Biomedical subjects

Guodong Cheng

Publications and source records attributed to Guodong Cheng.

5 recordsLinked to original sources

PubMed2003

[Ecological footprint calculation and development capacity analysis of China in 1999].

The ecological footprint method put forward and improved by William Rees and Mathis Wackernagel presents a methodologically simple but integrated framework for national natural capital accounting, which is capable of measuring the impact of Human's consumption on ecosystem. Based on the ecological footprint theory and calculation method, a flow network analysis method was introduced to illuminate the structure of complex ecological economic system, and the relationship among ecological footprint, diversity and development capacity was analyzed. In this paper, the ecological footprints of China and its provinces was calculated and compared with the national and local ecological carrying capacity. The results showed that the ecological footprints of China and most of its provinces were beyond the available ecological capacity, and China and its most provinces run 'national or regional ecological deficit'. In case of China, the national ecological deficit was 0.645 hm2 per cap in 1999. Secondly, we introduced a flow network analysis method, taking various ecological productive area as note, and adopted Ulanowicz's development capacity formula to analyze the relationship among ecological footprint diversity, development capacity and output. The results demonstrated that Ulanowicz's development capacity was a good predictor of economic system output. At the same time, two distinct ways to change development capacity were produced. Increasing ecological footprint or increasing ecological footprint's diversity would both increase development capacity. Due to the fact that the ecological footprints had already been beyond bio-capacities, the only way to increase development capacity was to increase ecological footprint's diversity. The positive relationship between ecological footprint diversity and resources utilization efficiency demonstrated that there was no conflict between increasing ecological footprint's diversity and reducing footprints while not comprising our quality of life.

China↗

PubMed2002

Cadmium and zinc interactions and their transfer in soil-crop system under actual field conditions.

The transfer of Cd and Zn from calcareous soils nearby a non-ferrous mining and smelting bases to the spring wheat (Triticum aestivum L.) and corn (Zea mays L.) tissues and the interactions between the two metals concerned were investigated under actual field conditions. Samples of soils and entire crops were randomly collected during harvest time in 1998 in the Baiyin region. The soil metal contents showed that the furrows had been polluted (mean values: 3.16 mg kg(-1) for Cd; 146.78 mg kg(-1) for Zn) and the significant spatial variation of the soil contamination existed here (ranges, Cd: 0.14-19.3 mg kg(-1); Zn: 43.5-565.0 mg kg(-1)). The translocation ratios of the two metals from soil to crop parts in the region studied were relatively lower and the order of the element transfer in different plant tissues was root > stem > grain. The transfer ratio of element Cd was lower than that of element Zn. Cd and Zn uptake by the crop structures could be best described by four models (P < 0.01): linear; exponential; quadratic; and cubic. Apart from a linear relationship between the element Cd in the corn grains and soils, models were generally non-lincar. An analysis of Cd-Zn interaction mechanism led to the conclusion that the effects of the two metals were synergistic to each other under field conditions, in which increasing Cd and Zn contents in soils could increase the accumulations of Zn or Cd in the two crops.

Cadmium↗

PubMed2002

[Dynamic tendency of arid oasis under the influence of water resources decrease--a case study of Ejina oasis in Heihe River Basin].

The runoff changes of arid inland river seriously influenced on the formations and changes of oasis in the lower reach. By the oasis patches dynamic modeling, the vegetation-water interrelated analysis, and the estimation of water demand by the ecological system, the dynamic tendency of the Ejina oasis in the lower reach of Heihe River Basin under difference water resources allocating were studied. The results showed that the lowest water demanded for preserving the present oasis area was about 5.7 x 10(8) m3 based on rational usage of the water resources. Considering the water demand of people and livestock, and the water lose in the water transport process, the incoming runoff through the Langxinshan section should be about 6.0 x 10(8) m3 to preserve the present oasis area before 2015. To regain the oasis area to the level at the primary of 1980s, the demand incoming runoff should be about 8.9 x 10(8) m3, and the runoff through the Zhengyixia section should be 10.9 x 10(8)-13.1 x 10(8) m3.

Disasters↗

PubMed2002

[Response of bryophytes to global change and its bioindicatortation].

Bryophytes are sensitive to atmosphere components concentration and global climate change resulted from relatively simple structures. Bryophyte is an ideal kind of biological indicator of global changes, environmental pollution, nutrient condition, forest integrity and ecosystem health. In order to use bryophytes as indicators to environmental and global changes, further studies on response and adaptation of bryophytes to the global changes are needed.

Animals↗

PubMed2002

[Oasis corridor landscape in arid regions: a case study of Jinta Oasis].

In arid region oasis, the main corridor landscape types include river, ditch, shelterbelt and road. This paper introduced their basic ecological effects on transporting mass and energy and on obstructing desert landscape expansion and incursion. Using Geographic Information System (GIS), the corridor distribution and its spatial relationship with other landscape types in the Jinta Oasis were analyzed. Based on the dynamically monitoring on the landscape pattern change of the Jinta Oasis during the latter 10 years, the driving functions of the corridors on this change were analyzed in detail. The results showed that all kinds of corridors' characteristics could be quantified by the indexes such as length and width, ratio of parameter and area, density, and non-heterogeneity. The total corridor length of Jinta Oasis is 1838.5 kilometers and its density is 2.1 km.km-2. The corridor density of the irrigated land, forest and resident area is maximal, showing that the affection degree of the oasis corridors on them is the most. The improvement of the corridor quality is one of the important driving factors on the irrigated land.

Agriculture↗