2 resultados para Agricultural Development
em Academic Archive On-line (Stockholm University
Resumo:
Rapid economic development has occurred during the past few decades in China with the Yangtze River Delta (YRD) area as one of the most progressive areas. The urbanization, industrialization, agricultural and aquaculture activities result in extensive production and application of chemicals. Organohalogen contaminants (OHCs) have been widely used as i.e. pesticides, flame retardants and plasticizers. They are persistent, bioaccumulative and pose a potential threat to ecosystem and human health. However, limited research has been conducted in the YRD with respect to chemicals environmental exposure. The main objective of this thesis is to investigate the contamination level, distribution pattern and sources of OHCs in the YRD. Wildlife from different habitats are used to indicate the environmental pollution situation, and evaluate selected matrices for use in long term biomonitoring to determine the environmental stress the contamination may cause. In addition, a method is developed for dicofol analysis. Moreover, a specific effort is made to introduce statistic power analysis to assist in optimal sampling design. The thesis results show extensive contamination of OHCs in wildlife in the YRD. The occurrences of high concentrations of chlorinated paraffins (CPs) are reported in wildlife, in particular in terrestrial species, (i.e. short-tailed mamushi snake and peregrine falcon). Impurities and byproducts of pentachlorophenol products, i.e. polychlorinated diphenyl ethers (PCDEs) and hydroxylated polychlorinated diphenyl ethers (OH-PCDEs) are identified and reported for the first time in eggs from black-crowned night heron and whiskered tern. High concentrations of octachlorodibenzo-p-dioxin (OCDD) are determined in these samples. The toxic equivalents (TEQs) of polychlorinated dibenzo-p-dioxin (PCDDs) and polychlorinated dibenzofurans (PCDFs) are at mean levels of 300 and 520 pg TEQ g-1lw (WHO2005 TEQ) in eggs from the two bird species, respectively. This is two orders of magnitude higher than European Union (EU) regulation limit in chicken eggs. Also, a novel pattern of polychlorinated biphenyls (PCBs) with octa- to decaCBs, contributing to as much as 20% of total PCBs therein, are reported in birds. The legacy POPs shows a common characteristic with relatively high level of organochlorine pesticides (i.e. DDT, hexacyclohexanes (HCHs) and Mirex), indicating historic applications. In contrast, rather low concentrations are shown of industrial chemicals such as PCBs and polybrominated diphenyl ethers (PBDEs). A refined and improved analytical method is developed to separate dicofol from its major decomposition compound, 4,4’-dichlorobenzophenone. Hence dicofol is possible to assess as such. Statistic power analysis demonstrates that sampling of sedentary species should be consistently spread over a larger area to monitor temporal trends of contaminants in a robust manner. The results presented in this thesis show high CPs and OCDD concentrations in wildlife. The levels and patterns of OHCs in YRD differ from other well studied areas of the world. This is likely due to the extensive production and use of chemicals in the YRD. The results strongly signal the need of research biomonitoring programs that meet the current situation of the YRD. Such programs will contribute to the management of chemicals and environment in YRD, with the potential to grow into the human health sector, and to expand to China as a whole.
Resumo:
Land Ownership and Development: Evidence from Postwar Japan This paper analyzes the effect of land ownership on technology adoption and structural transformation. A large-scale land reform in postwar Japan enforced a large number of tenant farmers who were cultivating land to become owners of this land. I find that the municipalities which had many owner farmers after the land reform tended to experience a quick entry of new agricultural machines which became available after the reform. The adoption of the machines reduced the dependence on family labor, and led to a reallocation of labor from agriculture to industries and service sectors in urban centers when these sectors were growing. I also analyze the aggregate impact of labor reallocation on economic growth by using a simple growth model and micro data. I find that it increased GDP by about 12 percent of the GDP in 1974 during 1955-74. I also find a large and positive effect on agricultural productivity. Loyalty and Treason: Theory and Evidence from Japan's Land Reform A historically large-scale land reform in Japan after World War II enforced by the occupation forces redistributed a large area of farmlands to tenant farmers. The reform demolished hierarchical structures by weakening landlords' power in villages and towns. This paper investigates how the change in the social and economic structure of small communities affects electoral outcomes in the presence of clientelism. I find that there was a considerable decrease in the vote share of conservative parties in highly affected areas after the reform. I find the supporting evidence that the effect was driven by the fact that the tenant farmers who had obtained land exited from the long-term tenancy contract and became independent landowners. The effect was relatively persistent. Finally, I also find the surprising result that there was a decrease, rather than an increase, in turnout in these areas after the reform. Geography and State Fragmentation We examine how geography affects the location of borders between sovereign states in Europe and surrounding areas from 1500 until today at the grid-cell level. This is motivated by an observation that the richest places in this region also have the highest historical border presence, suggesting a hitherto unexplored link between geography and modern development, working through state fragmentation. The raw correlations show that borders tend to be located on mountains, by rivers, closer to coasts, and in areas suitable for rainfed, but not irrigated, agriculture. Many of these patterns also hold with rigorous spatial controls. For example, cells with more rivers and more rugged terrain than their neighboring cells have higher border densities. However, the fragmenting effects of suitability for rainfed agriculture are reversed with such neighbor controls. Moreover, we find that borders are less likely to survive over time when they separate large states from small, but this size-difference effect is mitigated by, e.g., rugged terrain.