Prioritizing sites for conservation based on similarity to historical baselines and feasibility of protection

The concept of shifting baselines in conservation science implies advocacy for the use of historical knowledge to inform these baselines but does not address the feasibility of restoring sites to those baselines. In many regions, conservation feasibility varies among sites due to differences in resource availability, statutory power, and land‐owner participation. We used zooarchaeological records to identify a historical baseline of the freshwater mussel community's composition before Euro‐American influence at a river‐reach scale (i.e., a kilometer stretch of river that is abiotically similar) in the Leon River of central Texas (U.S.A.). We evaluated how the community reference position and the feasibility of conservation might enable identification of sites where conservation actions would preserve historically representative communities and be likely to succeed. We devised a conceptual model that incorporated community information and landscape factors to link the best conservation areas to potential cost and conservation benefits. Using fuzzy ordination, we identified modern mussel beds that were most like the historical baseline. We then quantified housing density and land use near each river reach identified to estimate feasibility of habitat restoration. Using our conceptual framework, we identified reaches of high conservation value (i.e., contain the best mussel beds) and where restoration actions would be most likely to succeed. Reaches above Lake Belton were most similar in species composition and relative abundance to zooarchaeological sites. A subset of these mussel beds occurred in locations where conservation actions appeared most feasible. Our results show how to use zooarchaeological data (biodiversity data often readily available) and estimates of conservation feasibility to inform conservation priorities at a local spatial scale.     

Freshwater fish diversity hotspots for conservation priorities in the Amazon Basin

Conserving freshwater habitats and their biodiversity in the Amazon Basin is a growing challenge in the face of rapid anthropogenic changes. We used the most comprehensive fish-occurrence database available (2355 valid species; 21,248 sampling points) and 3 ecological criteria (irreplaceability, representativeness, and vulnerability) to identify biodiversity hotspots based on 6 conservation templates (3 proactive, 1 reactive, 1 representative, and 1 balanced) to provide a set of alternative planning solutions for freshwater fish protection in the Amazon Basin. We identified empirically for each template the 17% of sub-basins that should be conserved and performed a prioritization analysis by identifying current and future (2050) threats (i.e., degree of deforestation and habitat fragmentation by dams). Two of our 3 proactive templates had around 65% of their surface covered by protected areas; high levels of irreplaceability (60% of endemics) and representativeness (71% of the Amazonian fish fauna); and low current and future vulnerability. These 2 templates, then, seemed more robust for conservation prioritization. The future of the selected sub-basins in these 2 proactive templates is not immediately threatened by human activities, and these sub-basins host the largest part of Amazonian biodiversity. They could easily be conserved if no additional threats occur between now and 2050.     

Effects of land use,cover, and protection on stream and riparian ecosystem services and biodiversity

Protected areas are an important part of broader landscapes that are often used to preserve biodiversity or natural features. Some argue that protected areas may also help ensure provision of ecosystem services. However, the effect of protection on ecosystem services and whether protection affects the provision of ecosystem services is known only for a few services in a few types of landscapes. We sought to fill this gap by investigating the effect of watershed protection status and land use and land cover on biodiversity and the provision of ecosystem services. We compared the ecosystem services provided in and around streams in 4 watershed types: International Union for Conservation of Nature category II protected forests, unprotected forests, unprotected forests with recent timber harvesting, and unprotected areas with agriculture. We surveyed 28 streams distributed across these watershed types in Quebec, Canada, to quantify provisioning of clean water, carbon storage, recreation, wild foods, habitat quality, and terrestrial and aquatic biodiversity richness and abundance. The quantity and quality of ecosystem services and biodiversity were generally higher in sites with intact forest—whether protected or not—relative to those embedded in production landscapes with forestry or agriculture. Clean-water provision, carbon storage, habitat quality, and tree diversity were significantly higher in and around streams surrounded by forest. Recreation, wild foods, and aquatic biodiversity did not vary among watershed types. Although some services can be provided by both protected and unprotected areas, protection status may help secure the continued supply of services sensitive to changes in land use or land cover. Our findings provide needed information about the ecosystem service and biodiversity trade-offs and synergies that result from developing a watershed or from protecting it.     

Boosting freshwater fish conservation with high-resolution distribution mapping across a large territory

The lack of high-resolution distribution maps for freshwater species across large extents fundamentally challenges biodiversity conservation worldwide. We devised a simple framework to delineate the distributions of freshwater fishes in a high-resolution drainage map based on stacked species distribution models and expert information. We applied this framework to the entire Chinese freshwater fish fauna (>1600 species) to examine high-resolution biodiversity patterns and reveal potential conflicts between freshwater biodiversity and anthropogenic disturbances. The correlations between spatial patterns of biodiversity facets (species richness, endemicity, and phylogenetic diversity) were all significant (r = 0.43–0.98, p < 0.001). Areas with high values of different biodiversity facets overlapped with anthropogenic disturbances. Existing protected areas (PAs), covering 22% of China's territory, protected 25–29% of fish habitats, 16–23% of species, and 30–31% of priority conservation areas. Moreover, 6–21% of the species were completely unprotected. These results suggest the need for extending the network of PAs to ensure the conservation of China's freshwater fishes and the goods and services they provide. Specifically, middle to low reaches of large rivers and their associated lakes from northeast to southwest China hosted the most diverse species assemblages and thus should be the target of future expansions of the network of PAs. More generally, our framework, which can be used to draw high-resolution freshwater biodiversity maps combining species occurrence data and expert knowledge on species distribution, provides an efficient way to design PAs regardless of the ecosystem, taxonomic group, or region considered.     

淡水水体底泥厌氧氨氧化菌的初步富集培养与氨氧化特性

对已通过16SrRNA基因方法检测到厌氧氨氧化菌(anammox菌)的江苏新沂河底泥样品在厌氧生物反应器中进行连续培养,研究这种新发现的anammox菌的生长特性,及其厌氧氨氧化效应.培养试验历时49d.经25d的启动期,反应器中氨氮和亚硝酸氮开始同时降低,并与厌氧氨氧化反应的化学计量关系类似.此后,反应器的氮转化量呈上升趋势(最大值接近0.17kg.m-.3d-1).底泥经培养后,anammox菌得到了富集,其数量从1%提高到5.6%,其倍增时间为12d.研究还发现反应器生物量的流失,出水中含有与anammox菌特异性基因探针杂交并正进行增殖的细菌细胞,但其生物特性有待深入研究.     

EBPR中两类细菌PAOs和GAOs竞争的研究进展

强化生物除磷(EBPR)工艺可以获取高效的除磷效果,已在很多污水处理厂得到广泛应用。但是大型污水处理厂在相当多的条件下,EBPR工艺也会出现周期性除磷效果的波动和不充分。针对这一难题,研究者试图采用许多手段来研究工艺中的主要微生物。文章针对典型的EBPR工艺和碳源、pH值、温度等因素对EBPR工艺中两类细菌聚磷菌(PAOs)和聚糖菌(GAOs)竞争的研究进展进行了论述,并展望了未来的研究方向。     

渗滤系统处理北方城市生活污水微生物数量变化的研究

本文应用粉煤灰渗滤系统处理北方寒冷地区城市污水,结果细菌数量去除率在89.6%—99.9%之间,粪大肠菌群数量去除率在90%—99.9%之间,此方法成本低、效果好,适合北方中小城镇污水处理。     

聚磷菌在不同碳源下的反硝化研究

利用SBR系统对聚磷菌进行了培养,并通过荧光原位杂交手段检测了系统中聚磷菌Candidatus Accumulibacter phosphatis的富集程度.聚磷菌也是一种普通异养菌,为了研究它的反硝化能力,排除了聚磷菌的正常释磷和吸磷过程,仅考察在不同碳源下反硝化性能.结果表明,乙酸和PHB都能成为聚磷菌反硝化的电子供体.当以乙酸为外在单一碳源时,其反硝化速率和PHB生成速率与起始硝酸盐浓度无关,但是当起始状态硝酸盐浓度越高时,消耗单位乙酸生成的PHB和硝酸盐还原量越小.以PHB为内在碳源和能源时,聚磷菌的反硝化速率呈现对于基质(硝酸盐)的零级动力学反应,比反硝化速率为0.973 3mg/(g.h),此外PHB平均比消耗速率为(以PHB计)2.462 6 mg/(g.h).     

Bioaccumulation and depuration of chromium in the selected organs and whole body tissues of freshwater fish Cirrhinus mrigala individually and in binary solutions with nickel

Contamination of aquatic ecosystems with heavy metals has been receiving increased worldwide attention due to their harmful e ects on human health and other organisms in the environment. Most of the studies dealing with toxic e ects of metals deal with single metal species, while the aquatic organisms are typically exposed to mixtures of metals. Hence, in order to provide data supporting the usefulness of freshwater fish as indicators of heavy metal pollution, it has been proposed in the present study to investigate the bioaccumulation and depuration of chromium in the selected organs of freshwater fingerlings Cirrhinus mrigala, individually and in binary solutions with nickel. The results show that the kidney is a target organ for chromium accumulation, which implies that it is also the “critical” organ for toxic symptoms. The results further show that accumulation of nickel in all the tissues of C. mrigala is higher than that of chromium. In addition, the metal accumulations of the binary mixtures of chromium and nickel are substantially higher than those of the individual metals, indicating synergistic interactions between the two metals. Theoretically the simplest explanation for an additive joint action of toxicants in a mixture is that they act in a qualitatively similar way. The observed data suggest that C. mrigala could be suitable monitoring organisms to study the bioavailability of water-bound metals in freshwater habitats.     

辽河铁岭段3条支流底栖动物调查及水质评价

对辽河铁岭段3条支流清河、柴河和混河入水库前的河段,利用底栖动物需氧特性,以需氧有机体百分率指标,对3条支流的水环境质量状况进行了监测调查和评价。