Alaska’s boreal forests are declining
, as increasing drought stress and fire kill off the next generation of conifer trees. Where boreal forest has disappeared, new plant communities—like grasslands and aspen forests—have begun to take its place.
Elsewhere, in the southeastern United States, droughts have decimated saltmarsh vegetation
, turning saltmarshes into mudflats or open water.
In the Southwest, pinyon pines have experienced widespread die-offs
during extreme droughts. Meanwhile, junipers and grasses have expanded.
Across the globe, natural resource managers now face the reality of stewarding such landscapes with vastly different species and functions. These are just three examples of drought-triggered ecological transformation, a growing phenomenon that is highlighted in a new paper in the journal BioScience
.
Research on ecological drought demonstrates that while many species are tolerant of water shortages, others may experience declines, with recovery taking years or even decades after drought ends. The new study, funded by the U.S. Geological Survey (USGS) National Climate Adaptation Science Center, discussed an even more extreme possibility—that some ecosystems will never recover from drought. Instead of returning to pre-drought conditions, some ecosystems may undergo transformation, or a shift into a new, persistent state, dominated by different forms of vegetation.
Ecosystem transformations represent a major challenge for natural resource agencies
. Those caused by drought can be particularly rapid and surprising. To aid preparedness, researchers synthesized science on the mechanisms involved in drought-triggered transformation. Their work provides a broad overview of this phenomenon and highlights three major points about drought’s ability to cause long-term ecological change:…
Read the full article here.
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