What microorganisms live inside wood? - Science Journal for Kids and Teens
When you think of microorganisms, what comes to mind? Sore throats, stuffy noses, and coughs? Some microorganisms can cause infections that make us sick. But many microorganisms help us stay healthy. All the microorganisms in a particular environment are part of its microbiome. There are microbiomes in the soil, the ocean, and even the human body. We wanted to explore the microbiomes found in the wood of living trees.
A biome is a large area defined by its climate and the plants and animals that live there. Tropical rainforests and temperate forests are major biomes. The main plants in these biomes are trees. Trees provide habitat for animals and other plants. They are also home to many microorganisms. These organisms are too tiny to see with the human eye. They are part of the tree's microbiome. Microbiomes are communities of organisms and viruses in a particular environment. They can include fungi, bacteria, algae, protists, and archaea. Microbiomes are everywhere on Earth. They are even found on the outside and inside the human body. Many of these microorganisms help keep you healthy.
We were interested in the microbiomes of trees. We wanted to find out the number and types of microorganisms in tree trunks, which are mostly made of wood. How do the microbiomes of different tree species compare? What about the microbiomes in different parts of the wood? Or in other parts of the tree? This is what we wanted to explore.
Methods
We collected samples from a research forest in northeastern Connecticut. The samples came from 150 trees representing 16 different species. We took our samples between July 19 and August 12 of 2021. For each tree, we collected wood samples using an increment borer. This is a type of drill that collects a core about the size of a pencil. We took our samples from the bark surface to the pith. The pith is the soft, spongy tissue at the center of the tree.
We processed the wood samples by splitting them into two sections. The sapwood is the outer part of the tree, closest to the bark. It consists of the new rings that trees grow every year to move water and sugar. The heartwood is near the pith, in the middle of the tree. Heartwood is old, non-living tissue, from rings many years old. We ground each section into a powder. We then used a kit to extract DNA from the microorganisms in the wood. We had the DNA sequenced. This told us the types of fungi, bacteria, and archaea, and the number of each present.