A collaboration between the trust, the British Science Association and the BBC's Springwatch to find out how fast spring 2015 moved up the country, the project inspired 17,000 viewers to submit around 20,000 new records.
Sparks, a senior lecturer in statistics, then analysed the data, concluding the speed of spring from south to north was just over 3 km/h.
He was presented with the Watkins Memorial medal and a decorative bowl handmade by last year's winner Peter Lyons at the awards event in Leeds, where he also claimed the Oak Award for most outstanding support.
Other winners were:
- Acorn Award for the most inspiring volunteer: Sally Williams, who helped set up conservation work controlling invasive plants at a Surrey site;
- Bluebell Award for best guardian of woods and trees: Emma Scaife Sanders, for her work scrutinising two planning authority areas in the south-east of England where threats to ancient woodland are frequent;
- Willow Award for best collaborative achievement: Heartwood Environmental Monitoring Group, a multi-disciplinary team of around 40 academics and others who record ancient woods and the biodiversity within them;
- Juniper Award for best champion of woods and trees: Rosanna Ballentine, for her work advising and inspiring others in the use of native trees in Northern Ireland, including schools and Queens University Belfast, and for her woodland photography;
- Aspen Award for most dedicated corporate volunteer: Sarah Brogan, a Sainsbury's store manager whose corporate fundraising team raised more than £3,000 for the trust this year, and who has promoted its work in local schools;
- Volunteer Manager of the Year Award: Helen Jones, Observatree engagement officer, for the support and knowledge given to volunteers on the trust's tree health project.
Lynn Thompson, volunteering development champion for the trust, said: "Our volunteers are terrific and their contribution invaluable. Their enthusiasm and passion for the cause results in many going above and beyond what we ask, always without expectation of awards and recognition."