对英国水獭(Lutra lutra)种群生长的长期监测

欧洲水獭自50年代来明显减少,正在从许多河流消失.本研究基于对英国西部3个自然建群的集水区和英国东部2个通过人工投放加速建群的集水区的长期监测(从1977年以来)结果.到2002年,在每条河流至少收集了16年的数据,在每条研究河上设置一系列研究点,记录水獭出现点的百分率、痕迹点的痕迹数,并通过结合以上2个参数计算年种群指数.在一条自然建群的西部河流,头5年水獭种群生长快速增长,接着生长缓慢.但在2个研究开始就已经有水獭的集水区,其生长比较稳定.东部河流水獭建群的速度缓慢,随时间有巨大的波动.年种群生长率约为1%～7%,在早期较高.对水獭的年度监测计划提出了建议.     

What are the implications of sea-level rise for a 1.5, 2 and 3 °C rise in global mean temperatures in the Ganges-Brahmaputra-Meghna and other vulnerable deltas?

Even if climate change mitigation is successful, sea levels will keep rising. With subsidence, relative sea-level rise represents a long-term threat to low-lying deltas. A large part of coastal Bangladesh was analysed using the Delta Dynamic Integrated Emulator Model to determine changes in flood depth, area and population affected given sea-level rise equivalent to global mean temperature rises of 1.5, 2.0 and 3.0 °C with respect to pre-industrial for three ensemble members of a modified A1B scenario. Annual climate variability today (with approximately 1.0 °C of warming) is potentially more important, in terms of coastal impacts, than an additional 0.5 °C warming. In coastal Bangladesh, the average depth of flooding in protected areas is projected to double to between 0.07 and 0.09 m when temperatures are projected at 3.0 °C compared with 1.5 °C. In unprotected areas, the depth of flooding is projected to increase by approximately 50% to 0.21–0.27 m, whilst the average area inundated increases 2.5 times (from 5 to 13% of the region) in the same temperature frame. The greatest area of land flooded is projected in the central and north-east regions. In contrast, lower flood depths, less land area flooded and fewer people are projected in the poldered west of the region. Over multi-centennial timescales, climate change mitigation and controlled sedimentation to maintain relative delta height are key to a delta’s survival. With slow rates of sea-level rise, adaptation remains possible, but further support is required. Monitoring of sea-level rise and subsidence in deltas is recommended, together with improved datasets of elevation.

     

Vegetation fire emissions and their impact on air pollution and climate

Gaseous and particulate emissions from vegetation fires substantially modify the atmospheric chemical composition, degrade air quality and can alter weather and climate. The impact of vegetation fire emissions on air pollution and climate has been recognised in the late 1970s. The application of satellite data for fire-related studies in the beginning of the 21th century represented a major break through in our understanding of the global importance of fires. Today the location and extent of vegetation fires, burned area and emissions released from fires are determined from satellite products even though many uncertainties persist. Numerous dedicated experimental and modeling studies contributed to improve the current knowledge of the atmospheric impact of vegetation fires. The motivation of this paper is to give an overview of vegetation fire emissions, their environmental and climate impact, and what improvements can be expected in the near future.     

Growth in otter (Lutra lutra) populations in the UK as shown by long-term monitoring

European otters declined dramatically from the 1950s, disappearing from many rivers. We report here on longterm monitoring (from 1977) in 3 catchments in western Britain that were recolonized naturally and in 2 catchments in eastern England that were reinforced by captive-bred otters. A minimum of 16-years data was collected on each river until 2002. At a series of sites in each study river, the percentages which were positive for otters and the number of spraints per sprainting site were recorded and combined to produce an annual index of population. One western river, naturally recolonized, showed rapid early population growth for 5 years, followed by slower growth, while growth was steadier in 2 catchments which already held some otters at the beginning of the study. Colonization on the eastern rivers was slower, with greater fluctuations over time. Annual population growth rates were estimated at 1-7%, higher in the earlier years. A strategy for annual monitoring of otters is recommended.     

Testing the metabolic theory of ecology: allometric scaling exponents in mammals

Many fundamental traits of species measured at different levels of biological organization appear to scale as a power law to body mass (M) with exponents that are multiples of 1/4. Recent work has united these relationships in a "metabolic theory of ecology" (MTE) that explains the pervasiveness of quarter-power scaling by its dependence on basal metabolic rate (B), which scales as M(0.75). Central to the MTE is theory linking the observed -0.25 scaling of maximum population growth rate (rm) and body mass to the 0.75 scaling of metabolic rate and body mass via relationships with age at first reproduction (alpha) derived from a general growth model and demographic theory. We used this theory to derive two further predictions: that age at first reproduction should scale inversely to mass-corrected basal metabolic rate alpha infinity (B/M)(-l) such that rm infinity (B/M)1. We then used phylogenetic generalized least squares and model selection methods to test the predicted scaling relationships using data from 1197 mammalian species. There was a strong phylogenetic signal in these data, highlighting the need to account for phylogeny in allometric studies. The 95% confidence intervals included, or almost included, the scaling exponent predicted by MTE for B infinity M(0.75), rm infinity M(-0.25), and rm infinity alpha(-1), but not for alpha infinity M(0.25) or the two predictions that we generated. Our results highlight a mismatch between theory and observation and imply that the observed -0.25 scaling of maximum population growth rate and body mass does not arise via the mechanism proposed in the MTE.     

<Emphasis Type="Italic">Acropora austera</Emphasis> connectivity in the south-western Indian Ocean assessed using nuclear intron sequence data

The hypervariable carbonic anhydrase 3/550 intron marker was sequenced in order to ascertain the levels of genetic variability and connectivity within and between reefal populations of the hard coral, Acropora austera, on the south-east African coastline. Populations were sampled from (north to south) Bazaruto and Inhaca islands (Mozambique), Rabbit Rock, Two-mile and Red Sands Reefs and Leadsman Shoal (Maputaland, South Africa). Populations at Inhaca Island contained two private alleles, part of the only monophyletic clade with fixed differences between populations in this study. Haplotype and nucleotide diversity were higher in the north of the study area. Indices of migration and haplotype sharing supported significant connectivity between populations in South Africa and Mozambique, which may be important in sustaining genetic diversity in the down-current South African A. austera populations. Measures of population subdivision indicated a significant amount of fixation of allele frequencies amongst populations. Although fine, such differentiation in a marker from the nuclear genome of a hard coral is consistent with some demographic isolation between A. austera populations in southern Mozambique and South Africa. Populations at Rabbit Rock and Inhaca Island were found to be significantly isolated from, and thus less connected to, A. austera populations at other reefs.     

The effects of organotin on female gastropods

Female masculinisation (FM) in gastropods (imposex, intersex and ovo-testis) has been documented in > 260 species globally. Biomonitoring studies use FM to indirectly assess the presence of tributyltin (TBT), a once popular biocide in antifouling paint, which has since been regulated. Laboratory studies confirm that FM in gastropods can be induced not only by TBT, but other tin (Sn) compounds, Sn "cocktails", steroids, and other contaminants such as Aroclor 1260. Even though FM in gastropods in the field has been attributed to TBT from boating activity, there is evidence that imposex occurred prior to the advent use of TBT in the 1960s, and for some species imposex occurs naturally. There are roughly 42 species that do not elicit a FM response even if they are exposed to TBT under laboratory conditions, collected sympatrically with other species displaying FM, and/or have TBT in their tissues. A geographic analysis of field studies in four regions indicates that the bulk of studies were conducted in Europe > Asia and Oceania > North America > Latin America. More data are needed regarding FM in Africa, the Middle East, and Latin America since data regarding the masculinisation of female gastropods in these areas are lacking. The most studied gastropod species used in TBT biomonitoring studies is the dogwhelk, Nucella lapillus. This review summarizes the progression of the literature from 1962 to 2009 outlining how the terminology, science, and theories have evolved over time.