Although plant fossils have provided us with valuable record of the terrestrial ecosystem for the past 400 million years, yet we have been unable to fully comprehend the biases that are introduced during their formation. Our project will explore the decomposition patterns of the various groups of plants (e.g. flowering plants, conifers, Ginkgo, ferns, and so on) decay. If we are able to unravel the decomposition rate of different groups in the plant world, it will open new pathways to a better understanding of the fossil record and thus, help us to reconstruct ancient ecosystems.
The discipline of Paleontology only studies those fossils - the remains of bygone organisms - that survived to become a fossil, which constitute only a very tiny proportion of the actual ancient ecosystem. All of our understanding of the past life and ecology is rooted on these fossils, but in order to successfully reconstruct the ancient ecosystem, we must have a full-fledged understanding of the biases of the fossil formation process. Taphonomy is the branch of paleontology that studies the process of fossilization, focusing on the pre-burial factors that may alter their assemblage - the effects of habitat, transport, and sinking - and affect our ability to interpret the past. For instance, leaves at the tops of trees are more likely to be transported by wind to a river or lake where fossils will be formed. Since the post-burial processes, such as decay, remain relatively unexplored, we need to study this extensively.
While the role of decay in the formation of animal fossils has been well documented, the details of the decay of plants are yet to be explored and understood. Since plants are made out of very different chemical components, we do not know how their composition affects their survival in order to be fossilized. Furthermore, variations in structures and chemistries exist among plant groups, which may also affect their chances of being preserved. For instance, fossil leaves of ferns and Ginkgo often look very different even when preserved in the same rocks. The reason behind this phenomenon is not understood and it may be so that the plants themselves control this! If certain plant groups decay at a faster rate than others, then it is possible that our views of plant diversity through time is biased. This is what we need to figure out.
In this project, we will be comparing the decay rates of 20 different species of 4 major groups of plants (flowering plants, conifers, Ginkgo, and ferns). We will carefully select the leaves from each group of these plants from a Botanical Garden after which we will decay them in a controlled environment for up to one year. Sampling will be charted between 6 different time steps. Our goal here is to determine the answer to three important questions: · How do leaves change over time? · Do they lose important characters that help us in identifying them? · Do certain species decay away entirely while others remain identifiable? We will then compare the results of the experiments to fossil plants. This will provide us with a deeper insight into the time frame in which plant fossils must form to preserve important morphology.
We will be conducting our experiments will be in an environmental chamber that efficiently controls temperature and humidity. Since plastic contains chemicals that may compromise future chemical analyses, we will use glassware. Thus, we have to procure deep glass Petri dishes for the decaying process. After removing the leaves from the decay environment, we will examine them using scanning electron microscopy to identify the important changes to the leaf that occur during decay. It is an expensive and time-consuming process and we really need your support to help us raise the fund for this project.