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231.
Effective biodiversity monitoring is critical to evaluate, learn from, and ultimately improve conservation practice. Well conceived, designed and implemented monitoring of biodiversity should: (i) deliver information on trends in key aspects of biodiversity (e.g. population changes); (ii) provide early warning of problems that might otherwise be difficult or expensive to reverse; (iii) generate quantifiable evidence of conservation successes (e.g. species recovery following management) and conservation failures; (iv) highlight ways to make management more effective; and (v) provide information on return on conservation investment. The importance of effective biodiversity monitoring is widely recognized (e.g. Australian Biodiversity Strategy). Yet, while everyone thinks biodiversity monitoring is a good idea, this has not translated into a culture of sound biodiversity monitoring, or widespread use of monitoring data. We identify four barriers to more effective biodiversity monitoring in Australia. These are: (i) many conservation programmes have poorly articulated or vague objectives against which it is difficult to measure progress contributing to design and implementation problems; (ii) the case for long‐term and sustained biodiversity monitoring is often poorly developed and/or articulated; (iii) there is often a lack of appropriate institutional support, co‐ordination, and targeted funding for biodiversity monitoring; and (iv) there is often a lack of appropriate standards to guide monitoring activities and make data available from these programmes. To deal with these issues, we suggest that policy makers, resource managers and scientists better and more explicitly articulate the objectives of biodiversity monitoring and better demonstrate the case for greater investments in biodiversitymonitoring. There is an urgent need for improved institutional support for biodiversity monitoring in Australia, for improved monitoring standards, and for improved archiving of, and access to, monitoring data. We suggest that more strategic financial, institutional and intellectual investments in monitoring will lead to more efficient use of the resources available for biodiversity conservation and ultimately better conservation outcomes.  相似文献   
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Hennhöfer, D., Götz, S. & Mitchell, S.F. 2012: Palaeobiology of a Biradiolites mooretownensis rudist lithosome: seasonality, reproductive cyclicity and population dynamics. Lethaia, Vol. 45, pp. 450–461. During the Cretaceous, rudist bivalves were among the most important benthic carbonate producers on tropical to sub‐tropical carbonate platforms. Yet questions concerning the biology of rudist bouquets remain unanswered to a great extent. In this study a monospecific bouquet of the small radiolitid rudist Biradiolites mooretownensis has been evaluated from a palaeobiological angle. Three‐dimensional, high‐resolution, quantitative analysis provides a detailed evaluation of growth and reproduction in an in situ rudist association. A total of 1237 consecutive tomograms with a vertical spacing of 0.1 mm were produced of which 1150 have been digitally measured for total area, number of specimens, packing density, spat density, recruitment, survival time, mortality and accommodation space. The results show constant coverage of about 60%, a stable packing density of 3.2 specimens per cm2 and constant reproduction throughout the bouquet. Time series analysis (spectral analysis) using PAST statistical software shows cyclic spat density every 14.9 mm of vertical growth. Combined with the results of the δ18O isotope analysis (showing cyclicities of 14 mm) one reproduction cycle appears to be annual. 46.4% of all counted specimens died before 3 mm of vertical growth. More than 93% of the initial spat does not exceed 15 mm shell height or 1 year respectively. Two mortality peaks in the juvenile’s life at 4 and 10–15 mm shell height either represent important obstacles in the ontogenetic development of the species or reflect external influences. □ Biradiolites, grinding tomography, palaeobiology, population dynamics, reproduction, rudists, sclerochronology, seasonality.  相似文献   
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Ellis, R. H., Simon, G. and Covell, S. 1987. The influence oftemperature on seed germination rate in grain legumes. III.A comparison of five faba bean genotypes at constant temperaturesusing a new screening method.—J. exp. Bot. 38: 1033–1043. A screening procedure which requires information on the progressof germination at only four temperatures was able to definethe response of the rate of seed germination to sub- and supra-optimaltemperatures for whole seed populations of each of five fababean (Vicia faba L.) genotypes. In one population of the cultivarSutton the models for sub- and supra-optimal temperatures derivedfrom the screen satisfactorily explained observations from anearlier separate investigation at a wider range of temperatures.Two discrete groups of genotypes were identified. Within eachgroup the base temperature Tb did not differ significantly:for the landraces Lebanese Local Large and Syrian Local Largethe value was estimated to be –7·5°C and forthe landrace Lebanese Local Small and the cultivars Sutton andAquadulce it was –4·0°C. The optimum temperaturefor the 50th percentile [To(50), at which temperature the rateof germination is maximal] also varied between these two groupsof genotypes, being 20·5–21·5°C forthe first group and 24·5–26·0°C forthe second. In several temperature regimes some of the viableseeds within a seed population failed to germinate. Nevertheless,even at temperatures where a substantial proportion of the seedsfailed to germinate the models defined by the screening methodpredicted the germination times of those seeds which did germinate. Key words: Faba bean, seed gemination rate, temperature  相似文献   
239.
A comparative study of Lower Cambrian Halkieria and Middle Cambrian Wiwaxia   总被引:3,自引:0,他引:3  
Two Cambrian lepidote metazoans known from different respective types of preservation have been compared in order to elucidate their biology and affinities. The widely distributed Lower Cambrian Halkieria is represented by isolated hollow sclerites, probably of originally calcareous composition. The Middle Cambrian Wiwaxia is known from the Burgess Shale as isolated sclerites (scales and spines) and as more or less complete individuals. Although Halkieria sclerites were mineralized and those of Wiwaxia were probably not, there are fundamental structural and morphological similarities between the two. Both bad an imbricating scaly and spiny armour consisting of hollow sclerites with a longitudinally fibrous structure. The sclerites did not grow, but were probably moulted during the course of ontogenetic growth. Halkieria and Wiwaxia are regarded as closely related. Both are referred to the Order Sachitida He 1980. The sclerite armour of Halkieria is reconstructed on the template provided by Wiwaxia. The interpretation of sachitid sclerites as protective armour is an alternative to the interpretation by Jell (1981, Alcheringa 5 )that sachitid sclerites were respiratory organs in an animal of probable annelid affinities. Sachitids are interpreted as sluggish, benthic deposit feeders that do not belong to any recognized phylum.  相似文献   
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