Global warming impacts on stream ecosystems
Global warming has altered, and will continue to alter, the way in which water temperature changes over time in stream ecosystems. These changes include an increase in the frequency and magnitude of heat waves and higher night-time temperatures. growing number of studies are investigating the effect of an increase in average temperature on the ecology of wetlands, forests, streams and other ecosystems. However, studies into the effect of changes in daily temperatures remain limited, although this may have a significant impact on the carbon cycle in streams. The 'Global warming effects on the stream carbon balance' (GWESCB) project addressed this issue by investigating the effects of global warming on the metabolism of carbon in stream ecosystems. The intention was to gain a better understanding of the effect of temperature on carbon cycling. An experiment was conducted to determine the effect of warmer night-time temperatures on a test stream's carbon metabolic balance. Results showed that warmer night-time temperatures enhanced respiration by organisms, leading to an increase in the release of carbon dioxide from the ecosystem. The work carried out by GWESCB revealed the need to consider changes in the daily temperature regime when predicting the impact of global warming on carbon metabolism in streams. This will help scientists understand how changes in carbon balance in streams will affect the global carbon balance, as streams connect to rivers and then to marine ecosystems. GWESCB therefore increased knowledge of how global warming influences the carbon cycle at both the ecosystem and global scales. This information can then be used to better forecast the effects of climate change.
Keywords
Global warming, stream, ecosystem, temperature, carbon balance, respiration