Chapter 19 – Measurement of light penetration in relation to seagrass

摘要: Seagrasses require light for photosynthesis, however, they live in a low and variable environment. have higher requirements than phytoplankton, macroalgae, some terrestrial plants as to support larger proportion of nonphotosynthetic tissue are rooted anoxic sediments. This chapter discusses five approaches measure aquatic habitats: Secchi disc, seagrass maximum depth limit, instantaneous photosynthetic photon flux density (PPFD), continuous PPFD, spectral distribution. The relative benefits limitations each, well the information that can cannot be provided by different methodologies discussed. examples two situations relevant biologists also discussed, measuring high tidal ranges where water is highly turbid captured canopy. Measuring quality has been only recently applied biology. lack research past may part attributed cost complexity instruments. Although instruments becoming less expensive easier use, comparison PAR, spectroradiometry still more costly complex. allows many new questions ecology physiology addressed. Caution must used application this technique clear objectives should established before quality.