151 research outputs found

    Evolution of a type : street vending as urban strategy in Guangzhou, China

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    As China continues its program of building new cities and encouraging urban resettlement from smaller towns and the countryside, informal activities that were once typical of urban areas – such as street vending – are being evicted by the government in the name of cleanliness and beautification. In reality, the motivation of eviction has to do with land values and the desire to replace the low-end population: street markets in the downtown areas could be developed into programs that bring large-scale money-making, like shopping malls; street vendors are viewed as undisciplined, messy and outmoded. If we recognize the conflict between the government and the public, how can landscape provide a framework of public open spaces that coordinates, compromises and bridges the gap? Can designers use street vending as urban strategy to revitalize urban development? This thesis takes street vending as activism. Through creating a matrix of spatial types for street vending worldwide, the next step of the evolution is discovered. Using a series of strategies to different urban conditions in Guangzhou, the project considers the direction of urbanization towards the east for three city areas: the historic city, the modern city and the new city. Finally, a new vending prototype is proposed to improve living environment and boost individual businesses in the urban village, New city

    Crop Production Simulation and Analysis of Climate Scenarios Based on the APSIM Model for the Long Term Run of the Western Loess Plateau

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    The APSIM model is an effective tool for making decisions on agricultural management. The model can simulate the biophysical process in farming systems, particularly economic and ecological features of the systems under climatic risk (Keating et al. 1998). The APSIM model has previously been used in the Loess Plateau (Tan, 2007; Chen et al. 2008). Based on climate data from the Loess Plateau from 1961-2010, we simulated three commonly grown crops, wheat, maize and lucerne. Additionally, by applying three climate change scenarios, we attempted to determine the production risk in the future, and gain an understanding of the impact of climate change on crop yield in the western Loess Plateau

    Does the Short-Term Grazing Affect Functional Group and Plant Species Diversity of Alpine Meadow in the Tibetan Plateau?

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    Grazing affects the physiological and ecological characteristics of the plant community, through livestock intake and trampling (Georgiadis et al. 1989). Previous studies in the Qinghai-Tibetan Plateau have shown that the composition and structure of alpine meadow plant communities respond to grazing (Niu et al. 2010). However, the changes to functional groups and species diversity caused by grazing are not well documented, especially with regards to short term effects (McLaren 2008). In this study, different grazing rates were used to determine the relationship between functional groups, community diversity and yak stocking rates. The objective of this study was to reveal plant functional group responses to grazing and to predict the evolutionary trend of alpine meadow plant functional groups and community diversity under different grazing conditions, thereby providing a theoretical basis for the management of degraded grassland and the conservation of grassland diversity

    Long-Term Effects of Tillage and Residue Management on the Soil Microbial Community Structure in the Loess Plateau

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    The severe soil erosion present in the Loess Plateau of western China has resulted from a combination of highly erodible soil, variable rainfall and intensive cultivation (Shi and Shao 2000). Conservation agriculture practices, including no till, crop residue retention and crop rotation, have been found to increase crop yield, improve water use efficiency, reduce energy inputs and improve soil fertility (Bukert et al. 2000; Rahman et al. 2008). The soil microbial community function and structure play key roles in the decomposition of organic matter, nutrient cycling and altering the availability of nutrients to plants, which has been shown to change under conservation agriculture (González-Chávez et al. 2010). The aims of our research are to quantify impacts of tillage and crop residue management on soil microbial community structural diversity on the Loess Plateau by PLFA techniques

    Temporal Variations in the Carbon and Nitrogen Ecological Stoichiometry of Lucerne

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    Ecological stoichiometry has been of great help in research investigating the coupling between plant and environment (Sterner and Elser 2002). It provides some synchronized evidence to explain the response and adaptability of plants to the environment. Carbon and nitrogen ecological stoichiometry (C/N) also embraces the use efficiency of nitrogen in plants. Previous research has focused on the spatial responses of plant C/N to different environmental factors (Yang and Wang 2011). However, there is still insufficient attention on the temporal variation in C/N, in the hope that such effort will help elucidate the mechanisms underlying plant growth/regrowth. Lucerne (Medicago sativa L) has long been globally utilised. It can be cut 3-4 times annually and lasts for many years. The regrowth process in lucerne is of fundamental importance for the continuous utilisation of the forage and the sustainability of lucerne production. In this study, temporal variations in carbon and nitrogen content and C/N were studied in lucerne leaf, stem and root, as part of an effort to clarify the lucerne growth/regrowth mechanisms from the viewpoint of ecological stoichiometry

    Leaf Nitrogen and Phosphorus Stoichiometry of Natural Plant Community and Restorable Plant Community in the Northern Qinghai-Tibet Plateau, China

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    The human engineering activities (highway, railway, cable, gas line and high line construction) has a negative impact on the alpine grassland ecosystem in the Qinghai-Tibet Plateau (QTP), and the natural restoration of plant community in land used for engineering construction is an important part of the rehabilitation of the degraded alpine grassland ecosystem. Previous studies have shown that the plant species and community diversity relationship in natural plant community and restorable plant community vary with the elevation (Guo et al. 2007) and restoration duration of land for engineering construction is more than 20 years at present (Ma et al. 2004). Understanding the mechanisms of plant species replacement in the process of plant restoration is important to restore the land used for engineering construction. The ecological stoichiometry is considered as an effective tool to disclose the inter-specific competition process and determine the succession trend (Güsewell 2004; Güsewell 2005; Yin et al. 2010). However, the stoichiometry relationship between natural plant community and restorable plant community is not well known yet. The objective of this study is to investigate the nitrogen (N) and phosphorus (P) stoichiometry of natural plant community and restorable plant community and its changes with elevation

    Effect of Plateau Pika (\u3cem\u3eOchotonacurzionae\u3c/em\u3e) Disturbance on Soil Microelements Content in Alpine Meadow

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    The plateau pika (Ochotonacurzoniae) creates the extensive disturbance on alpine meadow ecosystem in the QinghaiTibetan Plateau (Smith and Foggin, 1999, Delibes-Mateos et al., 2011), especially on soil nutrient (Davidson et al., 2012). Previous studies show that intermediate active burrows of plateau pika improved soil macro-element (organic matter, total nitrogen and total phosphorus) in alpine meadow (Guo et al., 2012). However, there is little knowledge about the underlying contribution of plateau pika disturbance in determining soil microelement in alpine meadow. The density of active burrow entrances is used to divide the disturbances levels of plateau pika to determine the effect of various disturbance levels of plateau pika on soil microelement content of alpine meadow in the Qinghai-Tibetan Plateau in this study
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