Sachi's focal taxon

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Lichens

Lichens are organisms that contain a symbiotic association between a mycobiont (a fungus) and a photobiont, usually cyanobacteria or algae. Morphologically, lichens are quite different from either the isolated mycobiont or the isolated photobiont. The photobiont provides food for the fungi while the fungi provides protection and allows the photobiont to survive in a much wider range of environments than they would otherwise be capable of. However there is also evidence that the relationship may be parasitic or commensalistic since the photobiont can often survive on its own, but the fungi cannot.

Lichens are a very diverse group of organisms, and can be found in a wide range of habitats. They thrive in extreme or harsh habitats where many other producers fail, making them an important source of food in, for instance, extremely cold climates. Lichens have shown a remarkable ability to survive severe desiccation, where they can essentially lose all of their water content, and be revived with the addition of water a long period of time later. The mechanism of this survival has not been well documented. There has not been much research on lichen distribution based on elevation change or latitudinal differences.

Lichens are a paraphyletic group and are classified by their fungal component, since the fungi usually associates with only one of two types of photobionts while the photobiont can associate with various fungal partners. Although the physical characteristics of lichens are often enough to determine the genus, without chemical analysis, it is difficult to determine the species. Therefore, although I did record the genus for some of my specimens, I will classify the lichens on this page based on form. There are four basic forms that lichens are classified by are foliose, fruticose, squamulose and crustose. [1]

Mount Kinabalu is a lichen heaven, so I collected many of my samples in the high elevations there. I will go through an overview of the forms and present some examples for each, however the rest of my individuals can be found within the table at the bottom of the page.

Morphotype: foliose

Nine lichens were of the foliose form. The foliose form often appears leaf-like on a substrate, and differs from crustose in that it can be flaked off.

Foliose Example One Cladonia

Color: Greenish Gray

Substrate: Wood

Location: Within 600 m of Laban Rata on main trail on Mount Kinabalu (3000-4000 m elevation).

Description: Found on a rotting log off of the side of the main trail with moss growing around it.

Foliose Example Two Parmelia

Color: Whitish Gray

Substrate: Rock

Location: On rock off of the side of the main trail within 500 m of Laban Rata on Mount Kinabalu.

Description: Pretty small but I noticed it for its interesting branching structure.


Morphotype: fruticose

Two lichens were identified as fruticose. The fruticose form appears bushy, stalked, or has a general stalk-like growth.

Fruticose Example Usnea


Color: Greenish Gray

Substrate: Branch

Location: On the branches off of the side of the main trail within 500 m of Laban Rata on Mount Kinabalu.

Description: This particular lichen was found in the upper elevations, or anywhere above the cloud forests, on Mount Kinabalu hanging in the branches. The sparse foliage and constant moisture make an excellent habitat for the lichen, and it is able to withstand the cold while many producers found in lower elevations are not.

Morphotype: squamulose

Four lichens were identified as squamulose. The squamuose form is characterized by scale-like structures.

Squamulose Example One Peltigera

Color: Brown

Substrate: Branch

Location: Found on branch in a shaded area close to the ground within 500 m of Laban Rata off of the main trail on Mount Kinabalu.

Description: This was an interesting specimen with ruffled edges, and was the first squamulose form that I collected. Anne Pringle and I had a bit of trouble identifying the genus at first, and it is tentatively a Peltigera.

Squamulose Example Two genus unknown

Color: Green

Substrate: Dirt

Location: Found on ground in a shaded area close to the ground within 500 m of Laban Rata off of the main trail on Mount Kinabalu.

Description: Was interesting because it was a dark forest green that I had not seen on other lichens before. This lichen was also covering a huge portion of the rock, which I had only previously noted with crustose forms.


Morphotype: crustose

Eleven lichens were identified as crustose. The crustose form is characterized by lichen that is lacking a lower cortex and, as the name implies, appear to be crusting on a substrate.

Crustose Example genus unknown

Color: Whitish Gray

Substrate: Rock

Location: Found on rock in a misty and shaded area close to the ground within 500 m of Laban Rata off of the main trail on Mount Kinabalu.


Description: There was such a wide diversity of crustose lichens on Kinabalu – basically any rock that you turned to had about twenty on it. This particular lichen interested me because it looked almost foamy and the color was very distinct.

Morphotype: combination

Two lichens were found to have a combination of the other forms. I have classified them in this category because they were difficult to place fully in one of the other categories, and without other examples of the same form or an expert’s opinion, I felt it was better to leave them in the combination form category.

Combination Example

Color: Whitish Gray

Substrate: Branch

Location: Found on shrubbery/twigs in a misty and shaded area close to the ground within 500 m of Laban Rata off of the main trail on Mount Kinabalu.

Description: I have only seen one other example of this form of lichen, and it still puzzles me. It appears to be a sort of foliose structure off of the branches, but the branchlike structures that the lichen is growing on may also be products of the lichen itself.



Data

The lichens were analyzed for various physical characteristics that were used to make a phylogenetic tree. Here is the character matrix that was made using the program Mesquite.

I then exported the character matrix and used the program PHYLIP to create an unrooted consensus tree using maximum parsimony, since there were originally 90 most parsimonious trees. I then exported that tree and utilized the program Treeview to make a more aesthetically pleasing tree. It can be seen below.


File:Picture_1.png

Discussion

One important note to make about the above tree is that it is unrooted, and since lichens do not have a common fungal ancestor from which all lichen fungi evolved, it is very difficult to estimate where the root may fall. The strongest support was found between taxon 28 and taxon 25 with a support value of .81. There was also strong support between the branches of taxon 20 and taxon 28 and taxon 2, with a support value of .84. Taxa 20, 25 and 28 may be the most closely related because they were all found in Maliau Basin, and they share the same form and color.

Unfortunately, the rest of the support values are .56 and below, which means that there was much variation in the trees. This may be because I had many taxa, but I did not have many character traits. In addition, it was difficult to find many of the character traits for sure based on photographs. If I were to re-do this project, I would take more thorough notes at the time of an observation, and if possible, I would take samples and perform a chemical analysis so I could hopefully discern the species of the specimen.


References

  1. Anne Pringle

My Focal Taxa

Individual Determined by Date Taxon Genus Species Morphotype
Indiv106 Sachi 6 July 2010 crustose
Indiv108 Sachi 6 July 2010 crustose
Indiv110 Sachi 8 July 2010 crustose
Indiv111 Sachi 8 July 2010 combination form
Indiv113 Sachi 8 July 2010 crustose
Indiv51 Anne 1 July 2010 Cladonia Cladonia
Indiv63 Anne 1 July 2010 Parmelia Parmelia
Indiv67 Anne 1 July 2010 Usnea Usnea
Indiv68 Anne 1 July 2010 Parmelia Parmelia
Indiv71 Anne 1 July 2010 Parmelia Parmelia
Indiv73 Sachi 1 July 2010 crustose
Indiv74 Anne 1 July 2010 Peltigera Peltigera
Indiv75 Sachi 1 July 2010 squamulose
Indiv77 Sachi 1 July 2010 crustose
Indiv78 Sachi 1 July 2010 crustose
Indiv79 Anne 1 July 2010 Xanthoria Xanthoria
Indiv80 Sachi 1 July 2010 foliose
Indiv81 Anne 1 July 2010 Parmelia Parmelia
Indiv82 Anne 1 July 2010 Parmelia Parmelia
Indiv83 Sachi 1 July 2010 foliose
Indiv84 Sachi 1 July 2010 foliose
Indiv85 Anne 1 July 2010 Lasallia Lasallia
Indiv86 Sachi 1 July 2010 combination form
Indiv87 Sachi 1 July 2010 fruticose
Indiv88 Sachi 1 July 2010 crustose
Indiv89 Sachi 1 July 2010 foliose
Indiv90 Sachi 1 July 2010 foliose
Indiv93 Sachi 5 July 2010 crustose