Maliau lichen project (proposal)

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Contents

A comparative view on Lichen dispersal

Introduction

Lichens are an unexplored realm of fungal diversity. Lichens can colonize on a wide array of substrates, including the forests at Maliau Basin in Sabah, Malaysia. An abundance of lichens of various morphotypes are often found living together in habitats as small as a single leaf. These single leaf communities provide an opportunity to examine various lichen colonization patterns through comparing age distributions of various morphologies.

  • Is there a difference in the age distributions of lichen morphotypes between older and newer leaves? In other words, is there a pattern in the age distribution between lichen morphotypes across habitat age?

Hypothesis

We expect there to be a difference in age distribution of the two morphotypes between the young and old leaves, in addition to a common pattern in morphotype colonization among differently aged leaves.

(Null Hypothesis: There is no difference between age distributions of various morphotypes and there is no pattern of colonization.)

Methods

The lichen colonies from older and newer leaves on the same tree specimen were compared. New leaves are defined as those that are shinier, greener, and closer to the budding portion of the tree. Since we have no method of correctly identifying the exact age of leaves, older leaves are defined as non-new leaves. The terms "older" and "newer" are used relative to each other in this study. A tree was selected based on leaf accessibility (2 meters or shorter), and presence of multiple lichen morphologies. Two new and two old leaves were selected per sampling. The two lichen morphologies to be studied were chosen based on apparent abundance and unique characteristics. Each lichen colony of the chosen morphotypes was labeled with an assigned number. Using a hand lens, microscope and caliper, the diameter of each colony was recorded. It will be assumed that diameter is a function of age.

Analysis

The age distributions of each morphotype on each leaf will be compared using R. The age distributions on different leaves within the same morphotype will be compared using a general linear model (ordinal leaf age vs. age distribution). The age distribution of the different mophotypes on each leaf will be compared (age distribution of morph A on leaf x vs. age distribution of morph B on leaf x). The difference between age distributions of distinct morphotypes on separate leaves will be compared to determine whether there is a pattern in age distribution of lichens across habitat age.