Role of Dendrochronology in Climate Change Research

Dendrochronology is the analysing data gathered by number and thickness of growth rings in dichotomous plants which has undergone secondary growth. Before learning about how these rings are important in climate change research, Let’s see the process of ring formation.

Secondary growth is exclusive to dicots. This is seen in shrubs and trees. Main feature of secondary growth is the plant girth increase. Two new meristems become active, Vascular and Cork cambium. Vascular cambium causes growth rings. Fusiform initials in vascular cambium produce secondary xylem tissues to the inside. Rate of xylem formation is much higher than phloem formation.

Cambial activity is sensitive to seasons. In spring thin-walled wider cavities are made and in autumn, thick narrow cavities are made. This process is dormant in winter. Rings made within a year are called an annual ring. Since the growth of plants are indeterminate, growth ring formation may occur till the death of a plant. This means careful observation of these rings reveal the climatic changes that plant and the associated environment had to experience.

Climate modelling is a method of predicting future climate change based on existing data. For modelling, data is crucial. Dendrochronology has given accurate baseline climate and environmental data for the last 2,000–5,000 years classified regionally. Significance of tree ring data is,they contain annual data methodically. This kind of organized data with minimum gaps between data points can generate strong models that predict future. Additionally, climate change can be detected region wise and relations between different regions can be compared.

CO2 levels in around the world and how it varies in recent 2000–5000 years can be plotted using growth ring evaluation.

With increasing greenhouse gasses, preventive measures to reduce adverse effects of climate change is important. Sustainable forest management is a key part of this discussion. Dendrochronology reveals data like water stress responses, impacts to a plant by a disturbance, data about wildfires, insect attacks, floods, wind and pathogen outbreak. Historic Data like this create a basis for future forest management strategies.

Another important use of studying growth rings is predicting extreme events. As mentioned earlier, growth rings contain data for each season lived. This is comparatively a short time. Sometimes climates may face a short extreme event in a normal overall climate. These are difficult to predict by standard models. Models can be refined by growth ring data to guess future extreme events.