长白山藓类植物在失水干燥及再水化过程中的CO_2同化能力和呼吸速率的变化

利用ＣＯ２红外分析仪检测了５种长白山藓类植物在失水干燥及重新吸水过程中的ＣＯ２交换速率．结果表明：５种藓类光合作用最适含水量［ｗ／（ｇ·ｇ－１）］为４～６；植物体蓄水过多时，会增加了ＣＯ２扩散阻力，光合速率下降，由于结构及生理上的差异，种与种之间净光合为０时含水量值变动较大．空气中干燥５ｄ的植物体吸水后，开始时有一个呼吸峰出现，之后呼吸速率逐渐恢复到正常状况；光合作用恢复速率要比呼吸作用慢．所有５种藓类植物在吸水１ｄ后光合活力即可恢复到失水之前的原初水平，说明空气中短期干燥对其光合能力无明显影响．     

环境条件变化对太湖沉积物磷释放的影响

本文系统研究了环境条件变化对太湖沉积物磷释放的影响，结果表明：温度、ＰＨ、氧化还原条件对沉积物磷释放有很大影响，获得了在不同环境条件下磷释放的方程，结果还表明，厌氧下（ＤＯ〈１．０ｍｇ．ｌ＾－１）沉积物磷的最大释放量明显高于好氧条件（ＤＯ〉８．０ｍｇ．ｌ＾－１），其释放速率分别为３．１４μｇ．ｇ＾－１．ｄ＾－１和２．７５μｇ＾－１．ｄ＾－１，相应的动力学方程可表示为ＣＰ＝Ａｅ＾ｂ／ｔ，观察到藻与沉     

九龙江口桐花树红树林对重金属的吸收与累积

探讨了福建九龙江口桐花树红树林对ＣＵ、Ｐｈ、Ｚｎ、Ｃｄ、Ｍｎ元素的吸收、累积及分布．结果表明：该林地土壤５种元素的储量关系为Ｍｎ＞Ｚｎ＞Ｐｈ＞ＣＵ≥Ｃｄ；植物体不同部位，各元素含量有着明显的差异，含量范围分别为Ｃｈ１．５１～５．７０、Ｐｂ１．３０～１０．７０、Ｚｎ１８．０～１００．１、Ｃｄ０．０４～０．２３和Ｍｎ１５．５～２３７．５（ｗ／１０－６）；植物对土壤元素的富集系数大小依次为Ｃｄ＞Ｚｎ＞Ｍｎ＞Ｃｕ＞Ｐｈ；群落现存生物量中，ＣＵ、Ｐｂ、Ｚｎ、Ｃｄ、Ｍｎ元素的现存累积量分别为１６．５６、６３．３０、４４５．０５、１．１４和１６５６．９３（ρＡ／ｍｇ·ｍ－２）．其中，地下部分别占７０．２％、８１．８％、７６．２％、７２．２％和８２．１％；林地残留物相应元素的储量分别为２１１．１１、１８４．００、１９４１．６９、６．１９和２２２４８．３１（ρＡ／μｇ·ｍ－２）．     

胡椒养分含量状况的研究

胡椒大、中量元素的含量在不同树龄中有所不同，幼龄期以氮最高，其Ｎ：Ｐ２Ｏ３：Ｋ２Ｏ：Ｃａ：Ｍｇ为１：０．１５：０．５３－０．９：０．２２－０．３８：０．１５－０．３０；成年龄则以Ｋ２Ｏ最高，Ｎ：Ｐ２Ｏ３：Ｋ２Ｏ：Ｃａ：Ｍｇ为１：０．１３：１．３２：０．４４：０．１６．在不施微肥的情况下，胡椒叶片缺Ｂ、Ｍｏ、Ｚｎ．成年龄胡椒各养分含量都是从萌芽期（收获后）开始，随生育期的进展而增加，到果实成熟期下降．一株中产胡椒Ｎ、Ｐ２Ｏ５、Ｋ２Ｏ总吸收量为２８２．４ｇ，其比例为１：０．１９：０．９．     

单甲脒农药对土壤微生物种群和土壤酶活性的影响

研究了单甲脒（Ｎ＇－２，４－二甲苯基－Ｎ－甲基甲脒，简称ＤＭＡ）对土壤微生物种群和土壤酶活性的影响．田间试验表明，喷洒单甲脒盐酸盐（ＤＭＡＨ）于棉花植株对土壤微生物种群和土壤酶活性无明显影响．实验室试验表明，投加ＤＭＡＨ于土壤对土壤微生物种群有不同的抑制作用；当ＤＭＡＨ在土壤中的浓度为２０ｍｇ／ｇ时，好氧异养菌总量开始降低，硝化细菌和放线菌、真菌的土壤ＤＭＡＨ抑制浓度分别为０．５ｍｇ／ｇ和０．１ｍｇ／ｇ．ＤＭＡＨ对土壤酶活性的影响亦不相同，脱氢酶对土壤中ＤＭＡＨ含量为１０ｍｇ／ｇ时其活性即有明显的减弱，而过氧化氨酶对ＤＭＡ的耐受性相当高，其活性的抑制浓度达５００ｍｇ／ｇ．试验还证明了土壤中ＤＭＡ的微生物降解作用．当ＤＭＡ在土壤中的浓度为５０～５００ｇ／ｇ时，其消解速率可从８．７５ｍｍ·ｋｇ－１·ｄ－１提高到４８ｍｇ·ｋｇ－１·ｄ－１．     

生物膜法控制硫化氢气体污染的试验研究

利用固定生物膜滤池控制硫化氢气体是一种经济有效的方法。试验条件是：温度２０℃～３３℃、滤层喷淋水量６００ｌ／ｍ３·ｄ。当进气Ｈ２Ｓ浓度Ｃｉｎ≤２３０ｍｇ／ｍ３，生物滤池Ｈ２Ｓ负荷Ｌ≤５６０ｇＨ２Ｓ／ｍ３·ｄ时，Ｈ２Ｓ去除率达到１００％，当Ｃｉｎ≤５７０ｍｇ／ｍ３，Ｌ≤２４３０ｇＨ２Ｓ／ｍ３·ｄ时，Ｈ２Ｓ去除率高于９８％，出气中Ｈ２Ｓ浓度≤１０ｍｇ／ｍ３。     

8种拟除虫菊酯农药对稀有鲫的急性、亚慢性毒性研究

８种拟除虫菊酯对稀有鲫的急性毒性和其中２种拟除虫菊酯的亚慢性毒性研究结果表明：溴氰菊酯、高效氯氰菊酯、氯氰菊酯、甲氰菊酯、氰戊菊酯、二氯炔戊菊酯、胺菊酯、甲醚菊酯对稀有鲫均属剧毒,它们的ρ（９６ｈＬＣ５０）／μｇ·Ｌ－１分别为３．１６,３．２４,６．３１,７．２１,７．３５,３２．４５,９１．７５和８８２．６;甲氰菊酯、二氯炔戊菊酯对稀有鲫７ｄ亚慢性毒性的最低有影响浓度ρ（ＬＯＥＣ）和最高无影响浓度ρ（ＮＯＥＣ）分别为０．８８～０．４４μｇ／Ｌ,４．０～２．０μｇ／Ｌ,以ρ（９６ｈＬＣ５０）／μｇ·Ｌ－１为基准,２种拟除虫菊酯的安全系数均为０．０６～０．１２５．     

Ag—Mn,Ag—Co和Ag—Ce复合氧化物上CO,丙酮和吡啶的催化燃烧

本文考察了Ａｎ－Ｍｎ，Ａｇ－Ｃｏ和Ａｇ－Ｃｅ复合氧化物上ＣＯ，丙酮和吡啶的催化氧化性能，结果表明，双组分Ａｇ－Ｍｎ／Ａｌ２Ｏ３和Ａｇ－Ｃｏ／Ａｌ２Ｏ３催化剂的氧化活性均高于单组分Ａｇ／Ａｌ２Ｏ３．在Ａｇ－Ｃｅ／Ａｌ２Ｏ３催化剂上，ＣＯ氧化反应的速率言程可用ｒ＝ｋＰｏ２＾ｍＰＣＯ来表示，随着催化剂中氧化铈含量的增加，对氧的反应级数明显下降。     

转化血型用蕃茄α－D－半乳糖苷酶的分离、纯化及理化性质

成熟蕃茄匀浆后，经硫酸铵盐析，ＤＥＡＥ－ＳｅｐｈａｄｅｘＡ－５０离子交换层析，ＳｅｐａｄｅｘＧ－１００凝胶过滤和Ｍｅｌｉｂｉｏｓｅ－Ａｇａｒｏｓｅ亲和层析，获得了α－Ｄ－半乳糖苷酶（Ｃ．Ｅ．３．２．１．１１）。酶制剂经ＰＡＧＥ检测为一条带；ＳＤＳ－Ｇ－ＰＡＧＥ测得酶Ｍｒ为３４０００；比活力５２．９Ｕ／ｍｇ·；提纯倍数为５２９０１产率为４５％．酶专－催化以α－Ｄ－半乳糖为末端ａ－（１，３）连接的糖苷键，以ＰＮＰＧ（对硝基苯－α－Ｄ－半乳糖昔）为废物，酶催化反应的Ｋｍ＝０．１１ｍｍｏｌ／Ｌ，Ｖｍａｘ为６７μｍｏｌ·ｍｇ１－·ｍｉｎ－１．ｔ稳定范是０～３５℃；ＰＨ稳定范围是４．０～７．０．最适ｐＨ为５．１．半乳糖是酶的竞争性抑制剂；Ｃｕ２＋、Ｚｎ２＋、Ｍｎ２＋、Ｆｅ３＋、Ａｇ＋和ＥＤＴＡ对酶活性无影响．纯酶制剂可作为Ｂ型血向Ｏ型血转化的工具酶液．     

欧洲红豆杉细胞培养的研究

从欧洲红豆杉（Ｔａｘｕｓｂａｃｃａｔａ）的嫩茎及什叶诱导出愈伤组织，并对之进行了愈伤组织培养及细胞悬浮培养研究；利用ＨＰＬＣ方法测定了培养物合成紫杉醇的能力．探索了提高培养细胞生长率及紫杉醇含量的一些措施．结果表明，欧洲红豆杉愈伤组织及悬浮培养细胞的生长速率已分别达到０．２７ｇ·Ｌ－１·ｄ－１和０．３５ｇ·Ｌ－１·ｄ－１，紫杉醇含量分别为０．００３１％和０．０１７％。     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

A palaeo-hydrogeological model for arsenic contamination in southern and south-east Asia

An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.     

Cost‐effective conservation of an endangered frog under uncertainty

How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.     

Threats to intact tropical peatlands and opportunities for their conservation

Large, intact areas of tropical peatland are highly threatened at a global scale by the expansion of commercial agriculture and other forms of economic development. Conserving peatlands on a landscape scale, with their hydrology intact, is of international conservation importance to preserve their distinctive biodiversity and ecosystem services and maintain their resilience to future environmental change. We explored threats to and opportunities for conserving remaining intact tropical peatlands; thus, we excluded peatlands of Indonesia and Malaysia, where extensive deforestation, drainage, and conversion to plantations means conservation in this region can protect only small fragments of the original ecosystem. We focused on a case study, the Pastaza‐Marañón Foreland Basin (PMFB) in Peru, which is among the largest known intact tropical peatland landscapes in the world and is representative of peatland vulnerability. Maintenance of the hydrological conditions critical for carbon storage and ecosystem function of peatlands is, in the PMFB, primarily threatened by expansion of commercial agriculture linked to new transport infrastructure that is facilitating access to remote areas. There remain opportunities in the PMFB and elsewhere to develop alternative, more sustainable land‐use practices. Although some of the peatlands in the PMFB fall within existing legally protected areas, this protection does not include the most carbon‐dense (domed pole forest) areas. New carbon‐based conservation instruments (e.g., REDD+, Green Climate Fund), developing markets for sustainable peatland products, transferring land title to local communities, and expanding protected areas offer pathways to increased protection for intact tropical peatlands in Amazonia and elsewhere, such as those in New Guinea and Central Africa which remain, for the moment, broadly beyond the frontier of commercial development.     

Human Influence and Classical Biogeographic Predictors of Rare Species Occurrence

Biogeographic theory predicts that rare species occur more often in larger, less‐isolated habitat patches and suggests that patch size and connectivity are positive predictors of patch quality for conservation. However, in areas substantially modified by humans, rare species may be relegated to the most isolated patches. We used data from plant surveys of 81 meadow patches in the Georgia Basin of Canada and the United States to show that presence of threatened and endangered plants was positively predicted for patches that were isolated on small islands surrounded by ocean and for patches that were isolated by surrounding forest. Neither patch size nor connectivity were positive predictors of rare species occurrence. Thus, in our study area, human influence, presumably due to disturbance or introduction of competitive non‐native species, appears to have overwhelmed classical predictors of rare species distribution, such that greater patch isolation appeared to favor presence of rare species. We suggest conservation planners consider the potential advantages of protecting geographically isolated patches in human‐modified landscapes because such patches may represent the only habitats in which rare species are likely to persist. Influencia Humana y Predictores Biogeográficos Clásicos de la Ocurrencia de Especies Raras     

Seasonal dynamics of macro-algae in the South Lake of Tunis

The macro-algae communities observed in the south lake of Tunis are characterized by the predominance of nitrophilous algae which are in the order of biomass importance:Ulva, Cladophora andEnteromorpha. We have noted seasonal changes of alga distribution. The wind appears to be one of the most important factors influencing this distribution. The total biomass reaches a maximum in the spring. Rapid decomposition of the biomass leads to a severe ecological imbalance, resulting in crises of anoxia and fish death. A restoration project has already started. It aims at removal of contaminated muds and the introduction of a new circulation system. The main objectives of this work were to collect information on the distribution and biomass of the phytobenthic communities as a first step in the constitution of a database for further comparison.     

Patterns and biases of climate change threats in the IUCN Red List

International Union for Conservation of Nature (IUCN) Red List assessments rely on published data and expert inputs, and biases can be introduced where underlying definitions and concepts are ambiguous. Consideration of climate change threat is no exception, and recently numerous approaches to assessing the threat of climate change to species have been developed. We explored IUCN Red List assessments of amphibians and birds to determine whether species listed as threatened by climate change display distinct patterns in terms of habitat occupied and additional nonclimatic threats faced. We compared IUCN Red List data with a published data set of species’ biological and ecological traits believed to infer high vulnerability to climate change and determined whether distributions of climate change‐threatened species on the IUCN Red List concur with those of climate change‐threatened species identified with the trait‐based approach and whether species possessing these traits are more likely to have climate change listed as a threat on the IUCN Red List. Species in some ecosystems (e.g., grassland, shrubland) and subject to particular threats (e.g., invasive species) were more likely to have climate change as a listed threat. Geographical patterns of climate change‐threatened amphibians and birds on the IUCN Red List were incongruent with patterns of global species richness and patterns identified using trait‐based approaches. Certain traits were linked to increases or decreases in the likelihood of a species being threatened by climate change. Broad temperature tolerance of a species was consistently related to an increased likelihood of climate change threat, indicating counterintuitive relationships in IUCN assessments. To improve the robustness of species assessments of the vulnerability or extinction risk associated with climate change, we suggest IUCN adopt a more cohesive approach whereby specific traits highlighted by our results are considered in Red List assessments. To achieve this and to strengthen the climate change‐vulnerability assessments approach, it is necessary to identify and implement logical avenues for further research into traits that make species vulnerable to climate change (including population‐level threats).     

Parasitic wasps orient to green leaf volatiles

Summary Undamaged plants emit low levels of green leaf volatiles (GLVs), while caterpillar-damaged and artificially damaged plants emit relatively higher levels of certain GLVs. Female braconid parasitoids,Microplitis croceipes, oriented to both damaged plants and to individual GLVs in no-choice tests in a wind tunnel, but seldom oriented to undamaged plants. Female ichneumonid parasitoids,Netelia heroica, also oriented to individual GLVs in a wind tunnel. Males of both wasp species failed to orient to the GLVs. These data show that leaf-feeding caterpillars can cause the release of GLVs, and that parasitic wasps can respond to these odors by flying upwind (chemoanemotactic response), which brings the wasps to their caterpillar hosts. This supports the hypothesis that plants communicate with members of the third trophic level,i.e., plants under herbivore attack emit chemical signals that guide natural enemies of herbivores to sites of plant damage. In this interaction, the GLVs serve as tritrophic plant-to-parasitoid synomones. That parasitoids from two different wasp families oriented to GLVs suggests that the response may be widespread among the Hymenoptera.Mention of a commercial or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture