Biomedical subjects

Ju Qian

Publications and source records attributed to Ju Qian.

2 recordsLinked to original sources

PubMed2006

The land ecological evolutional patterns in the source areas of the Yangtze and Yellow Rivers in the past 15 years, China.

Based on land ecological classification of the source regions of the Yangtze and Yellow Rivers and field investigation, two phases of TM remote sensing data obtained in 1986 and 2000 were compared. From spatial variations and type transformation trends, the spatial changes and evolutional patterns of land ecosystem in the source regions of the two rivers were analyzed using the analytical method of landscape ecological spatial patterns. Results show that middle and high-cover high-cold steppe areas degraded considerably by 15.82%, high-cover high-cold meadow areas by 5.15%, while high-cold swamp meadow areas decreased by 24.36%. Lake water area was reduced by 7.5%, especially the lakes in the source region of the Yangtze River. Land desertification is developing rapidly and the average of desertified land area has increased by 17.11%. Desertified land in the source region of Yellow River is expanding at an annual rate of 1.83%. Analysis of the evolutional pattern of land ecotypes shows that the general tendencies of spatial evolution in the regions are coverage reduction and desertification of high-cold steppe, cover reduction and steppification of high-cold meadows, and desiccation of swamp meadows. As a result, land ecological spatial distribution pattern in the region is changing and the state of eco-environment declining.

Biological Evolution↗

PubMed2003

[Several problems in ecological security assessment research].

Ecological security assessment is the identification and judgment of ecosystem completeness and sustainable ability to maintain ecosystem health under all kinds of risks, the core contents of which are ecological risk assessment and ecological health assessment. Ecological risk identification and ecological vulnerability are the composing elements of ecological risk assessment, while ecological health includes three aspects, i.e., ecological completeness, ecosystem vigor, and ecosystem resilience. In the studies of ecological security assessment, the rational combination of ecological risk and ecological health, and the establishment of integrated measure index system based on confirming spatial scale are needed. At present, risk factor identification index, exposure analysis index, and influence (response) analysis index are the broader construction systems of ecological risk index. Nevertheless, on the basis of the classification of EDI, REI and IRI, the method of superimposing exposure analysis index may be the development direction of establishing index system in the future. Among the methods of quantificational assessment, exposure-response analysis was one of the most extensive method used at present, but ecological model method to assess different-scale ecological security will be the main development field, and focused on the security of ecological processes in the future. Ecological security assessment must be intergraded with ecological prediction, security guarantee and management.

Ecology↗