Figure 3. Effects of macrophytes on net community production (NCP, mmol C m⁻² hr⁻¹).

(A) Increases in macrophyte cover were associated with increases in NCP for both the most abundant macrophyte, the red alga Prionitis sternbergii (red circles, solid trendline; R² = 0.68, P = 0.004), and all macrophytes (blue triangles, dashed trendline; R² = 0.47, P = 0.029). Inset image: P. sternbergii. Image credit: Matthew Bracken. (B) Macrophytes, including seaweeds and the surfgrass Phyllospadix, dominated cover in the pools, collectively occupying the majority of the substratum. Macrophytes in the “Other” category each contributed <5% of cover and included Cladophora, Endocladia, Mazzaella flaccida, and calcifying species. Invertebrates represented ∼15% of total cover.