Researchers map alpine greening in northeastern North America
The study finds significant greening across 88% of the alpine area examined—about 11,352 hectares—providing a regional map of vegetation change.
Loading… Բեռնվում է…
The study finds significant greening across 88% of the alpine area examined—about 11,352 hectares—providing a regional map of vegetation change.
Alpine landscapes across northeastern North America became greener over 41 years, according to a study published in Ecosphere. Researchers found significant greening across 88% of the alpine area studied—about 11,352 hectares—with none of the sites becoming browner. The study covered areas including New Hampshire’s White Mountains, New York’s Adirondacks and the mountains of Quebec’s Gaspé Peninsula.
Scientists have catalogued plants on these peaks for more than two centuries, but the region lacked a systematic, broad-scale geographic analysis, lead author Jonathan Chipman, a Dartmouth College geographer, told Eos. The satellite record provides that wider view, helping researchers place individual field studies in a regional context.
The researchers analysed nearly 1,000 images from the Landsat satellite mission, spanning 1984 through 2024. They used the normalized difference vegetation index, a measure that converts colours recorded in satellite images into a numerical value for vegetation greenness.
Greenness does not identify the plants producing it. Chipman stressed that this remote-sensing study—observing the landscape from satellites—did not establish which species were present. A shift from small alpine plants with less leaf area to leafier shrubs is a likely explanation, not a directly measured finding about species replacement.
Analysis
Warming could allow plants from lower elevations to move uphill as cold-adapted plants decline. Alternatively, alpine plants that tolerate warming better could outcompete their neighbours. Invasive species carried by hikers are another possible contributor.
The NIH–NASA competition seeks better measurements in laboratory drug-safety models, with submissions scheduled to open on 15 December 2026.
2 min
Chipman also suggested that nitrogen released into the atmosphere by industry may have fertilised plants on downwind peaks. Those emissions have fallen greatly, but their effects may persist in alpine ecosystems.
Arthur Bayle, a Université de Genève ecologist who was not involved in the study, noted pronounced greening well above the tree line, the upper limit of tree growth. He interpreted that pattern as evidence of changes beyond trees simply spreading uphill. Bayle cautioned that similar greening patterns need not reflect the same ecological processes.
Analysis
Greening was uneven across many peaks. Chipman proposed that the region’s frequent strong winds could help explain the differences: wind keeps exposed areas cooler, while windblown ice particles can abrade plants in winter. These conditions could limit vegetation growth even as temperatures rise.
The study did not establish wind as the cause of slower greening. Bayle said the hypothesis deserves further investigation.
Chipman suggested that slower-greening, wind-exposed areas might retain sensitive or rare alpine plants. Avoiding new trails or infrastructure in such places could help preserve future refuges for those plants. These are proposed uses of the findings, not adopted conservation measures.
The team plans to continue studying slower-greening areas to understand why their pace differs. Chipman said field studies of plant communities remain necessary: satellite observations complement that work rather than replace it.
The programme brings together national laboratories, universities and industry partners, with plans for a sensor-equipped test bed and self-adjusting pilot production lines.
2 min
Previously seen only through its infrared heat, the dusty feature is visible in reflected starlight, allowing researchers to test a possible collision origin.
4 min