Fungi Field Trip by Jaena Bautista

Fungi Field Trip

by Jaena Bautista

Fungi includes some of the most important organisms around us. It functions to break down dead organic materials, take part in the role of nutrient cycling through ecosystems, serve as food and much more. During the field trip, different kinds of fungi were observed. Some of which are the decomposers (saprobes), others are pathogenic which cause diseases to plants and lastly, mycorrhizal fungi which is in association with the root tips of plants. Most vascular plants could not grow without the symbiotic fungi, or mycorrhizae, that inhabit their roots and supply essential nutrients

Figure 1: Tree with fungal disease

One of the most interesting parts for me in the field trip is knowing that a tree can be sick just be looking at it. Seeing the picture from above, the black spots indicate that pathogenic fungi are starting to decompose and eat the bark from inside.

Figure 2: Fungi eats up heartwood

In this picture, it shows that tree is affected by fungal disease. Fungi have eaten most of the heartwood inside of the branch which caused the branch to fall off. In addition, the tree will bleed the sap which is seen as the white part in the picture.

Fungi that are wood rotters cause a great damage when they attack the heartwood of trees. The entry of fungi into the heartwood is due to exposure of the heartwood. This comes about when the lower branches become shaded and die. After falling off, the heartwood is exposed and fungi can gain entry. This may also occur when lower branches of trees are trimmed which causes heart rot to occur. Usually, the types of trees attacked is dependent upon the fungus.

The good news is that heartwood rots do not usually kill trees in a big hurry. They can live with a tree for decades before the tree succumbs. The rotting of the interior wood can weaken the tree, however, making it more vulnerable to breakage, wind throw, insect damage, and other diseases.

Some info: http://www.botany.hawaii.edu/faculty/wong/BOT135/LECT10.HTM

Figure 3: Leaf spots

Leaf spots are also caused by fungal pathogens. This is another type of parasitic relationship between a leaf and a fungus. As the fungus gains nutrients from the leaf, the leaf which is the host dies. Although the host is affected, decomposition and nutrient cycling still occurs ---this shows how beneficial fungi are to the ecosystem.

Figure 4: Fungi on manure

I can say fungi as saprobes (decomposers) are the most essential types. For we can see in the image, fungi also grows on manures. It decomposes the manure and brings nutrients back to the ecosystem. Together with bacteria, they are responsible for most of the recycling which returns dead material to the soil in a form in which it can be reused. Without fungi, these recycling activities would be reduced. We would be lost under piles of dead plant and animal remains.

To sum it all up, the field trip was not only fun but also gave us more information about fungi while experiencing it. This experience came up to be more than what I expected. I was more intrigued on how cycles on forests function and made me more curious on what else could I learn more. I would love to have more of these kinds of trips for educational purposes that just learning stuff from microscopes and books.