多棘扁甲轮在中国的新记录及对扁甲轮属的评论

正相对于西方而言,古北区的东侧,轮虫的研究资料非常缺乏~([3])。中国现存的很多轮虫资料也已经非常陈旧~([4—6]),当然,近年也有一些论文相继报道了这一淡水系统中非常重要的浮游动物类群~([7—12]),其中不乏涉及分子方法研究轮虫分类~([13])和轮虫的生态研究~([14])。但是从已有的资料可以发现,很多已知的轮虫分布大多集中在武汉、海南、洞庭湖、西藏等地,我们可以看到一个很显然的现象,即只有中国的这些地方被较为详细地研究过,     

Using a goal programming approach to design and evaluate protected areas for the conservation of multiple dimensions of biodiversity

The decline and loss of biodiversity provoked by human activities have caused ecologists and conservationists to center their attention on the design of conservation priority areas (PAs), focusing mainly on species conservation in terms of richness, rarity and/or vulnerability. However, biodiversity has multiple dimensions, evolutionary processes have recently been labeled the ‘missing component’ of conservation strategies, and increasingly more authors are suggesting that the ecological, evolutionary and historical aspects of biodiversity are key components of conservation planning. In this study we develop a prioritization system to design conservation PAs using the wild terrestrial mammals of the Iberian Peninsula as an example. We aim to contribute to the design of more suitable PAs by integrating ecological components of biodiversity (species richness, vulnerability and rarity), evolutionary aspects (accumulated genetic diversification) and historical information relevant to the study area. After selecting a set of biodiversity indicators, we applied a multi-objective technique (extended goal programming) to construct a combined index, where values in the top 90th percentile were then used to select the PAs. According to our most efficient and satisfactory results, some areas highlighted for their conservation are currently categorized as PAs, however, we found that it would be necessary to reconsider their extent, especially in northern Spain, where the historical aspects of biodiversity (the missing component) are more widely present. The need to determine PAs is unquestionable. However, it should also be a priority to move towards a model of sustainable and fair development.     

Polarization of Myosin II Refines Tissue Material Properties to Buffer Mechanical Stress

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A Study on actinobacterial diversity of Hampoeil cave and screening of their biological activities

Caves are oligotrophic, dark and less-explored environments and are considered as sources of promising microbial strains in biotechnology. Hampoeil Cave is located in massive dolomite with thin bedded limestone in northwestern of Iran. In an isolation and screening program, various samples from soil, water, floor, wall and ceiling of Hampoeil cave and its invertebrates were collected. Four various treatments and 10 different isolation media were used for the isolation of the actinobacteria. Screening of the isolates for antimicrobial activity against 10 bacteria and fungi, 5 hydrolytic enzymes production and resistance to 5 heavy metals have been performed. Among 33 various samples, 76 actinobacteria from various genera, including Streptomyces, Micromonospora, Micrococcus, Kocuria and Corynebacterium were isolated. Eighty percent of the strains had one of the studied hydrolytic enzyme activity. At least one type of antimicrobial activity was seen in 25.3% of the isolates. Resistance to one metal or more was seen in 26.32% of the isolates. The ratio of rare-actinobacteria in the oligotrophic samples to enriched samples is 20% more than Streptomyces. Percentage of strains with the highest activity in esterase, amylase, DNase, protease or lipase activity that were isolated from organic-rich environmental samples were 100, 100, 100, 82 and 82%, respectively. Also, 26.32% of the actinobacterial isolates resisted to heavy metals. It was concluded that Hampoeil cave is a good source in finding cave-living actinobacteria potent in producing hydrolytic enzymes and bioremediation.     

Rediscovery and phylogenetic placement of Olpidiopsis gillii (de Wildeman) Friedmann,a holocarpic oomycete parasitoid of freshwater diatoms

The genus Olpidiopsis of the Oomycota includes several species that are aquatic parasites and hyperparasites. Despite their widespread occurrence and potential ecological importance, only a handful of these species has been subjected to phylogenetic investigations, so far. Most species have not been observed and reported for several decades. In the current study, the freshwater diatom parasite Olpidiopsis gillii (de Wild.) Friedmann was rediscovered from the river Main in Germany and investigated for its phylogenetic placement using nuclear small ribosomal subunit (SSU) sequences. The absence of a zoospore diplanetism is a characteristic of the genus Olpidiopsis, which is in contrast to the diplanetism observed in species of Ectrogella. The phylogenetic reconstruction revealed that Olpidiopsis gillii is a basal lineage within the oomycetes, grouping together with the recently-described marine diatom parasite Olpidiopsis drebesii with high support, and loosely associated with Olpidiopsis species parasitising red algae. However, as there are no sequence data available for the type species of both Olpidiopsis and Ectrogella the taxonomic assignment of these simple holocarpic parasites of algae and diatoms remains fraught with uncertainty.     

Greater than the sum of the parts: how the species composition in different forest strata influence ecosystem function

The mechanisms underpinning forest biodiversity‐ecosystem function relationships remain unresolved. Yet, in heterogeneous forests, ecosystem function of different strata could be associated with traits or evolutionary relationships differently. Here, we integrate phylogenies and traits to evaluate the effects of elevational diversity on above‐ground biomass across forest strata and spatial scales. Community‐weighted means of height and leaf phosphorous concentration and functional diversity in specific leaf area exhibited positive correlations with tree biomass, suggesting that both positive selection effects and complementarity occur. However, high shrub biomass is associated with greater dissimilarity in seed mass and multidimensional trait space, while species richness or phylogenetic diversity is the most important predictor for herbaceous biomass, indicating that species complementarity is especially important for understory function. The strength of diversity‐biomass relationships increases at larger spatial scales. We conclude that strata‐ and scale‐ dependent assessments of community structure and function are needed to fully understand how biodiversity influences ecosystem function.     

Stability of grassland production is robust to changes in the consumer food web

Theory predicts that consumers may stabilise or destabilise plant production depending on model assumptions, and tests in aquatic food webs suggest that trophic interactions are stabilising. We quantified the effects of trophic interactions on temporal variability (standard deviation) and temporal stability (mean/standard deviation) of grassland biomass production and the plant diversity–stability relationship by experimentally removing heterotrophs (large vertebrates, arthropods, foliar and soil fungi) from naturally and experimentally assembled grasslands of varying diversity. In both grassland types, trophic interactions proportionately decreased plant community biomass mean and variability over the course of 6 years, leading to no net change in temporal stability or the plant diversity–stability relationship. Heterotrophs also mediated plant coexistence; their removal reduced diversity in naturally assembled grasslands. Thus, herbivores and fungi reduce biomass production, concurrently reducing the temporal variability of energy and material fluxes. Because of this coupling, grassland stability is robust to large food web perturbations.     

Increasing nitrogen depositions can reduce lichen viability and limit winter food for an endangered Chinese monkey

Increasing economic growth and industrial development in China is starting to impact even remote areas such as the Shennongjia nature reserve, where nitrogen pollution is becoming a major environmental threat. The epiphytic lichen flora is particularly rich in this area and is one of the components of this habitat most sensitive to nitrogen pollution. Since lichens represent an important food resource for the endangered monkey species Rhinopithecus roxellana, a reduction in lichen availability would have harmful consequences for the conservation of its habitat in the Shennongjia Mountains. To investigate the effects of increased nitrogen availability on the local lichen communities, so far scarcely considered, we conducted a one-year field experiment measuring growth, survival, and phosphomonoesterase activity of the widespread species Usnea luridorufa in response to nitrogen (up to 50 kg N ha⁻¹ year⁻¹ deposition) and phosphorus supply. Growth and survival of thalli and propagules of U. luridorufa decreased when treated with N deposition >12.05 kg N ha⁻¹ year⁻¹ and >2.14 kg N ha⁻¹ year⁻¹, respectively. The important role of phosphorus availability in relation to nitrogen supply was demonstrated by the increase in phosphomonoesterase activity with increasing nitrogen availability until a nitrogen toxicity threshold was reached. However, the high concentration of phosphorus in rainwater showed that phosphorus is not a limiting nutrient in the area.The results make a contribution to the knowledge of the negative effects of increased N deposition in the Shennongjia forest ecosystem.