Describe two ecological roles of fungi. Related concepts decomposer.pdf

Describe two ecological roles of fungi. Related concepts: decomposers, mycorrhizal symbiont.
Solution
Fungi as Decomposers
Fungi join bacteria as the primary decomposers in different ecosystems. They feed on the
organic remains of dead plants. They release special enzymes that break down lignin, a
structurally complex substance in wood. Because of their ability to break down wood, fungi are
considered the major wood decomposers in forests. To absorb organic matter, fungi release acids
to melt organic matter, and then they suck the acid back together with the melted organic matter.
Decomposing organic matter is considered by ecologists as the major ecological role of fungi.
Plant-Fungi Symbiosis
The symbiotic association between a vascular plant root and fungi is called mycorrhiza. In this
association, fungi colonize the roots of a plant and gain access to their tissues. The fungi build a
connection to the roots in such a way that they can exchange nutrients with each other. Plants
provide mycorrhizal fungi shelter and a supply of carbohydrates; in return, mycorrhizal fungi
improve the plant’s absorption capabilities for water and nutrients. Mycorrhizal fungi have a
larger surface-area ratio compared to roots, so they have higher absorptive capacity for water and
minerals. They make it easier for plants to absorb water and minerals in soils that are dry and
with low mineral concentration. Without mycorrhiza, it would be difficult for plants to absorb
water and minerals from such soils. It is estimated that about 90% of plants depends on
mycorrhizal fungi for survival..

1. Describe two ecological roles of fungi. Related concepts: decomposers, mycorrhizal symbiont.

Solution

Fungi as Decomposers
Fungi join bacteria as the primary decomposers in different ecosystems. They feed on the
organic remains of dead plants. They release special enzymes that break down lignin, a
structurally complex substance in wood. Because of their ability to break down wood, fungi are
considered the major wood decomposers in forests. To absorb organic matter, fungi release acids
to melt organic matter, and then they suck the acid back together with the melted organic matter.
Decomposing organic matter is considered by ecologists as the major ecological role of fungi.
Plant-Fungi Symbiosis
The symbiotic association between a vascular plant root and fungi is called mycorrhiza. In this
association, fungi colonize the roots of a plant and gain access to their tissues. The fungi build a
connection to the roots in such a way that they can exchange nutrients with each other. Plants
provide mycorrhizal fungi shelter and a supply of carbohydrates; in return, mycorrhizal fungi
improve the plant’s absorption capabilities for water and nutrients. Mycorrhizal fungi have a
larger surface-area ratio compared to roots, so they have higher absorptive capacity for water and
minerals. They make it easier for plants to absorb water and minerals in soils that are dry and
with low mineral concentration. Without mycorrhiza, it would be difficult for plants to absorb
water and minerals from such soils. It is estimated that about 90% of plants depends on
mycorrhizal fungi for survival.