阳极初始pH值对沉积型微生物燃料电池运行特性的影响

以太湖蓝藻水为主要处理对象,研究阳极区pH值对沉积型微生物燃料电池(Sediment Microbial Fuel Cell,SMFC)运行特性的影响.结果表明,SMFC系统阳极的碱性条件有利于功率密度的提高及污染物的去除.阳极初始pH值为5.5和8.5时,系统稳定运行功率密度和COD、VSS的去除率分别为3.5mW·m-2、7.3%、4.2%和5.4 mW·m-2、11.5%、9.2%.系统功率密度与污染物去除率呈正相关,污染物去除率越大,系统功率密度越高.     

外阻对污泥微生物燃料电池产电以及有机物降解的影响

重点考察了不同外阻（10、150和1 000Ω）对污泥微生物燃料电池（sludge microbial fuel cell,SMFC）产电性能及有机物去除速率的影响。结果表明,外阻对电池产电和有机物降解有显著影响,低电阻有利于电流产生及有机物消耗。当外阻为10Ω时,输出电流最高（4.2 mA）,且污泥溶解性化学需氧量（SCOD）去除速率最快（53 mg.d-1）。DGGE图谱显示,不同外阻导致阳极微生物菌落结构有明显差异;CV扫描发现外阻对生物膜氧化还原能力有显著影响,低电阻下运行的阳极生物膜氧化还原活性较强。本研究为理解外阻与阳极生物膜间的关系提供一条有益线索,也为MFC性能提高提供一条可操作性的途径。     

南方酸性森林土壤中铝活化过程参数化模型的建立与验证

基于模拟实验和原位观测,建立了适合我国南方酸性土壤的铝活化参数化模型.模拟实验发现,尽管Al3＋的活度随着浸提液pH值（pHw）的下降而显著增加（pAl=1.20pHw-0.30）,但同时受到土壤pH值（pHs）的显著影响（p〈0.01）.为反映土壤酸化程度（pHs）对铝活化过程的影响,假设三水铝石的pKsp随土壤pH...     

采用气体扩散电极降解酸性红B研究

采用Pt/C气体扩散电极(GDE)为阴极,对酸性红B溶液进行单室电解和双室电解.单室电解中,以GDE为阴极,效果远优于石墨阴极,H2O2生成量为石墨阴极的10倍,在pH=1时,具有最好的处理效果,电解40min,脱色率为78.3%.通过分室电解,对酸性红B的降解机理进行了分析,阳极区为阳极的直接氧化,受pH值、Fe2 和O2的影响较小;气体扩散阴极为通过还原O2生成H2O2,然后分解为羟基自由基,氧化有机物,受pH值,Fe2 ,O2的影响较大.当pH=3,Fe2 浓度为50mmol·l-1,空气流量为180L·h-1时,电解80min,阴极区的脱色率为94.2%,COD去除率为66.8%,而阳极区的脱色率为73.3%,COD去除率为56.2%,电流在阳极区和阴极区的利用效率加起来计算的“表观电流效率”达到145.3%.     

鸡爪槭光合特性对模拟酸雨的响应

研究了模拟酸雨（对照、pH 5.0、pH 4.0、pH 3.0、pH 2.0）胁迫对鸡爪槭（Acer palmatum Thunb.）叶片光合特性的影响。结果表明,试验前20 d,所有处理净光合速率日积分值（DIV of Pn）、蒸腾速率日积分值（DIV of Tr）及水分利用效率（WUE）日均值均显著高于对照（P〈0.05）。试验中后期（喷后40 d、喷后60 d）,pH 5.0的处理Pn日积分值均最高,WUE相对较高而Tr日积分值相对较低。pH≤4.0的处理在同一时期Pn日积分值、Tr日积分值均随pH值的降低而降低,WUE日均值变化趋势则相反。各处理Pn日积分值、Tr日积分值和WUE日均值均随试验时间的延长而降低。喷后60 d,pH 4.0的处理较pH 2.0和pH 3.0的处理WUE低而Pn日积分值和Tr日积分值则相反。综合分析表明,pH 5.0的酸雨处理有利于鸡爪槭叶片光合能力的发挥,酸度低于pH 3.0则会使光合能力下降,影响植株生长。     

乙草胺和丁草胺在土壤中的紫外光化学降解

采用实验室模拟实验研究了水分、pH值和表面活性剂对乙草胺和丁草胺在土壤中的紫外光降解行为的影响。结果表明，在湿度80％的土壤中，丁草胺和乙草胺的光解深度及光解速率均大于无水条件。随土壤pH值的增大，丁草胺在土壤中的光降解速率加快和光解深度加深。低浓度的阴 离子表面活性剂十二烷基苯磺酸钠（DDBS）促进丁草胺在土壤中的光解，使丁草胺在土壤中的光解深度增加。高浓度的DDBS对丁草胺在土壤中的光解有阻碍作用。阳离子表面活性剂十六烷基三甲基溴化铵（HDTMA）对丁草胺在土壤中的光解也有阻碍作用。     

环境因素对密云水库上游流域土壤有机碳和全氮含量影响的通径分析

土壤是全球重要的碳库和氮库,在全球碳氮循环中具有重要地位。密云水库是华北地区最大的水库和北京市最重要的地表水水源地,其上游流域山地广布,地形复杂,气候变化明显,土壤类型和植被类型多样,影响土壤碳氮库的环境因素具有较强的变异性。为揭示环境因素对密云水库上游流域土壤有机碳（soil organic carbon,SOC）和全氮（total nitrogen,TN）含量的作用效应,采用野外采样、实验室分析与逐步回归分析和通径分析相结合的方法,研究了气候（温度和降水）、地形（海拔和坡度）、土壤理化性质（土壤容重、含水量、pH值和粘粒含量）等环境因素对流域SOC和TN含量的影响。结果表明：温度、土壤容重、含水量、pH值和粘粒含量对SOC含量的影响显著（P＆lt;0.001）,其中各因子的直接通径系数依次为：土壤含水量（0.439）＞土壤容重（-0.324）＞pH值（-0.238）＞温度（-0.209）＞土壤粘粒含量（0.092）,间接通径系数依次为：土壤容重（-0.425）＞土壤粘粒含量（0.305）＞土壤含水量（0.287）＞pH值（-0.179）＞温度（-0.043）,因此,土壤含水量、pH值和温度主要通过直接作用影响SOC含量,而土壤容重和粘粒含量则主要通过其它因子的作用间接影响SOC含量。海拔、土壤容重、含水量、pH 值和粘粒含量对 TN 含量的影响显著（P＆lt;0.001）,其中各因子的直接通径系数依次为：土壤含水量（0.456）＞海拔（0.234）＞土壤容重（-0.228）＞pH 值（-0.190）＞土壤粘粒含量（0.094）,间接通径系数依次为：土壤容重（-0.484）＞土壤粘粒含量（0.301）＞海拔（0.247）＞土壤含水量（0.257）＞pH 值（-0.202）,因此,土壤含水量主要通过直接作用影响TN含量,而土壤容重和粘粒含量主要通过土壤含水量的作用间接影响TN含量,海拔和土壤pH值的直接作用与间接作用     

化感链霉菌6803菌株液体发酵工艺优化的研究

土壤微生物链霉菌6803菌株被证明对高等植物具有化感作用。采用单因子实验方法,研究液体发酵碳源、氮源、无机盐、发酵温度、发酵液初始pH值、摇床转速、发酵时间等对链霉菌6803菌株菌丝体产量及发酵液化感作用的影响,用均匀试验设计法优化了发酵工艺条件。结果表明：链霉菌6803菌株生长和产生化感作用的最佳发酵条件为：p（淀粉）=26．67g·L-1,p（蔗糖）=25．15g·L-1,p（NH4C1）=0．30g．L-1,黄豆饼粉浸液8．88％,所（NI-h）H2P04]=O．18g·L-1,p（FeS04．7H20）=O．002g·L-1,p（NaCl）=0．75g·L-1,pH值7．6,装量系数O．16,接种量3％,温度36℃,转速200r·min-1,发酵144h。本研究为利用微生物次生代谢产物作为天然除草剂奠定了基础。     

低传质阻力渗流式纳米电极电化学反应器处理活性艳蓝X-BR

采用渗流式电化学反应器,以碳纳米管和活性碳纤维作为反应器的阳极.选取活性艳蓝X-BR模拟废水作为实验对象,计算电化学过程的传质系数,考察电压、pH值和电解质对活性艳蓝脱色的影响,在优化条件下(电压为8V,pH=2,电解质浓度为1g·l-1),对浓度为200mg·l-1活性艳蓝X-BR的脱色率可达90%以上.     

酸雨胁迫对木荷叶片气体交换和叶绿素荧光参数的影响

通过盆栽试验,研究了3种不同pH值（2.5、4.0、5.6）的模拟酸雨溶液对2年生木荷（Schima superba）幼苗叶片气体交换和荧光参数的影响。结果表明：在不同酸雨处理下,净光合速率和气孔导度日变化均呈＂双峰＂型,最大净光合速率和最高表观量子效率（AQE）变化趋势依次是pH4.0〉pH5.6〉pH2.5,说明pH4.0处理对木荷光合作用有促进作用;在不同酸雨处理下,PSⅡ原初光能转换效率（Fv/Fm）、PSⅡ潜在活性（Fv/Fo）和相对叶绿素含量均呈现出pH4.0〉pH5.6〉pH2.5的变化趋势,pH4.0酸雨处理下表现出最高值,说明适度降低酸雨pH值（pH4.0）并不会对木荷的光合系统活性造成损伤,反而有促进作用,表明木荷对酸雨有较强的适应能力。     

Achieving Open Access to Conservation Science

Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación     

Some polyphagous Homoptera gain protection from their natural enemies by feeding on the toxic plantsSpartium junceum andErythrina corallodendrum (Leguminosae)

Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.     

Sequestration of cucurbitacin analogs by New and Old World chrysomelid leaf beetles in the tribe Luperini

Summary Two South American polyphagous leaf beetles,Diabrotica speciosa andCerotoma arcuata, selectively accumulated the bitter tasting compound 23,24-dihydrocucurbitacin D in their body after ingesting root tissues of cucurbit plants. Similarly, three Asian Cucurbitaceae-feeding specialists in the genusAulacophora were found to sequester the same compound. Cucurbitacin analogs were shown to deter feeding by a bird predator, indicating an allomonal role for these compounds in cucurbitacin-associated chrysomelid leaf beetles both of New and Old Worlds. The strong affinity to cucurbitacins, selective sequestration of the analogs and consequent protection from predators suggested an ecological adaptation mechanism developed in common among these two geographically isolated subtribes in the Luperini.     

Effects of Controlled Fire and Livestock Grazing on Bird Communities in East African Savannas

Abstract: In East Africa fire and grazing by wild and domestic ungulates maintain savannas, and pastoralists historically set fires and herded livestock through the use of temporary corrals called bomas. In recent decades traditional pastoral practices have declined, and this may be affecting biodiversity. We investigated the effects of prescribed fires and bomas on savanna bird communities in East Africa during the first and second dry seasons of the year (respectively before and after the rains that mark the onset of breeding for most birds). We compared abundance, richness, and community composition on 9‐ha burned plots, recently abandoned bomas, and control plots in the undisturbed matrix habitat over a 3‐year period. Generally, recently burned areas and abandoned bomas attracted greater densities of birds and had different community assemblages than the surrounding matrix. The effects of disturbances were influenced by interactions between primary productivity, represented by the normalized difference vegetation index, and time. Bird densities were highest and a greater proportion of species was observed on burned plots in the months following the fires. Drought conditions equalized bird densities across treatments within 1 year, and individuals from a greater proportion of species were more commonly observed on abandoned bomas. Yearly fluctuations in abundance were less pronounced on bomas than on burns, which indicate that although fire may benefit birds in the short term, bomas may have a more‐lasting positive effect and provide resources during droughts. Several Palearctic migrants were attracted to burned plots regardless of rainfall, which indicates continued fire suppression may threaten their already‐declining populations. Most notably, the paucity of birds observed on the controls suggests that the current structure of the matrix developed as a result of fire suppression. Traditional pastoralism appears critical to the maintenance of avian diversity in these savannas.     

What Every Conservation Biologist Should Know about Economic Theory

Abstract: The last century has seen the ascendance of a core economic model, which we will refer to as Walrasian economics. This model is driven by the psychological assumptions that humans act only in a self‐referential and narrowly rational way and that production can be described as a self‐contained circular flow between firms and households. These assumptions have critical implications for the way economics is used to inform conservation biology. Yet the Walrasian model is inconsistent with a large body of empirical evidence about actual human behavior, and it violates a number of basic physical laws. Research in behavioral science and neuroscience shows that humans are uniquely social animals and not self‐centered rational economic beings. Economic production is subject to physical laws including the laws of thermodynamics and mass balance. In addition, some contemporary economic theory, spurred by exciting new research in human behavior and a wealth of data about the negative global impact of the human economy on natural systems, is moving toward a world view that places consumption and production squarely in its behavioral and biophysical context. We argue that abandoning the straightjacket of the Walrasian core is essential to further progress in understanding the complex, coupled interactions between the human economy and the natural world. We call for a new framework for economic theory and policy that is consistent with observed human behavior, recognizes the complex and frequently irreversible interaction between human and natural systems, and directly confronts the cumulative negative effects of the human economy on the Earth's life support systems. Biophysical economics and ecological economics are two emerging economic frameworks in this movement.     

Effects of Coffee Management on Deforestation Rates and Forest Integrity

Knowledge about how forest margins are utilized can be crucial for a general understanding of changes in forest cover, forest structure, and biodiversity across landscapes. We studied forest‐agriculture transitions in southwestern Ethiopia and hypothesized that the presence of coffee (Coffea arabica)decreases deforestation rates because of coffee's importance to local economies and its widespread occurrence in forests and forest margins. Using satellite images and elevation data, we compared changes in forest cover over 37 years (1973–2010) across elevations in 2 forest‐agriculture mosaic landscapes (1100 km² around Bonga and 3000 km² in Goma‐Gera). In the field in the Bonga area, we determined coffee cover and forest structure in 40 forest margins that differed in time since deforestation. Both the absolute and relative deforestation rates were lower at coffee‐growing elevations compared with at higher elevations (?10/20% vs. ?40/50% comparing relative rates at 1800 m asl and 2300–2500 m asl, respectively). Within the coffee‐growing elevation, the proportion of sites with high coffee cover (>20%) was significantly higher in stable margins (42% of sites that had been in the same location for the entire period) than in recently changed margins (0% of sites where expansion of annual crops had changed the margin). Disturbance level and forest structure did not differ between sites with 30% or 3% coffee. However, a growing body of literature on gradients of coffee management in Ethiopia reports coffee's negative effects on abundances of forest‐specialist species. Even if the presence of coffee slows down the conversion of forest to annual‐crop agriculture, there is a risk that an intensification of coffee management will still threaten forest biodiversity, including the genetic diversity of wild coffee. Conservation policy for Ethiopian forests thus needs to develop strategies that acknowledge that forests without coffee production may have higher deforestation risks than forests with coffee production and that forests with coffee production often have lower biodiversity value. Efectos de la Administración Cafetalera sobre las Tasas de Deforestación y la Integridad de los Bosques     

Globalization of the Cashmere Market and the Decline of Large Mammals in Central Asia

As drivers of terrestrial ecosystems, humans have replaced large carnivores in most areas, and human influence not only exerts striking ecological pressures on biodiversity at local scales but also has indirect effects in distant corners of the world. We suggest that the multibillion dollar cashmere industry creates economic motivations that link western fashion preferences for cashmere to land use in Central Asia. This penchant for stylish clothing, in turn, encourages herders to increase livestock production which affects persistence of over 6 endangered large mammals in these remote, arid ecosystems. We hypothesized that global trade in cashmere has strong negative effects on native large mammals of deserts and grassland where cashmere‐producing goats are raised. We used time series data, ecological snapshots of the biomass of native and domestic ungulates, and ecologically and behaviorally based fieldwork to test our hypothesis. In Mongolia increases in domestic goat production were associated with a 3‐fold increase in local profits for herders coexisting with endangered saiga (Saiga tatarica).That increasing domestic grazing pressure carries fitness consequences was inferred on the basis of an approximately 4‐fold difference in juvenile recruitment among blue sheep (Pseudois nayaur)in trans‐Himalayan India. Across 7 study areas in Mongolia, India, and China's Tibetan Plateau, native ungulate biomass is now <5% that of domestic species. Such trends suggest ecosystem degradation and decreased capacity for the persistence of native species, including at least 8 Asian endemic species: saiga, chiru (Pantholops hodgsoni), Bactrian camel (Camelus bactrianus), snow leopard(Panthera uncia), khulan(Equus hemionus), kiang (E. kiang), takhi (E. przewalski), and wild yak (Bos mutus). Our results suggest striking yet indirect and unintended actions that link trophic‐level effects to markets induced by the trade for cashmere. Globalización del Mercado de Cachemira y la Declinación de Mamíferos Mayores en Asia Central     

The lichen-rich coastal heath vegetation on the isle of Anholt, Denmark — conservation and management

The high conservational value of the lichen-rich vegetation and landscape of the marine foreland Ørkenen on the isle of Anholt is treated from a Danish as well as a European perspective. The sensitivity of the lichen-rich vegetation to physical disturbance is emphasized. The impact of invasive species such asPinus mugo as well as the effect of atmospheric deposition of nutrients on the heaths at Anholt is described. Considerations related to the development of a management plan for Ørkenen are presented.     

Behavior and ecology of Old World Luperini beetles of the genusAulacophora (Coleoptera: Chrysomelidae)

Summary The attraction of Old World leaf beetles in the genusAulacophora to kairomones and parakairomones which are effective lures for New WorldDiabrotica andAcalymma were investigated. Beetles captured on sticky traps baited with single and multicomponent lures were no different from the control traps for two species ofAulacophora. Yellow colored traps and squash blossoms are attractive toAulacophora beetles which detect sub-microgram quantities of cucurbitacins on silica gel. Leaf feeding behavior and flight activity data are correlated with varietal preference of threeAulacophora species. The common response byDiabrotica andAulacophora to cucurbitacins reinforces the two groups' coevolutionary association with the Cucurbitaceae. The apparent lack of a common response toCucurbita blossom volatiles suggests recent evolutionary pathways are substantially different for these two groups of beetles.     

Use of stochastic patch occupancy models in the California red-legged frog for Bayesian inference regarding past events and future persistence

Assessing causes of population decline is critically important to management of threatened species. Stochastic patch occupancy models (SPOMs) are popular tools for examining spatial and temporal dynamics of populations when presence–absence data in multiple habitat patches are available. We developed a Bayesian Markov chain method that extends existing SPOMs by focusing on past environmental changes that may have altered occupancy patterns prior to the beginning of data collection. Using occupancy data from 3 creeks, we applied the method to assess 2 hypothesized causes of population decline—in situ die-off and residual impact of past source population loss—in the California red-legged frog. Despite having no data for the 20–30 years between the hypothetical event leading to population decline and the first data collected, we were able to discriminate among hypotheses, finding evidence that in situ die-off increased in 2 of the creeks. Although the creeks had comparable numbers of occupied segments, owing to different extinction–colonization dynamics, our model predicted an 8-fold difference in persistence probabilities of their populations to 2030. Adding a source population led to a greater predicted persistence probability than did decreasing the in situ die-off, emphasizing that reversing the deleterious impacts of a disturbance may not be the most efficient management strategy. We expect our method will be useful for studying dynamics and evaluating management strategies of many species.