Riverside (California)[US], April 9 (ANI): Scientists at the University of California have found a new tool that can better assess an important but overlooked indicator of global warming, which is a variety of bugs, worms and snails living in high mountain streams.
Get rare articles and stories on Science at latterly. Scientists at the University of California have found a new tool that can better assess an important but overlooked indicator of global warming, which is a variety of bugs, worms and snails living in high mountain streams.
Waters based invertebrates are especially vulnerable when the climate swings from historic droughts to massive floods. Because they serve as food for other forms of alpine life, such as birds, bats, frogs and fish, ecologists worry about the insects' ability to thrive.
Understandings how these small creatures are affected by climate change requires understanding where we ought to find them. Yet, classic ecological theories did not account for what a team of UC Riverside ecologists and their UC collaborators found in a recent survey of aquatic life in California's Sierra Nevada. As a step toward protecting them, the team applied a new theory for predicting biodiversity in high mountain streams.
Once such classic theory is the River Continuum Concept, which discusses how stream ecosystems function as they move from the stream sources down to bigger, more open rivers. According to the continuum concept, there should be a smooth gradient of change from high to low elevations. The team surveyed for stream biodiversity along a gradient, to test concepts like this one.
"We're a change, but only partially and not for the reasons the theory said we should," Anderson said.
"For example, we found that lakes tended to interrupt the smooth change we were supposed to have seen," he added.
The UCR team observed that the diversity of invertebrates generally increased in waters headed down and was lowest in steams situated immediately below lakes.
"We believe the lakes may have a disconnecting effect and are causing the downstream waterways to have to start over again in building diversity," said Matthew Green, UCR ecologist and first author of the new paper.
The team also found a great variety of life forms in cold, isolated streams high up in the headwaters. Despite the general trend toward an increase of diversity moving downstream, sometimes, differences in species among isolated headwaters could be as great as those between upstream and downstream.
"These are the aquatic life forms that are at the edge of the precipice of climate change," said Dave Herbert, a researcher from the Sierra Nevada Aquatic Research Laboratory, a UC Natural Reserve, and co-author of the paper.
The areas just below lakes were dominated by only a few species of invertebrates and insects with the ability to filter food particles. Other sites with mixed food sources had more species present.
The team recommended that interconnected systems of flowing water be protected from diversions, and from habitat damage caused by unrestrained land development. When waters are allowed to flow as they should, the number of resources available to creatures that live in them supports higher diversity.
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