The process of urbanization affects the urban warming.The change of urban warming was investigated by several urbanization factors in Changsha,China.The data of surface temperature(minimum,maximum and mean) of Changsh...The process of urbanization affects the urban warming.The change of urban warming was investigated by several urbanization factors in Changsha,China.The data of surface temperature(minimum,maximum and mean) of Changsha were analyzed to understand the possible effects of urbanization on the climate of this region owing to the population growth,built-up area expansion and energy consumption increases.The weights of these three factors were calculated by the analytical hierarchy process(AHP).Then,three weights were simulated with nonlinear method to obtain the urbanization development rate which was utilized to reveal the influence of the urbanization factors on the surface temperature.The result shows that there is a significant upward trend in the urban temperatures of Changsha.The temperature increase seems to be closely related to the rate of urbanization between 1993 and 2008,and there is an evidential increase trend of the influence on urban temperature by urbanization during 16 years.It is a quantifiable approach measuring the relationship between urbanization and urban eco-environment,and can be applied for the urban sustainability.展开更多
The ultrasonic communication in Concave-eared torrent flogs Odorrana tormota is believed to be an adaptation to avoid masking by the intense low-frequency noise of the rushing stream in their habitat. The acoustic ada...The ultrasonic communication in Concave-eared torrent flogs Odorrana tormota is believed to be an adaptation to avoid masking by the intense low-frequency noise of the rushing stream in their habitat. The acoustic adaptation hypothesis for ultrasonic origin predicts that some organisms subjecting to persistent acoustic interference from broadband, low-frequency en- vironmental noise, might shift their signal frequency upward into frequency bands with lower noise energy. In other words, low-frequency environmental noise might cause upward shifts of species＇ vocalization frequencies making their signals more conspicuous. Presently, it is unclear whether male O. tormota adjust their signal features in response to a change in the ambient noise level. We tested the prediction of the acoustic adaptation hypothesis by recording the vocalizations of male O. tormota in- habiting two streams with different background noise levels in Huangshan in central China and comparing their call features in- cluding the fundamental frequency （F0）. Results showed that the spectrotemporal characteristics of the vocal signals of males in the two habitats were indifferent, except the duration of the call harmonic segments and three parameters related to the call fun- damental frequency （F0）. In terms of the F0, the pooled and individual frog data showed that flogs inhabiting the noisier habitat tended to emit calls having higher F0. The higher F0 increases the signal-to-noise ratio, thus benefiting the detection of vocaliza- tion. Thus, similar to several anuran species, concave-eared torrent frogs also display noise-dependent adjustment of vocal pitch in their vocalizations for making them more audible展开更多
基金Projects(2008JT1013,2007JT3018,05SK3002) supported by the Key Program for Science and Technology in Hunan Province,ChinaProject(2007ZK2025) supported by the Key Program for Soft Science in Hunan Province,China
文摘The process of urbanization affects the urban warming.The change of urban warming was investigated by several urbanization factors in Changsha,China.The data of surface temperature(minimum,maximum and mean) of Changsha were analyzed to understand the possible effects of urbanization on the climate of this region owing to the population growth,built-up area expansion and energy consumption increases.The weights of these three factors were calculated by the analytical hierarchy process(AHP).Then,three weights were simulated with nonlinear method to obtain the urbanization development rate which was utilized to reveal the influence of the urbanization factors on the surface temperature.The result shows that there is a significant upward trend in the urban temperatures of Changsha.The temperature increase seems to be closely related to the rate of urbanization between 1993 and 2008,and there is an evidential increase trend of the influence on urban temperature by urbanization during 16 years.It is a quantifiable approach measuring the relationship between urbanization and urban eco-environment,and can be applied for the urban sustainability.
文摘The ultrasonic communication in Concave-eared torrent flogs Odorrana tormota is believed to be an adaptation to avoid masking by the intense low-frequency noise of the rushing stream in their habitat. The acoustic adaptation hypothesis for ultrasonic origin predicts that some organisms subjecting to persistent acoustic interference from broadband, low-frequency en- vironmental noise, might shift their signal frequency upward into frequency bands with lower noise energy. In other words, low-frequency environmental noise might cause upward shifts of species＇ vocalization frequencies making their signals more conspicuous. Presently, it is unclear whether male O. tormota adjust their signal features in response to a change in the ambient noise level. We tested the prediction of the acoustic adaptation hypothesis by recording the vocalizations of male O. tormota in- habiting two streams with different background noise levels in Huangshan in central China and comparing their call features in- cluding the fundamental frequency （F0）. Results showed that the spectrotemporal characteristics of the vocal signals of males in the two habitats were indifferent, except the duration of the call harmonic segments and three parameters related to the call fun- damental frequency （F0）. In terms of the F0, the pooled and individual frog data showed that flogs inhabiting the noisier habitat tended to emit calls having higher F0. The higher F0 increases the signal-to-noise ratio, thus benefiting the detection of vocaliza- tion. Thus, similar to several anuran species, concave-eared torrent frogs also display noise-dependent adjustment of vocal pitch in their vocalizations for making them more audible
