Increasing numbers of amphibian species require conservation breeding programs for their survival.A major challenge is the efficient rearing of tadpoles,many of which require complex habitats and specialised diets.Aqu...Increasing numbers of amphibian species require conservation breeding programs for their survival.A major challenge is the efficient rearing of tadpoles,many of which require complex habitats and specialised diets.Aquatic tadpoles of the West Australian frog Litoria moorei were kept at low density(1 tadpole per 1.95 litres water) in aquaria at 25℃.Fed on a staple diet of boiled lettuce and leaf litter,group of diets were supplemented with either control,Wardley Premium Spirulina Discs,Sera~(TM) GVG-mix tropical fish food,or a combination of Wardley Premium Spirulina discs and Sera~(TM) GVG-mix fish food.There was a relatively high loss(i.e.,found dead,euthanized due to scoliosis,or not found) of tadpoles fed with the lettuce/leaf litter alone,but this was increased significantly when supplemented with Wardley Premium Spirulina discs,either alone or with Sera~(TM) GVG-mix fish food,and Sera~(TM) GVG fish food alone.However,the survived tadpoles fed on the three supplements were all heavier after three weeks and at metamorphosis than those fed with lettuce/leaf litter alone,and reached metamorphosis quicker.It is concluded that any benefit of the food supplements in terms of increasing the rate of growth and development of the tadpoles is outweighed by greater mortality.There is now a need for the efficient rearing of tadpoles,many from novel species that need complex habitats.Further studies of diet are required due to the current conservation crisis of amphibians.展开更多
Temperate rainforests have historically been considered highly vulnerable to disturbance.Climate change,which is expected to increase the intensity,frequency,and impacts of disturbance events,is consequently a signifi...Temperate rainforests have historically been considered highly vulnerable to disturbance.Climate change,which is expected to increase the intensity,frequency,and impacts of disturbance events,is consequently a significant threat to their long-term persistence.However,data describing the long-term response of temperate rainforests to disturbance is rare.In the cool temperate rainforests of northern New South Wales,Australia,Nothofagus moorei is considered especially vulnerable to climate change due to a decreasing number of mature individuals,limited remaining suitable habitat,and low rates of sexual regeneration.In this study,we used over 50 years of empirical data from silvicultural experiments with multiple thinning intensities to characterise the demographic responses(i.e.,growth,mortality,and recruitment)of cool temperate rainforest species,including N.moorei,to disturbance over time.Cool temperate rainforest species showed resilience to disturbance,predominantly through their widespread ability to basally coppice.Nothofagus moorei,in particular,demonstrated higher rates of successful sexual and vegetative recruitment and grew faster in response to higher intensities of disturbance,in comparison to very low rates of recruitment pre-disturbance.These results challenge successional models that position rainforests as disturbance-sensitive ecosystems and identify N.moorei as a species that requires large-scale disturbance to successfully regenerate.Management regimes that actively exclude disturbance from these forests risk the local loss of disturbance-dependent rainforest species such as N.moorei.展开更多
文摘Increasing numbers of amphibian species require conservation breeding programs for their survival.A major challenge is the efficient rearing of tadpoles,many of which require complex habitats and specialised diets.Aquatic tadpoles of the West Australian frog Litoria moorei were kept at low density(1 tadpole per 1.95 litres water) in aquaria at 25℃.Fed on a staple diet of boiled lettuce and leaf litter,group of diets were supplemented with either control,Wardley Premium Spirulina Discs,Sera~(TM) GVG-mix tropical fish food,or a combination of Wardley Premium Spirulina discs and Sera~(TM) GVG-mix fish food.There was a relatively high loss(i.e.,found dead,euthanized due to scoliosis,or not found) of tadpoles fed with the lettuce/leaf litter alone,but this was increased significantly when supplemented with Wardley Premium Spirulina discs,either alone or with Sera~(TM) GVG-mix fish food,and Sera~(TM) GVG fish food alone.However,the survived tadpoles fed on the three supplements were all heavier after three weeks and at metamorphosis than those fed with lettuce/leaf litter alone,and reached metamorphosis quicker.It is concluded that any benefit of the food supplements in terms of increasing the rate of growth and development of the tadpoles is outweighed by greater mortality.There is now a need for the efficient rearing of tadpoles,many from novel species that need complex habitats.Further studies of diet are required due to the current conservation crisis of amphibians.
基金supported by the Bushfire and Natural Hazards Cooperative Research Centre and New South Wales National Parks and Wildlife Service.
文摘Temperate rainforests have historically been considered highly vulnerable to disturbance.Climate change,which is expected to increase the intensity,frequency,and impacts of disturbance events,is consequently a significant threat to their long-term persistence.However,data describing the long-term response of temperate rainforests to disturbance is rare.In the cool temperate rainforests of northern New South Wales,Australia,Nothofagus moorei is considered especially vulnerable to climate change due to a decreasing number of mature individuals,limited remaining suitable habitat,and low rates of sexual regeneration.In this study,we used over 50 years of empirical data from silvicultural experiments with multiple thinning intensities to characterise the demographic responses(i.e.,growth,mortality,and recruitment)of cool temperate rainforest species,including N.moorei,to disturbance over time.Cool temperate rainforest species showed resilience to disturbance,predominantly through their widespread ability to basally coppice.Nothofagus moorei,in particular,demonstrated higher rates of successful sexual and vegetative recruitment and grew faster in response to higher intensities of disturbance,in comparison to very low rates of recruitment pre-disturbance.These results challenge successional models that position rainforests as disturbance-sensitive ecosystems and identify N.moorei as a species that requires large-scale disturbance to successfully regenerate.Management regimes that actively exclude disturbance from these forests risk the local loss of disturbance-dependent rainforest species such as N.moorei.
