Tundra biome: a type of desert, cold desert

vegetation: begins a treeline - lack of energy restricts tree from reaching normal height

low precipitation: due to coldness of air unable to hold moisture

sunlight: artic region >66.5 degree latitude (N/S), hence 24hrs of sunlight for 6 months & 24hrs of darkness for the next 6 months

Snow & ice use energy to vaporise & melt

Air not high: due to energy being absorbed & not heating up the environment

Due to short growing seasons (~1 month), the tundra plants have much higher metabolic rates than temperate or tropical plants

Warm-blooded animals: have some means of regulating heat between heat production & loss

3 means of heat regulation:

heat loss control: insulation like fur, feathers, body fat, circulation control, evaporative cooling

heat production control: basal metabolic rate, shivering to increase metabolic heat

posture & behaviour:

Biome: animals & plants that look similar over large geographical region

Tundra biome categories: artic tundra, temperate alphine, tropical alphine

Artic tundra (treeless): narrow daily temperature range, soil churning due to permafrost, low wind velocity, low precipitation, long summer, low altitude with low UV exposure

Types: wet tundra, moist tundra, artic alphine tundra, treeline forest

vegetation: due to permafrost upper thawing limit, plants are shallow-rooted; summer thawing down to one-foot depth;

Whiteness: camouflage, higher insulating effect, radiates less heat (due to black body effect)

Shedding: of layers of hair or fur or fat during summer & vice versa for cold winter

Plants for short growing season: conserve energy by having leaves before growing season, small plant sizes require less water for growth; small, leathery leaves lose less water due to aridity; rapid phenological growth within first 1-2 weeks

respiration rate < photosynthesis rate: store up energy for the next growing season

perenial plants

asexual reproduction common

75% of plant biomass underground to avoid desication & cold

TTTreeline forest: permafrost >1 foot deep; permafrost forms lower limit to tree root growth, hence short trees

Temperate tundra: vegetation belt determined by altitude & occurs above treeline & all high mountainous temperate regions