Increased temperature, N and snowpack experiment for north of saddle from 2006 to ongoing, yearly

• Main Authors: Suding, Katharine N, Smith, Jane G, Niwot Ridge LTER
• Format: Dataset
• Language: English
• Published: Environmental Data Initiative 2020
• Subjects: Arctic; Antarctic; Indian; Ashton; Antarc*; Tundra
• Online Access: https://dx.doi.org/10.6073/pasta/81eb979c641a3af35ac67c2dfe7c1bf4; https://portal.edirepository.org/nis/mapbrowse?packageid=knb-lter-nwt.13.2

In 2006 we established a global change experiment in the Indian Peaks Wilderness in the Front Range of the Rocky Mountains to investigate how manipulations of warmer summer temperature, N deposition, and increased snowpack would affect the growth of alpine plants. The experiment was implemented on Niwot Ridge, where shrub cover has expanded by over 400% since 1946 (Formica et al. 2014). We established experimental plot north of the Niwot Ridge saddle, in an area of moist meadow tundra where willow shrub (Salix sp.) patches are present. Within experimental plots, Salix glauca seedlings were transplanted in 2006 and 2007 to test whether changing environmental conditions facilitated shrub survival and growth. In 2007 and 2008, phenological observations were recorded for all (2007) or abundant (2008) species in experimental plots. Measurements of plant species composition and aboveground net primary productivity (ANPP) are also made annually, and included in this data package. In July of 2016, a community transplant experiment was implemented to test whether changing environmental conditions support changes in alpine tundra plant communities. Two species characteristic of (1) dry meadow tundra (Tetraneuris acaulis, Erigeron pinnatisectus), (2) snowbed tundra (Ranunculus adoneus, Saxifraga rhomboidea) and (3) subalpine meadow (Trollius albiflorus, Polemonium pulcherrimum) were transplanted into experimental plots. Survival and growth of transplants is documented annually. References: Formica, A., Farrer, E.C., Ashton, I.W., and Suding, K.N. Shrub expansion over the past 62 years in Rocky Mountain Alpine Tundra: Possible causes and consequences. Arctic, Antarctic and Alpine Research 46, 616-631.