• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 1
  • Tagged with
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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.
1

Aspectos ecológicos e econômicos do plantio de Pinus elliottii Engelm var. elliottii como facilitadora da restauração de mata ripária em região de Cerrado (Assis, SP, Brasil) / Exotic species in forest restoration: ecological and economical aspects of using Pinus elliottii Engelm var. elliottii as pioneer in Cerrado region, Assis, SP, Brazil

Modna, Daniela 29 November 2007 (has links)
Os elevados custos de plantio e de manutenção de espécies nativas limitam a restauração florestal no Brasil. Buscando reduzir custos e acelerar a recuperação de vegetação ripária em região de cerrado, testou-se a utilização de espécie exótica de rápido crescimento (Pinus elliottii var. elliottii) como facilitadora da regeneração natural de espécies nativas lenhosas, no município de Assis, Estado de São Paulo, Brasil. A exploração de madeira e resina de Pinus poderia gerar receitas aos proprietários rurais e estimular ações de restauração com a compensação dos custos de plantio. Três tratamentos com plantio de Pinus nos espaçamentos 3 x 3 m, 3 x 2 m e 2 x 2 m, mais um quarto tratamento com áreas sem plantio (controle), foram instalados. Cada tratamento teve quatro repetições, em blocos ao acaso. Foram alocadas 16 parcelas (18 x 12 m cada) paralelamente ao rio, distando 20 a 40 m da margem. A área experimental fora utilizada como pastagem por duas décadas. Na ocasião do plantio (1995), predominavam gramíneas africanas. Plantas lenhosas e estruturas subterrâneas existentes foram preservadas. Avaliou-se área basal, cobertura de copas e sobrevivência das árvores plantadas, assim como composição florística, estrutura e cobertura de copas das plantas lenhosas em regeneração (altura mínima de 50 cm) em 1996, 1998, 1999, 2001 e 2006. Desejava-se verificar se: 1) Pinus facilitaria a regeneração da comunidade nativa; 2) Pinus dificultaria a regeneração da comunidade nativa ou 3) Pinus não alteraria a regeneração da comunidade nativa. Até 2006, a densidade média de plantas lenhosas regenerantes foi de 4923 ind/ha sob Pinus (maior quanto maior a densidade de Pinus) e de 3472 ind/ha no controle. Foram registradas 68 espécies lenhosas nativas em regeneração na área experimental, pertencentes a 31 famílias. Houve correlação positiva entre densidade das plantas regenerantes e densidade e área basal de Pinus, e correlação negativa entre parâmetros estruturais de Pinus e cobertura do terreno por gramíneas. Conclui-se que Pinus eliminou as gramíneas pelo sombreamento, favorecendo indiretamente as plantas nativas. Até 2006, não se constatou competição entre plantas nativas e Pinus pelos recursos do ambiente. Houve maior proporção de plantas zoocóricas regenerantes no controle, e correlação negativa entre proporção de regenerantes zoocóricos e parâmetros estruturais de Pinus. Foram favorecidas por Pinus 40% das espécies regenerantes e, 25%, prejudicadas. A sucessão deverá conduzir as duas situações a comunidades distintas, especialmente em função da tolerância das espécies à sombra, predominantes sob Pinus. A análise econômica do uso de Pinus elliottii como facilitadora da regeneração natural demonstrou menores custos de plantio (cerca de um terço dos custos de plantios mistos com espécies nativas), compensados por um ano de exploração de resina. Porém, as técnicas usuais de exploração podem danificar as plantas regenerantes do sub-bosque. Assim, a restauração da comunidade nativa exige meios menos impactantes de exploração dos plantios de espécies exóticas. / Among the obstacles to the native forests restoration in Brazil we find the high costs of planting high diversity of native trees. Searching for reduction of costs and vegetation recovery acceleration, the use of a fast growing exotic species (Pinus elliottii var. elliottii) as pioneer was tested in a riparian area in the cerrado domain, at Assis municipality, São Paulo State, Brazil. As observed in forest plantations with exotic species in the same region, we expected the natural regeneration of native species to occur under the planted exotic trees. In addition, the later exploitation of the exotic species could bring some profit to the land owner, surpassing the restoration costs, and thus stimulating forest restoration initiatives. Pinus was planted in three different spacings (treatments): 3 x 3 m, 3 x 2 m and 2 x 2 m, and a fourth treatment consisted of not planted plots (control). Every treatment had four replications in randomized blocks, the 16 plots (18 x 12 m each) settled along the stream, from 20 to 40 m far from the margin. The experimental area had been used as pasture for at least two decades, mostly covered by african grasses. Some native species then existing were preserved when the Pinus trees were planted, in 1995, without revolving the soil. Basal area, crown cover and survival of planted trees, as well as floristic composition, density and crown cover of native species regenerating in every plot (minimum height 50 cm) were assessed in 1996, 1998, 1999, 2001 and 2006. The aim was to verify if: 1) Pinus trees facilitating the regeneration of the native species, 2) Pinus trees obstructing the evolution of the native community or 3) the exotic species not affecting the native community. In 2006, density of the native woody species regenerating was 4923 ind/ha under Pinus and 3472 ind/ha in the control, from a total of 68 woody species (31 families) in the experimental area. Density of the regenerating community was positively correlated to density and basal area of Pinus. Thus, we concluded that Pinus eliminating grasses by shading (ground cover by grasses was inversely correlated to Pinus structure), indirectly favored the native woody species and are still not competing with them. The proportion of zoochorous species was negatively correlated to the Pinus density, showing that the exotic species does not attract animal seed dispersers. In the open areas (control), the zoochory was relatively more frequent. Density of some species (40%) increasing under Pinus and others (25%) decreasing or disappearing, which means secondary succession should go toward different directions if under Pinus plantation or in open areas. Analyzing the economical aspects of using Pinus as pioneer, we found that planting costs corresponded to a third part of those of planting mixed stands with native species. In addition, planting costs can be compensated by a single year of resin exploitation. However, current techniques of resin extraction or timber exploitation could cause considerable damages to the understory. Alternative exploitation techniques of the exotic species must be encouraged if restoration of the native community in the understory is expected.
2

Aspectos ecológicos e econômicos do plantio de Pinus elliottii Engelm var. elliottii como facilitadora da restauração de mata ripária em região de Cerrado (Assis, SP, Brasil) / Exotic species in forest restoration: ecological and economical aspects of using Pinus elliottii Engelm var. elliottii as pioneer in Cerrado region, Assis, SP, Brazil

Daniela Modna 29 November 2007 (has links)
Os elevados custos de plantio e de manutenção de espécies nativas limitam a restauração florestal no Brasil. Buscando reduzir custos e acelerar a recuperação de vegetação ripária em região de cerrado, testou-se a utilização de espécie exótica de rápido crescimento (Pinus elliottii var. elliottii) como facilitadora da regeneração natural de espécies nativas lenhosas, no município de Assis, Estado de São Paulo, Brasil. A exploração de madeira e resina de Pinus poderia gerar receitas aos proprietários rurais e estimular ações de restauração com a compensação dos custos de plantio. Três tratamentos com plantio de Pinus nos espaçamentos 3 x 3 m, 3 x 2 m e 2 x 2 m, mais um quarto tratamento com áreas sem plantio (controle), foram instalados. Cada tratamento teve quatro repetições, em blocos ao acaso. Foram alocadas 16 parcelas (18 x 12 m cada) paralelamente ao rio, distando 20 a 40 m da margem. A área experimental fora utilizada como pastagem por duas décadas. Na ocasião do plantio (1995), predominavam gramíneas africanas. Plantas lenhosas e estruturas subterrâneas existentes foram preservadas. Avaliou-se área basal, cobertura de copas e sobrevivência das árvores plantadas, assim como composição florística, estrutura e cobertura de copas das plantas lenhosas em regeneração (altura mínima de 50 cm) em 1996, 1998, 1999, 2001 e 2006. Desejava-se verificar se: 1) Pinus facilitaria a regeneração da comunidade nativa; 2) Pinus dificultaria a regeneração da comunidade nativa ou 3) Pinus não alteraria a regeneração da comunidade nativa. Até 2006, a densidade média de plantas lenhosas regenerantes foi de 4923 ind/ha sob Pinus (maior quanto maior a densidade de Pinus) e de 3472 ind/ha no controle. Foram registradas 68 espécies lenhosas nativas em regeneração na área experimental, pertencentes a 31 famílias. Houve correlação positiva entre densidade das plantas regenerantes e densidade e área basal de Pinus, e correlação negativa entre parâmetros estruturais de Pinus e cobertura do terreno por gramíneas. Conclui-se que Pinus eliminou as gramíneas pelo sombreamento, favorecendo indiretamente as plantas nativas. Até 2006, não se constatou competição entre plantas nativas e Pinus pelos recursos do ambiente. Houve maior proporção de plantas zoocóricas regenerantes no controle, e correlação negativa entre proporção de regenerantes zoocóricos e parâmetros estruturais de Pinus. Foram favorecidas por Pinus 40% das espécies regenerantes e, 25%, prejudicadas. A sucessão deverá conduzir as duas situações a comunidades distintas, especialmente em função da tolerância das espécies à sombra, predominantes sob Pinus. A análise econômica do uso de Pinus elliottii como facilitadora da regeneração natural demonstrou menores custos de plantio (cerca de um terço dos custos de plantios mistos com espécies nativas), compensados por um ano de exploração de resina. Porém, as técnicas usuais de exploração podem danificar as plantas regenerantes do sub-bosque. Assim, a restauração da comunidade nativa exige meios menos impactantes de exploração dos plantios de espécies exóticas. / Among the obstacles to the native forests restoration in Brazil we find the high costs of planting high diversity of native trees. Searching for reduction of costs and vegetation recovery acceleration, the use of a fast growing exotic species (Pinus elliottii var. elliottii) as pioneer was tested in a riparian area in the cerrado domain, at Assis municipality, São Paulo State, Brazil. As observed in forest plantations with exotic species in the same region, we expected the natural regeneration of native species to occur under the planted exotic trees. In addition, the later exploitation of the exotic species could bring some profit to the land owner, surpassing the restoration costs, and thus stimulating forest restoration initiatives. Pinus was planted in three different spacings (treatments): 3 x 3 m, 3 x 2 m and 2 x 2 m, and a fourth treatment consisted of not planted plots (control). Every treatment had four replications in randomized blocks, the 16 plots (18 x 12 m each) settled along the stream, from 20 to 40 m far from the margin. The experimental area had been used as pasture for at least two decades, mostly covered by african grasses. Some native species then existing were preserved when the Pinus trees were planted, in 1995, without revolving the soil. Basal area, crown cover and survival of planted trees, as well as floristic composition, density and crown cover of native species regenerating in every plot (minimum height 50 cm) were assessed in 1996, 1998, 1999, 2001 and 2006. The aim was to verify if: 1) Pinus trees facilitating the regeneration of the native species, 2) Pinus trees obstructing the evolution of the native community or 3) the exotic species not affecting the native community. In 2006, density of the native woody species regenerating was 4923 ind/ha under Pinus and 3472 ind/ha in the control, from a total of 68 woody species (31 families) in the experimental area. Density of the regenerating community was positively correlated to density and basal area of Pinus. Thus, we concluded that Pinus eliminating grasses by shading (ground cover by grasses was inversely correlated to Pinus structure), indirectly favored the native woody species and are still not competing with them. The proportion of zoochorous species was negatively correlated to the Pinus density, showing that the exotic species does not attract animal seed dispersers. In the open areas (control), the zoochory was relatively more frequent. Density of some species (40%) increasing under Pinus and others (25%) decreasing or disappearing, which means secondary succession should go toward different directions if under Pinus plantation or in open areas. Analyzing the economical aspects of using Pinus as pioneer, we found that planting costs corresponded to a third part of those of planting mixed stands with native species. In addition, planting costs can be compensated by a single year of resin exploitation. However, current techniques of resin extraction or timber exploitation could cause considerable damages to the understory. Alternative exploitation techniques of the exotic species must be encouraged if restoration of the native community in the understory is expected.
3

Försäkring av affärsrisker : Var dras gränsen i ansvarsförsäkringen och var borde den dras? / Insurance of business risks : Defining where the boundaries are set and where they should be set in the context of liability insurance.

Jonsson, Andreas January 2017 (has links)
I uppsatsen utreds vad försäkring är samt vad affärsrisker är och hur de försäkras inom ramen för ansvarsförsäkringen. Viktiga frågor är var, och varför, gränsen för affärsriskers försäkringsbarhet dras som den gör, samt huruvida en ny struktur och systematik kan ge upphov till en mer ändamålsenlig gränsdragning. För att kunna förstå och argumentera kring behandlingen av affärsrisker i ansvarsförsäkringen, samt för att kunna omfamna ämnessfären med ett helhetsgrepp, måste först en relation till försäkringens väsen byggas. Kunskapen om vad försäkring är och varför försäkring finns utgör oumbärliga fundament i argumentationen om affärsriskers försäkringsbara vara eller icke vara. De försäkringsrättsliga principerna och den normativa bas som bygger upp rättsområdet synliggör ramen för försäkringsavtalsparternas förhållande och rekvisiten för försäkringsbarheten. Dessa principer och normer utgör sedermera bakgrunden som affärsriskerna ses emot i analysen. Ansvarsförsäkringen täcker den försäkrades skadeståndsansvar. En uppdelning kan göras mellan hur täckning sker av kontraktuella skadestånds- och ersättningsansvar respektive utomobligatoriska skadeståndsansvar. I och med att professions- och rådgivningsansvaret behandlas annorlunda än ansvaret i andra tjänsteverksamheter finns det en principiell vinst i att belysa det separat. Affärsriskerna leder fram till ett eventuellt ansvar och hur de behandlas kan ses i de omfattnings- och undantagsvillkor som återfinns i den vanliga ansvarsförsäkringen och i GLI-försäkringen. I uppsatsen genomgås följande utvidgande och undantagande villkor: undantaget för ren förmögenhetsskada, undantaget för omhändertagen egendom, undantaget för garantier och utfästelser, undantaget för förutsebar skada, undantaget för skada på levererad egendom, tillägget för ren förmögenhetsskada, återkallelsetillägget, tillägget för ingrediens- och komponentskada, åtkomst- och återställandetillägget samt goodwilltillägget. Gränsdragningen för täckning av affärsrisker i ansvarsförsäkringen är spretig och förefaller inte utgå ifrån en bakomliggande systematik. De gemensamma nämnarna analyseras dock, vilket ger en uppfattning av de syften som försäkringsbranschen vill uppnå med avgränsningen mot vissa affärsrisker. Med erfarenheter från vad försäkringens väsen är, hur och varför gränsdragningen görs samt dess, ur ändamålssynpunkt, inte helt tillfredställande resultat, kan en ny struktur och systematik föreslås. Förhoppningsvis leder det till en mer genomtänkt och förståelig hantering av affärsrisker i ansvarsförsäkringsfrågor. / In this thesis, I examine what insurance is, together with what business risk is and how business risks are insured in the context of liability insurance. Important questions are where, and why, the boundaries of the insurability of business risks are set as they are, and also whether a new structure and systematics could give rise to a more suitable delimitation. To be able to understand and argue about how business risks are treated in the context of liability insurance, and also to be able to approach the sphere of the subject holistically, a relation to the essence of insurance must first be built. The knowledge about what insurance is and why it exists is an indispensable foundation for the argumentation around the insurability of business risks. The principles and the normative base that make up the legal area of insurance law reveal the framework of the relationship between the parties of the insurance contract and the requirements of insurability. These principles and norms subsequently form the background against which the business risks are seen in the analysis. The liability insurance covers the liability of the insured. A distinction can be made between how the insurance covers contractual liability and non-contractual liability. Since professional liability, such as the liability of advisors, is treated differently from the liability of other service businesses, there is a principal benefit in elucidating it separately. The business risks lead to a potential liability, and how they are treated can be seen in the regular and global liability insurance policies. In this thesis, the following expanding and excluding policies are covered. Exclusion of pure financial loss, property in trust, promise or guarantee, foreseeable damage and damage to delivered property. Addition of pure financial loss, recall, claims due to ingredients or components, access and restoration costs, and goodwill. The boundary of coverage of business risks in the context of liability insurance is fuzzy and does not appear to be set based upon any underlying systematics. The common denominators are, however, analyzed which gives an idea of the ends that the insurance industry wants to achieve through the delimitation against certain business risks. With knowledge of what constitutes the essence of insurance, of how and why the boundaries are set as they are and of their, from a purpose-oriented point of view, not entirely satisfactory results, a new structure and systematics can be proposed. Hopefully, it leads to a more thought-out and comprehensible treatment of business risks in matters regarding liability insurance.

Page generated in 0.2965 seconds