Microbes and Plants - Freshwater Ecology: Concepts and Environmental Applications - page 144

FIGURE 8.11 Selected aquatic fungi: (A) Aquatic deuteromycetes, (B) Zoophagus species
with trapped rotifers, and (C) Arthrobotrys oligospora and a trapped nematode (reproduced
with permission from Rheinheimer, 1991).
boreal, or polar regions. In one northern European wetland, lichens and
mosses were responsible for 9% of the carbon input to the bog (Mitsch
and Gosselink, 1993). Lichens on rocks near the waterline of lakes have
received some study (Hutchinson, 1975). Lichen species change with dis-
tance above the water as their tolerance of submergence decreases.
The taxonomy of lichens traditionally is based on external morphol-
ogy. The morphological differentiation between lichens requires determin-
ing if the form is foliose (leaf like), fruticose (finger-like projections), or
crustose (appressed to a solid surface). Chemical techniques may also be
used to distinguish species.
PLANTAE
Plants dominate in many shallow waters. Plants in water are called
macrophytes . They are the dominant organisms in wetlands and many lake
margins and streams. They can play an essential role in biogeochemistry
and ecology. For example, macrophyte beds can provide important spawn-
ing habitat and shelter for small fishes. Macrophytes can also be the dom-
inant photosynthetic organism in small or shallow lakes. Thus, they can