11 |
Rodent damage control in commercial forestry in the Natal Midlands, South Africa.Taylor, Stuart. January 1996 (has links)
Rodents cause damage in commercial forests by gnawing at the bark of the trees. It is currently
estimated that rodent damage in commercial forestry costs the industry R50 million per annum.
The species of rodents which cause the damage are not known, neither is the reason behind this
behaviour. Through stomach analysis it has been established that 3 species are involved Otomys
irroratus, Rhabdomys pumilio and Mastomys natalensis, however this behaviour is confined to the
winter. Chemical analysis of the bark reveals that the percentage concentration of nitrogen varies
seasonally. The period of high concentration correlates with periods when the natural food of the
rodents is restricted and when bark gnawing is most prevalent. In the past the industry's response
to the damage has been to treat the areas with rodenticides. Using standard CMR methods, the two
commercially-licensed rodenticides and raptor perches were tested to examine their efficacy as
rodent control strategies. It was found that at a lower application of I block of rodenticide every
third tree there is little difference in the effectiveness of the rodenticide brands and there is also
little reduction in the abundance of the rodents. At a higher application rate of I block per tree, the
abundance of rodents is reduced but termination of the treatment results in the rodent numbers
quickly recovering, indeed they surpassed their original population numbers within 4 months.
Apart from the environmental dangers of applying such concentrations of poison, this is clearly an
uneconomic solution. My results indicate that at first planting, the sites should be provisioned with
raptor perches at a density of 16 ha⁻².
Contrary to accepted policy the perches do not require cross
pieces, which add to the expense and offer no advantage in raptor residency time. In areas of very
high rodent abundance the provisioning of tree collars provide physical protection to the trees. An
additional benefit of the collars is that the collars cause a beneficial microclimate around the tree
which enhances its growth rate. When the tree is around 2 years old it should be pruned to a height of I ffi, the slash being left in the inter-row. Results show that trees treated in such a way
experience no further attack and the rodents browse on the prunings. As the cost of the perches is
reduced and the cost of pruning is non-recurring the recommendations provide an economical and
environmentally sympathetic alternative to rodenticide application. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1996.
|
12 |
Forêt habitée et développement durable : le cas d'un parc expérimental de la nordicité à Ville de La Baie /Mercier, Marc, January 2002 (has links)
Maîtrise (M.E.S.R.)--Université du Québec à Chicoutimi, 2002. / La seconde copie de la carte accompagne le document (2000): Étude de faisabilité du parc de la nordicité et du développement durable du Cap-à-L'Ouest, Ville De La Baie GV191.46S129E85.2000 (cartothèque). CaQCU Document électronique également accessible en format PDF. CaQCU
|
13 |
Bionomia e comportamento de atopozelus opsimus Elkins (Hemiptera reduviidae) mantidos em glycaspis brimblecombei Moore (Hemiptera : Psyllidae)Dias, Thaíse Karla Ribeiro [UNESP] 09 February 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:38Z (GMT). No. of bitstreams: 0
Previous issue date: 2009-02-09Bitstream added on 2014-06-13T19:16:48Z : No. of bitstreams: 1
dias_tkr_me_botfca.pdf: 4466963 bytes, checksum: 090abcd915b3484d0a00fd993ad53400 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Percevejos do gênero Atopozelus (Hemiptera: Reduviidae) são nativos da região Neotropical, com cinco espécies descritas e apenas três com registro no Brasil. Em agosto de 2007, no município de São Simão, estado de São Paulo, folhas de Eucalyptus camaldulensis infestadas por Glycaspis brimblecombei (Moore, 1964) (Hemiptera: Psyllidae) foram amostradas e nelas foi encontrado indivíduos de um pequeno percevejo verde, que se alimentava de psilídeos. Os percevejos foram identificados como Atopozelus opsimus (Elkins, 1954). Devido à recém descoberta desse predador e a escassez de informação sobre sua bioecologia, este trabalho objetivou estudar a morfologia e morfometria externa, o ciclo biológico e o comportamento de A. opsimus mantidos com G. brimblecombei em condições de laboratório (26 ± 2 oC, 70 ± 10% UR e fotofase de 13 horas). O estudo morfológico e o morfométrico possibilitaram caracterizar todos os estágios de desenvolvimento. Os parâmetros avaliados na biologia foram: duração e viabilidade do estágio ninfal, longevidade dos adultos, viabilidade e número de ovos por fêmea, número de posturas por fêmea, duração do período de incubação e do ciclo total. O percevejo apresentou cinco instares ninfais com duração total de 40, 3 ± 1,40 dias. Fêmeas apresentaram longevidade de 61,0 ± 8,0 e machos de 39,0 ± 5,1 dias. Ambos apresentaram ciclo médio total de vida longo de, 120,2 ± 8,4 e de 92,5 ± 5,9 dias para fêmeas e machos, respectivamente. Desde o primeiro estádio o percevejo se alimentou tanto de ninfas quanto de adultos do psilídeo-de-concha e também apresentou fitofagia e onivoria. Os adultos demonstraram capacidade de retirar a cobertura que protege os psilídeos. As fêmeas apresentaram cuidado parental e ensinam as crias onde buscar alimento. A. opsimus demonstrou particularidades incomuns aos diversos agentes de controle biológico... / Predatory bugs of genus Atopozelus (Hemiptera: Reduviidae) are native from Neotropical region, with five described species and three registered in Brazil. In August, 2007, in São Simão, state of São Paulo, Brazil, leaves of Eucalyptus camaldulensis infested by red gum lerp psyllid were collected and it was observed the presence of a small green bug, which feed on psyllids. The bug was identified as Atopozelus opsimus (Elkins, 1954). Due to the recent discovery of this predator and to the existence of few information of its bioecology, this study aimed to characterize external morphology and morphometry, life cycle and behavior of A. opsimus maintained in Glycaspis brimblecombei (Moore, 1964) in laboratory conditions (temperature of 26 ± 2 oC, 70 ± 10% RH and photophase of 13 h). The morphological and morphometric studies helped to observe the differences between development stages. Considering biology study, the parameters evaluated were: duration and viability of nymphal stage, adults longevity, number and viability of eggs per female, number of ovipositions per female, duration of incubation period and the total life cycle. The predator had five nymphal instars with total duration of 40.3 ± 1.40 days. Female and male longevity were 61.0 ± 8.0 and 39.0 ± 5.1 days, respectively. Both sexes have total life-cycle with 120.2 ± 8.4 and 92.58 ± 5.9 days for females and males, respectively. Since first stage the bug fed on nymphs and adults of red gum lerp psyllid, presenting phytophagy and omnivorous, too. Adults had ability to remove the lerp that protects psyllid nymphs. Females had maternal care and teaches the offspring where they get food. A. opsimus shows unusual features of the various biological control agents found in the nature, and become a promising agent in biological control programs in Eucalyptus spp. plantations infested by G. brimblecombei.
|
14 |
Srovnání efektivity obranných opatření proti lýkožroutu smrkovému (Ips typographus (L.)) na vybrané lokalitě Lesního Závodu Boubín. / Effectiveness of protective measures against spruce bark beetle (\kur{Ips typographus} (L.)) at selected localities of LZ BoubínVAČKÁŘOVÁ, Tereza January 2013 (has links)
The efficiency of various protective measures against the Spruce bark beetle (pheromone-baited traps, trap trees, poisoned traps - tripods.) and the impact of insecticide-treated trap trees on non-target organisms were studied in weekly periods in areas in the altitude of 1000m above sea level. Tree traps proved to be of much higher effectivity with an average of 3307 caught spruce bark beetles in comparison with pheromone-baited traps with only 457 beetles within the same period. Poisoned traps ? tripods baited with pheromone (FeSex Typo, producer ? Karel Ubik, CR) were more effective than pheromone traps and the average number of caught beetles was 1226. Among non-target insects caught in these traps were 61 species included 7 orders. The most common species was Thanasimus formicarius.
|
15 |
A Floresta Estadual Edmundo Navarro de Andrade como um espaço de contradições : entre a memoria e o esquecimento / Edmundo Navarro de Andrade State Forest as space of contradictions : between memory and forgetfulnessJoinhas, Luzia Aparecida 29 July 2008 (has links)
Orientador: Arleude Bortolozzi / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociencias / Made available in DSpace on 2018-08-11T17:23:46Z (GMT). No. of bitstreams: 1
Joinhas_LuziaAparecida_D.pdf: 42298501 bytes, checksum: 2ae25a18e905bf7f935cef4e72f80c3f (MD5)
Previous issue date: 2008 / Resumo: A atual Floresta Edmundo Navarro de Andrade ¿ antigo Horto Florestal de Rio Claro ¿ SP, Brasil, é analisada nesta tese como um espaço de contradição, portanto entre a memória e o esquecimento. Acentuadas ao longo do tempo e decorrentes do processo histórico de produção, apropriação e usos do território, as contradições atuais apresentam-se ainda mais agravadas, devidos aos impactos ambientais da expansão urbana na sua área de entorno. Nesse sentido, tendo como fio condutor a história do Horto Florestal, esse trabalho procura ressaltar as relações sociais, econômicas, políticas, culturais e ambientais aí estabelecidas.
Objetiva principalmente mostrar que o resgate da memória local ¿ individual e coletiva ¿ se faz necessário e urgente, para contribuir com a preservação do seu patrimônio cultural (bens construídos e a floresta). Este resgate da memória, no entanto deverá se dar na perspectiva de uma gestão integrada do território, compreendido como um conjunto inseparável entre o natural e o artificial. Considerando, portanto que objeto de estudo nesta tese compreende uma floresta urbana foi importante buscar uma integração entre sociedade e natureza por meio do entendimento dos aspectos técnicos e humanísticos. Assim sendo, procurou-se integrar uma análise documental (normas de legislação ambiental que regem a unidade de conservação) com as informações coletadas na pesquisa de campo a fim de detectar os conflitos existentes entre os desejos da população e o poder público local. Dessa forma, a Educação Patrimonial como suporte, poderá ser inserida no rol das ações que visem a combater o esquecimento do Horto Florestal por meio do fortalecimento da identidade cultural da população rio-clarense. Para a confirmação dessa hipótese foi importante dar vozes aos interlocutores, ou seja, os envolvidos na pesquisa, tais como: poder público local, os moradores, os visitantes e ONGs / Abstract: The Current Forest Edmundo Navarro de Andrade - former and antique Horto Florestal of Rio Claro - Brazil, is discussed in this thesis as a space of contradiction between memory and forgetfulness. Wide over time and arising from the production, ownership and territorial usage¿s historic process, current contradictions present themselves further aggravated due to the environmental impacts of the urban sprawl in its surroundings. In that sense, with the leitmotif on the Horto Florestal story, this work emphasizes the established social, economic, political, cultural and environmental relations. It aims mainly showing that local memory redemption - individual and collective - is necessary and urgent to contribute to the preservation of its cultural heritage -"the forest itself and its builted assets."This memory rescue, however should be given the perspective of a territorial integrated management, understood as an inseparable set between natural and artificial. Considering that the study object in this thesis abroads an urban forest, it was important to seek an integration between society and nature through both technical and humanistic aspects understanding. Therefore, it has striven to integrate a documentary analysis (standards of environmental legislation governing the conservation unit) with the information collected in the field to identify the conflicts between population demands and local public power. Thus, patrimonial education as a support may be included in the list of actions aimed at combating Horto Florestal forgetfulness, through ¿Rio-clarense¿ population cultural identity strengthening. For this hypothesis confirmation it was important to give an active voice to the interlocutors, namely those involved in research, such as: local public power, residents, visitors and NGOs / Doutorado / Análise Ambiental e Dinâmica Territorial / Doutor em Ciências
|
16 |
Sistemas agroflorestais para recuperação de matas ciliares em Piracicaba, SP. / Agroforestry systems for restoration of riparian forests in Piracicaba, SP.Patricia Pereira Vaz da Silva 09 April 2002 (has links)
A necessidade de recuperação de áreas ciliares degradadas tem subsídio na legislação, porém, o uso de sistemas agroflorestais para esse fim não é permitido. O objetivo desse trabalho é comparar a capacidade de recuperação de dois sistemas agroflorestais e de um plantio florestal com espécies arbóreas nativas, também avaliando as diferenças de custos de implantação e manejo. A pesquisa foi realizada no Estado de São Paulo, município de Piracicaba, às margens do Rio Corumbataí, na propriedade da Usina Costa Pinto, onde o cultivo de cana-de-açúcar ocupa a maior parte do uso do solo. Os tratamentos foram: (1) testemunha; (2) sistema florestal, com 10 espécies arbóreas nativas; (3) sistema agroflorestal simples, com as mesmas arbóreas nativas, guandu e feijão-de-porco como adubo verde; (4) sistema agroflorestal complexo, com diversas espécies frutíferas, girassol e capim napier, além das mesmas arbóreas nativas e das duas leguminosas. Os fatores mensurados foram: altura e diâmetro à altura do colo das arbóreas nativas, custos, liberação de CO2 do solo, biomassa microbiana e fertilidade do solo. O SAF simples apresentou as maiores alturas médias, com um aumento de 36% em relação ao sistema florestal. O SAF complexo apresentou resultados intermediários, com altura média 10% superior à do sistema florestal. Separando as espécies em pioneiras e não pioneiras, as primeiras não apresentaram diferença entre os tratamentos, tendo as não pioneiras crescido cerca de 35% melhor no SAF simples. Supõe-se que as leguminosas tenham cumprido a função de pioneiras, melhorando o ambiente e propiciando o melhor crescimento das não pioneiras. A média do diâmetro de todas as espécies para cada tratamento apresentou diferença entre o SAF simples (51% maior) e o SAF complexo, sendo ambos semelhantes ao sistema florestal, que foi intermediário. Entre pioneiras e não pioneiras, as diferenças foram semelhantes, sendo o SAF simples 67% superior ao SAF complexo, entre as pioneiras, e 33% superior entre as não pioneiras. As análises de solo, tanto de biomassa microbiana, liberação de CO2 ou de fertilidade, não mostraram diferenças entre os tratamentos. Numa estimativa com base nas modificações sugeridas a partir dos dados do experimento, o SAF simples pode ter um custo 16% inferior ao do sistema florestal, principalmente devido à redução da necessidade de manutenção do sistema. O SAF complexo apresentou o maior custo dos três tratamentos, pois, além da grande demanda de mão-de-obra, o sistema encontra-se fora dos padrões legais para venda de sementes. O estudo da heterogeneidade do ambiente reforça a necessidade do uso de métodos de implantação e de manejos diferentes para cada situação encontrada e permitiu inter-relacionar os blocos quanto à degradação, com base nas médias dos blocos, para todos os parâmetros avaliados. Seguindo critérios semelhantes, as espécies arbóreas nativas também foram ordenadas segundo a sucessão, de acordo com a teoria de Götsch: Sangra dágua, Embaúba, Cordia, Mutambo, Pau Viola, Tamboril, Trema, Canafístula, Aroeira, Canelinha. Em condições de grande fragmentação da matriz florestal e forte domínio de gramíneas, o uso de sistemas agroflorestais na recuperação de matas ciliares pode trazer efeitos positivos ao crescimento das árvores nativas e redução no custo de implantação. / Riparian forest is the vegetation that borders rivers, ponds and lakes, and although it is protected by law, agricultural systems are widely used in these areas. Restoration of deforested riparian zones is requested by law, but agroforestry systems are not accepted for this purpose. The objective of this research was to compare the restoration success and the costs of three kinds of restoration management systems: two agroforestry systems and one forestry system, intending to give basis for changes in public policies. This research was carried out in São Paulo State, Piracicaba County, in the Corumbataí River watershed, in the farm of Usina Costa Pinto, where sugar cane fills most of the lanscape. The treatments were: (1) control; (2) forestry system, with 10 native tree species; (3) agroforestry system 1, where two herbaceous/shrub legume species were included in addition to trees; (4) agroforestry system 2, were 10 edible fruit species, sunflower and napier grass were added. Management was evaluated by measuring height and diameter of the native tree species, soil respiration, microbial biomass and soil fertility. Comparing the mean height of all species, agroforestry system 1 showed the best results, which was 36% better than the forestry system. Agroforestry system 2 showed intermediate results: mean height was 10% higher than the one achieved in forestry system. When the species were grouped according to ecological succession, pioneers didnt present any difference between treatments, but not-pioneers grew 35% better in agroforestry system 1. Probably, legume plants played the role of pioneers, improving the environment and supporting a better development of the non-pioneers. The mean diameter at ground level of all the species showed differences between agroforestry system 1 (51% better) and agroforestry system 2, but both were not different from the forestry system, which had intermediate results. There were similar differences when the species were grouped in pioneers and non-pioneers. For pioneers, agroforestry system 1 was 67% better than agroforestry system 2 and, for non pioneers, this difference was of 33%. There were no differences among treatments in soil fertility, microbial biomass and soil respiration. Estimating the costs, on the basis of modifications suggested after data analysis, agroforestry systems 1 may cost 16% less than forestry system, due to less necessity of interventions for weeds control. Agroforestry system 2 had the highest cost because it demanded much more work than other treatments and this system, like agroforestry system 1, is out of legal standard for seed production. Studies on the environment heterogeneity allowed to rank blocks, based on the block means of all the measured parameters. Based on the same principles, the native tree species were also ranked according to Götsch succession theory: Croton urucurana, Cecropia pachystachya, Cordia superba, Guazuma ulmifolia, Cytharexyllum myrianthum, Enterolobium contortisiliquum, Trema micrantha, Peltophorum dubium, Schinus terebinthifolius, Nectandra megapotamica. In conditions of high fragmentation of natural forests and high density of weeds, agroforestry systems may cause positive effects in riparian forests restoration, favoring better growing of native trees and lower costs of restoration.
|
17 |
Fastighetsköpares värdering av skyddad skogsmarkMalmqvist, Kristin, Sundin, Jonna January 2019 (has links)
I Skatteverkets fastighetstaxering 2017 infördes ett nytt ägoslag för skogsmark. Mark skyddad av biotopskyddsområde eller naturreservat går nu som ägoslaget produktiv skogsmark med avverkningsrestriktioner. Eftersom detta är ett relativt nytt ägoslag saknas underlag som kan stödja värdering vid fastighetstaxering. Examensarbetet fokuserar på hur fastighetsköpare värderar förekomst av skyddad skogsmark vid fastighetsköp. Det undersöks även hur skyddad skogsmark presenteras vid försäljning hos mäklarfirmor och i skogsbruksplaner. Syftet med arbetet är att få en ökad förståelse för fastighetsköpares värdering av skyddad skogsmark och klargöra hur den skyddade skogsmarken tas i beaktande vid fastighetsköp. Tidigare forskning inom området har bland annat berört naturvärden och nyckelbiotoper. För att få svar på frågeställningarna har två metoder använts: enkätstudie och granskning av prospekt och skogsbruksplaner. Enkäter har skickats ut till privatpersoner som har köpt en skogsfastighet där det finns förekomst av skyddad skogsmark. Fastighetsköparna har svarat på hur deras syn på värdet av skogsfastigheten påverkades av att det finns skyddad skogsmark. Resultatet visar bland annat att marknadsvärdet för naturreservat eller biotopskyddsområde ligger högre än värdet av impediment och lägre än halva värdet av produktiv skogsmark. Granskning av prospekt och skogsbruksplaner har visat att den information som ges inför köp enbart uppgår till att ange att det finns naturreservat eller biotopskydd på fastigheten. Huruvida begränsad information angående skyddad skogsmark kan påverka priset diskuteras i avsnitt 5.2. Valet av metod bedöms inte medföra några etiska risker som behöver tas hänsyn till. Arbetet knyter an till flera miljömål, bland annat det nationella miljömålet Levande skogar. / A new type of classification for forest land was introduced in the Swedish Tax Agency's property taxation of 2017. Forest land protected by biotope protection area or nature reserve is now called productive forest land with forestry restrictions. This is a relatively new type of classification and there is a lack of basis to support property valuation. The thesis focuses on how property buyers value protected forest land when purchasing a property. The type of information that is given to the property buyer is also investigated. The purpose of the thesis is to provide information that can be used when working with valuation of protected forest land with forestry restrictions. Previous research in this field has included, among other things, nature values and key biotopes. Two methods have been used in order to get answers to the thesis questions. Questionnaire survey, and study of estate agent leaflets and forestry plans. The surveys have been sent out to private property owners who have bought a forest property with presence of protected forest land. The property buyers have responded to how they think the value of the forest property was affected by the existence of protected forest land. The result shows, among other things, that the market value of nature reserves or biotope protection area is higher than the value of land with limited growth (e.g. swamps) and lower than half of the value of productive forest land. The study of estate agent leaflets and forestry plans has shown that the information provided for purchases only amounts to stating that nature reserves or biotope protection exists on the property. Whether limited information about protected forest land can affect the price is discussed in section 5.2. The choice of method is not considered to entail any ethical risks that need to be considered. The work connects to several environmental goals, including Sweden's national environmental goal “Sustainable Forests”.
|
18 |
TÉCNICAS DE GEOPROCESSAMENTO NA DETERMINAÇÃO DO íNDICE DE PERIGO DE INCÊNDIOS / GEOPROCESSING TECHNIQUES TO DETERMINATE THE FIRE DANGEROUS LEVELIllana, Vinícius Borges 13 April 2006 (has links)
The forest fire is considered an environmental impact, because provokes physic, biotic and anthropic environment characteristics changes or modifications. Brasil
doesn't have an adequate fire politic support. It's necessary to obtain more precise information about the national territory, like the area size, existence of accesses ways and artificial lakes, land relief, climatic and vegetation characteristics. These informations are essential to define the most significant fire risk regions and establish intensive fire prevention programs. The actual research objectivates the knowledge and techniques aplications about SR, SIG, geoprocessing and forest fires to elaborate the Combustion and Fire Ignition Dangerous Levei to the hydrographic micro basin of the Ibicuí Mirim river sources. The study area is located in the central
part of the Rio Grande do Sul State between the coordinates 29°26'32" to 29°33'57 of south latitude and 53°40'49" to 53°48'27 of west latitude. Are 8454,10 hectares of total area, from which approximately comes 60% of the water that is consumed in the city of Santa Maria. The city digital cartographic base used was elaboreted from
existent analogic datas (topographic maps - 1:50.000 scale), besides the digital mosaico It was executed elaboration plans throught Pls crossing, providing
informations used in the Fire Dangerous Levei elaboration. With the geoprocessing knowledge and techniques aplications, SR, SIG and forest fire, became possible to
develop the Fire Dangerous Levei to the studied areas. Thus, with the results, preventive actions can be implemented like: fire towers, construction of artificial
lakes, cleaning and the improvement of the actions in the forest to the environment protection. / O incêndio florestal é considerado um impacto ambiental, pois provoca alterações ou modificações na característica dos meios, físico, biótico e antrópico. O Brasil carece
de uma política adequada de prevenção de incêndio, mas para isso, é necessário obter informações mais precisas sobre o território nacional, como o tamanho da área, existência de acessos e açudes, características do relevo, climáticas e da
vegetação. Essas informações são fundamentais para se definir as regiões de maior riso de incêndios e estabelecer programas intensivos de prevenção de incêndios.
Desta forma, este trabalho teve como objetivo, à aplicação de conhecimento e técnicas sobre SR, SIG, geoprocessamento e incêndios florestais, para a elaboração
do índice de Perigo de Ignição, de Combustibilidade e de Incêndio, para a região da micro bacia hidrográfica das nascentes do rio Ibicuí Mirim/RS. A área de estudo
localiza-se na porção central do estado do Rio Grande do Sul, entre as coordenadas 29°26'32" a 29°33'57" de latitude sul e 53°40'49" a 53°48'27" de longitude oeste. Possui uma área total de 8454,10 ha, da qual provêm aproximadamente 60% da
água que é consumida no município de Santa Maria. A base cartográfica digital utilizada, foi elaborada a partir de dados existentes em meio analógico (cartas topográficas - escala 1:50.000), além da utilização do mosaico digital. Foram
gerados planos de informações (mapa de uso da terra, exposição, clinográfico, entre outros), utilizados nos cruzamentos dos Pls, proporcionando deste modo,
informações usadas na criação do índice de Perigo de Incêndio. Conclui-se que, as aplicações de conhecimentos e técnicas de geoprocessamento, SR, SIG e incêndios
florestais, foi possível desenvolver o índice de Perigo de Incêndio para a área estudada. Por fim, através dos resultados, ações preventivas podem ser tomadas,
como: torre de incêndio, construções de aceiros, açudes, melhoria no ordenamento florestal, entre outras, com o intuito de proteção ambiental.
|
19 |
Robust strategies to isolate the causal effect of improved fallows on farmer welfare and onfarm environmental quality in ZambiaKuntashula, Elias January 2014 (has links)
This study attempts to explain the inability of resource constrained farmers in Zambia to invest in soil fertility enhancing improved fallows, a sustainable land use practice developed by the World Agroforestry Centre (ICRAF) in the 1980s. Although several studies in the laboratory and field have shown that improved fallows positively impact on farmers’ welfare, the reliability of such conclusions comes into question given their use of improper identification strategies. Secondly, although there is general consensus that improved fallows additionally co-produce environmental services, the literature acknowledges that such services are not only imprecisely defined but also rarely quantified. Most estimates for environmental services have been confined to controlled field trials and laboratory experiments. Consequently, this research was designed to answer the following questions: 1) Would the use of randomisation procedures to estimate impact provide additional support to the foregone conclusions by most literature regarding the positive impact of improved fallows on farmer welfare? 2) Studies from on-station experiments show that improved fallows provide environmental services; do such conclusions hold for improved fallows planted on-farm where the near ideal experimental conditions are not guaranteed?
A structured questionnaire was used to interview 324 randomly selected small scale farmers in Chongwe district of Zambia between November and December 2011. The data was analysed using well-grounded and robust matching and switching regression counter factual analysis tools.
The rigorous econometric methods confirmed the positive impact of improved fallows on household maize yields, maize productivity, per capita maize yield and maize income. Insignificant impact results were however obtained when broader welfare indicators – overall per capita, crop income and value of crop production were considered. The study attributes these later results to two possible areas; first, most of the maize sold that contributes to crop income may be coming from other input sources such as the inorganic fertiliser that is common in the study area. Second, the non-use of the technology on cash crops (for example cotton) in subsequent periods after a year or two of maize cropping reduces the technology’s contribution to the households’ cash crop income portfolio. Had the study only used maize income or value of maize income to measure overall crop income (or value of crop production), or had it just made a simple comparison between adopters and non adopters, the likelihood of not finding any insignificant results on the efficacy of improved fallows would have been high. The study thus concludes that the use of improved fallows should be diversified to cover the entire cash crop portfolio especially a year or so after maize cropping when most of the nitrogen supplied by technology has been used up. More importantly, the study recommends use of better and more robust methodologies in evaluating impact of interventions.
The positive effects of improved fallows on on-farm environmental quality, controlling for farmers’ biophysical and socio-economic characteristics were confirmed. Estimates from OLS regression, matching and the more robust endogenous switching regression showed that the technology had a significant causal effect on households’ consumption of fuel wood obtained from natural forests. The technology can provide up to 1,086 kg or about 51% of annual household fuel wood requirements in the year the fallows are terminated. This amount is substantial enough to make a positive contribution towards reducing encroachment on public forests and thus control the rate of deforestation. In addition to promoting the technology for soil fertility improvement (the role which is widely accepted by the farmers), explicit extension messages conveying the technology’s capacity to provide various products that contribute to farmer welfare as well as provide on farm environmental quality should be made available. / Thesis (PhD)--University of Pretoria, 2014. / lk2014 / Agricultural Economics, Extension and Rural Development / PhD / Unrestricted
|
20 |
Práva a povinnosti vlastníka lesa / Rights and duties of a forest ownerSlaměníková, Hana January 2014 (has links)
Rights and duties of the owner of the forest This diploma thesis deals with the legal regulation of rights and duties of forest owner and defines the basic terms related to this topic. The thesis consists of seven parts, whereas chapter one is introductory and chapter nine is conclusion. Chapter Two deals with the basic information of the history of the forest legislation. Chapter Three pays attention on the forest in the Czech republic and provides a describtion of different forest types located in our territory. Chapter Four provides legal definitions of basic terminology. Chapter Five mentions the ownership of forest owners and restrictions of their property rights. The main attention is paid to chapter Six and Seven, which include a summary of the most important rights and duties with which the forest ownership is undoubtedly associated. Chapter Eight deals with the liability of forest owner and sanctions, that may be required. The aim of my thesis is to focuse on rights and duties of forest owner within forest inventory etc. The main source of this work is the Forest Act.
|
Page generated in 0.0867 seconds