How do snowpack depth and proximity to trees affect subnivean plant growth Robin Reibold Winter Ecology: Spring 2014 Mountain Research Station, University of Colorado, Boulder
Dec 19, 2015
How do snowpack depth and proximity to trees affect subnivean plant growth
Robin Reibold
Winter Ecology: Spring 2014Mountain Research Station,
University of Colorado, Boulder
Background
• Plant requirements for growth– Temp above freezing– Light for photosynthesis– Nutrients
• Light snow has the highest insulative value[1]
• Deep/Dense snow has lower light penetrance[2]
Hypothesis
• Being closer to trees will increase subnivean plant growth– Being near trees will increase snow depth over
clear areas[3]– Longwave radiation from tree
• Deeper snowpack will increase subnivean plant growth– Insulative value– Not too deep, still
need light getting through
Methods
• Three types of site– Meadow– Tree in Meadow– Tree in Forest
• 5 samples at each• Measured– Temp, depth,
amount of growth
W S N E
1
2
Observations
• Many tree sites had a thin layer (1-4cm) of snow on top of a thin layer of ice
• Despite the ice, some green shoots were still growing under and through
• Dominant species were grasses– Small number of forbs and mosses
• The bottom half of the meadow was very wind scoured meaning lower snowpacks
Comparison of sites
• The clear sites all had higher snowpack depths• Temperature was seemingly unaffected by proximity to trees• T depended on snowpack depth
Conclusions
• Snow depth is a more important factor for subnivean plant growth than proximity to trees
• Clear areas have higher productivity but trees seem to increase chance of success in a meadow
• Hypothesis is refuted– Being close to trees has negative effect on growth
• When combined with deep snow see no growth
– Deeper snowpack is best indicator
Citations
• [1]http://www.sciencepartners.info/?page_id=595• [2]Bohren C, Colors of snow, frozen waterfalls and icebergs,
JOSA, 23:12:p1646-52, 1983• [3]Lawrence D, Slater A, Contribution of snow condition
trends to future ground climate, Climate dynamics, 34:7-8:p969-81, 2010
• [4]Kappen L, Plant activity under snow and ice, with particular reference to lichens, Arctic, 46:4:p297-302, 1993
• [5]Olofsson J, Ericson L, Torp M, Stark S, Baxter R, Carbon balance of arctic tundra under increased snow cover mediated by a plant pathogen, Nature climate change, 1:p 220-23, 2011