Shrub encroachment in North American grasslands: shifts in growth form dominance rapidly alters control of ecosystem carbon inputs

Shrub encroachment into grass-dominated biomes is occurring globally due to a variety of anthropogenic activities, but the consequences for carbon (C) inputs, storage and cycling remain unclear. We studied eight North American graminoid-dominated ecosystems invaded by shrubs, from arctic tundra to Atlantic coastal dunes, to quantify patterns and controls of C inputs via aboveground net primary production (ANPP). Across a fourfold range in mean annual precipitation (MAP), a key regulator of ecosystem C input at the continental scale, shrub invasion decreased ANPP in xeric sites, but dramatically increased ANPP (>1000gm-2) at high MAP, where shrub patches maintained extraordinarily high leaf area. Concurrently, the...

Categories: Publication; Types: Citation, Journal Citation; Tags: Global Change Biology, LAI, MAP, Wiley-Blackwell, aboveground net primary production, All tags... carbon, climate change, grasslands, growth form, shrubland, Fewer tags