Dinoflagellate cysts as potential indicators of industrial pollution in a Norwegian Fjord

Variation in dinoflagellate cyst assemblages through the last approximately 300 years was studied in two sediment cores, one from the heavily polluted Frierfjord, and one from the adjoining, relatively unpolluted Brevikfjord, in order to docu1ent possible dinoflagellate responses to pollution. Changes in the cyst-flora were compared with historical information on the development of industry and also with geochemistry of the sediments, reflecting aspects of pollution. In the Frierfjord core, increasing pollution was accompanied by a decrease in cyst concentration, possibly reflecting reduced production, at least of dinoflagellates, and a shift toward more heterotrophic species, possibly reflecting reduced light penetration in the euphotic zone, or increased production of prey for the heterotrophs. These trends seem to have reversed as pollution decreased after about 1975, suggesting that cyst assemblages contain signals that may prove useful for tracing the development of pollution. Cyst assemblages in the Brevikfjord core only showed minor changes.

automated test program generation for an industrial optimizing compiler

Association for Computing Machinery, ACM; IEEE; IEEE Computer Society; SIGSOFT

Estimation and Spatiotemporal Analysis of Methane Emissions from Agriculture in China

National Natural Science Foundation of China [30721140307, 30590380]; Chinese Academy of Sciences (CAS) [KZCX2-YW-432]

Industrial development and land use/cover change and their effects on local environment: a case study of Changshu in eastern coastal China

The interactions among industrial development, land use/cover change (LUCC), and environmental effects in Changshu in the eastern coastal China were analyzed using high-resolution Landsat TM data in 1990, 1995, 2000, and 2006, socio-economic data and water environmental quality monitoring data from research institutes and governmental departments. Three phases of industrial development in Changshu were examined (i.e., the three periods of 1990 to 1995, 1995 to 2000, and 2000 to 2006). Besides industrial development and rapid urbanization, land use/cover in Changshu had changed drastically from 1990 to 2006. This change was characterized by major replacements of farmland by urban and rural settlements, artificial ponds, forested and constructed land. Industrialization, urbanization, agricultural structure adjustment, and rural housing construction were the major socio-economic driving forces of LUCC in Changshu. In addition, the annual value of ecosystem services in Changshu decreased slightly during 1990-2000, but increased significantly during 2000-2006. Nevertheless, the local environmental quality in Changshu, especially in rural areas, has not yet been improved significantly. Thus, this paper suggests an increased attention to fully realize the role of land supply in adjustment of environment-friendly industrial structure and urban-rural spatial restructuring, and translating the land management and environmental protection policies into an optimized industrial distribution and land-use pattern.

Environmental Kuznets Curve for SO_2 Emissions in China

This study examines the link between the economic growth and the environmental quality. Based on a panel data set, a N-shaped Environmental Kuzents Curve has been found for the sample period: a cubic relationship between per capita GDP and emissions of sulphur dioxide (SO2). We also find that energy consumption is an important determinant of environmental degradation. The empirical results suggest that we should promote environmental protection as soon as possible.

Comparative study on CO2 emissions from different types of alpine meadows during grass exuberance period

Potentilla fruticosa scrub, Kobresia humilis meadow and Kobresia tibetica meadow are widely distributed on the Qinghai-Tibet Plateau. During the grass exuberance period from 3 July to 4September, based on close chamber-GC method, a study on CO2 emissions from different treatments was conducted in these meadows at Haibei research station, CAS. Results indicated that mean CO2emission rates from various treatments were 672.09+152.37 mgm-2h-1 for FC (grass treatment); 425.41+191.99 mgrn-2h-1 for FJ (grass exclusion treatment); 280.36+174.83 mgrn-2h-1 for FL (grass and roots exclusion treatment); 838.95+237.02 mgm-2h-1 for GG (scrub+grass treatment); 528.48+205.67 mgm-2h-1for GC (grass treatment); 268.97 ±99.72 mgm-2h-1 for GL (grass and roots exclusion treatment); and 659.20±94.83 mgm-2h-1 for LC (grass treatment), respectively (FC, FJ, FL, GG, GC, GL, LC were the Chinese abbreviation for various treatments). Furthermore, Kobresia humilis meadow, Potentilla fruticosa scrub meadow and Kobresia tibetica meadow differed greatly in average CO2 emission rate of soil-plant system, in the order of GG＞FC＞LC＞GC. Moreover, in Kobresia humilis meadow,heterotrophic and autotrophic respiration accounted for 42% and 58% of the total respiration of soil-plant system respectively, whereas, in Potentilla fruticosa scrub meadow, heterotrophic and autotrophic respiration accounted for 32% and 68% of total system respiration from G-G; 49% and 51%from GC. In addition, root respiration from Kobresia humilis meadow approximated 145 mgCO2m-2h-1,contributed 34% to soil respiration. During the experiment period, Kobresia humilis meadow and Potentilla fruticosa scrub meadow had a net carbon fixation of 111.11 grn-2 and 243.89 grn-2,respectively. Results also showed that soil temperature was the main factor which influenced CO2 emission from alpine meadow ecosystem, significant correlations were found between soil temperature at 5 cm depth and CO2 emission from GG, GC, FC and FJ treatments. In addition, soil moisture may be the inhibitory factor of CO2 emission from Kobresia tibetica meadow, and more detailed analyses should be done in further research.

Methane emissions by alpine plant communities in the Qinghai-Tibet Plateau

For the first time to our knowledge, we report here methane emissions by plant communities in alpine ecosystems in the Qinghai-Tibet Plateau. This has been achieved through long-term field observations from June 2003 to July 2006 using a closed chamber technique. Strong methane emission at the rate of 26.2 +/- 1.2 and 7.8 +/- 1.1 mu g CH4 m(-2) h(-1) was observed for a grass community in a Kobresia humilis meadow and a Potentilla fruticosa meadow, respectively. A shrub community in the Potentilla meadow consumed atmospheric methane at the rate of 5.8 +/- 1.3 mu g CH4 m(-2) h(-1) on a regional basis; plants from alpine meadows contribute at least 0.13 Tg CH4 yr(-1) in the Tibetan Plateau. This finding has important implications with regard to the regional methane budget and species-level difference should be considered when assessing methane emissions by plants.

Nitrous oxide emissions from two alpine meadows in the Qinghai-Tibetan Plateau

Nitrous oxide (N2O) emission was measured in a Kobresia humilis meadow and a Potentilla fruticosa meadow in the Qinghai-Tibet Plateau from June 2003 to July 2006. Five treatments were setup in the two alpine meadows. Two bare soil treatments were setup in the K. humilis meadow (BSK) and in the P. fruticosa meadow (BSP) by removing the above- and belowground plant biomass. Three plant community treatments were setup with one in the K. humilis meadow (herbaceous community in the K. humilis meadow-HCK) and two in the P. fruticosa meadow (herbaceous community in the P. fruticosa meadow-HCP, and shrub community in the P. fruticosa meadow-SCP). Nitrous oxide emission from BSP was estimated to be 38.1 +/- 3.6 mu g m(-2) h(-1), significantly higher than from BSK (30.2 +/- 2.8 mu g m(-2) h(-1)) during the whole experiment period. Rates from the two herbaceous blocks (HCK and HCP) were close to 39.5 mu g m(-2) stop h(-1) during the whole experimental period whereas shrub community (SCP) showed significant high emission rates of N2O. Annual rate of N2O emission was estimated to be 356.7 +/- 8.3 and 295.0 +/- 11.6 mg m(-2) year(-1) from the alpine P. fruticosa meadow and from the alpine K. humilis meadow, respectively. These results suggest that alpine meadows in the Qinghai-Tibetan Plateau are an important source of N2O, contributing an average of 0.3 Tg N2O year(-1). We concluded that N2O emission will decrease, due to a predicted vegetation shift from shrubs to grasses imposed by overgrazing.

Methane emissions from different vegetation zones in a Qinghai-Tibetan Plateau wetland

We measured methane (CH4) emissions in the Luanhaizi wetland, a typical alpine wetland on the Qinghai-Tibetan Plateau, China, during the plant growth season (early July to mid-September) in 2002. Our aim was to quantify the spatial and temporal variation of CH4 flux and to elucidate key factors in this variation. Static chamber measurements of CH4 flux were made in four vegetation zones along a gradient of water depth. There were three emergent-plant zones (Hippuris-dominated; Scirpus-dominated; and Carex-dominated) and one submerged-plant zone (Potamogeton-dominated). The smallest CH4 flux (seasonal mean = 33.1 mg CH4 m(-2) d(-1)) was, observed in the Potamogeton-dominated zone, which occupied about 74% of the total area of the wetland. The greatest CH4 flux (seasonal mean = 214 mg CH4 m(-2) d(-1)) was observed in the Hippuris-dominated zone, in the second-deepest water area. CH4 flux from three zones (excluding the Carex-dominated zone) showed a marked diurnal change and decreased dramatically under dark conditions. Light intensity had a major influence on the temporal variation in CH4 flux, at least in three of the zones. Methane fluxes from all zones increased during the growing season with increasing aboveground biomass. CH4 flux from the Scirpus-dominated zone was significantly lower than in the other emergent-plant zones despite the large biomass, because the root and rhizome intake ports for CH4 transport in the dominant species were distributed in shallower and more oxidative soil than occupied in the other zones. Spatial and temporal variation in CH4 flux from the alpine wetland was determined by the vegetation zone. Among the dominant species in each zone, there were variations in the density and biomass of shoots, gas-transport system, and root-rhizome architecture. The CH4 flux from a typical alpine wetland on the Qinghai-Tibetan Plateau was as high as those of other boreal and alpine wetlands. (C) 2004 Elsevier Ltd. All rights reserved.