The inner shelf mud wedge of the East China Sea(ECS) is a high-sedimentation-rate fine-grained sediment unit that has preserved a continuous environmental evolution history since the last deglaciation. We present a hi...The inner shelf mud wedge of the East China Sea(ECS) is a high-sedimentation-rate fine-grained sediment unit that has preserved a continuous environmental evolution history since the last deglaciation. We present a high-resolution clay mineralogical study from Core MD06-3040 to semi-quantitatively evaluate terrigenous sediment contributions from various potential provenances throughout the Holocene. The results showed that the clay mineral assemblage is composed of dominant illite(34–49%), moderate smectite(16–41%) and chlorite(15–28%), and minor kaolinite(5–12%). Provenance analysis suggested that most fine-grained terrigenous sediments originated from the Yangtze River, with minor sediments derived from Taiwan island and negligible sediments from nearby Zhejiang and Fujian provinces. Time series variation in the contribution of the Yangtze source fluctuated in the range of 38–80%, whereas that of Taiwan island had a converse variation pattern from ~10%to ~55%, and the contribution of Fujian was relatively stable in the range of 7–11% throughout the Holocene. The fluctuations of clay mineral assemblages and variations of clay mineral contributions from different provenances of Core MD06-3040 were controlled by the variability of precipitation in the Yangtze drainage associated with periodic fluctuations in the East Asian monsoonal circulation.展开更多
Predator odors can elicit fear responses in prey and predator odor recognition is generally associated with physiological responses. Prey species are often more likely to respond to the odor of familiar ra- ther than ...Predator odors can elicit fear responses in prey and predator odor recognition is generally associated with physiological responses. Prey species are often more likely to respond to the odor of familiar ra- ther than alien predators. However, predator na＇ivety in an introduced prey species has rarely been investigated. We examined the physiological response, as shown by changes in ventilatory vari- ables, of an introduced terrestrial herbivore, the European rabbit Oryctolagus cuniculus, in Australia, to the odor of potential predators and to control odors （distilled water and horse）, to explore if res- ponses were limited to historical （cat and fox） predators, or extended to historically novel predators （snake and quoll）. All odors except distilled water elicited a response, with rabbits showing long- term higher respiratory frequencies and lower tidal volumes after introduction of the odors, indi- cating an increase in alertness. However, the intensity of the rabbits＇ reaction could not be directly linked to any pattern of response with respect to the history of predator-prey relationships. Rabbits exhibited significantly stronger reactions in response to both cat and quoll odors than they did to dis- tilled water, but responses to horse, fox, and snake odor were similar to that of water. Our results show that the introduced rabbit can respond to both historical and novel predators in Australia, and suggest that shared evolutionary history is not necessarily a prerequisite to predator odor recognition.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 91528304, 41530964 & 41676028)
文摘The inner shelf mud wedge of the East China Sea(ECS) is a high-sedimentation-rate fine-grained sediment unit that has preserved a continuous environmental evolution history since the last deglaciation. We present a high-resolution clay mineralogical study from Core MD06-3040 to semi-quantitatively evaluate terrigenous sediment contributions from various potential provenances throughout the Holocene. The results showed that the clay mineral assemblage is composed of dominant illite(34–49%), moderate smectite(16–41%) and chlorite(15–28%), and minor kaolinite(5–12%). Provenance analysis suggested that most fine-grained terrigenous sediments originated from the Yangtze River, with minor sediments derived from Taiwan island and negligible sediments from nearby Zhejiang and Fujian provinces. Time series variation in the contribution of the Yangtze source fluctuated in the range of 38–80%, whereas that of Taiwan island had a converse variation pattern from ~10%to ~55%, and the contribution of Fujian was relatively stable in the range of 7–11% throughout the Holocene. The fluctuations of clay mineral assemblages and variations of clay mineral contributions from different provenances of Core MD06-3040 were controlled by the variability of precipitation in the Yangtze drainage associated with periodic fluctuations in the East Asian monsoonal circulation.
文摘Predator odors can elicit fear responses in prey and predator odor recognition is generally associated with physiological responses. Prey species are often more likely to respond to the odor of familiar ra- ther than alien predators. However, predator na＇ivety in an introduced prey species has rarely been investigated. We examined the physiological response, as shown by changes in ventilatory vari- ables, of an introduced terrestrial herbivore, the European rabbit Oryctolagus cuniculus, in Australia, to the odor of potential predators and to control odors （distilled water and horse）, to explore if res- ponses were limited to historical （cat and fox） predators, or extended to historically novel predators （snake and quoll）. All odors except distilled water elicited a response, with rabbits showing long- term higher respiratory frequencies and lower tidal volumes after introduction of the odors, indi- cating an increase in alertness. However, the intensity of the rabbits＇ reaction could not be directly linked to any pattern of response with respect to the history of predator-prey relationships. Rabbits exhibited significantly stronger reactions in response to both cat and quoll odors than they did to dis- tilled water, but responses to horse, fox, and snake odor were similar to that of water. Our results show that the introduced rabbit can respond to both historical and novel predators in Australia, and suggest that shared evolutionary history is not necessarily a prerequisite to predator odor recognition.
