Winter Plant Adaptations

Major Challenges for Plants Sunlight Sunlight Very little and week Very little and week Water Water Frozen and Drought Frozen and Drought Wind Wind High winds often High winds often Snow Loading Snow Loading Build up of snow on branches Build up of snow on branches Cold Temps Cold Temps Freeze water, slows photosynthesis Freeze water, slows photosynthesis

Tree Adaptations Leaf Drop (deciduous) Why? Why? Lose too much H2O Lose too much H2O Maintenance costs high photosynthesis low Maintenance costs high photosynthesis low Snow Loading Snow Loading

Leaf Drop (continued) How? How? Less light triggers production of Abscic Acid Less light triggers production of Abscic Acid Chlorophyll dies exposing Carotenes (yellow and orange) and Xanthophylls (yellow) Chlorophyll dies exposing Carotenes (yellow and orange) and Xanthophylls (yellow) Leaf dies, dries, and falls Leaf dies, dries, and falls Trees lose their leaves at different times Trees lose their leaves at different times Ash and Walnut then Maples finally Oak and Ironwood Ash and Walnut then Maples finally Oak and Ironwood

Drawbacks to Leaf Loss Behind Conifers in Springtime Behind Conifers in Springtime Lots of energy to re-grow Lots of energy to re-grow Lots of energy to store for spring Lots of energy to store for spring Sugars stored in roots are yummy Sugars stored in roots are yummy Deer, rabbits, and mice, eat saplings, buds, and bark of young trees because of all of the nutrients Deer, rabbits, and mice, eat saplings, buds, and bark of young trees because of all of the nutrients

Conifers Retain leaves (still lose just not all at once) Retain leaves (still lose just not all at once) Benefits: Benefits: Head start in spring Head start in spring Grow longer in fall Grow longer in fall Some photosynthesis in winter Some photosynthesis in winter Don’t have to store up as much energy Don’t have to store up as much energy

Conifers (continued) Drawbacks Drawbacks Water Loss Water Loss Have tight stoma Have tight stoma Thick cuticles Thick cuticles Snow Loading Snow Loading Cone Shape Cone Shape Supporting branches Supporting branches Color Color Grow close together Grow close together Roots, wind Roots, wind

Other Conifer Adaptations Raise solute concentration in cells Raise solute concentration in cells Dehydrate cells Dehydrate cells Move water into extra cellular spaces Move water into extra cellular spaces Store up energy Store up energy Get water Get water Below frost line Below frost line Internal reservoirs Internal reservoirs Subnivean water vapor Subnivean water vapor Generate heat to move H2O Generate heat to move H2O

Other Winter Challenges Warm Days Warm Days Uses energy reserves Uses energy reserves Opens stoma Opens stoma Melts insulating snow Melts insulating snow Humans Humans Harvesting (Christmas) Harvesting (Christmas) Compacting Snow (snowmobiles) Compacting Snow (snowmobiles) Running over Running over Road Salt Road Salt Vehicle exhaust Vehicle exhaust

Natures Challenges Flagging Flagging Breaking off of branches on ones side Breaking off of branches on ones side Usually wind + snow or ice Usually wind + snow or ice Animals: Animals: Girdle a tree Girdle a tree Mice, Rabbits, porcupines Mice, Rabbits, porcupines Eat succulent ends Eat succulent ends Deer, Moose, Elk Deer, Moose, Elk