Oxfordshire Woodland Group

On 04th April 2011 I took a photo of wildflowers in bloom underneath a maple tree which included dog violets, lilley-of-the-valley, primroses, snakes head fritilarias, dock, etc.

2 years later on 04th April 2013 after experiencing a very cold and prolongued winter / delayed start to spring the effect on plant life is fairly obvious.

3 weeks later the weather has warmed up and the snakes head fritillaries and the violets are now flowering however the violets are being shaded out by the other vigorous broad leafed plants like dock and cow parsely.

Is this phenological outcome down to global warming or simply year to year climate variations ?

Chilterns