Amphibians play considerable ecological roles in both freshwater and terrestrial environments,acting as ecosystem engineers,keystone species,and linking energy and nutrient flow between aquatic and terrestrial habitats.Yet,drastic declines have been observed in many amphibian populations in recent decades and about one-third of all known amphibian species are threatened by extinction.Amphibians are generally considered sensitive indicators of environmental health,and recent declines may signal ailing ecosystems.Important threats to amphibian populations include habitat loss,invasive species,over-exploitation,pollution and climate change,and these threats may act together,either additively or synergistically.Yet,we still know very little about the role and magnitude of synergistic effects among these stressors.I will investigate the importance of and relationships among pollution,climate change and invasive species,on lowland wetland amphibians in Hong Kong.I will compare the lethal concentrations of several commonly used agricultural pesticides on the target amphibian and invasive species,and investigate whether synergistic effects of thermal stress and pesticides exist by measuring critical thermal limits,oxygen consumption,heat shock protein expression,growth and mortality.Information generated from this study will be useful in developing conservation measures to better protect local amphibian populations.