Nonvascular Plants

Trainor described algae as photosynthetic, nonvascular plants that contain chlorophyll a and have simple reproductive structures. 29 The fossil record indicates that algae may have existed before the Cambrian period.30 This survey focuses on marine macroalgae, commonly referred to as seaweed. Seaweeds are the largest forms of algae and live attached to solid substrata between and... 

Coal is formed from peat and the vascular plant remains that accumulate in peat bogs. Anaerobic conditions are considered mandatory for the accumulation and preservation of peat and the formation of coal. Two major types of coals are known humic coal and sapropelic coal (see Breger, 1963, 1976). The former are formed from peat accumulations rich in humic substances derived predominantly from vascular plant remains. The latter represent coal formed from algal (boghead coal) or spore (cannel coal) accumulations. In many respects, sapropelic coal can be considered to have an aquatic origin similar to that of humin of aquatic sediments which forms from the accumulation of aquatic nonvascular plant debris in clastic sediments. Conversely, kerogen can also have the properties of humic coals (Breger and Brown, 1962) is the source materials to the sediment at the time of deposition are predominantly derived from vascular plants. 

In peat, humin is also composed of the three structural entities mentioned above. The anaerobic nature of peat precludes the extensive decomposition that occurs in aerobic soils, and biomolecules are likely to be better preserved. Carbohydrates are major components of humin in near-surface intervals but are decomposed and lost with depth in the peat. Lignin and the paraffinic structures are selectively preserved with depth. When the humin of peat is delignified, the paraffinic structures remain. These components are likely to be derived from nonvascular plant contributors to the peat, namely, algae. 

Part of the large variation in estimates of biomass and NPP is, however, methodological. There is a 5-fold variation among studies and years in estimates of aboveground biomass and NPP at a single site (Toolik Lake tussock tundra)(Epstein et al, 2000). The largest variation reflects whether nonvascular plants were included or excluded and the definition of live moss. Moss biomass varies... 

A few studies have been carried out on the trace element composition of nonvascular plants. Schwarz (835) has reported briefly on the selenium content of yeast, and Wey (993) used activation analysis to determine the Mn and Cu contents of chlorella cells. Marine algae have been analyzed for As, Ba, Br, Cs, Co, Ca, I, Hg, Mo, Rb, Re, Sr, U, V, and W by Fukai and Meinke (302,303), Hamaguchi et al. (384), Lunde (572) and Stevenson et al. (919). Merlini and co-workers (609,610) report on the use of nondestructive activation analysis to determine some of these elements in microplankton from fresh water aquatic systems. 

M. caldariorum may have just two CesA genes and to date it is unclear whether they interact within rosettes (Roberts and Roberts 2004). Further examination of CesA genes from M. caldariorum and nonvascular plants (see below) may clarify the relationship between CesA diversification and evolution and assembly of the rosette. 

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