In the mountain ranges of North America, vegetation may be more adaptable to climate variations than previously thought, suggests a new study. Photo: AFP
Vegetation in the mountain ranges of North America appears to be adapting more quickly than previously expected to climate change, a study suggests.
While this theory needs to be supported by future research, the ability of these plants to withstand climate change could provide important data for biodiversity conservation in these regions.
Climate disruption has visible consequences on the planet's ecosystems. This is the case, for example, in the mountain ranges that are gradually losing their snow cover and whose summits are becoming increasingly green.
These changes have important consequences for the fauna and flora that inhabit them, as they are forced to migrate to regions located further north and at higher altitudes.
But according to a new US study from Brown University, the vegetation cover of several mountain ranges has been shifting higher at a faster rate than previously expected... which could be good news.
The study is based on the analysis of satellite imagery taken at high altitudes between 1984 and 2011, in nine mountain ranges of western North America (Canada, United States, Mexico).
This data allowed the study authors to quantify changes in vegetation cover at different altitudes in mountain ranges harboring a diverse range of ecosystems and climates (desert, tropical, subarctic, coastal, etc).
According to this research, published in the journal PLOS Climate, upward altitude shifts in vegetation in various ecosystems were ubiquitous, and could reach up to 112m per decade.
"This realised velocity is 4.4 times larger than previously reported for plants, and is among the fastest rates predicted for the velocity of climate change," the researchers say.
The upward migration of these mountain plants may be related to several factors, including pesticide use, livestock grazing or the occurrence of fires.
But the fact that this common phenomenon is observed in nine mountain ranges with distinct climates is probably explained by the rise in temperatures induced by global warming.
"Our analysis extends previous efforts by explicitly testing the hypothesis that vegetation is keeping pace with changes in temperature at high elevation," the scientists say.
However, some results show that, although plants can climb rapidly, the pace does not always match the temperature changes in specific areas.
"Mountain ranges vary in their relationships between elevation and vegetation cover, with subtropical mountains showing relatively large amounts of cover even at high elevations, whereas subarctic ones have a nearly complete loss of vegetation at high elevations," the study authors note, for example.
"Understanding such shifts in species distribution could provide insights on the velocity of climate change and aid conservation planning," the researchers conclude in a news release.
More research is needed, however, as the study does not take into account changes over the past 12 years. – AFP Relaxnews
