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This paper selected four major ecosystem services,biodiversity conservation,soil conservation,water conservation and nutrients conservation,to evaluate the ecosystem services of the Three Gorges Reservoir(TGR) area using GIS and RS techniques.We investigated the importance and spatial distribution of these services in a quantitative way.The results indicate that:(1) The percentage of the area with extremely and strongly important biodiversity conservation service reaches 15% of the total TGR area.The areas with extremely important biodiversity conservation present patchy distributions in the northeastern,central and southeastern parts of the TGR area;(2) The percentage of the areas with extremely important soil conservation is 68.80%.These areas are mainly distribute in Wanzhou and the regions northeast to Wanzhou;(3) The areas dominated by the slightly important water conservation service are widely distributed in the study region and are followed by those with extremely important water conservation service.The areas with extremely important water conservation service are located along the main streams,and the areas with moderately important water conservation service are distributed along the two sides of the main streams;(4) The areas with slightly important nutrients conservation service occupy the largest areas of the TGR area and are followed by those with extremely important nutrients conservation.The areas with extremely important nutrients conversation service are mainly distributed in zonal distribution along two sides of the rivers and streams,and the ridges;(5) The percentage of the areas with extremely and moderately important ecosystem services is about 50%.The areas with extremely important ecosystem services are distributed along the first watershed of main rivers and streams,and the ridges in the paralleled ridge-valley region in the west of the study region.The areas with moderately important ecosystem services are mainly distributed along the two sides of the above-mentioned areas and scatteringly distributed along the main streams.

Since the late 20th century,giant jellyfish blooms have occurred in successive years in the northern part of the East China Sea and the Yellow Sea and resulted in ecological disasters in these areas.The main genera in bloom were Nemopilema and Cyanea spp.with N.nomurai as the dominant species.Fishery resources decreased sharply and normal fishing was seriously affected in the sea area where giant jellyfish bloomed.Massive aggregations of N.nomurai had occurred in Liaodong Bay,part of the Bohai Sea since the end of the 20th century in successive years.These blooms had serious impacts on the structure of fishery resources of Liaodong Bay.The dynamic distribution of juvenile and adult N.nomurai and the dominant ecological type reported,juvenile medusae,were analyzed based on the sampling data obtained during the anchor drift net surveys in inshore waters within a 10m isobath of the northern Liaodong Bay,Bohai Sea from late May to mid to late July from 2008 to 2011 combined with sampling data from trawl fishery resource surveys within a 20m isobath of northern Liaodong Bay and fishing pier interview surveys in August every year.In our study,many N.nomurai juvenile medusae were found in the inshore waters of Liaodong Bay in June,concentrated around the 5m isobath in coastal estuaries of the Shuangtaizi River.The average catch density of N.nomurai was 52.8 ind·net-1·h-1 in early and mid June,and 46 ind·net-1·h-1 in late June.The highest catch density,667 ind·net-1·h-1,was found within the 5m isobath in coastal estuaries of the Shuangtaizi River.During July,the amount decreased markedly with the medusae increasing to adult size.The average catch density of N.nomurai was 5.1 ind·net-1·h-1 in early July and 1.8 ind·net-1·h-1 in mid to late July.After June the higher density area moved to deep waters.Few adult medusae of N.nomurai were found within the 5m isobath in inshore waters of northern Liaodong Bay in mid August,while a high-density area of adult medusae was found in the waters 10—20 meters in depth in northern Liaodong Bay.The sea surface temperatures and salinities in areas inhabited by N.nomurai in June were 17.7—27.3℃ and 24.3—31.9 Practical Salinity Unit,respectively.The sea surface temperatures and salinities of high density areas with juvenile medusae of N.nomurai in June in Liaodong Bay region were 20.4—24.4℃ and 24.7—31.6 PSU,respectively.Coastal estuaries of the northern Liaodong Bay were one of the possible nursery areas of N.nomurai.When the juvenile medusae of N.nomurai grew to adults,they swam into deep waters from shallow waters.In contrast to the adults,the relatively high temperatures and low salinity area of coastal estuaries was an optimum environment for growth of juvenile medusae of N.nomurai.

In order to investigate high densities and planting methods of summer maize in north China,in 2010—2011,two varieties(Ludan 981,LD981,and Ludan 818,LD818) were selected and planted in two densities(6 0000 and 90000 plants/hm2) at two planting methods(single and double plants at one place).In this experiment,eight treatments were designed to study the effect of planting methods on root-shoot development and grain yield of summer maize under high densities.The results showed that vertical distribution of canopy resulted in a trend that dry matter weight increased with planting density increased;however,root vertical distribution resulted in a opposite trend.Under high density conditions,there were different competitive ability of root and shoot between different maize varieties.The canopy of LD981 was more sensitive to space,and its space competition of root was stronger than that of the canopy,hence,the yield limiting factor of LD981 was the kernel storage capacity;however,the root of LD818 was more sensitive to space,and its space competition of canopy was stronger than that of the root,hence,the yield limiting factor of LD818 was the spike number per unit.Under the condition of 60000 plants/hm2,the quality of canopy structure and function of LD981 was better,double plants at one place reduced competitive stress in the canopy,as a result,achieved root and shoot equilibrium.Hence,the population yield enhanced;under the condition of 90000 plants/hm2,the quality of canopy structure and function of LD818 was better,double plants at one place alleviated root competition,the quality of canopy structure and function improved partly,therefore,the root and shoot coordinated,which let to the yield increased.

In order to reveal the effects of population of Kerria yunnanensis on diversity of ground-dwelling ant,investigation of ground-dwelling ant diversity in 4 plots,with infestation rate of Kerria yunnanensis on host plant branches being 60%,30%,10% and 0%,respectively,was carried out by pitfall trapping in lac plantation in Yayi Town,Mojiang County,Yunnan Province of China.1) Species composition and relative abundance: 1136 ant individuals were collected in the plot Ⅰ,representing 26 species,the common species were Pheidole spathifera,Pheidole yeensis and Aphaenogaster beccarii.984 ant individuals were collected in the plot Ⅱ,representing 24 species,the common species were Monomorium chinensis,P.spathifera,P.yeensis and Pheidole pieli.607 ant individuals were collected in the plot Ⅲ,representing 24 species,the common species were Crematogaster macaoensis,M.chinensis and P.spathifera.419 ant individuals were collected in the plot Ⅳ,representing 26 species,the common species were Odontoponera transversa,M.chinensis and P.spathifera.2) ant diversity: relative abundance was in the order as ⅠⅡⅢⅣ.Honeydew can increase number of individuals and relative abundance,but none significant effects on species richness.3)Community similarity: Plots with lac insects hosting were different from the plot without lac insects hosting,there were some differences of community structure between each plot with different level of lac insects infestiation.4)Indicator species: Anoplolepis gracilipes and Tetramorium walshi were the indicator species of plot Ⅰ,Technomyrmex bicolor was the indicator species of plot Ⅲ,none indicator species in plot Ⅱ and plot Ⅳwas found.Lac population maintained higher ground-dwelling ant community diversity by honeydew resources,and changed the ground-dwelling ant community structure.

The lake′s morphological characters is closely related to the functions of lake ecosystem.It is fundamental to evaluate service function and healthy conditions.According to historical literatures,maps,water and sediment data from 1986 to 2010,8 indicators of morphological characters including the exposed frequency of bottomland,hydrodynamic conditions and geometry form of the lake were selected to evaluate the healthy condition of the lake ecosystem during the typical years by catastrophe progression method.It showed that:(1) The East Dongting Lake has a relatively good health status(the average membership grade was 0.7486),but with great fluctuations(0.6775—0.7965);then followed by South Dongting Lake,(0.7311);the West Dongting Lake(0.7269) was the worst one with a minimum fluctuation of health relative membership degree(0.7026—0.7487);(2) In the last 20 years,the health standard of Dongting Lake Basin had showed a tendency of " worse at the beginning then improved".It had the lowest healthy membership grade in 1998(0.6912),and the highest value was in 2004(0.7711),the values of the other typical years were in the middle,which might be the result of the strong support from both the implementation of "4350" project and Three Gorges dam.