Conservation for the landscape ecological diversity in Wulingyuan scenic area of China

Wulingyuan is located at the mountainous area of the middle reach of the Yangtze River, it is one of the three nature heritages in China which ranks in the “List of World's Heritage” by UNESCO. It is characterized by quartz sandstone peaks landform with several landform components(pattern, corridor) and rich in landscape ecological diversity and biodiversity. The main patterns(ecosystem) include mid-height mountain peaks, rift-valley and streams among peaks, peaks and gullies on slopes, square mountain-platforms and peaks among blind valleys and so on. The corridor system consists of natural corridors and artificial corridors among which the stream corridors account for a major part. The fracturing of habitat is unfavorable for the biodiversity conservation, but meanwhile the habitat diversity leads to an increase in biodiversity. Therefore, it is still rich in landscape ecological diversity in Wulingyuan. The biodiversity at the level of landscape component(ecosystem) and the function of the Wulingyuan complex ecosystem, and the measures for the biodiversity conservation in Wulingyuan ecotourism area are discussed in this paper.

The reservoir characteristics research of Devonian Jinbaoshi Formation,Northwest Sichuan Basin,SW China

A great breakthrough was achieved on the Middle Devonian's oil-gas exploration in the Longmenshan area in northwestern Sichuan.However,only the Guanwushan Formation was researched in detail.The underlying formation-Jinbaoshi Formation as a set of the potential well reservoir and its reservoir characteristics have not been discussed.Based on the section's fine description,thin section analysis,and core borehole logging,combined with petrophysical analysis,the reservoir characteristics,controlling factors,and evolution process of the Jinbaoshi Formation reservoir in the Longmenshan area are deeply studied in this paper.The results showed that the Jinbaoshi Formation has developed a set of sand-shale interbedding deposit of terrigenous clastic and carbonate rocks.The reservoir lithology is mainly quartz sandstone and calcareous quartz sandstone.The quartz sandstone reservoir has good physical properties,but the calcareous quartz sandstone has the characteristics of strong heterogeneity,low porosity,and permeability.Residual intergranular pores are mainly developed in the reservoir space.And the development of intercrystalline pores and intergranular dissolved pores can also be seen,but the development frequency is low,and the scale is small.Among them,the Devonian Jinbaoshi Formation quartz sandstone's average porosity is about 8%,and the highest is 18.43%.The main diagenesis types of the Jinbaoshi Formation are compaction,recrystalization,and dissolution.Compaction is the main reason for the destruction of original pores,and dissolution is the main driving force for later porosity and permeability improvement.Rock fragments,calcareous silty clasts,and bioclastic grains are the main dissolution objects.The formation of intergranular dissolved pores significantly improves the physical properties of the reservoir.Therefore,the reservoir development of the Jinbaoshi Formation is mainly controlled both by favourable sedimentary facies and diagenesis.Quartz sandstone and calcareous sandstone of the Jinbaoshi Formation were controlled by early sedimentary facies in the syngenetic rock stage and developed more early intergranular pores;in the early diagenesis stage,compaction-pressure solution and cementation resulted in residual intergranular pores.In the middle-late diagenesis stage,the calcareous cement is dissolved,and more pores were formed.