Carbon ecological security assessment based on the decoupling relationship between carbon balance pressure and ecological quality in Xuzhou City, China

Building a carbon ecological security (CES) framework helps to scientifically evaluate and manage the regional carbon cycle and eco-environment and support regional ecological security patterns. This paper adopted the pressure-state-response-immune (PSRI) model and the carbon balance index method to evaluate the ecological quality and carbon balance pressure. Then, based on the decoupling model and the improved four-quadrant model, the CES framework was constructed to evaluate the changing trend of the CES of Xuzhou City from 2005 to 2020. The results showed that the carbon balance pressure of Xuzhou City showed a pattern of "low-high-low" from east to west, and most areas tended to have a carbon balance and surplus in 2020. The ecological quality showed an overall upward trend during the study period. Protection and restoration drove the response and immune index growth from 2010 to 2020. In the Thirteenth Five-Year Plan stage, the nine districts of Xuzhou City were in a stable decoupling state, and the overall decoupling process was ideal. The CES of districts showed individual differences in the general upward trend. The carbon balance pressure of Gulou and Quanshan Districts was the main factor restricting the districts' CES. Therefore, based on the empirical results, this research proposes relevant suggestions to enhance carbon ecological security to achieve regional green and low-carbon development.

[Multi-scale effects of urban landscape pattern on plant diversity in Xuzhou City, Jiangsu Province, China.]

The changes of urban surface landscape will lead to damage, fragmentation, and losses of biodiversity, resulting in urban biodiversity decline. In order to explore the responses of urban plant diversity to the changes of landscape pattern, we chose the urban area surrounded by round-city highway as research object, set 36 plots in different directions with the Gupeng Square as the center, investigated the plant group in each of the plots through coverage rank method of Braun-Blanquet, and examined the features of plant species diversity in Xuzhou's greenlands. Meanwhile, we divided the landscape of the research area into seven categories: buildings, grasslands, forest lands, waste lands, water areas, roads and farmlands with the help of Erdas, GIS software and Landsat TM remote sensing images from 2005 to 2015 as basic data source. The features of landscape pattern in the research area were analyzed by Fragstats software. We set nine different buffer districts within each of the sample plot by applying the space analyzing function of GIS, calculated 39 landscape pattern metrics using Fragstats, and explored the features of how plant diversity responsed to landscape pattern. After that, the landscape pattern metrics with significant influence on the plant diversity of urban greenlands under different extents were selected by redundant analysis (RDA). The results showed that the plant diversity had obvious temporal and spatial scale effects in responses to landscape pattern and landscape elements. In 2005, the patch area and shape metrics of unused land and farmland could better explain plant diversity in 800 m buffer zone. The patch fragmentation and connectivity metrics of construction land had significant impacts on plant diversity within the extent of 800-2000 m. In 2015, grassland and forest landscapes better explained plant diversity in the 800 m buffer zone while construction sites and unused land had a remarkable impact on plant diversity in the extent of 1000-2000 m. The current plant diversity was more strongly influenced by the 2005 landscape type metrics, indicating that the plant diversity lagged in its response to the changes of landscape pattern. The pattern metrics of landscape level were more consistent with the landscape-class level metrics, indicating that the interaction between species and spatial scale was more dependent on the landscape type. This study would provide effective decision-making information for Xuzhou City planning and construction as well as effective protection of urban green space biodiversity.

[Knowledge, attitude and practice (KAP) of foodborne parasitic diseases among middle school students in Xuzhou City]

OBJECTIVE

To investigate the status of knowledge, attitude and practice (KAP) of foodborne parasitic diseases among middle school students in Xuzhou City, so as to provide a reference to the health education.

METHODS

A total of four middle schools were selected and their students were investigated with the basic information questionnaire and questions of foodborne parasitic diseases.

RESULTS

The awareness rates of parasitic diseases, hazards and transmission were 56.50%, 66.33% and 70.50% respectively. The awareness rates of transmission of the diseases in the senior high school students and urban students were higher than those in the junior middle school students and rural students (χ² = 8.684, 8.470, both P < 0.05). The formation rates of not drinking raw water and not eating raw food were higher among the female students than those among the male students (χ² = 7.675, 15.230, both P < 0.05). The formation rate of not eating raw food was higher among the senior high school students than that among the junior middle school students (χ² = 49.276, P < 0.001), and the formation rates of washing hands before meals and not keeping pets were higher among the urban students than those among the rural students (χ² = 5.833, 13.443, both P < 0.05). Totally 64.83% of the students would not eat food that might be infected with foodborne parasites, and the proportion of girls was higher than that of the boys (χ² = 11.690, P < 0.05), and 20.5% of the students would suggest others not eating food that might be infected with foodborne parasites, and 81% of the students would plan to get rid of bad habits.

CONCLUSIONS

The cognition of foodborne parasitic diseases is poor among the middle school students in Xuzhou City. The health education work on foodborne parasitic diseases should be strengthened.