Vlog: What's that Leaf?

A lot of trees have very similar leaves. So how do you tell them apart? Today I look at Beech, Hornbeam, Whitebeam and Hazel. Of course, these have all been covered in depth on this blog - check out my index page here. 

I also find myself puzzling over a curious phenomenon - why, particulalrly at dusk, do I occasionally find myself walking through a patch of air that is significantly warmer/colder than the ir around it? 

 Answers on a postcard, please. or, even better, in the comments section.