19 March 2020
Tomrrow marks the astronomical start of Spring and nature is waking up!
We have two definitions of when Spring starts: astronomical and meteorological. Tomorrow, 20th March marks the first day of the astronomical spring but the meteorological spring started on the 1st March.
So, what is the difference and why do we have two definitions for spring? Astronomical spring is determined by the Earth’s position in relation the Sun, however the Earth doesn’t orbit the Sun in exactly 365 days, and therefore the start of the season may fall on a slightly different day each year. The first day of astronomical Spring usually falls on the 20th or 21st March.
Meteorological spring is based on annual temperature cycles. The year is split into four seasons, each lasting three months and Spring always begins on the 1st March and lasts until the 31st May.
The first day of spring is also known as the ‘vernal equinox’ in reference to the day being qual in length to the night. ‘Vernal’ is derived from the Latin word ‘ver’ meaning the production of spring and ‘equinox’ translates to ‘equal night’.
The start of spring in the northern hemisphere marks the beginning of autumn in the southern hemisphere, however regardless of location, the beginning of the spring season is celebrated across the world with fairs and festivals as a sign of renewal, warmer weather, longer days and the start of the growing season.
Each spring, the earth explodes into life with buds bursting, flowers blossoming and leaves emerging. Nature is most active during the spring months.
In terms of trees, elder and hawthorn are amongst the first species to come into leaf with blackthorn being the first to blossom (main picture).
Hawthorn and blackthorn can be tricky to differentiate between, but spring makes identification easy with hawthorn coming into leaf then blossoming in May, hence it’s nickname the ‘Mayflower’, with blackthorn blossoming first the later developing leaves later on.
The Woodland Trust’s Natures Calendar provides an excellent guide of what to look out for and when. You can also record your sightings to help scientists monitor how climate change may be affecting our native plants and wildlife.
Post your pics on social media using #Naturescalendar and tag us @cityoftreesmcr.
You could also download the iNaturalist app where you can observe and upload your wildlife and nature sightings to help with global biodiversity tracking!