Development of Customized Fire Behavior Fuel Models for Boreal Forests of Northeastern China

Knowledge of forest fuels and their potential fire behavior across a landscape is essential in fire management. Four customized fire behavior fuel models that differed significantly in fuels characteristics and environmental conditions were identified using hierarchical cluster analysis based on fuels data collected across a boreal forest landscape in northeastern China. Fuel model I represented the dense and heavily branched Pinus pumila shrubland which has significant fine live woody fuels. These forests occur mainly at higher mountain elevations. Fuel model II is applicable to forests dominated by Betula platyphylla and Populus davidiana occurring in native forests on hill slopes or at low mountain elevations. This fuel model was differentiated from other fuel models by higher herbaceous cover and lower fine live woody loading. The primary coniferous forests dominated by Larix gmelini and Pinus sylvestris L. var. mongolica were classified as fuel model III and fuel model IV. Those fuel models differed from one another in average cover and height of understory shrub and herbaceous layers as well as in aspect. The potential fire behavior for each fuel model was simulated with the BehavePlus5.0 fire behavior prediction system. The simulation results indicated that the Pinus pumila shrubland fuels had the most severe fire behavior for the 97th percentile weather condition, and had the least severe fire behavior under 90th percentile weather condition. Fuel model II presented the least severe fire potential across weather conditions. Fuel model IV resulted in greater fire severity than Fuel model III across the two weather scenarios that were examined.     

石化废水深度处理用臭氧催化氧化体系的研究＊

文章就臭氧催化氧化体系在石化废水处理中的作用进行了深入研究,对催化剂载体、催化剂配伍体系以及臭氧的投加方式进行了优化筛选。根据实验,多元催化掺杂体系较一元催化体系氧化效果好,CODCr的去除率可由一元催化时的20%提高到多元催化时的33%;在臭氧的投加方式上,分段投加要优于单级投加,臭氧投加分配比例为6∶3∶1时,CODCr的去除率可由单一投加时的9%提高到分级投加时的19%。     

Numerical simulation for impacts of hydrodynamic conditions on algae growth in Chongqing Section of Jialing River, China

Hydrodynamic conditions are important factors for planktonic algae growth, through introducing two parameters which express the optimal velocity and the velocity range for planktonic algae growth, a new velocity factor was put forward for the formula of growth rate. Therefore, the two-dimensional unsteady ecological dynamic model for algae growth was established to analyze the effects of hydrodynamic conditions on algae growth in Chongqing Reach of Jialing River in China. The temporal and spatial distribution of Chlorophyll-a (Chl-a) concentration was simulated numerically for various water levels, under climate conditions in period of high frequency for algae blooms of Three Gorges Reservoir and nutrition status at present in the research reach. The corresponding locations and areas of likely algae blooms were analyzed and forecasted. The results showed that about 0.04 m s⁻¹ was the optimal velocity for algae growth, and the occurrence of algae blooms in large scale is almost impossible because of relatively high water flow velocity for Jialing River.     

Population viability of the Siberian Tiger in a changing landscape: Going, going and gone?

The Amur tiger (Panthera tigris altaica) is a flagship species of the boreal forest ecosystem in northeastern China and Russia Far East. During the past century, the tiger population has declined sharply from more than 3000 to fewer than 600 individuals, and its habitat has become much smaller and greatly fragmented. Poaching, habitat degradation, habitat loss, and habitat fragmentation have been widely recognized as the primary causes for the observed population decline. Using a population viability analysis tool (RAMAS/GIS), we simulated the effects of poaching, habitat degradation, habitat loss, and habitat fragmentation on the population dynamics and extinction risk of the Amur tiger, and then explored the relative effectiveness of three conservation strategies involving improving habitat quality and establishing movement corridors in China and Russia. A series of controlled simulation experiments were performed based on the current spatial distribution of habitat and field-observed vital rates. Our results showed that the Amur tiger population could be viable for the next 100 years if the current habitat area and quality were well-maintained, with poaching strictly prohibited of the tigers and their main prey species. Poaching and habitat degradation (mainly prey scarcity) had the largest negative impacts on the tiger population persistence. While the effect of habitat loss was also substantial, habitat fragmentation per se had less influence on the long-term fate of the tiger population. However, to sustain the subpopulations in both Russia and China would take much greater conservation efforts. The viability of the Chinese population of tigers would rely heavily on its connectivity with the largest patch on the other side of the border. Improving the habitat quality of small patches only or increasing habitat connectivity through movement corridors alone would not be enough to guarantee the long-term population persistence of the Amur tiger in both Russia and China. The only conservation strategy that allowed for long-term persistence of tigers in both countries required both the improvement of habitat quality and the establishment of a transnational reserve network. Our study provides new insights into the metapopulation dynamics and persistence of the Amur tiger, which should be useful in landscape and conservation planning for protecting the biggest cat species in the world.     

Trap barricading and decorating by a well-armored sit-and-wait predator: extra protection or prey attraction?

Animals may build multiple structures to provide benefits to counter the costs of building. Many orb web spiders add multiple structures, e.g., barricading barrier webs and silk decorations, to their webs and these structures have been hypothesized to function to deter predators or attract prey. The heavily armored spiny spiders construct barrier webs around their orb webs and decorate them with conspicuous silk tufts. Why these organisms, already well protected by a thick cuticle and spines, make the extra investment of building barrier webs and adding conspicuous silk decorations is not known. We predicted that these structures function to both attract prey and deter predators. Field experiments were conducted in two consecutive years using orb webs built by the East Asian spiny spider Thelacantha brevispina. We either (1) concealed the decoration, (2) removed the barrier webs, or (3) left the decorations and barrier webs intact. We found year and treatment to interactively influence prey interception rates. In 2010, but not in 2009, we found prey interception with T. brevispina webs to be greater when the decorations were conspicuous than when they were concealed suggesting that the decorations may lure prey. Prey interception was lower when the barrier webs were present without decorations compared to when they were absent without decorations. The prey-attracting function of the decorations thus may counter the reduction in prey interception incurred by adding a barrier web. Predatory wasp interactions were not influenced by any of our treatments, probably because the spiders’ thick cuticle is the primary means of protection from wasps. Bird predation events, while rare, occurred only when decorations were concealed or the barrier webs were removed. It is therefore plausible that the tuft decorations both lure prey and deter birds.     

Atmospheric-particulates-bound mercury Hg(p) study at five characteristic sampling sites in Taiwan

The main purpose for this study is to observe the seasonal and month variations for particulates-bound mercury Hg(p) in total suspended particulates (TSP) concentration, dry deposition at five characteristic sampling sites during years of 2009-2010 in central Taiwan. The results show that the highest and lowest monthly average particulates-bound mercury Hg(p) concentrations in TSP were occurred in Dec. and Oct. at Gao-mei (wetland), Chang-hua (downtown) and He-mei (residential) sampling site. In addition, the results show that the highest and lowest monthly average particulates-bound mercury Hg(p) dry deposition was occurred in Feb. and Oct. at Quan-xing (industrial) sampling site. This study reflected that the mean highest particulates-bound mercury Hg(p) concentrations in TSP and mean highest particulates-bound mercury Hg(p) dry deposition were occurred at Gao-mei (wetland) and Quan-xing (industrial). However, the mean lowest particulates-bound mercury Hg(p) concentrations in TSP and mean lowest particulates-bound mercury Hg(p) dry deposition were also occurred at Gao-mei (wetland). Regarding seasonal variation, the order of mean-particulates-bound mercury Hg(p) concentrations in TSP in winter and spring were Gao-mei (wetland) > Quan-xing (industrial) > Bei-shi (suburban/coastal) > Chang-hua (downtown) > He-mei (residential). Finally, the order of mean-particulates-bound mercury Hg(p) dry deposition in fall, spring and summer were Quan-xing (industrial) > Bei-shi (suburban/coastal) > Chang-hua (downtown) > He-mei (residential) > Gao-mei (wetland).     

Impact of urbanization on natural ecosystem service values: a comparative study

With rapid population growth and rural to-urban migration in many Chinese cities, a large amount of natural lands have been converted to urban and agricultural lands recently. During this process of land conversion, economic development and quality of life improvement are considered as major goals, and their influences on ecological systems have often been neglected. The degradation of natural ecological systems due to land use change, however, has become severe,and may require immediate attentions from urban planners and local governments. Taking HaDaQi industrial corridor, Heilongjiang Province, China,as a case study area, this paper examined the trend of land use changes during 1990–2005, and quantified their influences on natural eco system service values. In particular, this study applied two major valuation methods, and examined whether different valuation methods generate significantly different results. Analysis of results suggests that human dominated land uses (e.g., urban and agriculture)have expanded rapidly at the cost of natural lands (e.g., wetlands and forest). Due to these land use changes, the total ecosystem service value decreased 29% (2.26% annually) from 1990 to 2005 when the first method was applied, and this rate is estimated to be 15.7% (1.13% annually)with the second approach. Moreover, the annual rate of ecosystem service value decline during 2000–2005 is about four times higher than that in 1990–2000 with both methods, suggesting much more severe ecosystem degradation during 2000–2005.     

煤质活性炭在饮用水处理应用中值得探讨的问题

本文介绍了煤质活性炭在饮用水处理应用中存在的如何选择活性炭的性能指标,煤质活性炭新旧国家标准的变化及煤质活性炭的再生等值得探讨问题。本文对煤质活性炭饮用水处理的应用具有一定的意义。     

Occurrence and behaviour of nonylphenol and octylphenol in Nanming River, Guiyang City, China

Occurrence, variation and behaviour of nonylphenol (NP) and octylphenol (OP) were studied in surface water and groundwater in Guiyang, Guizhou Province, southwestern China. Discharge of wastewater from Guiyang City was the main source of alkylphenols (APs) entering the aquatic environment. The concentrations of NP and OP in river water ranged from 40 to 1582 ng L(-1) and from below the lowest limit of detection (LOD) to 67 ng L(-1), respectively. NP and OP were also detected in groundwater. Both NP and OP exhibited spatial and temporal variations in river water and groundwater. It was found that concentrations of NP and OP in river water was low upstream and dramatically increased downstream, and higher concentration of NP was found in winter compared to that in summer. Proportions of NP and OP were trapped by suspended particulate matter (SPM), which accounted for 7.6-50.0% and 3.4-25.6% of their total concentration in the river water system, respectively. Seasonal changes in water flow were responsible for the temporal variations of APs. To determine the behaviour of APs along the river, a mass balance equation based on chloride was used. The results showed that a mixing process was the predominant factor to determine upstream APs concentrations; while the discharge of wastewater controlled the concentrations of APs downstream. Considering the adverse effect of APs on organisms, combined effect modeling was used to assess the toxicity to fish. It was found that the predicted mixture effect for APs in river water on fish vitellogenin induction was low upstream and medium downstream, respectively.