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A growing awareness of increasing trends in coastal erosion and flooding due to climate change is triggering a demand for the rapid assessment of the potential responses of the coastlines around the world, principally in locations where human occupation is especially endangered. Investigations of present and future physical vulnerability and associated social risk have, therefore, become crucial for coastal management. In order to provide a quick and simple methodology for the identification of vulnerable coastal segments, Sharples (2006) has proposed a mapping methodology, called the smartline approach, which consists of representing, by means of simple lines, a geomorphic classification of the hinterland, backshore and beaches. The aim of this paper is to apply the smartline approach to coastal vulnerability assessment with inclusion of social data. The results show that this methodology is appropriate for the indication of coastal segments with varying degrees of vulnerability to erosion and flooding and for the appraisal of the resulting social risk. 相似文献
84.
Future atmospheric CO2 levels will most likely have complex consequences for marine organisms, particulary photosynthetic calcifying organisms.
Corallina officinalis L. is an erect calcifying macroalga found in the inter- and subtidal regions of temperate rocky coastlines and provides important
substrate and refugia for marine meiofauna. The main goal of the current study was to determine the physiological responses
of C. officinalis to increased CO2 concentrations expected to occur within the next century and beyond. Our results show that growth and production of inorganic
material decreased under high CO2 levels, while carbonic anhydrase activity was stimulated and negatively correlated to algal inorganic content. Photosynthetic
efficiency based on oxygen evolution was also negatively affected by increased CO2. The results of this study indicate that C. officinalis may become less competitive under future CO2 levels, which could result in structural changes in future temperate intertidal communities. 相似文献
85.
Conservation and protection of soil and water resources and visual aspects of landscape, as well as the promotion of biodiversity, are some of the central tasks of environmental policy development and social politics in the future. One of the main questions is: ‘which agricultural systems are able to guarantee sustained resource-conserving land use?’ Based on the ecological risk concepts of the 1970s and 1980s, a potential impact model was developed using a universal assessment algorithm derived from fuzzy logic. The model estimated the potential impact of agricultural land use on ecosystem function using a few resource indicators. Intervention intensities of agricultural land-use are set in relation to site conditions and aggregated for each of several defined potential impact categories. The interpretation with respect to risk and the calculation of potential impact values are explained. 相似文献
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Dieter Helm 《Environmental Sciences Europe》2003,15(2):85-94
On behalf of the Federal Environment Ministry the Federal Environmental Agency operates the German Environmental Specimen Bank (ESB), which targets are to record and evaluate pollution data of selected ecological systems. Scope of the present study is to check the possibilities of the Hasse diagram technique (HDT) for the assessment of ESB data, mainly with regard to evaluations and conclusions. Xenobiotic body burden in Bream musculature (Abramis brama), measured in 1997, was exemplary used to answer these questions. Focus was put on ecosystemic assessment. The results clearly show that HDT is a valuable method for the graphical display, interpretation and comparative evaluation of pollution data. HDT visualises data qualitatively and in summary. Additionally, differences between pollution patterns are revealed, which suggest different contamination processes and entries. An ecosystemic approach of assessment is achieved by simultaneous consideration of different xenobiotics. 相似文献
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Plants as transmission channels for insect vibrational songs 总被引:6,自引:0,他引:6
Axel Michelsen Flemming Fink Matija Gogala Dieter Traue 《Behavioral ecology and sociobiology》1982,11(4):269-281
Summary The vibrational songs of several species of cydnid bugs and small cicadas (leafhoppers and planthoppers) living on various types of plants are recorded by means of laser vibrometry. The recorded vibrational songs are analysed with respect to amplitude, frequency spectrum and structure in the time domain (Figs. 2–5).The emission of vibrational songs from singing insects on plants is simulated. A small magnet is glued to the surface of the plant and moved by means of an electromagnet about one cm away (Fig. 1). The vibrations are recorded by means of laser vibrometry. The propagation velocity of the vibrations increases with the square root of frequency, i.e. in the way expected for bending waves.The mechanical properties of plants ranging from soft bean plants to stiff reeds and maples are measured. The results are used for calculating the theoretical propagation velocities of bending waves. The measured and the calculated values are rather close (Table 1). Although the mechanical properties of the plants studied vary widely, the propagation velocities at a certain frequency are of the same order of magnitude (Table 1).In all the plants studied, only little vibrational energy is lost by friction at frequencies below some kHz. Communication by means of bending waves is possible over distances of some meters. The bending waves are reflected with little loss of energy both from the root and from the top of the plant. The vibration signals may therefore travel up and down the plant several times before decaying completely (Fig. 7). The vibration at a certain spot on the plant depends not only on the distance to and nature of the emitter, but also on the modes of vibration of the plant. The amplitude of vibration does not decrease monotonically with distance from the emitter (Fig. 6).These filtering properties of the plants mean that it is essentially impossible to predict which frequencies in the signals will be amplified or attenuated in the plant at the location of the receiving animal. The vibrational signals recorded from the animals cover wide frequency bandwidths. The signals are therefore well adapted to the filtering properties of the plants, but the signals of the species studied here do not appear to be particularly adapted to specific properties of the host plants.The muscular power needed for communication by means of various types of vibrational signals is calculated. The result of this calculation supports the conclusion that the signals recorded here are carried by means of bending waves.The communication strategies open to small insects are considered. Vibrational signals appear to be an efficient means of communication, but only certain types of signals are suited, because the plants cause a considerable distortion of the signals. One kind of distortion, the dispersive property, may — in theory — be used by the listening animals to obtain information about the direction and distance to the singing animals.Dedicated to Dr. F. ossiannilsson, whose pioneering studies led to the suggestion that small insects may use plants as transmission channels for their songs 相似文献
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