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Study on Physical Activity Characteristics of Formal and Informal Sports Grounds in Urban Parks: A Case Study in Shenzhen
HAN Xili, ZHANG Xinyue
Acta Scientiarum Naturalium Universitatis Pekinensis    2023, 59 (6): 981-990.   DOI: 10.13209/j.0479-8023.2023.084
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Using the System for Observation of Play and Recreation in Communities (SOPARC), 36 observations were conducted in three parks in Shenzhen, China, to count the physical activity levels of 12297 visitors in 78 target sports grounds. The gender and age differences in the physically active populations were analyzed in formal and informal sports grounds. The results indicate that the physical activity levels of children and adolescents were significantly higher than those of middle-aged and elderly individuals, and males exhibited significantly higher physical activity levels than females. Among formal sports grounds, the physical activity levels on soccer fields, basketball courts, tennis courts, and ping-pong tables were significantly higher than those on other sports grounds. In informal sports grounds, the physical activity levels of children’s non-apparatus activity spaces were the lowest. Some informal sports areas supported a greater variety of physical activities, such as dancing, badminton, soccer, and kite-flying, on park squares and open grassy areas. The research findings can provide environmental strategies for constructing urban parks that are conducive to enhancing physical activity levels.
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Change of NDVI during Growing Season and Its Relationship with Climate in North China and the Adjacent Areas from 1982 to 2014
ZHANG Xinyue, FENG Yuhao, ZENG Hui, TANG Zhiyao
Acta Scientiarum Naturalium Universitatis Pekinensis    2021, 57 (1): 153-161.   DOI: 10.13209/j.0479-8023.2020.108
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Using data from 690 meteorological observatories and GIMMS NDVI 3g data from 1982 to 2014, trend analysis, wavelet partial cross-correlation analysis, partial correlation analysis and lag analysis were used to explore the change rule of NDVI during the growing season (May to October) and its relationship with climate in North China and the adjacent areas in the past 33 years. The results showed that the average growing season NDVI increased from 0.44 in the 1980s to 0.49 in the 2010s. NDVI in the growing season increased rapidly in the central part of the research area, but decreased in the northwest desert area. The increase of NDVI in the growing season of the research area was benefited from the increase of temperature and precipitation, and the influence of precipitation was greater. NDVI of the research area was positively correlated with the temperature in most areas. Except for the southeastern part of the study area, NDVI and precipitation had strong positive correlation. At 15-day resolution, the response of NDVI to temperature in the growing season in most areas did not have obvious lag or was lagged in one period (15 days), and the response to precipitation was lagged about 1–2 periods (15–30 days). Therefore, in general, vegetation growth in North China and the adjacent areas responded more rapidly to temperature than precipitation.
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Spatiotemporal Dynamics of Soil Extracellular Enzyme Activity and Its Influence on Potential Mineralization Rate of Soil Organic Carbon in Forests of Daxing’an Mountain Range
ZUO Yiping, ZHANG Xinyue, ZENG Hui, WANG Wei
Acta Scientiarum Naturalium Universitatis Pekinensis    2018, 54 (6): 1311-1324.   DOI: 10.13209/j.0479-8023.2018.089
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In order to explore spatiotemporal dynamics of soil extracellular enzyme activity (EEA) and its influence on potential mineralization rate of soil organic carbon (SOC) of the Daxing’an Mountain range, soil samples of three forests (Pinus sylvestris forest; Birch forest; Larch pine forest) and three ground cover plants in Larch forest (Grass; Ledum; Moss) were collected from Daxing’an Mountain range in summer and winter. Activities of six enzymes including carbon- (C) (β-1,4-glucosidase, β-1,4-xylosidase, β-D-cellobiohydrolase), nitrogen- (N) (N-acetyl-β-glucosaminidase, leucine aminopeptidase) and phosphorus- (P) (acid phosphatase) acquisition, potential mineralization rate of SOC and main environmental factors were analyzed and potential driving mechanisms were explored. Results showed that Both Pinus sylvestris forest and Birch forest exhibited significant higher activities of enzyme C, N and P in summer, however, Larch forest showed contrary seasonal dynamic with soil EEA of moss soil significantly higher in winter. From summer to winter, soils of three forests and three ground cover plants all experienced reduced P vs. N limitation. Besides, soils of Pinus sylvestris forest and Birch forest both experienced increased C vs. nutrient limitation, however, Larch forest showed contrary seasonal dynamics with the existence of moss. In Pinus sylvestris forest and Larch forest, potential mineralization rate of SOC exhibited higher in winter while Birch forest showed contrary trend. Analysis showed that potential mineralization rate of SOC was influenced by enzyme C and enzyme N significantly, whereas little influenced by enzyme P. C vs. nutrient limitation had little correlation while P vs. N limitation had significant negative correlation with potential carbon mineralization rate.

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