کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
82077 158371 2011 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Boreal lichen woodlands: A possible negative feedback to climate change in eastern North America
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علم هواشناسی
پیش نمایش صفحه اول مقاله
Boreal lichen woodlands: A possible negative feedback to climate change in eastern North America
چکیده انگلیسی

Because of successive forest fires, closed-canopy black spruce forests are susceptible to a shift towards open lichen–spruce woodlands in parts of the boreal forest of eastern North America. The shift from dark black spruce canopies to pale lichen ground cover offers a dramatic contrast in reflectance that may compensate for the CO2 emissions from forest fires in terms of radiative forcing. We have therefore looked at the climate change feedback that would result from the generation of lichen woodlands through changes in albedo and in stored carbon. Using albedo estimates based on MODIS imagery and incoming solar radiation for the period between 2000 and 2008 along with forest biomass estimates for eastern Canada, we have estimated that net radiative forcing for the conversion from closed-canopy coniferous forests to open lichen woodlands would be about −0.12 nW m−2 ha−1, and would therefore generate a cooling effect in the atmosphere. Based on current estimates of area in open lichen woodlands within the closed-canopy black spruce–moss forests of eastern Canada, we estimate that a current net forcing of −0.094 mW m−2 has already arisen from such conversions. As projections of future climate have been linked to increased probability of forest fires, the generation of open lichen woodlands provides a possible negative feedback to climate change. Results also suggest that carbon sequestration through the afforestation of boreal lichen woodlands may not provide a climate change mitigation benefit.

Research highlights▶ In boreal forests of the Province of Québec, in eastern Canada, forest fire frequency may increase as a result of climate change. ▶ Repeated fires in some forest types dominated by Picea mariana may push these ecosystems into a new stable state of open lichen woodlands. ▶ The resulting net radiative forcing provides a net cooling effect to the climate system.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Agricultural and Forest Meteorology - Volume 151, Issue 4, 15 April 2011, Pages 521–528
نویسندگان
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