Deciduous Trees of Montreal
During the past couple weeks, my research team and I have observed many different species of deciduous trees throughout our local communities in Montreal. As our weather has been getting colder, and we transition through seasons, our environment has been changing all around us. When I first started my observations, most trees were green and full of leaves, but within the short span of a couple weeks, I have noticed many colors changing and an abundance of leaves dropping.
This observation is due to the fact these trees are all in the process of shedding their leaves as winter approaches in order to survive the harsh weather conditions. All deciduous trees undergo this adaptation to conserve water and energy, and the hormone that initiates the process of abscission (falling of the leaves) is one of the reasons for the new red, orange, and yellow colors we see.
While making my observations I found the ginkgo tree particularly interesting, whose distinctive fan-shaped leaves I noticed immediately while passing by. Ginkgo trees have many unique adaptations, such as the ability to make protective chemicals that fend off dieses and drought, and their extremely long-life span which can be up to 3,000 years!
I observed a few species of elm trees throughout my research and decided to investigate the phylogeny placement of the American elm species. The placement of American elms on the phylogeny tree can be shown by placing it into increasingly specific categories. Starting with eukaryotes, then breaking off into the broad group of species within the plant kingdom, it is further categorized into flowering plants (Magnoliopsida). More specifically eudicots, and then rosids. Branching off into the elm family (ulmaceae), the genus ulmus (species of elms) who are in the plant family of ulmaceae contains 118 species- one of which is the American elm (ulmus americana).
Elm trees first appeared around 20 million years ago in central Asia, then spread over most of the northern hemisphere, inhabiting North America and Europe. American elms reach their reproductive maturity quickly and produce a good seed crop before 20 years of age, and then continue to reproduce at a great rate throughout their life. American elms were a possibly long-lived species before a new disease arose in Europe that had a greatly negative impact on the elm population, and although mature American elm are still present today, they have become much sparser.
