Which ecosystem is likely to have the lowest gross primary productivity?

Gross primary productivity (GPP) refers to the total amount of organic matter produced by photosynthetic organisms within an ecosystem. It is an indicator of the ecosystem's energy capture and overall productivity.

Deserts typically exhibit the lowest gross primary productivity among the ecosystems listed. This is primarily due to their extreme environmental conditions, such as low rainfall, high temperatures, and limited availability of nutrients. The scarcity of water significantly limits plant growth, which in turn restricts the rate of photosynthesis. Because primary producers like plants form the base of the food web by converting sunlight into chemical energy, a lower number of plants directly correlates with reduced GPP.

In contrast, ecosystems like coral reefs, grasslands, and wetlands possess higher productivity levels. Coral reefs thrive with high biodiversity and extensive photosynthetic activity from symbiotic algae. Grasslands support a variety of grasses and herbaceous plants that thrive with adequate sunlight and rainfall, contributing to substantial biomass and productivity. Wetlands are also highly productive due to rich nutrient availability and saturated soil conditions that support various plant species.

Thus, due to the harsh and limiting characteristics of desert environments, they yield the lowest gross primary productivity compared to other ecosystem types.