Why do not all workers work? Colony size and workload during emigrations in the ant Temnothorax albipennis

Here, we study distribution of workload and its relationship to colony size among worker ants of Temnothorax albipennis, in the context of colony emigrations. We find that one major aspect of workload, number of items transported by each worker, was more evenly distributed in larger colonies. By contrast, in small colonies, a small number of individuals perform most of the work in this task (in one colony, a single ant transported 57% of all items moved in the emigration). Transporters in small colonies carried more items to the new nest per individual and achieved a higher overall efficiency in transport (more items moved per transporter and unit time). Our results suggest that small colonies may be extremely dependent on a few key individuals. In studying colony organisation and division of labour, the amount of work performed by each individual, not just task repertoire (which tasks are performed at all), should be taken into account.     

Global status of and prospects for protection of terrestrial geophysical diversity

Conservation of representative facets of geophysical diversity may help conserve biological diversity as the climate changes. We conducted a global classification of terrestrial geophysical diversity and analyzed how land protection varies across geophysical diversity types. Geophysical diversity was classified in terms of soil type, elevation, and biogeographic realm and then compared to the global distribution of protected areas in 2012. We found that 300 (45%) of 672 broad geophysical diversity types currently meet the Convention on Biological Diversity's Aichi Target 11 of 17% terrestrial areal protection, which suggested that efforts to implement geophysical diversity conservation have a substantive basis on which to build. However, current protected areas were heavily biased toward high elevation and low fertility soils. We assessed 3 scenarios of protected area expansion and found that protection focused on threatened species, if fully implemented, would also protect an additional 29% of geophysical diversity types, ecoregional‐focused protection would protect an additional 24%, and a combined scenario would protect an additional 42%. Future efforts need to specifically target low‐elevation sites with productive soils for protection and manage for connectivity among geophysical diversity types. These efforts may be hampered by the sheer number of geophysical diversity facets that the world contains, which makes clear target setting and prioritization an important next step.     

Science-Driven Management of Protected Areas: A Philippine Case Study

The lack of scientific baseline information hinders appropriate design and management of protected areas. To illustrate the value of science to management, we consider five scenarios for the 202.0 km² Puerto Princesa Subterranean River National Park, Philippines: (1) closure to human activities, (2) and (3) two levels of increase in unplanned human activities, (4) creation of a forest corridor and (5) additional allocation of land for permanent or shifting agriculture. We then use habitat-specific bird density estimates to simulate the net effect of each scenario on 18 focal bird populations. Closure has significant benefits—populations of five species are predicted to increase by >50 % and nine by >25 %, but two secondary forest flycatchers, including the endemic and ‘Vulnerable’ Palawan flycatcher, decline dramatically, while the creation of a 4.0 km² forest corridor yields average increases across species of 2 ± 4 % (SD). In contrast, heavier unplanned park usage produces declines in all but a few species, while the negative effects of an extra 2.0 km² of shifting cultivation are 3–5 times higher than for a similar area of permanent agriculture and affect species whose densities are highest in primary habitats. Relatively small changes within the park, especially those associated with agricultural expansion, has serious predicted implications for local bird populations. Our models do not take into account the full complexities of bird ecology at a site, but they do provide park managers with an evidence base from which to make better decisions relating to biodiversity conservation obligations which their parks are intended to meet.     

地下水铀污染的原位微生物还原与固定:在美国能源部田纳西橡树岭放射物污染现场的试验

总结了美国斯坦福大学和橡树岭国家实验室等在美国能源部田纳西州橡树岭综合试验基地进行的铀污染原位微生物修复阶段性试验结果.本试验利用微生物以乙醇为电子供体还原地下水和沉积物中的六价铀为不溶解的四价铀,使之原位固定化.随后通过加入溶解氧和硝酸盐来试验微生物还原后的地下水层中还原固定态铀的稳定性.通过预处理和长期间隔注入乙醇...