recap

29.4 recap

Fungi are important to humans in many ways. Some species are consumed directly as food, while others are important in food production. Fungi serve as important indicators of ecosystem health and are critical in reforestation and in pollution remediation efforts. Several species are important model organisms for studies of eukaryote cell and molecular biology. Fungi are widely used to combat diseases and pests.

learning outcomes

You should be able to:

  • Describe the ways baker’s yeast is used in food and drink.

  • Give examples of uses of molds in food products.

  • Summarize how fungi can be used for food.

  • 632

    Assess the advantages of using lichens, over traditional measures, to monitor environmental conditions.

  • Generate plans for land use that take advantage of the importance of mycorrhizal associations.

Question 1

What are some of the ways in which fungi or fungal products contribute to the human food supply?

Some fungi are eaten directly (including mushrooms and a few lichens), but fungi play a bigger role in the production of bread (from baker’s yeast), cheese (fungi give many cheeses their distinctive flavors), and drinks (through fermentation of yeasts). In addition, fungi enhance and facilitate the growth of many crop plants.

Question 2

What are some advantages of using surveys of lichen diversity and museum collections of lichens to measure long-term changes in air quality, compared with direct measurements of atmospheric pollutants?

The museum lichen collections represent an indirect record of past air quality that can be used in areas where no direct measurements of air quality were originally taken. In addition, lichen diversity surveys represent a fast and inexpensive way to monitor air quality across an environment.

Question 3

Can you develop a strategy for tree harvest that would ease the difficulty and expense of reforestation projects by retaining viable communities of mycorrhizal fungi?

By using selective tree harvest, rather than clear-cutting, forests may be managed to retain largely intact communities of many organisms, including mycorrhizal fungi. If some of the original forest trees are retained, replacement of harvested trees is greatly facilitated by the continued presence of viable mycorrhizal fungal communities.

Question 4

Consider the data below for lichens at five survey sites. Predict the relative order of the sites with respect to their distance from the center of a large city. Other factors (besides distance to city center, such as prevailing wind direction) might affect your prediction. Can you think of two other major factors that might influence these results?

Site number Number of
lichen species		 Tree branches covered
in lichens (%)
1 5 38
2 1 2
3 3 15
4 8 75
5 13 100

Site 5 shows the highest diversity and density of lichens and so is probably farthest from the city center. Site 4 is next, followed by Site 1, then Site 3, and finally Site 2. In addition to distance from the city center and prevailing wind direction, other predictive factors could include distance to point-pollution sources (such as factories or power plants) and distance to major highways (a source of pollution from automobile exhaust). Other answers are also possible; it is important for such studies to control for factors such as the species of tree examined and the exposure of the branches to similar light and humidity conditions.