Final answer:
Depth of penetrating sunlight is a limiting factor for net primary productivity in both terrestrial and aquatic ecosystems because it affects photosynthesis, which is vital for the production of organic matter.
Step-by-step explanation:
The depth of penetrating sunlight is a factor that can limit net primary productivity in both terrestrial and aquatic ecosystems. In terrestrial ecosystems, factors like fog, dust, and insect swarms may temporarily reduce sunlight, but these are not generally permanent features. Both the depth of penetrating sunlight is a limiting factor for net primary productivity in terrestrial and aquatic ecosystems. In terrestrial ecosystems, the depth of penetrating sunlight affects the growth and productivity of plants. In aquatic ecosystems, the availability of sunlight at different depths determines the distribution and productivity of organisms. Low water availability in both ecosystems also contributes to the limitation of net primary productivity.
In contrast, aquatic ecosystems, especially deeper waters, are characteristically influenced by the depth at which sunlight can penetrate, which affects photosynthesis and the communities of organisms. In both ecosystems, sunlight is vital for photosynthesis and production of organic matter, but in aquatic systems, particularly oceans and deep lakes, there is a distinct separation into photic zones where sunlight reaches and aphotic zones where it does not.