Sphagnum fuscum Endangered species lists within some German states. Switzerland has labelled "S. fuscum" as vulnerable. In the United States, "S. fuscum" is reported to be at risk in the state of North Carolina. Across Europe, "S. fuscum’s" habitats are under protection. Germany and Switzerland have both placed the moss under “special protection.” This species is associated with "Sphagnum angustifolium", "S. fallax", "S. magellanicum", "S. papillosum", more infrequently with "S. teres", and "S. warnstorfii" in richer sites. "Sphagnum fuscum" is easily discernible from other species of Sphagnum, as it tends to be reddish brown in color, and is more likely to form
Carnivorous plant more or less than this optimum will take up less carbon dioxide than an optimal plant, and hence growing less well. These plants will be at a selective disadvantage. At zero investment the growth is zero, because a non-carnivorous plant cannot survive in a habitat with absolutely no soil-borne nutrients. Such habitats do not exist, so for example, "Sphagnum" absorbs the tiny amounts of nitrates and phosphates in rain very efficiently and also forms symbioses with diazotrophic cyanobacteria. In a habitat with abundant soil nutrients but little light (as shown above), the gross photosynthesis curve will be lower and flatter,