A 2.5‐million‐year perspective on coarse‐filter strategies for conserving nature's stage

Climate change will require novel conservation strategies. One such tactic is a coarse‐filter approach that focuses on conserving nature's stage (CNS) rather than the actors (individual species). However, there is a temporal mismatch between the long‐term goals of conservation and the short‐term nature of most ecological studies, which leaves many assumptions untested. Paleoecology provides a valuable perspective on coarse‐filter strategies by marshaling the natural experiments of the past to contextualize extinction risk due to the emerging impacts of climate change and anthropogenic threats. We reviewed examples from the paleoecological record that highlight the strengths, opportunities, and caveats of a CNS approach. We focused on the near‐time geological past of the Quaternary, during which species were subjected to widespread changes in climate and concomitant changes in the physical environment in general. Species experienced a range of individualistic responses to these changes, including community turnover and novel associations, extinction and speciation, range shifts, changes in local richness and evenness, and both equilibrium and disequilibrium responses. Due to the dynamic nature of species responses to Quaternary climate change, a coarse‐filter strategy may be appropriate for many taxa because it can accommodate dynamic processes. However, conservationists should also consider that the persistence of landforms varies across space and time, which could have potential long‐term consequences for geodiversity and thus biodiversity.     

Nutrient Removal and Loading Rate Analysis of Louisiana Forested Wetlands Assimilating Treated Municipal Effluent

The relationship between nutrient removal and loading rate was examined using data from five forested wetlands in Louisiana that have received secondarily treated effluent from 3 to 60 years. Loading rates ranged from 0.65 to 26.80 g/m²/yr for total nitrogen and 0.18 to 8.96 g/m²/yr for total phosphorus. At loading rates below 20 g/m²/yr, total nitrogen concentrations in surface waters of Louisiana forested wetlands were reduced to background concentrations (i.e., ≤3 mg/l). Similarly, at loading rates below 2 g/m²/yr, total phosphorus concentrations were also generally reduced to background concentrations (i.e., ≤1 mg/l). These data demonstrate that freshwater forested wetlands can reduce nutrient concentrations in treated effluent to background concentrations present in relatively undisturbed wetlands. An understanding of the relationship between loading rates and nutrient removal in natural wetlands is important, particularly in Louisiana where discharges of fresh water are being used in ecosystem restoration.     

Understanding global sea levels: past, present and future

The coastal zone has changed profoundly during the 20th century and, as a result, society is becoming increasingly vulnerable to the impact of sea-level rise and variability. This demands improved understanding to facilitate appropriate planning to minimise potential losses. With this in mind, the World Climate Research Programme organised a workshop (held in June 2006) to document current understanding and to identify research and observations required to reduce current uncertainties associated with sea-level rise and variability. While sea levels have varied by over 120 m during glacial/interglacial cycles, there has been little net rise over the past several millennia until the 19th century and early 20th century, when geological and tide-gauge data indicate an increase in the rate of sea-level rise. Recent satellite-altimeter data and tide-gauge data have indicated that sea levels are now rising at over 3 mm year⁻¹. The major contributions to 20th and 21st century sea-level rise are thought to be a result of ocean thermal expansion and the melting of glaciers and ice caps. Ice sheets are thought to have been a minor contributor to 20th century sea-level rise, but are potentially the largest contributor in the longer term. Sea levels are currently rising at the upper limit of the projections of the Third Assessment Report of the Intergovernmental Panel on Climate Change (TAR IPCC), and there is increasing concern of potentially large ice-sheet contributions during the 21st century and beyond, particularly if greenhouse gas emissions continue unabated. A suite of ongoing satellite and in situ observational activities need to be sustained and new activities supported. To the extent that we are able to sustain these observations, research programmes utilising the resulting data should be able to significantly improve our understanding and narrow projections of future sea-level rise and variability.     

Fe/La定向修饰凹凸棒土稻壳基颗粒成型生物炭：磷酸盐吸附行为与机制

本研究合成一种新型除磷载Fe/La定向修饰凹凸棒土稻壳基颗粒成型生物炭吸附材料（Fe-La/AC）,考察了材料表面特性、Fe/La投加量、热解温度、保温时间以及凹凸棒土投加量等对磷素吸附影响规律. Fe/La最佳投加量为2：2 mmol,AT添加量为30%,热解温度为350 ℃,热解时间2 h,制备的Fe-La/AC对磷酸根的最大吸附量可以达到47.62 mg·g^-1（以磷计）. 傅里叶红外光谱分析表明Fe、La主要以铁镧氧化物及铁镧水合氯化物的形式存在于炭材料表面,Fe和La提供了磷酸盐吸附的活性中心. 该材料吸附动力学过程符合准二级动力学模型,吸附等温线拟合分析Langmiur模型更适于描述Fe-La/AC对磷酸盐的吸附过程,表明吸附动力学主要受化学作用控制. 磷酸盐吸附机制主要涉及静电吸引、配体交换和内层络合作用. 本研究制备的Fe-La/AC颗粒成型生物炭,可作为低磷浓度废水处理及水体富营养化调控的一种高效除磷吸附剂,具有较大的实际应用前景.     

Effect of sub-lethal damage to juvenile colonies of massive Porites spp. under contrasting regimes of temperature and water flow

In this study, juvenile colonies of massive Porites spp. (a combination of P. lutea and P. lobata) from the lagoon of Moorea (W 149°50′, S 17°30′) were damaged and exposed to contrasting conditions of temperature and flow to evaluate how damage and abiotic conditions interact to affect growth, physiological performance, and recovery. The experiment was conducted in April and May 2008 and consisted of two treatments in which corals were either undamaged (controls) or damaged through gouging of tissue and skeleton in a discrete spot mimicking the effects of corallivorous fishes that utilize an excavating feeding mode. The two groups of corals were incubated for 10 days in microcosms that crossed levels of temperature (26.7 and 29.6°C) and flow (6 and 21 cm s⁻¹), and the response assessed as overall colony growth (change in weight), dark-adapted quantum yield of PSII (F _v/F _m), and healing of the gouged areas. The influence of damage on growth was affected by temperature, but not by flow. When averaged across flow treatments, damage promoted growth by 25% at 26.7°C, but caused a 25% inhibition at 29.6°C. The damage also affected F _v/F _m in a pattern that differed between flow speeds, with a 10% reduction at 6 cm s⁻¹, but a 4% increase at 21 cm s⁻¹. Regardless of damage, F _v/F _m at 21 cm s⁻¹ was 11% lower at 26.7°C than at 29.6°C, but was unaffected by temperature at 6 cm s⁻¹. The lesions declined in area at similar rates (4–5% day⁻¹) under all conditions, although the tissue within them regained a normal appearance most rapidly at 26.7°C and 6 cm s⁻¹. These findings show that the response of poritid corals to sub-lethal damage is dependent partly on abiotic conditions, and they are consistent with the hypothesis that following damage, calcification and photosynthesis can compete for metabolites necessary for repair, with the outcome affected by flow-mediated mass transfer. These results may shed light upon the ways in which poritid corals respond to biting by certain corallivorous fishes.