - prairie temporaire) a été comparé avec les monocultures des deux espèces ligneuses. L'originalité des travaux réside notamment dans l'alliance de l'étude de processus intervenant aux échelles de l'organe et de l'arbre pour décrire les processus d'interactions entre espèces et les performances globales des différents types de mélanges, par rapport aux monocultures correspondantes.Les interactions entre espèces dans une plantation ne sont pas statiques mais changent au fur et à mesure que le peuplement se développe. La nature des interactions entre le peuplier et les légumineuses dans la parcelle agroforestière a évolué d'une compétition prédominante, au début de la plantation, vers une facilitation grâce à un enrichissement du sol en azote. Les performances de croissance des peupliers étaient accrues, par rapport à la monoculture, associées à une efficience d'utilisation de l'eau plus élevée qu'en monoculture ainsi qu'à une réduction de compétition entre les houppiers permettant une meilleure interception de la lumière en agroforesterie. En revanche, une efficience d'utilisation de l'eau plus élevée des peupliers associés à l'aulne qu'en monoculture n'a pas été associée à de meilleures performances de croissance des deux espèces comparativement à leurs monocultures respectives. Globalement, l'aulne n'était que très peu affecté par les mélangesPlantations of fast-growing species (e.g. poplars, willows, eucalyptus) are widely used for biomass supply. However, these plantations are often monospecific systems and are generally very resource demanding. This is particularly the case for plantations of species belonging to the Populus genus, which can be grown under intensive cultivation conditions, and which use large quantities of water and nitrogen to produce large volumes of biomass. In this context, mixed forest or agroforestry plantations appear as an interesting alternative to monocultures. Indeed, they can produce more by using more efficiently the resources necessary for the growth of the different components of the mixture by playing on the complementarity between the species. The introduction of nitrogen-fixing species in these mixtures can also be an additional asset to reduce the need for synthetic nitrogen inputs.In any plantation, forest or agroforestry, intraspecific interactions (individuals of the same species) or interspecific interactions (between individuals of two different species) can be negative, positive, or neutral. To date, the interactions between species that determine whether a given mixture will be more productive than the corresponding monocultures are still poorly understood and studies of their impact on resource-use efficiency are scarce. The overall objective of the PhD work was to evaluate the impact of several species mixtures, both forest and agroforestry, on tree growth performance through effects on functional (resource-use efficiencies), structural (crown architecture) and phenological (spring and fall bud and leaf phenology) determinants. The main hypothesis was that thanks to symbiotic nitrogen fixation and complementarity between species, trees in mixtures would be more productive and use resources more efficiently than in monoculture.This objective was pursued on an instrumented plantation on the La Bouzule site (54), installed in spring 2014, composed of mixtures of woody (poplars and alders) and herbaceous (legumes, graminoids) species, as well as their respective monocultures. The functioning of three types of mixtures including nitrogen-fixing species (poplars/alfalfa - clover succession; poplars/alders; alders/cereal - temporary grassland succession) was compared with monocultures of the two woody species. The originality of the work lies on the combination of the study of processes occurring at the organ and tree scales to describe the interaction processes between species and the overall performance of the different types of mixtures, compared to their respective monocultures.Species interactions in a plantation are not static but change as the stand develops. The nature of the interactions between poplars and legumes in the agroforestry plot evolved from a predominant competition at the beginning of the plantation to facilitation through soil nitrogen enrichment. The growth performances of the poplars were increased compared to the monoculture, associated with a higher water-use efficiency than in monoculture and a reduction of competition between the canopies allowing a better interception of light in agroforestry. In contrast, higher water-use efficiency of poplars associated with alder than in monoculture was not associated with better growth performances of both species compared to their respective monocultures. Overall, alder was only slightly affected by the mixtures
35
Ambrose, Fossoh Fonge. "Plantations and national development : a case study of plantation agriculture in the socio-economic and spatial development of the S.W. Province of Cameroon". Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63334.
Testo completo
36
Kempadoo, Roshini. "Creole in the archive : Imaginery, presence, and location of the plantation worker of two plantations, nearby villages and towns in Trinidad(1838-1938)". Thesis, Goldsmiths College (University of London), 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498379.
Testo completo
37
Geiger, Mark W. "Missouri's hidden Civil War financial conspiracy and the decline of the planter elite, 1861-1865 /". Diss., Columbia, Mo. : University of Missouri-Columbia, 2006. http://hdl.handle.net/10355/4423.
Testo completoAbstract (sommario):
Thesis (Ph. D.)--University of Missouri-Columbia, 2006.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on July 18, 2008) Vita. Includes bibliographical references.
38
Nyffeler, Martin. "Spiders as biological control agents in cotton plantations in Texas". Bern : [s.n.], 1996. http://www.zb.unibe.ch/download/eldiss/habil/96nyffeler_m.pdf.
Testo completo
39
Cozens, Russel David. "Insect and disease risk factors in established interior spruce plantations". Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24426.
Testo completoAbstract (sommario):
Forest insects and diseases active in immature interior spruce stands in the central interior of British Columbia and their possible implications in forest management practices have been surveyed. Collection records, spanning the period 1949 to 1982, from the Forest Insect and Disease Survey of the Canadian Forestry Service were reviewed for the Prince George Timber Supply Area and the pest incidence in immature interior spruce stands summarized.
Twenty-two plantations, established between 1963 and 1973, were surveyed to determine the relative incidence of the major insect and pathogen pests of immature spruce in Supply Block 'G' of the Prince George Timber Supply Area. A bud midge, likely Rhabdophaga swainei Felt (Diptera: Cecidomyiidae), and a terminal weevil, Pissodes strobi Peck (Coleoptera: Curculionidae), were found to consistently infest and damage a significant number of immature interior spruce trees.
A spruce stand stocking profile was developed as a basis for discussion of management practices in plantations and immature stands. The stocking profile can be used in the determination of not only pest management policy decisions but in stand management decisions affecting stand density and, ultimately, merchantable yield at harvest.
The findings confirmed that forest management must be actively practiced throughout the life of a forest stand. To be successful, however, stand management guidelines and merchantable yield projections are required. These guidelines and projections must include the influences of insects and diseases upon the forest crop in their development model. This information is particularly important in the development of complete Timber Supply Area plans and for the flagging of pest hazard periods during the development of spruce forests.Forestry, Faculty of
Graduate
40
Germain, André Yvon. "Fertilization of stagnated sitka spruce plantations of northern Vancouver Island". Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/24427.
Testo completoAbstract (sommario):
Extensive areas of Sitka spruce plantations established during the last 15 years on the CH-phase of the salal-moss ecosystem association on northern Vancouver Island are presently exhibiting symptoms of severe chlorosis and growth check. Investigations into the poor performance of these plantations are described in this thesis. Comparisons of the soil nutrient levels between this poorly productive CH-phase and the adjacent highly productive HA-phase were made. In addition, fertilization screening trials were established in order to identify possible limiting nutrients and determine the potential responsiveness of Sitka spruce to fertilization.
Soil samples were collected over an age sequence of cutovers from both phases in order to compare differences in the soil nutrient status and to determine the effects of time since harvesting on N mineralization rates.
Significantly greater amounts of total and available P and total, KC1 extractable, and mineralizable N (p=.01) were found in the mineral soil and humus of the HA-phase. The mineral soil of the HA-phase also had significantly higher (p=.05) concentrations of exchangeable K. In addition, this phase had a significantly lower (p=.01) C/N ratio. Although significant differences were noted in the mineral nutrient composition of the two phases, in all cases (with the possible exception of mineralizable N), the absolute differences between the two phases did not appear large enough to account for the dramatic differences in productivity.
Harvesting plus slashburning appears to have had little effect on the rates of N mineralization in the humus or mineral soil of the HA-phase. However, in the CH-phase harvesting plus slashburning has had a significant influence on the mineralization rates of the humus but not of the mineral soil. Harvesting initially resulted in a significant (p=.05) increase in the mineralization rates, however, within five years they returned to levels comparable to that of the control.
Fertilization screening trials were established in five Sitka spruce plantations ranging in age from 8 to 14 years. All plantations were growing on the CH-phase and were exhibiting symptoms of chlorosis and growth check. Changes in the first-year needle dry-weight, needle nutrient composition, and leader growth were monitored. Treatments for these trials consisted of a N, P, K factorial experiment, and one separate treatment of a complete nutrient mixture. Each treatment was replicated seven times in each of the five plantations.
N or N plus K fertilization resulted in a 10% increase in needle dry-weight and a 25 to 30% increase in first-year leader growth response over that of the control. P fertilization had a strong synergistic effect and when added in combination with N or N plus K resulted in a needle dry-weight increase of 40 to 41% and a leader growth increase of 78 to 83%. A limited sample of naturally occurring hemlock in some of the plots exhibited similar trends, although leader growth increases were somewhat greater.
Fertilization with P and K, alone or together, had no effect on leader growth or needle weight despite the severe deficiencies of these two elements. However, P had a positive influence on the uptake of N, K, Ca and Mg, whereas K positively affected Ca and depressed Mg.
After N fertilization, foliar N concentrations increased dramatically, ranging from a mean of 3.2% for the lowest (200 kg N/ha) application rate to 4.1% for the highest (400 kg N/ha) application rate. The high foliar N concentrations had a significant negative influence on foliar K concentrations. This decline in K concentrations could only partially be attributed to a growth dilution effect and occurred whether or not K was added. A similar effect on P, Ca or Mg was not noted. The high N concentrations also appeared to have had a negative influence on both needle weight and leader growth as there was a tendency for the response of both to decline as N concentrations increased.
There were significant differences in both leader growth and needle weight responses between some of the plantations, but treatments receiving both N and P fertilizers consistently gave the greatest responses. The individual treatment, however, which gave the greatest and most consistent overall response was that containing all macro- and micro-nutrients.
Results from this study indicate that the poor performance of Sitka spruce plantations established on the CH-phase of the salal-moss ecosystem is partially due to a severe N and P deficiency. These deficiencies are associated with the complete invasion of these cutovers by salal. It has also been shown that the Sitka spruce in these plantations would be highly responsive to N and P fertilization. Although K does not appear to limit growth and no apparent benefits were gained from K fertilization, a severe N induced K deficiency is likely.Forestry, Faculty of
Graduate
41
Kraenzel, Margaret. "Carbon storage of Panamanian harvest-age teak (Tectona grandis) plantations". Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=31249.
Testo completoAbstract (sommario):
Reforestation is being considered as a mitigation option to help combat the climate change predicted to result from atmospheric carbon dioxide pollution. Forestry-based carbon storage projects are being introduced in many tropical countries, and assessment of species-specific carbon storage potentials is made difficult by a lack of species-level information. This study focuses on teak (Tectona grandis), to measure many of the characteristics affecting the carbon storage potential both of the trees themselves and of the plantations they are in. Root-to-shoot ratio, above- and belowground biomass, as well as tissue carbon content were measured in 20-year-old teak trees in Panamanian plantations. A regression relating diameter at breast height (DBH) to total tree carbon storage for trees of various sizes was developed. To scale up to the plantation level, this regression was used to estimate the carbon storage of the trees of four plantations. Litter, undergrowth, and soil were studied to estimate carbon storage in these compartments. These estimates were collated to form a global estimate of carbon storage in Panamanian harvest age teak plantations. Various methods of calculation of carbon storage in short-rotation plantations are discussed. This work will allow greater precision in the assessment of carbon storage in individual plantations.
42
Moffatt, Colin. "Insect community response to field layer manipulation in broadleaved plantations". Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402085.
Testo completo
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Veale, Lucy. "An historical geography of the Nilgiri cinchona plantations, 1860-1900". Thesis, University of Nottingham, 2010. http://eprints.nottingham.ac.uk/13041/.
Testo completoAbstract (sommario):
In 1859, the British government launched an expedition to South America with the aim of collecting seeds and plants of the quinine-producing cinchona tree for establishing plantations in British India, so as to relieve the British Government of the escalating costs and uncertainties in the supply of this valuable, and increasingly popular anti-malarial drug. Drawing on recent work on the commodities of empire, tropical acclimatization, and imperial medicine, this thesis provides a detailed study of the first British cinchona plantations established on the Nilgiri Hills of Southern India. Focused on the period between 1860 and 1900, and at the local geographic scale, the research critically examines the engagement and connections between government officials, planters, venture capitalists, labourers, plant material and ideas in the context of the cinchona plantations through a thorough study of archival and secondary sources. Contributions are also made to the study of the spaces of science and the management of the tropical environment. Cinchona is placed in a wider context of the history of botany and plantations in the Nilgiri region, and the major events in the development of cinchona plantations described. In the resulting historical geography the Nilgiri cinchona plantations emerge as a 'nodal' point in the global cinchona network that also relied upon global networks of imperial power, capital and leisure tourism. The experiment was essentially an exertion of power but one that also demonstrated the very vulnerable nature of the empire.
44
Van, der Sijde J. H. R. (Jan Herman Robert). "The assessment of fire history in plantations of Mpumalanga North". Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53616.
Testo completoAbstract (sommario):
Thesis (MScFor) -- Stellenbosch University, 2003.ENGLISH ABSTRACT: Fire is a threat to all forest plantations. As a result, growers are forced to take active measures to reduce the incidence and extent of fires in their plantations. This thesis is an attempt to collate 846 fire records for eight Komatiland Forests (KLF) plantations in Mpumalanga North for the period 1950 to 1999. Up to now, these reports and the information therein, were not utilised by KLF for planning or for evaluating fire management practices. The only other studies in South Africa, using similar data, were conducted by LeRoux (1988) and Kromhout (1990). A brief background of the forestry industry in South Africa, and in particular Mpumalanga is presented. The main text of the report covers a presentation on fire causes, extent of damage (both in area and in Rand value) and various aspects related to time of ignition and response times. A detailed analysis was done to identify possible relationships between the variables related to compartment, climate and different fire suppression activities. A cause and frequency prediction model was developed that will assist fi re managers in identifying and determining probabilities of fires per cause. Statistical guidelines regarding the planning of fire management around fires caused by honey hunters, lightning, work-related factors, and the activities of people (public, own labour, contractors) are presented. Conclusions were drawn from the results of the analyses of the fire data, which covered a period of 47 years. Recommendations regarding guidelines for strategic fi re management for the Mpumalanga North plantations were made. The main conclusions are: • Statistics on previous fires are very useful in fire management planning as it supplies valuable information on fire causes, time of ignition , past performance related to response times, fire fighting times and damaged caused. • • • • The average area lost due to fires in the study area is 209.9 ha or 0.43% of the plantation area per annum. People-related fires (arson, smokers, picnickers, children and neighbours) caused most of the wild fires (48%), followed by lightning (22%). Some plantations performed poorly, with the occurrence of up to double the number of fires per 1 000 ha of plantation compared to other plantations in the same geographic area. There are definite patterns in the frequency of fires per cause with month of the year. These patterns are valuable for the development of strategies to manage fires caused by honey hunters, lightning fires and work-related fires.
AFRIKAANSE OPSOMMING: Brande is 'n bedreiging vir aile bosbou plantasies. Dit is dus noodsaaklik dat kwekers maatreeHs tref om die voorkoms en omvang van brande in plantasies te beperk. Hierdie tesis poog om 846 vuurverslae se inligting te ontleed ten opsigte van agt Komatiland Forests (KLF) plantasies in Mpumalanga Noord vir die tydperk 1950 tot 1999. Tot op hede is min van die inligting wat in die verslae vervat is deur KLF vir beplanning- en evalueringsdoeleindes ten opsigte van brandbestuur gebruik. Die enigste soortgelyke studies wat op brandverslagdata in Suid-Afrika gedoen is, is gedoen deur Le Roux (1988) en Kromhout (1990). 'n Kort agtergrond oor die bosbouindustrie in Suid-Afrika en spesifiek Mpumalanga word gegee. Die tesis gee 'n oorsig oor brandoorsake, skade wat deur brande veroorsaak word (oppervlakte sowel as finansieHe waarde) en verskeie aspekte rakende brandbestuur soos tyd van ontstaan en reaksietye. Data is volledig ontleed om moontlike verwantskappe te probeer vind tussen vak-, klimaat- en brandbestuursveranderlikes. 'n Oorsaak- en frekwensievoorspellingsmodel is ontwikkel wat brandbestuurders sal help om waarskynlikhede van brande per oorsaak te identifiseer. Statistiese riglyne ten opsigte van bestuursbeplanning vir weerligvure, brande deur heuninguithalers, brande as gevolg van plantasiewerksaamhede en ook brande deur mense (publiek, eie arbeid en kontrakteurs) is daargestel. Brandrekords wat oor 'n periode van 47 jaar gestrek het, is ontleed. Afleidings wat uit die resultate gemaak is, kan benut word om riglyne daar te stel vir strategiese brandbestuur in Mpumalanga Noord plantasies. Die hoof gevolgtrekkings is: • Statistiek van vorige vure is baie nuttig in brandbestuursbeplanning aangesien dit waardevolle inligting verskaf oor brand oorsake, tyd van ontstaan, historiese werkverrigting rakende reaksietye en blustye, sowel as skade wat veroorsaak is. Die gemiddelde oppervlakte beskadig in die studie area is 209.9 ha, of 0.43% van die plantasie oppervlakte per jaar. Menslike aktiwiteite (brandstigting, rakers, piekniekvure, kinders en vure van bure) het die meeste brande veroorsaak (48%), gevolg deur weerlig (22%). Sommige plantasies het swak gevaar en het tot soveel as dubbel die aantal vure per 1 000 ha plantasie gehad in vergelyking met ander plantasies in dieselfde geografiese gebied. Daar is duidelike patrone gevind in die frekwensie van brande per oorsaak oor maande van die jaar. Hierdie patrone is nuttig vir die ontwikkeling van bestuurstrategie vir brande wat veroorsaak word deur heuningversamelaars, weerlig en werkverwante aktiwiteite (plantasieaktiwiteite).
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Duarte, Marina Melo. "How is forest restoration plantations\' functioning affected by tree diversity?" Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-22082018-181301/.
Testo completoAbstract (sommario):
Tropical forests restoration is an important tool for climate change mitigation and biodiversity conservation. We can ally both of these elements, according to the biodiversity and ecosystem (BEF) functioning theory, which says that diversity enhances ecosystem functions, as primary productivity. Nevertheless, the greatest part of BEF studies up to very recently have focused on grasslands and not on as complex ecosystems as tropical forests. It is necessary to better understand above- and below-ground processes through which biodiversity acts on ecosystem functions. This work aimed to investigate effects of tree richness on both above- and below-ground ecological processes. It was based on two tropical forests undergoing restoration, in Sardinilla (Panama) and in Anhembi (Brazil). The former was especially designed for BEF studies and allowed to untangle effects of biodversity on ecosystem functions. The latter had more than a hundred species in plots and permitted investigation of the effects of high tree richness levels. In both Sardinilla and Anhembi, we investigated if tree richness levels affected an above-ground ecological process, light interception, and which mechanisms could be related to it. Richness could enhance light interception and mechanisms as spatial (horizontal and vertical) and temporal light distribution. It promoted both selection and complementarity effects. In Anhembi, we investigated if species richness influenced below-ground processes related to soil carbon stocks. Stand richness enhanced fine root production and stock. Effects of stand number of species on litter decomposition and stock were not linear. Richness of litter content, however, did not affect its decomposition rates. Number of stand species did not influence litter production. Differences of litter production, stock and fine root production among distinct richness levels did not change over the time. However, distribution of fine roots over the space, within different layers of soil, was affected by number of tree species. We concluded that even very high richness levels could not saturate some of the ecological processes studied. Diversity acted on both above- and below-ground processes, in various and sometimes opposite ways, counting on multi-direction feedbacks. It is very important to understand these mechanisms in order to potencialize biodiversity convervation and carbon sequestration by tropical forest restoration. Future studies may focus on untangling effects of diversity on below-ground processes (which have not been exhaustively explored in research), on understanding how high diversity levels affects natural regeneration and on investigationg functional traits provided by different species.A restauração de florestas tropicais é uma importante ferramenta para a mitigação de mudanças climáticas e conservação de biodiversidade. Essas duas medidas podem ser aliadas, de acordo com a teoria de biodiversidade e funcionamento de ecossistemas (BEF, do inglês: biodiversity and ecosystem functioning), segundo a qual a diversidade pode favorecer funções do ecossistema, como a produtividade primária. Entretanto, a maior parte dos estudos de BEF até muito recentemente focaram em campos de gramíneas e não em ecossistemas tão complexos quanto florestas tropicais. É necessário entender tanto processos acima quanto abaixo do solo pelos quais a biodiversidade atua no funcionamento de ecossistemas. Este trabalho teve como objetivo verificar o efeito da riqueza de espécies arbóreas em processes ecológicos acima e abaixo do solo. Ele se baseou em duas áreas de estudo, em Sardinilla (Panamá) e em Anhembi (Brasil). A primeira foi especialmente projetada para estudos de BEF e permitiu destrinchar efeitos da biodiversidade em funções do ecossistema. A segunda possuía parcelas com mais de cem espécies, permitindo explorar os efeitos de altos níveis de riqueza. Tanto em Sardinilla quanto em Anhembi, investigamos se a riqueza de espécies arbóreas influenciou um processo ecológico acima do solo, a interceptação de luz, bem como mecanismos que podem estar associados a ele. A riqueza de espécies aumentou a interceptação de luz pelo dossel e estimulou mecanismos como a distribuição de luz ao longo do espaço (horizontal e vertical) e tempo. Ela promoveu tanto efeito de seleção quanto de complementaridade. Na área de Anhembi, investigamos se a riqueza de espécies influenciou processes abaixo do solo relacionados ao estoque de carbono nesse compartimento. A riqueza no dossel aumentou a produção e o estoque de raízes finas. Número de espécies do dossel teve efeito não linear sobre taxas de decomposição e estoque de serapilheira. A riqueza do conteúdo da serapilheira, contudo, não influenciou sua decomposição. O número de espécies do dossel também não influenciou a produção de serapilheira. As diferenças de produção e estoque de serapilheira e de produção de raízes finas, entre diferentes níveis de riquezas, não se alteraram ao longo do tempo. Contudo, o número de espécies arbóreas promoveu maior distribuição de raízes finas em diferentes camadas do solo. Concluímos que elevados níveis de riqueza não saturaram alguns processes ecológicos estudados. A diversidade foi capaz de atuar em processos tanto acima quanto abaixo do solo, por vários meios, muitas vezes em sentidos opostos, contando com feedbacks multidirecionais. É muito importante entender esses mecanismos para potencializar a conservação da biodiversidade e a provisão de funções ecossistêmicas, no processo de restauração de florestas tropicais, em um contexto internacional de necessidade de mitigação de mudanças climáticas. Estudos futuros devem focar em efeitos da diversidade em processos abaixo do solo (que são os menos abordados em estudos até o momento), em entender como altos níveis de diversidade podem afetar a regeneração natural em florestas e em explorar os atributos funcionais apresentados por cada espécie.
46
Oliveira, Tânia Sofia Moreira de Paiva de Almeida. "Models to support eucalyptus plantations management under a changing environment". Doctoral thesis, ISA/UL, 2015. http://hdl.handle.net/10400.5/9270.
Testo completoAbstract (sommario):
Doutoramento em Engenharia Florestal e dos Recursos Naturais - Instituto Superior de AgronomiaThe objective of this work was the development of a tool to support eucalyptus stands management with the capacity of predicting forest development under different management options, thus providing forest managers with useful information in the form of variable outputs with interest for forest management. The tool uses the 3-PG model as the basis for growth predictions so that it can be used under a changing climate. The first thing to be done was the improvement of the crown ratio equation, taking advantage of the great amount of available data. With more precise equations, new values of biomass where estimated and a new set of aboveground biomass equations was developed. Biomass values are not only an important model output, but also a vital piece in the hybridization of the GLOBULUS growth and yield model and the 3-PG whole stand process based model. The linkage of the models resulted in a hybrid model with more detailed outputs that were further complemented with a diameter distribution model. The 3-PG fertility ratio is an important parameter of the model, but is estimated in a subjective way. The improvement with an equation that predicts it from soil characteristics is important not also because it is a flaw that is recurrently appointed to the model, but also because it will allow it to be sensible to fertilizations
FCT
47
Sesbou, Abdessadeck. "Stratégie de développement des plantations d' Eucalyptus camaldulensis au Maroc". Bordeaux 1, 1990. http://www.theses.fr/1990BOR10596.
Testo completoAbstract (sommario):
Ce travail fait le point sur l'état actuel concernant les plantations d'eucalyptus camaldulensis au Maroc et propose une stratégie du développement de ces plantations. La première partie décrit l'état actuel : 1) la ressource forestière, tant du point de vue surfaces, volumes et production biologique actuels que des possibilités d'évolution ; 2) les techniques et pratiques sylvicoles utilisées dans le cas d'eucalyptus camaldulensis en les replaçant dans le contexte historique ; 3) les utilisations industrielles ou artisanales en partant de l'utilisation papetière très majoritaire jusqu'a l'intérêt mellifère non négligeable pour les plantations locales. La deuxième partie constitue un bilan exhaustif de toutes les recherches menées jusqu'ici sur eucalyptus camaldulensis tant au Maroc qu'à l'étranger. Elle comporte 3 domaines : 1) la sylviculture où sont présentés essentiellement des travaux sur l'amélioration génétique et les techniques culturales (préparation du sol, fertilisation, myccorhization, traitement en futaie ou en taillis, densités de plantations, éclaircies, despressages. . . ); 2) la valorisation du bois qui concerne les propriétés du bois intéressantes pour une utilisation papetière (densité du bois, rendement papetier, longueur des fibres, taux d'écorce) ou en bois d'oeuvre (retrait et collage, contraintes de croissance, durabilité, couleur, fibre torse et défaut du kino) ; 3) la recherche de procédés de transformation: déroulage, tranchage, composites bois-ciment,. . . Dans une troisième partie, une esquisse d'une proposition de stratégie de développement des plantations d'eucalyptus camaldulensis à partir de l'analyse et des recherches présentées dans les deux premières parties. Elle est basée sur l'amélioration génétique par voie clonale avec prise en compte de la qualité du bois en fonction des utilisations
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Howe, Chris. "Ground-dwelling vertebrate communities in remnant vegetation within Bluegum plantations". Thesis, Howe, Chris (2008) Ground-dwelling vertebrate communities in remnant vegetation within Bluegum plantations. Honours thesis, Murdoch University, 2008. https://researchrepository.murdoch.edu.au/id/eprint/32596/.
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Delle, James A. "A Spatial Analysis of Sugar Plantations on St Eustatius N.A". W&M ScholarWorks, 1989. https://scholarworks.wm.edu/etd/1539625500.
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Bergman, Stephanie. "Building Freedom: Nineteenth Century Domestic Architecture on Barbados Sugar Plantations". W&M ScholarWorks, 2010. https://scholarworks.wm.edu/etd/1539720281.
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