Final answer:
When all living organisms are included, plants contain about 70% of the biomass found on Earth's land surface, with the biomass differing based on environmental factors such as climate and nutrient availability which affect photosynthesis and primary productivity.
Step-by-step explanation:
When all living organisms are included, plants contain about 70% of the biomass found on Earth's land surface. Biomass refers to the amount of organic matter present in an individual organism or in all the organisms at a given trophic level. It serves as a crucial source of energy and nutrients within ecosystems.
Terrestrial biomes which are the land habitats present on Earth, have varying amounts of biomass depending on factors such as climate and soil quality. Environments with warm and wet climates exhibit optimized conditions for photosynthesis and plant growth, leading to high net primary productivity and consequent high biomass production. Plants, being the dominant producers on land, convert solar energy into glucose through photosynthesis, resulting in a large accumulation of biomass across various ecosystems.
Freshwater ecosystems, which cover a much smaller surface area of the Earth compared to terrestrial and marine ecosystems, also contain biomass, but to a lesser extent. Marine ecosystems, while extensive and having significant biodiversity, do not accumulate biomass in the same way as terrestrial ecosystems, partly due to differences in photosynthetic processes and available nutrients that limit the growth of phytoplankton, which are major producers in these environments.