What typically characterizes the ET and NPP levels in tundras?

In tundra ecosystems, evapotranspiration (ET) levels are typically low due to the cold temperatures and limited water availability. The low temperatures reduce the rate of evaporation, while the frozen ground and short growing season restrict water access for plants. Consequently, the potential for transpiration is also diminished.

Net Primary Productivity (NPP) in tundras is also low when compared to more temperate and tropical ecosystems. The primary reasons for this low NPP include the harsh climatic conditions, short growing seasons, and nutrient-poor soils. Plants in tundra environments are adapted to survive under these limitations, often growing slowly and having shorter lifespans, thereby producing less biomass overall.

Therefore, the combination of low evaporation rates and limited primary productivity characterizes the tundra ecology, leading to the conclusion that low ET aligns with low NPP in these ecosystems.