How do climate change scenarios affect amphibian larvae?: Warming and brownification alter Rana temporaria tadpole life history, stoichiometry and nutrient cycling in ponds
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
With global warming mean temperatures and browning of waters are predicted to increase. This will affect nutrient pathways between terrestrial and aquatic ecosystems as well as internal nutrient cycling by aquatic consumers. Using a large scale pond facility, with enclosures manipulated with warm/ambient temperature and clear/humic water, I experimentally tested the effects of likely climate change scenarios on tadpole (Rana temporaria) growth and development, tadpole mediated nutrient cycling and body stoichiometry. Nutrient cycling was estimated by measurements of tadpole nutrient release. Additionally, emergent frog body stoichiometry was analysed in order to ease future estimations of nutrient translocation from water to land. Both warming and browning induced plastic responses in tadpole life history. Warming positively affected tadpole development and growth. Browning had a strong positive effect on tadpole growth under ambient temperatures. Body stoichiometry was kept within a narrow stoichiometric range, but reflected differences in tadpole life history and responses to the experimental treatments. Warming increased tadpole body P content, likely due to increased development and growth rates, while browning had a positive effect on body N and N excretion rates, likely under influence of seston nutrient content. N:P ratios of seston, tadpole body and excretion rates followed the same pattern, with strong positive effects of brownification. I conclude that stoichiometric principles can explain consumer mediated nutrient cycling and that warming effects depend on brownification scenarios. The climate change scenarios tested in this study can have substantial impact on nutrient dynamics within and across ecosystem boundaries.
Place, publisher, year, edition, pages
2015. , 17 p.
brownification, warming, stoichiometry, life history, Rana temporaria
IdentifiersURN: urn:nbn:se:umu:diva-111562OAI: oai:DiVA.org:umu-111562DiVA: diva2:871571