Long series relationships between global interannual CO2 increment and climate: evidence for stability and change in role of the tropical and boreal-temperate zones

Interannual variability in global CO₂ increment (averaged from the Mauna Loa and South Pole Stations) shows certain strong spatial relationships to both tropical and temperate temperatures. There is a fairly strong positive year-round correlation between tropical mean annual temperatures (leading by 4 months) and annual CO₂ throughout the time series since 1960, agreeing with the generally held view that the tropics play a major role in determining inter-annual variability in CO₂ increment, with a major CO₂ pulse following a warm year in the tropics. This ‘almost no lag’ climatic response is very strong during winter and relatively stable in time. However, the correlation with tropical temperature appears to have weakened in the first years of the 1990s in correspondence of the Pinatubo eruption and the positive phase of the AO/NAO. A secondary concurrent temperature signal is linked to summer variations of north temperate belt. Northern summer temperatures in the region 30–60 °N—and especially in the land area corresponding to the central east USA—have become relatively more closely correlated with CO₂ increment. This trend has become increasingly stronger in recent years, suggesting an increasing role for growing season processes in the northern midlatitudes in affecting global CO₂ increment. Once non-lagged annual tropical temperature variations are accounted for, terrestrial ecosystems, especially the temperate-boreal biomes, also show a coherent large scale lagged response. This involves an inverse response to annual temperature of preceding years centered at around 2 years before. This lagged response is most likely linked to internal biogeochemical cycles, in particular N cycling. During the study period north boreal ecosystems show a strengthening of the lagged correlation with temperature in recent years, while the lagged correlation with areas of tropical ecosystems has weakened. Residuals from a multiple correlations based on these climatic signals are directly correlated with SO, confirming an additional important role of upwelling in interannual variability of CO₂ increment. Cooler summers following the Pinatubo eruption and the possible influence of the North Atlantic Oscillation (NAO/AO) are discussed as factors responsible for the shift in the relative importance of different regions over time during the series of data.     

好氧颗粒污泥实现同步硝化反硝化

采用人工配制的模拟生活污水，通过对运行条件的调控，在序批式反应器(SBR)中培养出了高活性的好氧颗粒污泥，颗粒污泥浓度达到4．55g/L以上，SVI值在32.5左右，反应器对于COD、NH3—N的去除率分别在83.6％—92.8％和82.3％—98.5％之间。实验结果表明：由于好氧颗粒污泥的存在，SBR反应器内发生了同步硝化反硝化(SND)反应，而不是通常所认为的顺序式硝化反硝化(SQND)反应。     

The effects of different carbon sources on microbial mediation of arsenic in arsenic-contaminated sediment

Changes in speciation and mobility of As by indigenous bacteria in As-contaminated sediments (339 mg/kg) from an abandoned Au–Ag mine area in Korea were investigated after biostimulation with a variety of carbon sources, including acetate, lactate and glucose in batch experiments. Sequential extraction analysis designed to determine the form of As occurrence revealed that 40 and 47% of As were present in the sediment as Fe-associated and residual fractions, respectively. After 22-day incubation with acetate and lactate, the presence of indigenous bacteria increased the amount of total dissolved As from both Fe-associated and residual fractions in the sediment. More than 99% of dissolved As existed as As(V) in biotic slurries in contrast to sterile controls (less than 50% of total dissolved As), which indicated that indigenous bacteria transformed some dissolved As(III) to As(V). In real environments, depending on the pH, microbially-produced aqueous As(V) may be either immobilized through adsorption or reduced to As(III) after migration to the anoxic subsurface.     

Lag Effects in the Impacts of Mass Coral Bleaching on Coral Reef Fish, Fisheries, and Ecosystems

Abstract:  Recent episodes of coral bleaching have led to wide-scale loss of reef corals and raised concerns over the effectiveness of existing conservation and management efforts. The 1998 bleaching event was most severe in the western Indian Ocean, where coral declined by up to 90% in some locations. Using fisheries-independent data, we assessed the long-term impacts of this event on fishery target species in the Seychelles, the overall size structure of the fish assemblage, and the effectiveness of two marine protected areas (MPAs) in protecting fish communities. The biomass of fished species above the size retained in fish traps changed little between 1994 and 2005, indicating no current effect on fishery yields. Biomass remained higher in MPAs, indicating they were effective in protecting fish stocks. Nevertheless, the size structure of the fish communities, as described with size-spectra analysis, changed in both fished areas and MPAs, with a decline in smaller fish (<30 cm) and an increase in larger fish (>45 cm). We believe this represents a time-lag response to a reduction in reef structural complexity brought about because fishes are being lost through natural mortality and fishing, and are not being replaced by juveniles. This effect is expected to be greater in terms of fisheries productivity and, because congruent patterns are observed for herbivores, suggests that MPAs do not offer coral reefs long-term resilience to bleaching events. Corallivores and planktivores declined strikingly in abundance, particularly in MPAs, and this decline was associated with a similar pattern of decline in their preferred corals. We suggest that climate-mediated disturbances, such as coral bleaching, be at the fore of conservation planning for coral reefs.     

北京市区公路旁尘土中铂族元素的化学形态

用ICP-MS 法检测北京市区公路旁尘土中铂、铑和钯各种形态的含量及总含量.结果表明,北京市区采样点公路旁土壤中铂,铑和钯的总量分别为154.23 ng·g-1,62.77 ng·g-1和 77.97 ng·g-1,其中非残留态的百分比含量为铑(37.82%) ＞钯(27.45%) ＞铂(26.87%);在自然条件作用下可进入地下水和可被植物吸收部分的百分比为铑(29.14%)＞钯(23.87%)＞＞铂(7.92%).     

Simulating study on the effect of acid precipitation on forest soil weathering

The effect of acid rain on the forest soils in China was discussed on the basis of simulating studies. The soils were collected from five typical areas, including Chongqing in Sichuan Province and Guiyang in Guizhou Province, where there has been heavier acid rain in southwest China, and Huitong in Hunan Province, Zhouzhi in Shaanxi Province, and Xinglong in Hebei Province, all of which were selected as control. Field investigation and sampling were made in the typical forests in all the above five areas. The relationship between pH values in precipitation and rates of soil weathering, the difference between the rates of soil weathering in different areas, and the cause of such a difference, have been worked out. The prediction was also conducted on the supply dynamics of nutrient and toxic elements in various forest ecosystems which were affected by acid deposition in order to understand the long-term effects of acid precipitation on the forest ecosystems studied.     

塿土中可给态镍浸提方法的研究

在前人工作的基础上,应用主成分分析、逐步回归分析和通径分析的方法,提出了(土娄)土中可给态镍的浸提方法及影响可给态镍的土壤性质.结果表明,DTPA浸提法可作为(土娄)土中可给态镍的浸提方法,铁锰氧化物结合态镍是(土娄)土可给镍的主要来源.碳酸盐结合态镍和有机质结合态镍是(土娄)土可给镍的潜在来源.它们在调控可给态镍的储量上起着重要作用.影响(土娄)土可给态镍最重要的土壤性质是pH和E_h_7.     

基于生态系统对宝鸡传统乡村旅游新模式探究

基于生态系统对宝鸡传统乡村旅游新模式进行了探究。首先通过分析宝鸡部分传统乡村旅游的现状,对宝鸡传统乡村旅游现状进行了介绍。提出宝鸡开展民俗旅游的一些不足之处;其次说明基于生态系统理念,对宝鸡传统乡村旅游和生态环境的促进作用;然后提出观光主题公园与乡村民俗旅游的结合,可以更好地促进乡村生态环境和乡村旅游的可持续性发展,更能充分开发旅游资源,丰富旅游项目,促进乡村环境和乡村经济的双重发展,使宝鸡传统乡村旅游新模式得到发展。     

一种高效测试污泥可生物降解性的实验方法研究

污泥的可生物降解性能由其有机组分的生物可及度和组分分子的复杂度共同决定。通过采用化学分级提取方法研究污泥组分的生物可及度,使用不同强度的提取溶液分离出4种化学可及度不同的提取组分,同时结合三维荧光光谱法对各组分中有机物质的复杂度进行分析。分析结果表明:组分的化学可及度与其生物可及度之间存在正相关关系;生物可及度较高,其成分有机物分子结构简单的组分SPOM(soluble particulate organic matter,SPOM)与REOM(readily extractible organic matter,REOM)在厌氧消化过程中降解率较高,分别为59.2%与46.3%的COD;而生物可及度低,组成复杂的组分SEOM(slowly extractible organic matter,SEOM)与PEOM(poorly extractible organic matter,PEOM)的生物降解率分别只有18.4%和5.8%的COD。     

A metapopulation approach of the dynamics of arthropods from Mediterranean-type ecosystems

In this paper we developed a general stage-structured, Leslie-type model, suitable to simulate dynamics of soil arthropods under typical Mediterranean conditions. In order to explore arthropods’ life-history strategies in relation to enhanced spatial heterogeneity of the Mediterranean ecosystems, metapopulation characteristics were considered and different habitat quality regimes, in terms of dominant microclimatic conditions, were taken into account. Environmental stochasticity in temperature and humidity was incorporated into the model, and an elasticity analysis was conducted to quantify contribution of different life-history traits to metapopulation growth rate. The application of the model revealed well-known life-cycle characteristics of Mediterranean arthropods, such as seasonally fluctuating population sizes and skewing phenologies, a fact that confirms models’ reliability. Furthermore, the model seems able to elucidate controversial points of the animals’ life-cycle development, such as the long-term maintenance of populations in the field and the underlying mechanisms related to the adjustment to the specific features of the Mediterranean ecosystem. Subpopulations inhabiting various microsites display different dynamics and the interaction between these subpopulations, via dispersion, seems to be able to ensure stochastic equilibrium for the system. Dispersal appears to play a decisive role, allowing arthropods to conform to spatial severities and habitats fragmentation, rescuing individuals and recolonizing previously extinct habitats.