<p>En svår och ständigt aktuell fråga är hur landsbygd och glesbygd ska definieras och avgränsas. För att utföra sådana avgränsningar har en stor mängd olika definitioner och mätmetoder tagits fram. Problemet med många av dem är att de ger mycket grova och statiska indelningar och att de ibland bygger på subjektiva eller svårpreciserade kriterier. Samhällsstrukturen har förändrats, exempelvis är tillgången till bil stor idag vilket ökar tillgängligheten och tillåter att människor bosätter sig längre från arbete och service. Det i sin tur bidrar till att gränsen mellan landsbygd och tätort suddas ut och blir mer diffus. Med tanke på dagens teknik anser många att nya mer sofistikerade mätmetoder bör utvecklas, gärna metoder som nyanserar begreppen.</p><p>I det här examensarbetet introduceras och testas en ny mätmetod för befolkningsgleshet och tillgänglighet. Målet har varit en metod mycket väl lämpad för anpassning till olika skalor och som tar hänsyn till befolkningens geografiska fördelning och storlek. Tillgänglighetsfaktorn i måttet är baserad på vägnätets utsträckning vilket ger verklighetstrogna mätvärden. Till metoden valdes att utveckla ett särskilt mått, ett gleshetsindex, för att visa hur metoden på ett entydigt sätt kan användas på flera olika nivåer, exempelvis lokal och regional. Mätmetoden har testats och utvärderats med ArcGIS och nätverksanalys med aktuella demografiska data från 2008 i form av statistik för totalbefolkning. Avgränsningsområdet har varit Hudiksvalls och Nordanstigs kommuner.</p><p>Mätmetoden går i korta drag ut på att det område som ska mätas delas in i ett rutnät. Från varje ruta mäts hur många invånare som går att nå inom en bestämd sträcka längs vägnätet. Sträckan är metodens huvudvariabel och den kan anpassas efter den nivå mätningen ska utföras på, i den här studien användes 5, 10, 20 och 30 kilometer. Det uppmätta invånarantalet för varje ruta divideras med mätsträckan i kilometer och det ger måttenheten invånare per kilometer.</p><p>Mätningar utfördes med ett flertal mätsträckor och resulterade dels i en kartserie producerad med den nya mätmetoden och dels i en kartserie producerad med en annan mätmetod, baserad på befolkningsdensitet inom cirklar, för jämförelser och utvärdering. Det gleshetsindex som utvecklades fick namnet RURIX (av Rurality Index) och en kartserie producerades också för att illustrera hur mätvärden skulle kunna klassificeras enligt RURIX.</p><p>Resultaten visade att den nya mätmetoden ger bra och realistiska mätvärden över hela avgränsningsområdet. Högre mätvärden visade sig, vid alla mätsträckor, finnas främst där folk är bosatta och där vägnätet är väl utbyggt medan låga värden visade sig i glesbefolkade områden som antingen har dåligt utbyggt eller helt saknar vägnät. Resultaten från jämförelsemetoden klargjorde att enbart ett täthetsmått inte tar hänsyn till befolkningens fördelning och tillgänglighet vilket var tydligt vid mätningar på regional nivå där de högsta mätvärdena med jämförelsemetoden hamnade i otillgängliga och nästintill obefolkade skogsområden i avgränsningsområdets södra delar. En positiv och viktig egenskap för den nya mätmetoden är att den visat sig fungera mycket bra vid olika skalor och den kan därför med fördel användas för mätning på olika nivåer och för olika ändamål. Den har även stor potential att vidareutvecklas och i jämförelse med en metod som enbart mäter befolkningstäthet är fördelarna tydliga.</p> / <p>A difficult and constant concern is how to define and delimit rural and sparsely populated areas. To be able to achieve such delimitations, a wide range of definitions and measures have been produced. The problem with many of them is that they give too crude and static definitions and are sometimes based on criteria that are subjective and hard to specify. The structure of the society has changed, for example the access to cars is high, which increases the accessibility and possibility to commute and allows people to settle further away from work and services. This contributes to making the limits of rural and urban areas more diffuse. Taking into consideration the technology that is available today, new sophisticated measures should be developed to make the concept of e.g. rural more distinct.</p><p>In this thesis a new method of measurement for population sparsity and accessibility is introduced. The goal has been a method well suited for adaptation to different scales and one that takes into consideration the geographic distribution and size of the population. The accessibility factor of the method is based on the extent and spread of the road network which results in realistic population sparsity values. Directly linking to the method, a special measure, the Rurality index was developed in order to show how the method can be used at several different levels in a clear-cut way, e.g. local or regional. The method was tested and evaluated using ArcGIS and network analysis based on the 2008 census materials. The study areas were the municipalities of Hudiksvall and Nordanstig in Sweden.</p><p>The method involves a few steps. Initially, the area to be measured is divided into a grid. Then, for every cell in the grid the number of habitants within a certain distance along the road network is summarized. The distance is the method’s main variable and it can easily be adjusted according to the actual level of the measurement, in this study, 5, 10, 20 and 30 kilometers were used. Lastly, the measured population within reach of the chosen distance is divided by the distance in kilometers giving the values using the measuring unit of habitants per kilometer.</p><p>Measurements were performed using several distances and resulted in a series of maps produced with the new method, as well as a series of maps produced using a different resulting method, based on the population density within circles, for comparison and evaluation. The rurality index was given the abbreviated name RURIX (Rurality Index), and a series of maps were produced to illustrate how the measurement values could be classified using RURIX.</p><p>The results of the study showed that the new method gives good and realistic results throughout the study area. At all measurement distances the highest values could be found where people actually are settled and in areas where the road network is well extended, while lower values are focused on sparsely populated areas with a poor road network. The results of the method of comparison showed that a population density measuring alone cannot considerate the distribution of the population and accessibility. This was clearly shown in this regional level study, where the highest values were found within remote and poorly populated areas in the southern parts of the study area. A positive and important feature is that it worked well on a wide range of scales and can therefore be used with great benefit for measurements at different levels and for different purposes. The method also has potential for further development and, compared with methods that only measure population density, its advantages is clear.</p>

Wir betrachten folgende Teile: die zusätzlichen Kohlenstoff(C)-emissionen, welche aus der Umwandlung von natürlichem Umland durch Stadtwachstum resultieren, und die Änderung des C-Flusses durch 'urbanisierte' Ökosysteme, soweit atmosphärisches C durch diese in umliegende natürliche Ökosysteme entlang der Kette &ldquo;Atmosphäre -> Vegetation -> abgestorbene organische Substanzen&rdquo; gepumpt wird: d.h. C-Export; für den Zeitraum von 1980 bis 2050. Als Szenario nutzen wir Prognosen der regionalen Stadtbevölkerung, welche durch ein 'Hybridmodell' generiert werden für acht Regionen. Alle Schätzungen der C-Flüsse basieren auf zwei Modellen: das Regression Modell und das sogenannte G-Modell. Die Siedlungsfläche, welche mit dem Wachstum der Stadtbevölkerung zunimmt, wird in 'Grünflächen' (Parks, usw.), Gebäudeflächen und informell städtisch genutzte Flächen (Slums, illegale Lagerplätze, usw.) unterteilt. Es werden jährlich die regionale und globale Dynamik der C-Emissionen und des C-Exports sowie die C-Gesamtbilanz berechnet. Dabei liefern beide Modelle qualitativ ähnliche Ergebnisse, jedoch gibt es einige quantitative Unterschiede. Im ersten Modell erreicht die globale Jahresemission für die Dekade 2020-2030 resultierend aus der Landnutzungsänderung ein Maximum von 205 Mt/a. Die maximalen Beiträge zur globalen Emission werden durch China, die asiatische und die pazifische Region erbracht. Im zweiten Modell erhöht sich die jährliche globale Emission von 1.12 GtC/a für 1980 auf 1.25 GtC/a für 2005 (1Gt = 109 t). Danach beginnt eine Reduzierung. Vergleichen wir das Emissionmaximum mit der Emission durch Abholzung im Jahre 1980 (1.36 GtC/a), können wir konstatieren, daß die Urbanisierung damit in vergleichbarer Grösse zur Emission beiträgt. Bezogen auf die globale Dynamik des jährlichen C-Exports durch Urbanisierung beobachten wir ein monotones Wachstum bis zum nahezu dreifachen Wert von 24 MtC/a für 1980 auf 66 MtC/a für 2050 im ersten Modell, bzw. im zweiten Modell von 249 MtC/a für 1980 auf 505 MtC/a für 2050. Damit ist im zweiten Fall die Transportleistung der Siedlungsgebiete mit dem C-Transport durch Flüsse in die Ozeane (196 .. 537 MtC/a) vergleichbar. Bei der Abschätzung der Gesamtbilanz finden wir, daß die Urbanisierung die Bilanz in Richtung zu einer 'Senke' verschiebt. Entsprechend dem zweiten Modell beginnt sich die C-Gesamtbilanz (nach annähernder Konstanz) ab dem Jahre 2000 mit einer fast konstanten Rate zu verringern. Wenn das Maximum im Jahre 2000 bei 905MtC/a liegt, fällt dieser Wert anschliessend bis zum Jahre 2050 auf 118 MtC/a. Bei Extrapolation dieser Dynamik in die Zukunft können wir annehmen, daß am Ende des 21. Jahrhunderts die &ldquo;urbane&rdquo; C-Gesamtbilanz Null bzw. negative Werte erreicht. / We calculate the additional carbon emissions as a result of the conversion of natural land in a process of urbanisation; and the change of carbon flows by &ldquo;urbanised&rdquo; ecosystems, when the atmospheric carbon is exported to the neighboring territories, from 1980 till 2050 for the eight regions of the world. As a scenario we use combined UN and demographic model&prime;s prognoses for regional total and urban population growth. The calculations of urban areas dynamics are based on two models: the regression model and the Gamma-model. The urbanised area is sub-divided on built-up, &bdquo;green&ldquo; (parks, etc.) and informal settlements (favelas) areas. The next step is to calculate the regional and world dynamics of carbon emission and export, and the annual total carbon balance. Both models give similar results with some quantitative differences. In the first model, the world annual emissions attain a maximum of 205 MtC/year between 2020-2030. Emissions will then slowly decrease. The maximum contributions are given by China and the Asia and Pacific regions. In the second model, world annual emissions increase to 1.25 GtC in 2005, beginning to decrease afterwards. If we compare the emission maximum with the annual emission caused by deforestation, 1.36GtC per year, then we can say that the role of urbanised territories (UT) is of a comparable magnitude. Regarding the world annual export of carbon by UT, we observe its monotonous growth by three times, from 24 MtC to 66 MtC in the first model, and from 249 MtC to 505 MtC in the second one. The latter, is therefore comparable to the amount of carbon transported by rivers into the ocean (196-537 MtC). By estimating the total balance we find that urbanisation shifts the total balance towards a &ldquo;sink&rdquo; state. The urbanisation is inhibited in the interval 2020-2030, and by 2050 the growth of urbanised areas would almost stop. Hence, the total emission of natural carbon at that stage will stabilise at the level of the 1980s (80 MtC per year). As estimated by the second model, the total balance, being almost constant until 2000, then starts to decrease at an almost constant rate. We can say that by the end of the XXI century, the total carbon balance will be equal to zero, when the exchange flows are fully balanced, and may even be negative, when the system begins to take up carbon from the atmosphere, i.e., becomes a &ldquo;sink&rdquo;.

En svår och ständigt aktuell fråga är hur landsbygd och glesbygd ska definieras och avgränsas. För att utföra sådana avgränsningar har en stor mängd olika definitioner och mätmetoder tagits fram. Problemet med många av dem är att de ger mycket grova och statiska indelningar och att de ibland bygger på subjektiva eller svårpreciserade kriterier. Samhällsstrukturen har förändrats, exempelvis är tillgången till bil stor idag vilket ökar tillgängligheten och tillåter att människor bosätter sig längre från arbete och service. Det i sin tur bidrar till att gränsen mellan landsbygd och tätort suddas ut och blir mer diffus. Med tanke på dagens teknik anser många att nya mer sofistikerade mätmetoder bör utvecklas, gärna metoder som nyanserar begreppen. I det här examensarbetet introduceras och testas en ny mätmetod för befolkningsgleshet och tillgänglighet. Målet har varit en metod mycket väl lämpad för anpassning till olika skalor och som tar hänsyn till befolkningens geografiska fördelning och storlek. Tillgänglighetsfaktorn i måttet är baserad på vägnätets utsträckning vilket ger verklighetstrogna mätvärden. Till metoden valdes att utveckla ett särskilt mått, ett gleshetsindex, för att visa hur metoden på ett entydigt sätt kan användas på flera olika nivåer, exempelvis lokal och regional. Mätmetoden har testats och utvärderats med ArcGIS och nätverksanalys med aktuella demografiska data från 2008 i form av statistik för totalbefolkning. Avgränsningsområdet har varit Hudiksvalls och Nordanstigs kommuner. Mätmetoden går i korta drag ut på att det område som ska mätas delas in i ett rutnät. Från varje ruta mäts hur många invånare som går att nå inom en bestämd sträcka längs vägnätet. Sträckan är metodens huvudvariabel och den kan anpassas efter den nivå mätningen ska utföras på, i den här studien användes 5, 10, 20 och 30 kilometer. Det uppmätta invånarantalet för varje ruta divideras med mätsträckan i kilometer och det ger måttenheten invånare per kilometer. Mätningar utfördes med ett flertal mätsträckor och resulterade dels i en kartserie producerad med den nya mätmetoden och dels i en kartserie producerad med en annan mätmetod, baserad på befolkningsdensitet inom cirklar, för jämförelser och utvärdering. Det gleshetsindex som utvecklades fick namnet RURIX (av Rurality Index) och en kartserie producerades också för att illustrera hur mätvärden skulle kunna klassificeras enligt RURIX. Resultaten visade att den nya mätmetoden ger bra och realistiska mätvärden över hela avgränsningsområdet. Högre mätvärden visade sig, vid alla mätsträckor, finnas främst där folk är bosatta och där vägnätet är väl utbyggt medan låga värden visade sig i glesbefolkade områden som antingen har dåligt utbyggt eller helt saknar vägnät. Resultaten från jämförelsemetoden klargjorde att enbart ett täthetsmått inte tar hänsyn till befolkningens fördelning och tillgänglighet vilket var tydligt vid mätningar på regional nivå där de högsta mätvärdena med jämförelsemetoden hamnade i otillgängliga och nästintill obefolkade skogsområden i avgränsningsområdets södra delar. En positiv och viktig egenskap för den nya mätmetoden är att den visat sig fungera mycket bra vid olika skalor och den kan därför med fördel användas för mätning på olika nivåer och för olika ändamål. Den har även stor potential att vidareutvecklas och i jämförelse med en metod som enbart mäter befolkningstäthet är fördelarna tydliga. / A difficult and constant concern is how to define and delimit rural and sparsely populated areas. To be able to achieve such delimitations, a wide range of definitions and measures have been produced. The problem with many of them is that they give too crude and static definitions and are sometimes based on criteria that are subjective and hard to specify. The structure of the society has changed, for example the access to cars is high, which increases the accessibility and possibility to commute and allows people to settle further away from work and services. This contributes to making the limits of rural and urban areas more diffuse. Taking into consideration the technology that is available today, new sophisticated measures should be developed to make the concept of e.g. rural more distinct. In this thesis a new method of measurement for population sparsity and accessibility is introduced. The goal has been a method well suited for adaptation to different scales and one that takes into consideration the geographic distribution and size of the population. The accessibility factor of the method is based on the extent and spread of the road network which results in realistic population sparsity values. Directly linking to the method, a special measure, the Rurality index was developed in order to show how the method can be used at several different levels in a clear-cut way, e.g. local or regional. The method was tested and evaluated using ArcGIS and network analysis based on the 2008 census materials. The study areas were the municipalities of Hudiksvall and Nordanstig in Sweden. The method involves a few steps. Initially, the area to be measured is divided into a grid. Then, for every cell in the grid the number of habitants within a certain distance along the road network is summarized. The distance is the method’s main variable and it can easily be adjusted according to the actual level of the measurement, in this study, 5, 10, 20 and 30 kilometers were used. Lastly, the measured population within reach of the chosen distance is divided by the distance in kilometers giving the values using the measuring unit of habitants per kilometer. Measurements were performed using several distances and resulted in a series of maps produced with the new method, as well as a series of maps produced using a different resulting method, based on the population density within circles, for comparison and evaluation. The rurality index was given the abbreviated name RURIX (Rurality Index), and a series of maps were produced to illustrate how the measurement values could be classified using RURIX. The results of the study showed that the new method gives good and realistic results throughout the study area. At all measurement distances the highest values could be found where people actually are settled and in areas where the road network is well extended, while lower values are focused on sparsely populated areas with a poor road network. The results of the method of comparison showed that a population density measuring alone cannot considerate the distribution of the population and accessibility. This was clearly shown in this regional level study, where the highest values were found within remote and poorly populated areas in the southern parts of the study area. A positive and important feature is that it worked well on a wide range of scales and can therefore be used with great benefit for measurements at different levels and for different purposes. The method also has potential for further development and, compared with methods that only measure population density, its advantages is clear.

Chromolaena odorata (L.) King and Robinson (chromolaena, triffid weed) (Asteraceae: Eupatorieae) is one of the most problematic weeds in the subtropical northeastern parts of South Africa. Calycomyza eupatorivora Spencer (Diptera: Agromyzidae) was introduced as a biological control agent for the control of this weed. No study has yet been done to quantify field populations of C. eupatorivora since its establishment in 2003. The aim of this study was therefore to measure aspects of the field population and laboratory behaviour of C. eupatorivora on C. odorata. The first objective was to determine the percentage leaf area mined by larvae of C. eupatorivora on C. odorata plants exposed to three densities of mated flies, and also to determine the number of mines produced by these different densities, and their distribution on the plant. It also attempts to determine the relationship between chromolaena leaf quality and usage by C. eupatorivora. The maximum percentage of leaf area damaged was 37.5% for one of the trials involving five pairs of flies. Mean percentage leaf area damaged was slightly higher with five (28.5%) than ten pairs (22.0%) of adults and was lowest with one pair (6.5%), but these differences were not significant. In relation to the mean number of mines per plant, five and ten pairs of flies caused slightly more mines than one pair. The other significantly different parameter was number of leaves mined per plant, which was higher for five pairs. Within a plant, C. eupatorivora probably selects a subset of leaves with certain chemical and physical characteristics for oviposition since certain leaves were left unmined while others received multiple eggs. Percentage water content did not differ between mined and unmined leaves, but clear patterns were shown by acid detergent lignin which was higher in unmined leaves and nonstructural carbohydrates which were much higher in mined leaves. It is likely that leaf age plays a role in its suitability. The second objective was to quantify C. eupatorivora infestation levels, by counting and examining larval leaf mines, on C. odorata in the field at four times ('seasons' - September, December, March and July) over a 12-month period, and at three study sites that each included two habitats, viz. open and shady. At each of these six sampling sites, line transects were laid out and plants/branches sampled along them. Both plant/branch height and the number of leaves increased between September and March, and plants in the open habitats were taller and had more leaves than those in the shaded habitats. At the third site, the shady habitat supported taller plants with more leaves compared to the same habitat at the other sites. There was a steep increase in the number of C. eupatorivora mines from December to March. The mean number of mines, both total and in relation to leaves available, was highest in March, and was higher in the shaded habitats compared to the open habitats. The mean number of mines per damaged leaf was slightly higher in December compared to the other seasons, and was also higher in the open than the shaded habitats. Mean larval mortality was high (70%) in September but decreased to 32% in December, and increased again in late summer. The overall levels of mining by C. eupatorivora were low, with less than 5% of leaves sampled having mines. Taken together, the laboratory and field trials suggest that C. eupatorivora is restricted to a subset of the leaves of C. odorata for its development; that the field population is unable to make full use of the resource of young, palatable leaves that develop in early- to mid-summer because it only becomes large in late summer; and that the high mortality rate of young larvae negatively affects both the population of the fly and the level of damage to the plant. Given that these results were obtained in an area where the population of C. eupatorivora is relatively high, it is unlikely that the fly is having anything more than a negligible effect on C. odorata in South Africa at present. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.

A population survey was conducted on Galago moholi along the road system at Loskop Dam Nature Reserve, Mpumalanga province, South Africa. The data were analyzed using the maximum perpendicular distance, mean perpendicular distance, and maximum reliable perpendicular distance methods. Vegetation sample plots were constructed at the location of each individual sighted in order to analyze the species’ habitat use. The results indicate that the species density of G. moholi is significantly lower at Loskop Dam Nature Reserve than previously reported at other sites within South Africa. G. moholi was found to prefer areas with high concentrations of Dichrostachys sp., Combretum sp., or Acacia sp. One individual was observed consuming vegetative matter, which may indicate that the population within the reserve is utilizing available resources in a different way than populations in other parts of southern Africa. / Department of Anthropology

Thesis (M. Town and regional planning)--Stellenbosch University , 2000. / ENGLISH ABSTRACT: An ever increasing segment of the population in the current low density category contributes to the sprawling South African city as we know it today. To provide for the housing needs o f people, precious agricultural land is being used, and the historic character o f towns is being destroyed. Densification of the city structure has been put forward as a solution to this problem. In this way, different components of the city may be connected and existing infrastructure may be optimally utilised. The concept of densification is gaining popularity in all spheres o f planning. The implementation of densification requires suitable policy, as well as the strict application of the aforesaid. A densification policy must include consultation with all parties involved with a view to finding a balance between the need for land for development purposes, the conservation of agricultural land, the conservation of the historic character o f towns and cities, as well as being in the public interest. A theoretical investigation was done in which all aspects regarding densification, and its implementation in the South African context were studied. Attention was also given to policy formulation. This was followed by an empirical study, based on the Paarl municipal region as an example, in an attempt to reconcile theory and practice. It was found that although densification enjoys great support, the perception held by professional planners as to appropriate methods for the achievement o f higher densities did not correspond wholly with theoretical arguments in this regard. It was also found that it is important to view densification in relation to the environment in which it is applied, and to create an executable policy for a specifically designated area. / AFRIKAANSE OPSOMMING: Snelgroeiende bevolkingsgetalle in ‘n lae-digtheidsmilieu dra by tot die uitgebreide Suid- Afrikaanse stad soos ons dit vandag ken. In die proses word kosbare landbougrond gebruik om in die behuisingsbehoefte van die mens te voorsien en die historiese karakter van dorpe word vernietig. As oplossing vir hierdie probleem word verdigting van die stad voorgestel, om sodoende verskillende komponente van die stad te verbind en reeds bestaande infrastruktuur tot die optimum te benut. Die konsep van verdigting geniet toenemende gewildheid in alle sfere van beplanning. Implementering van verdigting kan slegs deur die daarstelling van geskikte beleid en die toepassing daarvan geskied. By die formulering van ‘n verdigtingsbeleid moet alle rolspelers in die proses geraadpleeg word en ‘n middeweg tussen die behoefte aan grond vir ontwikkeling, die bewaring van kosbare landbougrond, die bewaring van die historiese karakter van ‘n stad en die publiek se belange gevind word. ‘n Deeglike teoretiese ondersoek is geloods, wat teoretiese aspekte omtrent verdigting en die implementering van verdigting binne die Suid-Afrikaanse konteks ondersoek het. Daar is ook aandag aan beleidsformulering gegee. Dit is opgevolg deur ‘n empiriese studie wat binne Paarl se munisipale gebied uitgevoer is en teoretiese inligting met die praktyk probeer versoen. In hierdie studie is bevind dat alhoewel verdigting van die stad groot ondersteuning geniet, die persepsie van professionele persone in die beplanningsprofessie oor metodes om hoër digthede te bereik, nie heeltemal met die voorgestelde metodes vervat in teoretiese bronne ooreenstem nie. Daar is ook bevind dat dit belangrik is om verdigting binne die konteks van die omgewing waarin dit toegepas word, te beskou en sodoende ‘n uitvoerbare beleid vir ‘n spesifieke omgewing op te stel.

Thesis (MSc (Geography and Environmental Studies))--University of Stellenbosch, 2005. / Land degradation in Lesotho is undermining the finite resource on which people depend for survival. Use of satellite imagery has been recommended for monitoring land degradation because remotely sensed data enable monitoring of large areas at more frequent intervals than intensive ground based research. Various techniques have been developed for land cover change detection. In the present study, vegetation changes were identified by image differencing, which involved finding the difference between the earlier date NDVI image and the later date image. NDVI images are among products that are generated from the NOAA AVHRR sensor to provide information about the quantity of biomass on the earth’s surface. The resulting NDVI change data showed land areas that had experienced vegetation loss, which were identified as potentially degraded. The change data were combined with other data sets to determine how potentially degraded areas were influenced by different environmental variables and population pressure. These data sets included land cover, ecological zones, elevation, soil and human and livestock populations. By integrating NDVI data with ancillary data, land degradation was attributed to both demographic pressure and biophysical factors. Widespread degradation was detected on the arable parts of the Lowlands where cultivation was intensive and human settlements were extensive. Signs of grassland depletion and forest decline were also evident and were attributed to population expansion, overgrazing and indiscriminate cutting of trees and shrubs for firewood. Extensive biomass decline was also associated more with soils in the lowlands derived from sedimentary rocks than soils of basalt origin that occur mostly in the highlands. Significant degradation was evident on gentle slopes where land uses such as cultivation and expansion of settlements were identified as the main causes of the degradation. There was evidence of greater vegetation depletion on north and east-facing slopes than on other slopes. The depletion was attributed to the fragility of ecosystems resulting from intense solar radiation. The study demonstrated that NOAA AVHRR NDVI images could be used effectively for detecting land cover changes in Lesotho. However, future research could focus on obtaining and using high resolution data for detailed analysis of factors driving land degradation.

As pessoas do senso comum repetem os equívocos dos primeiros exploradores europeus quanto ao número de animais visíveis na Amazônia. Induzidas no passado pela grandeza do próprio bioma e incertezas do que existia além das matas ciliares, ou modernamente por programas televisivos, pressupõem a existência de grandes concentrações de animais selvagens neste bioma, semelhantes às encontradas nas planícies africanas ou no pantanal mato-grossense. No entanto, reza à lenda, que a Amazônia é ciumenta com seus bichos. Vê-los exige sacrifício e paciência do pesquisador. No presente estudo foi necessário percorrer 1.600 km, distribuídos em 17 meses entre 2005 e 2006, oitocentos quilômetros na Floresta Nacional do Tapajós (FNT) e 800 km na Floresta Nacional de Saracá-Taquera (FNS-T), ambas no estado do Pará (Brasil), para reunir detecções sobre os primatas nelas contidas que permitissem um robusto tratamento estatístico. Mesmo assim, para algumas espécies naturalmente raras, como por exemplo, Pithecia p. chrysocephala da região do Rio Trombetas, ou Ateles marginatus na região do Rio Tapajós, a freqüência de detecção ao redor de 10, para ambas as espécies, foi muito baixa para permitir inferências seguras. Considerando 40 detecções como o ideal, seria necessário então quadruplicar o esforço amostral, o que por limitações de tempo e recursos é inviável. Outras espécies descritas e observadas por residentes na região do Rio Trombetas, como Saguinus midas e Saimiri sciureus, sequer foram detectadas na floresta de terra firme. Provavelmente não suportando a competição com os primatas simpátricos do interior das florestas intactas foram compelidas a ocuparem e especializarem-se na exploração de florestas periféricas, onde seus alimentos preferidos, os insetos e frutos menores são mais abundantes. Por meio do programa SAS, foi calculado a ANOVA para testar a hipótese nula, de que não existiam diferenças populacionais entre as duas comunidades de primatas, uma vez que ambas ocorrem dentro de um mesmo bioma: floresta de terra firme do oeste da Amazônia e não estão a mais de 240 km uma da outra. Esta hipótese foi rejeitada em favor da hipótese alternativa de que as comunidades diferem entre si. Os 397 grupos de primatas detectados foram desigualmente distribuídos (130 x 267 em favor da FNS-T). Ou dito de outra forma: 1 grupo detectado a cada 6 km de caminhada no Tapajós contra 1 grupo detectado a cada 3 km no Trombetas. Os testes de Tukey e G de Sokal e Hohlf foram importantes auxiliares para facilitar o entendimento de como as duas comunidades de primatas diferiram, respondiam e se adaptavam a estrutura das respectivas florestas. Das 200 árvores amostradas em cada uma das flonas, a FNS-T apresentou 92 espécies diferentes, contra 74 na FNT. Assim o índice de Shannon e Wiener foi mais alto na região do Rio Trombetas do que na do Rio Tapajós (6,17 x 5,74 respectivamente). A cobertura do dossel também foi maior na região do Rio Trombetas quando comparado com a do Rio Tapajós (96% na FNS-T contra 88% na FNT). Estes dois índices reforçam-se mutuamente e sua interpretação sugere que a FNT vem sofrendo maiores perturbações do que a FNS-T. Considerando a colonização mais antiga e maior da população de entorno da Cuiabá-Santarém (BR-163) e o maior número de residentes dentro da FNT (10.500 pessoas), do que dentro da FNS-T (2.500 pessoas), é provável que o número tão discrepante de grupos de primatas em favor da FNS-T, reflita a maior pressão antrópica sofrida pela comunidade de primatas do Rio Tapajós. Interpretamos que as diferenças antrópicas entre as flonas (embora um epifenômeno), foram mais importantes na discrepante abundância de primatas do que as especificidades locais (na estrutura da floresta e oferta de recursos alimentares). (Figura 94, apêndice). / Common sense people have repeated the mistakes of early European explorers as to the number of observable animals in the Amazon region. In the past based, on the greatness of the biome itself and uncertainties as to what existed beyond the riparian forests, or nowadays, through television shows, they assume the existence of great concentrations of wild animals in such biome, likewise those found in African plains or in the Mato Grosso pantanal. However, the Amazon region is said to be \'jealous\' about its animals. Observing them requires the researcher\'s sacrifice and patience. At this study, one had to traverse 1,600 km in 17 months between 2005 and 2006, eight hundred kilometers within the Tapajós National Forest (FNT) and 800 km within the Saracá-Taquera National Forest (FNS-T), both in the state of Pará (Brazil), to gather detections of the primates therein allowing a solid statistical treatment. Even so, for some naturally rare species, such as Pithecia p. chrysocephala of the Trombetas river region, or Ateles marginatus, at the Tapajós river region, the frequency of detection nearing 10 for both species was too low for accurate inferences. Considering 40 detections as the ideal number, the sampling effort would be four-fold, which is not viable due to time and resource limitations. Other species described and observed for the Trombetas river region, as Saguinus midas and Saimiri sciureus, were not even detected at the upland forest. Probably succumbing to the competition with sympatric primates of inner intact forests, they were compelled to occupying and specializing in exploring peripheral forests, where their favorite foods - insects and small fruit - are abundant. By means of SAS software, the ANOVA was calculated to test the null hypothesis, that there were no population differences between both primate communities, since both occur within the same biome - upland forest of western Amazon and are no more than 240 km apart. This hypothesis was rejected in favor of an alternative hypothesis that the communities differ from one another. The 397 primate groups detected were unequally distributed (130 x 267 favoring the FNS-T). In other words, 1 group detected every 6 km of trekking at the Tapajós region versus 1 group detected every 3 km at the Trombetas region. The Tukey\'s test and G-test of Sokal and Hohlf were important tools in facilitating the understanding of how the two primate communities differed, responded and adapted to the structure of the respective forests. Out of 200 trees sampled in each forest, the FNS-T presented 92 different species, versus 74 at the FNT. This way, the Shannon-Wiener index was higher at the Trobetas river region than at the Tapajós river region (6.17 x 5.74 respectively). Also the canopy was higher at the Trombetas river region in comparison with that of the Tapajós river region (96% at the FNS-T versus 88% at the FNT). Both indexes are mutually reinforced, suggesting that the FNT has undergone more disturbances than the FNS-T. Considering the older and larger colonization of the population neighboring the Cuiabá-Santarém highway (BR-163) and the larger number of residents within the FNT (10,500 people), than within the FNS-T (2,500 people), such discrepant number of primate groups in the FNS-T is likely to reflect the higher anthropic pressure suffered by the primate community of the Tapajós river region. The anthropic differences between the forests, although an epiphenomenon, are interpreted as more important at the discrepant abundance of primates than the local specificities (on the forest structures and food resource supply).

Orientador: Sílvio José Bicudo / Banca: Teresa Losada Valle / Banca: José Carlos Feltran / Banca: Marina Aparecida de Moraes Dallaqua / Banca: Ricardo Augusto Dias Kanthack / Resumo: A poda da parte aérea da mandioca é prática comum nos cultivos comerciais destinados à industrialização. Vem sendo praticada principalmente por possibilitar o controle das plantas infestantes com herbicidas no segundo ciclo vegetativo. Seus efeitos no desenvolvimento das plantas e na produtividade de raízes de mandioca ainda não são claros e resultados controversos são encontrados na literatura. Com o objetivo de estudar os efeitos da poda foram realizados seis experimentos, em dois ambientes: Botucatu, experimentos 1, 3 e 5 e em São Manuel, experimentos 2, 4 e 6. Os experimentos 1 e 2 tiveram como causas de variação cinco variedades de mandioca cultivadas com e sem poda. Os experimentos 3 e 4 avaliaram nove épocas de poda frente a uma testemunha conduzida sem poda. Os experimentos 5 e 6 tiveram como causas de variação quatro densidades de plantio avaliadas com e sem poda. Concluiu-se que: a poda altera a produtividade de matéria seca de raízes de maneira distinta considerando a variedade e o ambiente; a poda anterior ao período de repouso fisiológico ou após o início do segundo ciclo vegetativo reduz a produtividade de matéria seca de raízes; em altas densidades de plantio, a poda reduz de maneira significativa a produtividade de matéria seca de raízes. Desse modo, a poda da parte aérea da mandioca não deve ser recomendada de maneira genérica, devendo considerar entre outros, os fatores avaliados no presente estudo / Abstract: Cassava pruning is common in commercial crops destined for industrialization, a practice mainly aimed at enabling weed control with herbicides in the second growth cycle. Its effects on plant development and cassava yields remain unclear and controversial results are reported in the literature. With the objective of studying the effects of pruning, six experiments were conducted in two environments: in Botucatu, experiments 1, 3 and 5, and in São Manuel, experiments 2, 4 and 6. In experiments 1 and 2, the established variables were five varieties of cassava cultivated with and without pruning. Experiments 3 and 4 evaluated nine pruning dates compared with control cultivated without pruning. The established variables in experiments 5 and 6 were four planting densities, evaluated with and without pruning. It can be concluded that: cassava pruning causes distinct alterations in the productivity of dry root matter, depending on the variety and culture environment; pruning before or after the period of physiological rest or after the onset of the second growth cycle reduces the productivity of dry root matter; and pruning in high planting densities significantly reduces the productivity of dry root matter. Thus, cassava pruning cannot be recommended as a general practice, as currently occurs, and the factors evaluated in this study should be taken into consideration / Doutor

Nas ultimas décadas, a sociologia começou a mudar a sua analise sobre o mundo rural e a repensar os temas da sociedade rural latino-americana. Uma das razões, é que o espaço rural não pode mais ser caracterizado exclusivamente pelas atividades agropecuárias. A análise territorial não deixa de lado as dinâmicas sociais e de produção agrária que se desenvolvem no território, mas não faz delas o seu eixo exclusivo. A ruptura entre o rural e o agrário que permite esta analise, possibilita redescobrir fenômenos existentes na sociedade rural latino-americana, para, assim, pensar nos desafios atuais. Então, a unidade de analise desta tese é a ocupação não agrícola, de famílias que vivem em municípios inseridos em territórios de baixa densidade populacional. Nesses municípios, analisam-se os dados acerca da dinâmica das ocupações, a organização produtiva local, os dados da situação do desenvolvimento social e as formas de ocupação do território. O estudo da dinâmica das ocupações nos territórios de baixa densidade populacional, apresentado possibilita compreender as relações com o desenvolvimento social do território e a diversificação das ocupações como expressão da dinâmica do modelo produtivo desenvolvido no mesmo. O qual é capaz de integrar as demandas do mercado externo, de articular os diferentes interesses dos atores produtivos, criando redes institucionais capazes de gerar espaços de interação com o Estado, que desenvolve política pública, promove o contexto material (infra-estrutura) e institucional (organizacional), para produzir as condições para o dinamismo produtivo e a diversificação das ocupações. / During the last decades, the sociology has begun to change the analysis about the rural world and rethink its issues upon the rural society in Latin America. One of the reasons is that the rural space cannot be characterized only by the agricultural activities. The territorial analysis does not leave aside the social dynamics and agricultural production that is developed inside the territory, but doesn’t make them its unique axis. The break down between the rural and the agrarian matter that gives this review, allows the rediscovering of the phenomena that exists in the Latin American rural society, and then think about the current challenges. So, the analysis unit of this thesis is the non-agricultural occupation of families living in municipalities included in areas of low population density. In these municipalities we analyze the data about the dynamics of occupations, the local productive organization, the data of the situation of social development and the forms of occupation of the territory. The study of the dynamics of occupation in the territories of low population density presented, allows the understanding of the relationship between the social development of the territory and the diversification of the occupations as an expression of the dynamics of the productive model developed on it. This view is valid to integrate the demands of the external market, to articulate the interests of different productive actors, creating institutional networks capable of generating spaces for interaction with the state that develops public policy, promotes the material background (infrastructure) and institutional (organizational), all together to produce the conditions for a productive dynamics and diversification of productive occupations.