["Safe and just operating space" for the sustainable development of the social-ecological system in the Liangzi Lake Catchment, Hubei Province, China.] / 湖北梁子湖流域社会生态系统可持续发展的"å®‰å ¨å ¬æ­£ç©ºé—´".

The increases of human activities threaten the health of the earth's ecosystem, and pre-sent a big challenge to regional sustainable development and environment conservation. How to maintain a safe ecological environment together with social and economic development is an important issue for sustainable development. Under the theoretical framework of "safe and just operating space", we integrated lake sediment records, environmental monitoring data, and socio-economic data in Liangzi Lake Catchment, analyzed the status of key eco-environmental processes and achievement degree (the completion of the current value of social basic indicators relative to the target value) of residents' social welfare, and constructed a "safe and just operating space" for the sustainability of local social-ecological system. The results showed that the indicators including freshwater utilization, cultivated land resources, air quality, soil and sediment regulation, and chemical pollution in the catchment had exceeded the environmental ceiling and were at the "dangerous" level, which should be regulated in the future. As for the social welfare, the achievement degree of clean water, sanitation facility, and industrial innovation were relatively low. The per capita GDP was negatively correlated with soil and water conservation and air quality, indicating the negative effects of social and economic development on water, soil, and air. With multi-source environmental data, especially long-term limnological records, we effectively reconstructed the historical environmental change process, revealed the deficiency of environment and residential well-being in local social ecosystem management, which would provide important insights for regional sustainable development.

Emission control for precursors causing acid rain (V): Improvement of acid soil with the bio-briquette combustion ash.

The bio-briquette technique which mixes coal, biomass and sulfur fixation agent and bio-briquettes under 3-5 t/cm2 line pressure has aroused people's attention in view of controlling the air pollution and the acid rain. In this paper, the physicochemical properties of bio-briquette and its ash were investigated. And the acid soil was improved by the bio-briquette combustion ash, which contained nutritive substances such as P, N, K and had the acid-neutralizing capacity (ANC). The pH, EC, effective nutrient elements (Ca, Mg, K, P and N), heavy metal elements (Al, Cu, Cd, Cr, Zn and Mn) and acid-neutralizing capacity change of ash-added soils within the range of 0-10%, were also studied. Specially, when 5% bio-briquette combustion ash was added to the tested soil, the content of the effective elements such as Ca, Mg and K rose by 100 times, 7 times and twice, respectively. The total nitrogen also increased by about twice. The results showed the oxyanions such as that of Al, Cu, Cd, Cr, Zn and Mn were not potentially dangerous, because they were about the same as the averages of them in Chinese soil. It is shown that the ANC became stronger, though the ANC hardly increases in the ash-added soil. On the basis of the evaluation indices, it is concluded that the best mixture ratio is to add 2.5%-8% of the bio-briquette combustion ash to the tested soil.

[Nutrient dynamics over the past 100 years and its restoration baseline in Dianshan Lake].

The restoration of eutrophic lakes requires a good knowledge on the history and baseline of nutrients in the lakes. This work conducted an analysis on 210Pb/137Cs, water content, loss-on-ignition, sedimentary total phosphorus (TP), total nitrogen (TN), total organic carbon (TOC) and diatoms in the four sediment cores from Dianshan Lake (near Shanghai City). Good coherence in palaeoproxies between the cores indicates a relatively stable sedimentary environment. With increasing human impact, diatom communities shifted from oligo-trophic species Cyclotella bodanica, C. ocelata, Achnanthes minutissima, Cocconeis placentula var lineate, Cymbella sp. , Fragilaria pintata, F. brevistrata, F. construens var venter to recent eutrophic species including Cyclostephanos dubias, C. atomus, Stephanodiscus minitulus, S. hantzschi, Aulacoseria alpigena. The epilimnetic TP over the past 100 years reconstructed using an established diatom-TP transfer function matches well with the monitoring TP where exists. Based on the sedimentary nutrient characteristics and diatom-reconstructed nutrient dynamics, we proposed that the nutrient baseline for Dianshan Lake is 50-60 microg x L(-1), 500 mg x kg(-1) and 550 mg x kg(-1) for water TP concentration, sedimentary TP and TN, respectively.