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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The edaphic and climatic effects on production and wine quality of Cabernet Sauvignon in the Lower Olifants River region

Bruwer, Rachel Jacoba 03 1900 (has links)
Thesis (MScAgric (Viticulture and Oenology))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Cabernet Sauvignon is the most planted red cultivar in South Africa and the second most planted red cultivar in the Olifants River region. The cultivar is prone to vigorous growth with low yields. Excessive irrigation could accentuate these cultivar characteristics. Considering the foregoing, the aim of the study was to describe how Cabernet Sauvignon will react to climate, soil type (texture) and irrigation within the Lower Olifants River wine region to enable growers to make the right decisions regarding long term as well as short term cultivation practices. This study is part of a project carried out by the ARC Infruitec-Nietvoorbij at Stellenbosch to determine the effects of soil type and atmospheric conditions on yield and wine quality of Cabernet Sauvignon in different grape growing regions of South Africa. Similar studies are being carried out in the Orange River, Stellenbosch and Swartland regions of South Africa. The Lower Olifants River region could be divided into three climatic regions. Furthermore, two climatic regions is evident regarding the formation of grape wine colour and aromas. Proximity to the Atlantic Ocean would play an important role in a cultivar establishment policy. The variation in stem water potential (ΨS) could be related to soil water status expressed in terms of matric potential (ΨM). In the case of sandy soils, ΨS decreased substantially more as the ΨM decreased compared to the sandy loam soils. The reason could be that the unsaturated hydraulic conductivity in sandy soils decreased more rapidly as the ΨM decreased compared to the heavier soils. Thus could explain why the grapevines in the sandy soils experienced more water stress than the ones in the sandy loam soils at a given ΨM. Climate had a strong influence on grapevine water status with grapevines nearer to the ocean experiencing less water stress compared to the ones further inland. This was especially true for grapevines in the sandy soils. Vegetative growth and yield of grapevines in the sandy soils were more sensitive to water deficits compared to the ones in the sandy loam soils. For deficit irrigated grapevines in the sandy soils, vegetative growth and yield decreased by ca. 30% when ca. 55% less water was applied from flowering to harvest. Yield reduction were ca. 15% with no or very little influence on vegetative growth with ca. 80% reduction in water applied from flowering to harvest for grapevines in the sandy loam soils. The influence of soil texture on wine quality and style were evident under intensive irrigation as well as over different climatic regions. Overall sensorial potential wine quality of grapevines in sandy soils tended to be higher compared to the ones in the sandy loam soils. Deficit irrigation tended to increase wine colour intensity, irrespective of soil texture. Furthermore, deficit irrigation in sandy loam soils tended to increase wine fullness and the berry characteristics of the wine. Berry characteristics of wines from the sandy soils tended to be higher compared to the ones from the sandy loam soils. Too severe water deficits in sandy soils could be detrimental to wine quality. Climate tended to have an influence on wine style of grapevines in the sandy soils with wines produced further away from the ocean tended to have higher berry characteristics. Irrigation management could be a powerful tool to manipulate the grapevine in sandy soils. For grapevines the sandy loam soils in addition to regulated deficit irrigation, additional canopy management practices could be needed to improve wine quality. / AFRIKAANSE OPSOMMING: Cabernet Sauvignon is die mees aangeplante rooidruif kultivar in die Suid-Afrikaanse wynbedryf. In die Olifantsriver streek is dit naas Shiraz, die tweede mees aangeplante rooidruif kultivar. Cabernet Sauvignon is bekend as ‘n groeikragtige skaamdraer. Indien oorbesproei word, kan hierdie potensiële nadelige eienskappe nog meer na vore tree. Die doel van die studie is om die invloed van die klimaat, grond en besproeiing op Cabernet Sauvignon se vegetatiewe groei, produksie en wyngehalte in die Benede Olifantsrivier streek te bepaal. Hierdie inligting kan produsente help om ingeligte kortsowel as langtermyn besluite te maak rakende die verbouing van Cabernet Sauvignon. Hierdie studie vorm deel van ‘n breër studie in die Suid-Afrikaanse wynbedryf, gedryf deur die Landbou Navorsingsraad (LNR) Infruitec-Nietvoorbij, Stellenbosch om die invloed van atmosferiese toestande en grond op die produksie en wyngehalte van Cabernet Sauvignon te bepaal. Soortgelyke projekte word uitgevoer in die Oranjerivier, Stellenbosch en Swartland wynstreke. Die Benede Olifantsrivier streek kan verdeel word in drie klimaatstreke op grond van temperatuurdata. In terme van die ontwikkeling van druifkleur en aromas, kan die streek verdeel word in twee klimaatstreke. Die afstand vanaf die Atlantiese Oseaan kan ‘n belangrike rol speel in die ontwikkeling van ‘n kultivarriglynplan vir die streek. Grondwaterstatus, uitgedruk as die matrikspotensiaal (ΨM), kan aanleiding gee tot variasie in middag blaarwaterpotensiaal (ΨS) lesings. Die ΨS van die sand gronde verlaag vinniger soos die ΨM verlaag invergelyke met die sandleem gronde. Dit kan moontlik wees as gevolg van die verskil in die grond onversadigde hidroliese konduktiwiteit. Sand gronde se hidroliese konduktiwiteit verlaag vinniger soos die ΨM verlaag, invergelyke met sandleem gronde. Dit verklaar waarom wingerde in sand gronde by dieselfde ΨM, meer waterspanning ondervind as wingerde in sandleem gronde. Klimaat het ‘n invloed op die waterstatus van die wingerdstok. Wingerde nader aan die see het minder waterspanning ondervind invergelyke met wingerde wat verder in die binneland geleë is. Dit was veral die geval met wingerde in die sand gronde. Vegetatiewe groei en produksie van wingerde in die sand gronde is meer sensitief vir waterspanning as wingerde in die sandleem gronde. Tekortbesproeiing in die sand gronde het die groei asook produksie met ongeveer 30% verlaag deur ongeveer 55% minder water toe te dien vanaf blom tot oes. In teenstelling daarmee is die produksie van wingerde in die sandleem gronde met ongeveer 15% verlaag met geen tot baie min verlaging in die groeikrag. Ongeveer 80% minder water is toegedien vanaf blom tot oes. Grondtekstuur kan wyngehalte en -styl beïnvloed ten spyte van intensiewe besproeiing en klimaatsverskille. Sensoriese potensiële wyngehalte van wingerde in die sand gronde was beter invergelyke met dié van die sandleem gronde. Die wyne vanaf die sand gronde het ook geneig om oor meer bessie intensiteit te beskik as wyne vanaf die sandleem gronde. Tekortbesproeiing neig om die wynkleur intensiteit te verhoog, ongeag van grondtekstuur. Tekortbesproeiing in die sandleem gronde kan ook die volheid van die wyne verbeter, asook die bessie intensiteit van die wyn verhoog. Te hoë waterspanning in die sand gronde kan wyngehalte nadelig beïnvloed. Klimaat kan ook die wynstyl vanaf sand gronde beïnvloed met wyne verder vanaf die see wat oor meer bessie intensiteit beskik as wyne nader aan die see. Beheerde tekortbesproeiing kan as ‘n kragtige hulpmiddel gebruik word om wingerde in die sand gronde te manipuleer. Vir wingerde in die sandleem gronde, addisioneel tot beheerde tekortbesproeiing en normale loofbestuurspraktyke, kan ekstra loofbestuurspraktyke bv. die verwydering van sylootlote, dalk nodig wees om wyngehalte te verbeter.
12

The effect of within-vineyard variability in vigour and water status on carbon discrimination in Vitis vinifera L. cv Merlot

Rossouw, Gerhard C. 03 1900 (has links)
Thesis (MScAgric (Viticulture and Oenology))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: Within-vineyard variability in vigour and water status commonly occurs in South African vineyards. Different soil types found over short distances are probably the main cause of vigour variability, while differences in grapevine water status are commonly induced by lateral water flow in the vineyard, blocked irrigation emitters and differences in soil water-holding capacity. These factors can cause heterogeneous ripening and differences in fruit quality between different parts of the vineyard, an aspect that needs to be avoided as far as possible in order to produce quality wines. Measurements of carbon isotope discrimination (CID) have proved to be a tool to assess grapevine physiology in order to study the effects of environmental parameters on leaf carbon dioxide (CO2) gas exchange and stomatal conductance (gs). Grapevine water deficit stress/strain in reaction to these environmental conditions can then be determined by observing the amount of 13C absorbed by plant material after discrimination of 13C has taken place, and this is influenced by the grapevine stress condition and can indicate water-use efficiency. In this study, the variability of grapevine water status and vigour was determined in order to quantify these parameters in different parts of the vineyard. Two separate trials were conducted, the first at Wellington, South Africa, where different irrigation regimes resulted in variability in grapevine water status between plots. The second trial was at Stellenbosch, South Africa, where plots were divided among different vigour classes and irrigation was applied in different quantities for different irrigation treatments. Within-vineyard variability in water status (Wellington and Stellenbosch) and vigour (Stellenbosch) were then quantified and the effects on some grapevine physiological parameters and berry composition were measured. The treatments in the Wellington trial led to differences in grapevine water status, which could be quantified by measurements of stem water potential (SWP) and leaf water potential (LWP). Soil variability also led to differences in grapevine vigour, which were quantified by measurements of pruning mass, leaf area and shoot length. The effect of the variability in grapevine water status on grapevine physiology was assessed by measuring CID, which was the main focus of the study. Other physiological measurements, such as gs and leaf and canopy temperature, were also conducted. The effect of these conditions on grape berry composition was also studied. In the Stellenbosch trial, soil water content, plant water status measurements (SWP, predawn LWP and LWP), physiological measurements (CID and gs) and berry size measurements were used to classify plots into water status treatments (“wet” and “dry” treatments). The effect of vigour differences was analysed separately from these treatments by using pruning mass as a covariate in the statistical analyses. The effect of vigour variability on the measurements was studied by looking at the effect of the covariate on the measurements, while shoot growth rate, shoot length and leaf area measurements were conducted as vegetative growth measurements. Differences in measurements were then studied between the treatments and between the vigour levels of the different plots. In the Wellington trial, plant water status was determined by irrigation, showing increased stress for treatments that received less irrigation. The differences in plant water status then caused differences in grapevine physiology between the treatments, leading to increased gs for increased irrigation. This of course influenced leaf internal CO2 and therefore CID, although CID was also clearly influenced by berry development. Berry size was influenced by irrigation, with larger berries found in wetter treatments, while berry chemical composition was influenced by the irrigation regime, with increased irrigation leading to increased pH and leading to trends showing increased total soluble solids and malic acid, and reduced total and tartaric acid and colour intensity. In the Stellenbosch trial, plots with higher vigour had increased shoot growth rate, longer shoots and increased leaf area, although topping influenced this. Wet treatment vines also showed slightly longer shoots and larger leaf areas. There were differences in soil water content between the wet and dry treatments, and this led to differences in plant water status. Vigour also influenced pre-dawn LWP, especially in the 2007 season, as higher-vigour vines struggled more to rehydrate through the night. Differences in plant water potential led to differences in grapevine physiology, with increased gs for vines from the wet treatment, while higher-vigour vines had slightly increased gs. The differences in gs led to gas exchange differences and therefore differences in CID, meaning that water status and vigour influenced CID. CID measurements illustrated the long term effect of water status on plant physiology, while measurements such as SWP illustrated the short term effects. CID measurements therefore proved to be accumulative over the season, in contrast to SWP measurements that were much more dependent on the current state of grapevine water status. Other physiological measurements showed that wet-treatment vines had higher photosynthetic rates and evapotranspiration and lower leaf temperatures, while higher-vigour vines had slightly increased evapotranspiration and decreased leaf temperatures. Wet-treatment vines had larger berries, while a higher vigour also led to slightly larger berries. Berry composition was influenced by treatment, where wet-treatment vines had increased pH and total soluble solids, while higher-vigour vines had increased juice pH and, in the 2008 season, decreased total soluble solids. Extremely stressed conditions did not show significant effects on plant water potential, but SWP measurements indicated slightly higher stress for the extremely stressed vines and LWP showed slightly less stressed conditions for these vines. Measurements of gs showed slightly lower values for the extremely stressed vines, while measurements of CID showed large significant differences, with the extremely stressed vines having measurements showing high stress. The measurement therefore indicated highly stressed conditions accurately, while other physiological measurements, such as photosynthetic rate, evapotranspiration and leaf temperatures, only showed trends and no significant differences. Measurements of stomatal conductance reacted to plant water status measurements throughout the diurnal measurement days, while CID only reacted slightly with gs changes during these days and was perhaps influenced more by berry chemical composition and development at this early stage of the season. Vigour and water status therefore influenced grapevine physiology, with a more direct effect by water status and an indirect effect by vigour due to microclimatic differences. This also influenced berry composition and therefore quality. In future studies, CID measurements should be done on juice from which organic acids have been removed in order to eliminate the effect of seasonal berry composition on the measurement. Measurements of CID proved to be an integrative, but sensitive, indicator of grapevine stress, especially at the end of the season. It might at best be useful as a post-harvest management tool for producers or grape buyers, especially for irrigation control, as has also been stated by Van Leeuwen et al. (2007). / AFRIKAANSE OPSOMMING: Binne-wingerd variasie in groeikrag en waterstatus is algemeen in Suid-Afrikaanse wingerde. Verskillende grondsoorte wat na aan mekaar voorkom, is seker een van die vernaamste oorsake van variasie in groeikrag, terwyl verskille in wingerdwaterstatus algemeen deur laterale watervloei in die wingerd, verstopte besproeiingspuite en verskille in grond waterhouvermoë geïnduseer word. Hierdie faktore kan aanleiding gee tot heterogene rypwording en verskille in vrugkwaliteit tussen verskillende dele van die wingerd, ‘n aspek wat so ver moontlik vermy moet word om kwaliteitwyne te kan produseer. Die meting van koolstof-isotoopdiskriminasie (KID) is bewys om as gereedskap te kan dien vir die assessering van wingerdfisiologie om die effekte van omgewingsparameters op blaar koolstofdioksied (CO2) - gasuitruiling en stomatale geleiding (gs) te bestudeer. Die stres/stremming as gevolg van ‘n watertekort in die wingerd in reaksie op hierdie omgewingstoestande kan dan bepaal word deur te kyk na hoeveel 13C deur die plantmateriaal geabsorbeer word ná 13C-diskriminasie plaasgevind het, en dít word deur die wingerdstrestoestande beïnvloed en kan ‘n aanduiding verskaf van die doeltreffendheid van waterverbruik. In hierdie studie is die variasie in wingerdwaterstatus en groeikrag bepaal om hierdie parameters in verskillende dele van die wingerd te kwantifiseer. Twee afsonderlike proewe is uitgevoer, die eerste by Wellington, Suid-Afrika, waar verskillende besproeiingsregimes gelei het tot verskille in die wingerdwaterstatus tussen persele. Die tweede proef was by Stellenbosch, Suid-Afrika, waar persele tussen verskillende groeikragklasse verdeel is en besproeiing in verskillende hoeveelhede vir verskillende besproeiingsbehandelings toegepas is. Binne-wingerd variasie in waterstatus (Wellington en Stellenbosch) en groeikrag (Stellenbosch) is toe gekwantifiseer en die effekte op sekere wingerd-fisiologiese parameters en korrelsamestelling is gemeet. Die behandelings in die Wellington-proef het gelei tot verskille in wingerdwaterstatus, wat deur metings van stamwaterpotensiaal (SWP) en blaarwaterpotensiaal (BWP) gekwantifiseer kon word. Grondverskille het ook gelei tot verskille in wingerdgroeikrag, wat deur metings van snoeimassa, blaaroppervlak en lootlengte gekwantifiseer is. Die effek van die variasie in wingerdwaterstatus op wingerdfisiologie is deur metings van KID bepaal wat die hooffokus van hierdie studie was. Ander fisiologiese metings, soos gs en blaar- en lowertemperatuur, is ook gedoen. Die effekte van hierdie toestande op die samestelling van die druiwekorrels is ook bestudeer. In die Stellenbosch-proef is grondwaterinhoud, metings van plantwaterstatus (SWP, voorsonopgang SWP en BWP), fisiologiese metings (KID en gs) en metings van korrelgrootte gebruik om die persele in waterstatusbehandelings (“nat” en “droë” behandelings) te verdeel. Die effek van verskille in groeikrag is apart van hierdie behandelings geanaliseer deur snoeimassa as ‘n kovariaat in die statistiese analises te gebruik. Die effek van groeikragvariasie op die metings is bestudeer deur ondersoek in te stel na die effek van die kovariaat op die metings, terwyl lootgroeitempo-, lootlengte- en blaaroppervlakmetings as metings van vegetatiewe groei uitgevoer is. Verskille in metings tussen die behandelings en tussen die groeikragvlakke van die verskillende persele is toe bestudeer. In die Wellington-proef is plantwaterstatus deur besproeiing bepaal, met verhoogde stres in behandelings waar daar minder besproeiing toegedien is. Die verskille in plantwaterstatus het dan verskille in wingerdfisiologie tussen die behandelings veroorsaak, wat gelei het tot ‘n verhoogde gs in die geval van verhoogde besproeiing. Dit het natuurlik ‘n effek op die interne CO2 van die blaar en dus op KID gehad, hoewel KID ook duidelik deur korrelontwikkeling beïnvloed is. Korrelgrootte is deur besproeiing beïnvloed, met groter korrels in die natter behandelings, terwyl die chemiese samestelling van die korrel deur besproeiingsregime beïnvloed is. Verhoogde besproeiing het pH verhoog en gelei na tendense wat verhoogde totale oplosbare vaste stowwe en appelsuur, en verminderde totale suur, wynsteensuur en kleurintensiteit getoon het. In die Stellenbosch-proef het persele met hoër groeikrag ook verhoogde lootgroeitempo, langer lote en verhoogde blaaroppervlak getoon, hoewel dit deur top beïnvloed is. Wingerdstokke van die nat behandeling het ook effe langer lote en groter blaaroppervlakke getoon. Daar was verskille in grondwaterinhoud tussen die nat en droë behandelings en dit het verskille in plantwaterstatus veroorsaak. Groeikrag is ook deur voor-sonopgang BWP beïnvloed, veral in die 2007-seisoen, aangesien stokke met hoër groeikrag meer gesukkel het om in die nag te rehidreer. Verskille in plantwaterpotensiaal het gelei tot verskille in wingerdfisiologie, met ‘n verhoogde gs vir stokke in die nat behandeling, terwyl stokke met hoër groeikrag ‘n effens verhoogde gs getoon het. Die verskille in gs het gelei tot verskille in gasuitruiling en dus verskille in KID, wat beteken dat waterstatus en groeikrag ‘n invloed op KID het. KID was meer verteenwoordigend van die langtermyneffekte van water status op plantfisiologie, terwyl metings soos SWP die korttermyneffekte weerspieël het. KID metings was dus akkumalatief oor die seisoen, terwyl SWP metings meer ‘n weerspieëling was van die huidige toestand van plantwaterpotensiaal. Ander fisiologiese metings het getoon dat stokke in die nat behandeling ‘n hoër fotosintesetempo en evapotranspirasie sowel as laer blaartemperature ondervind het, terwyl die stokke met hoër groeikrag effe verhoogde evapotranspirasie en verminderde blaartemperature getoon het. Stokke in die nat behandeling het groter korrels gehad, terwyl hoër groeikrag ook effens groter korrels veroorsaak het. Korrelsamestelling is deur die behandelings beïnvloed, met stokke in die nat behandeling wat verhoogde pH en totale oplosbare vaste stowwe getoon het, terwyl stokke met hoër groeikrag verhoogde pH van die sap en verminderde totale oplosbare vaste stowwe (laasgenoemde in die 2008-seisoen) gehad het. Uitermate toestande van stres het geen beduidende effekte op plantwaterpotensiaal getoon nie, hoewel SWP-metings effens hoër stres vir die uitermate gestresde wingerde getoon het en BWP effens minder gestresde toestande vir hierdie stokke getoon het. Metings van gs het effens laer waardes vir die uitermate gestresde stokke getoon, terwyl metings van KID groot noemenswaardige verskille getoon het, met die metings vir die uitermate gestresde wingerde wat hoër stres aangedui het. Dié meting het dus hoogs gestresde toestande akkuraat aangedui, terwyl ander fisiologiese metings, soos tempo van fotosintese, evapotranspirasie en blaartemperature net tendense en nie beduidende verskille aangedui het nie. Metings van stomatale geleiding het dwarsdeur die dae waarop daaglikse metings gedoen is op plantwaterstatusmetings gereageer, terwyl KID net effens met gs-veranderinge op hierdie dae gereageer het en moontlik meer deur die chemiese samestelling en ontwikkeling van die korrel in hierdie vroeë stadium van die seisoen beïnvloed is. Groeikrag en waterstatus het dus wingerdfisiologie beïnvloed, met ‘n meer direkte effek deur waterstatus en ‘n indirekte effek deur groeikrag as gevolg van mikroklimaatsverskille. Dit het ook korrelsamestelling en dus kwaliteit beïnvloed. In toekomstige studies moet KID-metings gedoen word op sap waarvan die organiese sure verwyder is om die effek van seisoenale korrelsamestelling op die meting uit te sluit. Metings van KID is getoon om ‘n integrerende, maar gevoelige, aanduider van wingerdstres te wees, veral aan die einde van die seisoen. Dit is ten beste miskien bruikbaar as naoesbestuursgereedskap vir produsente of druiwekopers, veral vir besproeiingsbeheer, soos ook reeds deur Van Leeuwen et al. (2007) aangedui is.
13

Šešupės tvenkinio Marijampolėje aplinkosauginės būklės pagerinimas / Improvement of the environmental condition of the Šešupė pond in Marijampolė

Nagrockienė, Erika 21 June 2013 (has links)
Magistro baigiamojo darbo tikslas – išanalizuoti Šešupės tvenkinio būklės situaciją ir būklės gerinimo kryptis, bei ištirti investicinių projektų galimybes vandens telkinio būklei pagerinti. Šiame darbe yra nagrinėjama Šešupės tvenkinio aplinkosauginė būklė ir tiriamos investicinių projektų galimybės Šešupės tvenkinio būklei pagerinti. Tyrimai atlikti Šešupės tvenkinyje 2012 metais gegužės ir spalio mėn. Imti mėginiai vandens tyrimams iš trijų skirtingų vietų ir išanalizuoti aplinkotyros laboratorijoje. Atliekant vandens cheminės būklės tyrimus analizuoti šie vandens būklės rodikliai: PO-P4, Skendinčios medžiagos, Permanganato indeksas, Pb, pH, O2, N-NH4, N-NO2, N-NO3, Nb, BDS7. Tyrimams panaudoti duomenys gauti prieš tvenkinio tvarkymą ir prasidėjus rekonstrukcijai. Tyrimų metu nustatyta, kad vandens cheminė būklė ženkliai nepakito. Didžiausi vandens cheminės būklės pakitimai rasti nustatant bendrą azotą, kuris parodo vandens būklės pablogėjimą. Išaiškintos priežastys, dėl kurių atsirado vandens cheminės būklės pakitimai. Taip pat buvo nagrinėjamas geriausio scenarijaus pasirinkimas alternatyvų analizės būdu. Šiame projekte geriausias sprendimas pasirenkamas atlikus daugiakriterinę alternatyvų analizę. / The aim of this master's final paper is to analyze the condition of the Šešupė pond and the directions for improvement of this condition and also to study the possibility to implement investment projects for improvement of the condition of the pond. This paper analyzes the environmental condition of the Šešupė pond and studies the possibility to implement investment projects for improvement of the condition of the Šešupė pond. Analyses were conducted in the Šešupė pond during the period from May to October 2012. Water samples for the analyses were collected at three different places of the pond and analyzed in an environmental science laboratory. The analysis of water chemical status included the following water status indicators: PO-P4, materials in suspension, permanganate index, Pb, pH, O2, N-NH4, N-NO2, N-NO3, Nb, BDS7. Data used for the analyses were obtained before reconstruction of the pond and at the beginning of reconstruction. The analysis has shown that the water chemical status has not changed significantly. The most significant changes of the water chemical status were found during the analysis of total nitrogen which is the indicator of water status deterioration. The reasons of the changes of the water chemical status were clarified. Also I have studied the selection of the best scenario through the analysis of the alternatives. The best solution in this project is selected after multi-criteria analysis of the alternatives.
14

ヒノキの樹幹および枝の直径日変化と水分生理状態

上田, 正文, UEDA, Masafumi 12 1900 (has links) (PDF)
農林水産研究情報センターで作成したPDFファイルを使用している。
15

Granulat på konstgräsplaner i Gävle kommun : Miljöpåverkan vid spridning via dagvattensystem

Norell, Lina, Sundqvist, Josefine January 2018 (has links)
Konstgräsplaner kan beaktas som en betydande utsläppskälla av mikroplaster. Fyllnadsmaterialet som används på konstgräsplaner kallas granulat och går under definitionen mikroplast. De som används främst på den svenska marknaden är SBR, TPE, EPDM och R-EPDM. Granulatet sprids främst via dagvattnet från konstgräsplaner som då riskerar att hamna i närliggande vattendrag. Tidigare studier har påvisat att granulatet kan urlaka toxiska ämnen som riskerar att förorena vattendragen. Vattenlevande organismer kan misstolka små partiklar som föda, vilket kan ge konsekvenser som bland annat förstoppning och svält. Ämnena som kan urlaka tillhör samlingsnamnet miljögifter och är stabila, toxiska, reproduktionsstörande och ackumulerande. Syftet med denna studie är att ge en beskrivning av vilka fyllnadsmaterial som används på konstgräsplaner i Gävle och undersöka hur dessa partiklar kan spridas samt identifiera åtgärdsförslag för att minska spridningen. Syftet är också att redovisa konstgräsplanernas dagvattenutlopp och vattendragens status för att redogöra för den potentiella miljöpåverkan som granulatet kan ge upphov till. Metoderna som använts i arbetet är litteraturstudie, personlig kommunikation, fältobservationer, kartsystem och figurer samt vattenprov.   Gavlefastigheter äger fem konstgräsplaner i Gävle kommun, vilka är Träffen IP, Gavlevallen, Nynäs IP, Sörby IP och Andersberg. På dessa planer används SBR- TPE- och R-EPDM-granulat. På planområdet förekommer dagvattenbrunnar och granulatet kan spridas till dessa genom ytavrinning vid höga regnflöden, snöplogning och smältvatten samt att spelarna får med sig partiklarna från planen. De flesta planer har dräneringssystem kopplat till dagvattenledningar som kan sprida urlakande ämnen till vattendrag. Dagvattenledningarna har utlopp i Testeboån, Bäckebrobäcken, Gavleån och Hemlingbybäcken. Granulatets fysikaliska egenskaper är en betydande roll om partikeln sedimenterar till botten eller om den kan transporteras med vattendraget. De konstgräsplaner som främst är i behov av åtgärder för att minska spridningen av granulat är Sörby, Anderberg och Nynäs.   Vattendragens statusklassning uppnår ej god kemisk status och ämnen som förekommer i förhöjda halter varierar beroende på vattendrag. Enligt tidigare studier kan flera av dessa ämnen urlaka från granulatet, vilket innebär att det finns en risk för ett tillskott av dessa ämnen om spridning sker. / Artificial turfs have been shown to be a significant source of microplastics. The filling material used on artificial turf is called granules and are under the definition microplastic. There are different kinds of granules on the Swedish market, these are SBR, TPE, EPDM and R-EPDM. The granules spread mainly through stormwater from artificial turf, which may then end up in nearby streams. Previous studies have shown that the granules can release toxic substances that risk contaminating the water. Aquatic organisms can misinterpret microscopic particles as food, which can cause consequences such as constipation and starvation. The substances that may leach from the granules belongs to the collective name environmental toxins and are stable, toxic, reproductive and accumulative.   The purpose of this study is to provide a description of the filling material that are used in artificial turfs in Gävle, investigate how these granules can spread and then identify suggestions to reduce the spread. The purpose is also to present the artificial turf's stormwateroutlets and water status to describe the potential environmental impact that the granulate may cause. The methods used in this work are literature studies, personal communication, field observations, map systems and figures and water samples.   Gavlefastigheter owns five artificial turfs in the municipality of Gävle which are Träffen IP, Gavlevallen, Nynäs IP, Sörby IP and Andersberg. These turfs use SBR- TPE and R-EPDM granules. There are open water wells on every turf area and granules can spread to these by surface water at intensive rain, snow plowing and meltwater and with the players when they leave the turf. Most turfs have drainage systems connected to stormwater pipelines that can spread leachable substances to water. The water pipelines have outlets in Testeboriver, Bäckebrostream, Gavleriver and Hemlingbystream. The physical properties of the granules have a significant effect if the particle sinks to the bottom or if it is transported along with the water. The artificial turfs that are primarily in need of taking actions to reduce the spread of granules are Sörby, Anderberg and Nynäs.   The waters do not achieve good chemical status and substances that occur at high concentrations varies depending on the kind of water. According to previous studies, several of these substances may leach from the granules which means that there is a risk of a contribution of these substances if spreading occurs.
16

Aquisição do carbono e atividade fotoquímica em sistemas de restauração ecológica com estrutura e diversidade de espécies contrastantes

Bertholdi, Angelo Albano da Silva. January 2019 (has links)
Orientador: Luiz Fernando Rolim de Almeida / Resumo: A implantação de sistemas de restauração possibilita o restabelecimento da estrutura e funcionamento de ecossistemas degradados. Além disso, alta diversidade taxonômica e funcional dos sistemas de restauração garante a performance e estabilidade de ecossistemas restaurados. A efetividade e monitoramento dos sistemas de restauração são quantificados por variáveis alométricas, porém, desconsideram-se variáveis relacionadas a aquisição de carbono e atividade fotoquímica. Dessa forma, o objetivo deste estudo foi o avaliar as respostas ecofisiológicas de plantas em diferentes sistemas de restauração florestal e avaliar se a capacidade de perda de água e reidratação de espécies de crescimento rápido e lento favorece o estabelecimento e desenvolvimento de sistemas de restauração com estrutura e diversidade de espécies contratantes. Portanto, avaliamos, durante um ano, variáveis relacionadas à disponibilidade de água no solo e ambiente, estrutura dos sistemas de plantio, relações hídricas, atividade fotoquímica e aquisição e acúmulo de carbono nas folhas, em 7 espécies (divididas em espécies de crescimento rápido e lento) pertencentes a três sistemas de restauração: plantio de alta diversidade, sistema agroflorestal e consórcio madeira e lenha, estes sistemas estão implantados em dois tipos de solo: Nitossolo Vermelho (Área 1 – solo argiloso) e Argissolo Vermelho Amarelo (Área 2 – solo arenoso). Os resultados indicaram que sistemas implantados na área 1 apresentaram maior eficiência ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The restoration systems implantation enables the restoration of degraded ecosystems structure and functioning. In addition, restoration systems high taxonomic and functional diversity guarantees restored ecosystems performance and stability. The restoration systems effective-ness and monitoring are quantified by allometric variables, however, variables related to carbon acquisition and photochemical activity are disregarded. Thus, the aim study was to evaluate the ecophysiological responses of plants in different forest restoration systems and to evaluate if the water loss and rehydration capacity of fast and slow growth species favors the establishment and development of systems with contracting structure and species diversity. Therefore, we evaluated, for one year, variables related to the soil and environment water availability, planting systems structure, water relations, photochemical activity and carbon acquisition in leaves, in 7 species (divided into fast and slow growth species). These systems are implanted in two soils types: fertile loamy Ultisol (Site 1) and sandy Alfisol soil (Site 2). The results indicated that systems implanted in site 1 showed higher photosynthetic efficiency and carbon accumulation during water deficiency periods. The wood and wood consortium presented lower complexity in the structure and higher photosynthetic efficiency in times with low water availability in the soil. The mixed plantation using commercial timber and firewood tree species o... (Complete abstract click electronic access below) / Doutor
17

Skånska vattenråds bidrag till att uppnå EU:s vattendirektivs mål om god vattenstatus : En kvalitativ studie av vattenråds organisationsstruktur och prioriteringar i Skåne / The Contributions of Water Councils in Scania to Achieve the Aim of the EU Water Framework Directive Regarding Good Water Status : A qualitative study of the organizational structure and prioritizations of water councils in Scania

Tangvald, Nils January 2023 (has links)
Vattenförvaltning inom EU har, enligt EU:s vattendirektiv, som mål att samtliga vattenförekomster ska uppnå god status senast 2027. Sverige är ett av de EU-länder där målet ej har uppnåtts med uppmätt icke-tillfredsställande status i en del vattenförekomster i exempelvis Skåne; en situation som inte beräknas förbättras inom tidsfristen. I Sverige styrs vattenförvaltning lokalt med kommuner och myndigheter som beslutsfattande organ i enlighet med vattenmyndighetens sexårsplan. EU:s vattendirektiv kräver inkludering av intressenter och allmänheten i förvaltningen, vilket har lett till bildandet av vattenorganisationer såsom vattenråd. Dessa har till uppgift att verka som lokalkunskap för särskilda avrinningsområden, där ett nätverk av aktörer bildas för att möjliggöra påverkan av inriktning i vattenförvaltningen. Forskning visar på samarbetsproblematik mellan aktörer i vattenråd, brist på kunskap och intresse bland allmänheten och intressenter samt fall där ekonomiska och sociala mål har prioriterats före ekologiska, vilket har försvårat implementeringen av EU:s vattendirektiv. Syftet med studien är att undersöka hur skånska vattenråd utifrån nuvarande organisationsstruktur och prioriteringar kan bidra mer i arbetet för målet om god vattenstatus enligt EU:s vattendirektiv. Studien utgick från ett strategiskt urval och semistrukturerad intervju-metodik eller fokusgrupper bestående av intervjupersoner med hög expertis. Resultatet analyserades med hjälp av följande teorier: Environmental governance, vattenförvaltning, flernivåstyre, politisk samstämmighet, social inlärningsteori samt reflektiv och reflexiv kommunikation. Studiens resultat visar att de undersökta skånska vattenråden gör vad de kan för att bidra utifrån nuvarande förutsättningar, men att finansieringsbegränsningar, extern påverkan av andra aktörer i avrinningsområdena och brist på samarbete mellan olika nivåer i vattenförvaltningen förhindrar mångas utveckling. Organisatoriskt och prioriteringsmässigt fungerar majoriteten av de undersökta vattenråden väl och visar god potential, men förbättring inom det ovannämnda hade behövts om ett närmande av EU:s vattendirektivs mål skall uppnås i lokala skånska vattenförekomster. / Water management within the EU, according to the EU Water Framework Directive (WFD), has the aim to achieve good water status in all water bodies no later than 2027. Sweden is one EU country where the aim has not been reached, with measured non-satisfactory status in numerous water bodies in Scania for example; a situation not predicted to improve before the deadline. In Sweden, water management is governed locally with municipalities and agencies as decision-makers in accordance with the six-year plan of the water agency. Since the WFD requires stakeholder and public participation, the creation of water organisations such as water councils has been conducted. These act as local knowledge bodies in certain catchment basins, creating a network of actors to enable an influence on the orientation of water management. Research has shown collaboration issues between actors in water councils, a lack of knowledge and interest amongst the public and stakeholders, and cases where economic and social aims have preceded ecological ones. These factors in turn have aggravated the implementation of the WFD. The purpose of this study is to investigate how water councils of Scania, from current organizational structure and prioritizations, have the possibility to increase their contribution towards the aim of the WFD regarding good water status. The study was conducted from a strategic selection and semi-structured interviews or focus groups, including interviewees with high expertise. The result was analyzed using the following theories: Environmental governance, water governance, multi-level governance, policy coherence, social learning and reflective as well as reflexive communication. The results of the study demonstrate a situation where water councils contribute their utmost from current capabilities, yet are prevented to develop further due to financial limitations, external impacts from other actors in catchment basins, and a lack of collaboration between different levels of water management. From an organizational and prioritization point of view, the majority of investigated water councils work well and showcase high potential, with improvements of the aforementioned needed for the approach of the WFD’s aim in local water bodies of Scania.
18

Non-contacting techniques for detecting plant drought stress in a closed environment

Yang, Yang January 2003 (has links)
No description available.
19

La construction sociale du statut juridique de l’eau : le cas du Québec et du Mexique

Vega Cardenas, Yenny 05 1900 (has links)
L’eau a longtemps été considérée comme une ressource commune non susceptible d’appropriation et accessible à tous. De nos jours, toutefois, face à l’inégale répartition de l’eau sur la planète, à l’augmentation constante de la population et à la multiplication des usages qui entraînent la surexploitation et la pollution des ressources hydriques, l’eau prend une valeur nouvelle. L’eau devient de plus en plus un enjeu stratégique, politique et commercial. En conséquence, la redéfinition du statut juridique de l’eau devient un objet de débat important. Ce débat est avant tout un débat rhétorique et une « bataille » idéologique entre des groupes qui soutiennent différentes approches et qui cherchent à obtenir le monopole de la nouvelle réalité et créer ainsi le nouveau droit. Deux grandes approches s’affrontent pour redéfinir la ressource. La première, celle qui envisage l’eau comme un bien économique, soutient que pour éviter les problèmes de gaspillage et de pollution, l’eau doit être soumise aux lois de l’offre et de la demande. La deuxième, celle qui considère l’eau comme une chose commune, non appropriable et hors commerce, soutient que la valeur d’une ressource aussi vitale que l’eau ne peut être établie par les lois du marché puisque cette alternative ne permet pas d’assurer l’accès à l’eau aux plus démunis de la société. Cette approche prône également la reconnaissance d’un droit humain à l’eau. Notre thèse tente de déterminer comment s’effectue le choix du statut juridique de l’eau, et ce, tant au Québec qu’au Mexique. Notre question de recherche est traitée selon une perspective constructiviste en vertu de laquelle le statut juridique de l’eau serait une réalité « construite » et le nouveau droit serait le résultat des luttes, des oppositions et des compromis entre les acteurs sociaux impliqués. Notre terrain d’étude est le Québec et le Mexique. En effet, ce sont des territoires intégrés économiquement par le biais de l’ALENA où l’on observe des variations importantes en termes de ressources, de prélèvements et de consommation. Au Québec, nous analysons le débat qui a eu lieu lors de la Consultation sur la gestion de l’eau au Québec (1999), notamment les discours concernant le statut de l’eau, la gestion publique/privée des services d’eau et l’exportation en vrac de la ressource. Au Mexique, nous analysons les représentations des acteurs sociaux à l’occasion de l’adoption de la Loi des eaux nationales de 1992, notamment les questions qui comportent un lien étroit avec la symbolique de l’eau. Or, nous avons remarqué que le résultat de ces constructions sociales au sein de ces territoires est complètement différent. Au Québec, on a confirmé le statut de l’eau en tant que chose commune, tandis qu’au Mexique, c’est plutôt la symbolique de l’eau en tant que bien économique qui a été adoptée dans la nouvelle législation portant sur l’eau. / Water has been considered for a long time as a common good not susceptible to appropriation and accessible to all. Nowadays, however, in front of the uneven distribution of water on the planet, the constant increase of the population and the increase of water uses which pulls the overexploitation and the pollution of water resources, water takes a new value. Indeed, it becomes more and more a strategic, political and commercial issue. Consequently, the redefining of legal status of water becomes an important object of debate. This is above all a rhetoric debate and an ideological "battle" between groups who support different approaches. Indeed, these ideologies are the fruit of different speeches conceived by social actors who have contrary interests and ideologies and that aim at having the monopoly of the new reality and creating the new law. There are two important approaches which are in confrontation. The first one, conceive water as an economic good, and considers that to avoid problems of wasting and pollution, water must be subjected to the laws of supply and demand. The second conceive water as a common good and supports that the value of a resource so vital as water cannot be established by the laws of the market, because this alternative does not allow to assure access to water to the most deprived of the society. This approach advocates the recognition of water as a human right. Our thesis aims at finding how the choice of the legal status of water is made in Quebec and in Mexico. This question will be treated according to a constructivist perspective according to which the legal status of water would be a "constructed" reality and, thus, the new law would be the result of fights, oppositions and also, compromises between the involved social actors. Our analysis covers Quebec and Mexico. In fact, those are territories economically integrated by NAFTA where we observe important variations in terms of resources, uses and consumption of water. In Quebec, we analyze the representations of different actors during the Consultation on Water Management held in 1999, and more particularly the speeches concerning the status of water, the privatization of water services and the bulk water exports. In Mexico, we analyze the representations of social actors surrounding the adoption of the National Water Law of 1992, and more particularly the questions concerning the symbolism of water. Now, we found that the result of these constructions within these territories is completely different. In Quebec, the status of water as a common good has been confirmed, whereas in Mexico, it is rather the symbolism of water as an economic good which was adopted in the new Mexican legislation. / El agua ha sido considerada por mucho tiempo como un bien común inapropiable y de libre acceso. No obstante, frente al aumento constante de la población, a la multiplicación de los diversos usos que provocan la sobreexplotación y a la contaminación de los recursos hídricos, el agua retoma un valor nuevo. Ésta es considerada cada vez más como un recurso estratégico, político y comercial. El tema de la redefinición del estatus jurídico del agua o su calificación jurídica es cada vez más importante en los debates que conciernen al manejo del agua. Al respecto, hay dos grandes enfoques que se enfrentan: el primero considera el agua como un bien económico y sostiene que para evitar los problemas de despilfarro y de contaminación, el agua debe estar sometida a las leyes de la oferta y la demanda. El segundo considera el agua como un bien común, inapropiable y fuera de comercio, este enfoque sostiene que el valor de un recurso tan vital como el agua, no puede ser establecido por las leyes del mercado ya que esta alternativa no permite asegurar el acceso al agua a los menos favorecidos de la sociedad. Este enfoque también preconiza el reconocimiento de un derecho humano al agua. Nuestra tesis pretende identificar cómo se efectúa la elección del estatus jurídico del agua, tanto en Québec como en México. Nuestra investigación tomara una perspectiva constructivista en virtud de la cual consideramos que la calificación jurídica del agua es una realidad "construida". El nuevo derecho corresponderá a las luchas, oposiciones y compromisos entre los actores sociales implicados. Tomamos como campo de investigación Québec (Canada) y México, territorios integrados económicamente por el Tratado de Libre Comercio de América del Norte (TLCAN) donde se observa variaciones importantes en términos de recursos, de usos y de consumos. En Quebec, analizamos las representaciones de los actores sociales que participaron a la consulta pública sobre la gestión del agua que tuvo lugar en (1999), más particularmente los discursos que hacen referencia a la calificación jurídica del agua, al manejo público o privado de los servicios de agua y a la exportación del recurso a grande escala. En México, analizamos los discursos de los actores sociales que hubieran podido tener alguna incidencia en el contenido de la Ley de aguas nacionales de 1992. Observaremos que el resultado de estas construcciones sociales, al interior de estos Estados es completamente diferente: en Québec, se confirmará que el agua es un bien común, mientras que en México la Ley de aguas nacionales hace de ella un bien económico.
20

La construction sociale du statut juridique de l’eau : le cas du Québec et du Mexique

Vega Cardenas, Yenny 05 1900 (has links)
L’eau a longtemps été considérée comme une ressource commune non susceptible d’appropriation et accessible à tous. De nos jours, toutefois, face à l’inégale répartition de l’eau sur la planète, à l’augmentation constante de la population et à la multiplication des usages qui entraînent la surexploitation et la pollution des ressources hydriques, l’eau prend une valeur nouvelle. L’eau devient de plus en plus un enjeu stratégique, politique et commercial. En conséquence, la redéfinition du statut juridique de l’eau devient un objet de débat important. Ce débat est avant tout un débat rhétorique et une « bataille » idéologique entre des groupes qui soutiennent différentes approches et qui cherchent à obtenir le monopole de la nouvelle réalité et créer ainsi le nouveau droit. Deux grandes approches s’affrontent pour redéfinir la ressource. La première, celle qui envisage l’eau comme un bien économique, soutient que pour éviter les problèmes de gaspillage et de pollution, l’eau doit être soumise aux lois de l’offre et de la demande. La deuxième, celle qui considère l’eau comme une chose commune, non appropriable et hors commerce, soutient que la valeur d’une ressource aussi vitale que l’eau ne peut être établie par les lois du marché puisque cette alternative ne permet pas d’assurer l’accès à l’eau aux plus démunis de la société. Cette approche prône également la reconnaissance d’un droit humain à l’eau. Notre thèse tente de déterminer comment s’effectue le choix du statut juridique de l’eau, et ce, tant au Québec qu’au Mexique. Notre question de recherche est traitée selon une perspective constructiviste en vertu de laquelle le statut juridique de l’eau serait une réalité « construite » et le nouveau droit serait le résultat des luttes, des oppositions et des compromis entre les acteurs sociaux impliqués. Notre terrain d’étude est le Québec et le Mexique. En effet, ce sont des territoires intégrés économiquement par le biais de l’ALENA où l’on observe des variations importantes en termes de ressources, de prélèvements et de consommation. Au Québec, nous analysons le débat qui a eu lieu lors de la Consultation sur la gestion de l’eau au Québec (1999), notamment les discours concernant le statut de l’eau, la gestion publique/privée des services d’eau et l’exportation en vrac de la ressource. Au Mexique, nous analysons les représentations des acteurs sociaux à l’occasion de l’adoption de la Loi des eaux nationales de 1992, notamment les questions qui comportent un lien étroit avec la symbolique de l’eau. Or, nous avons remarqué que le résultat de ces constructions sociales au sein de ces territoires est complètement différent. Au Québec, on a confirmé le statut de l’eau en tant que chose commune, tandis qu’au Mexique, c’est plutôt la symbolique de l’eau en tant que bien économique qui a été adoptée dans la nouvelle législation portant sur l’eau. / Water has been considered for a long time as a common good not susceptible to appropriation and accessible to all. Nowadays, however, in front of the uneven distribution of water on the planet, the constant increase of the population and the increase of water uses which pulls the overexploitation and the pollution of water resources, water takes a new value. Indeed, it becomes more and more a strategic, political and commercial issue. Consequently, the redefining of legal status of water becomes an important object of debate. This is above all a rhetoric debate and an ideological "battle" between groups who support different approaches. Indeed, these ideologies are the fruit of different speeches conceived by social actors who have contrary interests and ideologies and that aim at having the monopoly of the new reality and creating the new law. There are two important approaches which are in confrontation. The first one, conceive water as an economic good, and considers that to avoid problems of wasting and pollution, water must be subjected to the laws of supply and demand. The second conceive water as a common good and supports that the value of a resource so vital as water cannot be established by the laws of the market, because this alternative does not allow to assure access to water to the most deprived of the society. This approach advocates the recognition of water as a human right. Our thesis aims at finding how the choice of the legal status of water is made in Quebec and in Mexico. This question will be treated according to a constructivist perspective according to which the legal status of water would be a "constructed" reality and, thus, the new law would be the result of fights, oppositions and also, compromises between the involved social actors. Our analysis covers Quebec and Mexico. In fact, those are territories economically integrated by NAFTA where we observe important variations in terms of resources, uses and consumption of water. In Quebec, we analyze the representations of different actors during the Consultation on Water Management held in 1999, and more particularly the speeches concerning the status of water, the privatization of water services and the bulk water exports. In Mexico, we analyze the representations of social actors surrounding the adoption of the National Water Law of 1992, and more particularly the questions concerning the symbolism of water. Now, we found that the result of these constructions within these territories is completely different. In Quebec, the status of water as a common good has been confirmed, whereas in Mexico, it is rather the symbolism of water as an economic good which was adopted in the new Mexican legislation. / El agua ha sido considerada por mucho tiempo como un bien común inapropiable y de libre acceso. No obstante, frente al aumento constante de la población, a la multiplicación de los diversos usos que provocan la sobreexplotación y a la contaminación de los recursos hídricos, el agua retoma un valor nuevo. Ésta es considerada cada vez más como un recurso estratégico, político y comercial. El tema de la redefinición del estatus jurídico del agua o su calificación jurídica es cada vez más importante en los debates que conciernen al manejo del agua. Al respecto, hay dos grandes enfoques que se enfrentan: el primero considera el agua como un bien económico y sostiene que para evitar los problemas de despilfarro y de contaminación, el agua debe estar sometida a las leyes de la oferta y la demanda. El segundo considera el agua como un bien común, inapropiable y fuera de comercio, este enfoque sostiene que el valor de un recurso tan vital como el agua, no puede ser establecido por las leyes del mercado ya que esta alternativa no permite asegurar el acceso al agua a los menos favorecidos de la sociedad. Este enfoque también preconiza el reconocimiento de un derecho humano al agua. Nuestra tesis pretende identificar cómo se efectúa la elección del estatus jurídico del agua, tanto en Québec como en México. Nuestra investigación tomara una perspectiva constructivista en virtud de la cual consideramos que la calificación jurídica del agua es una realidad "construida". El nuevo derecho corresponderá a las luchas, oposiciones y compromisos entre los actores sociales implicados. Tomamos como campo de investigación Québec (Canada) y México, territorios integrados económicamente por el Tratado de Libre Comercio de América del Norte (TLCAN) donde se observa variaciones importantes en términos de recursos, de usos y de consumos. En Quebec, analizamos las representaciones de los actores sociales que participaron a la consulta pública sobre la gestión del agua que tuvo lugar en (1999), más particularmente los discursos que hacen referencia a la calificación jurídica del agua, al manejo público o privado de los servicios de agua y a la exportación del recurso a grande escala. En México, analizamos los discursos de los actores sociales que hubieran podido tener alguna incidencia en el contenido de la Ley de aguas nacionales de 1992. Observaremos que el resultado de estas construcciones sociales, al interior de estos Estados es completamente diferente: en Québec, se confirmará que el agua es un bien común, mientras que en México la Ley de aguas nacionales hace de ella un bien económico.

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