Trees in Animation - noise/flickering

[SHORT CUTS]

Good Day!
I could need some pointers on how to tackle noise/flickering in trees. I have a low poly city and of course quite a few trees in it. Most of the scene is rendering fine using the standard settings (UHD Chache is set to Animation) and a noise threshold of 2.5, rendertimes are quite high which was unexpected but it renders almost without any hassle. (frames without lots of trees are taking 10-15 minutes, frames with quite a few trees in it up to 1 hour). Unfortunatly there is still some noise/flickering in the trees. I cant really lower the noise threshold, rendertimes will explode, so is there any other setting i could adjust to get them quite noise free?

Attached is a small clip, i know its hard to see in the preview and short clip. Hope it helps anyway.

[maru]

It is most probably not enough AA.
Some ideas:
-The most important thing is to render more passes. It can be done by either letting the image render longer (more time = more passes) or lowering the GIvsAA balance in Render Setup > Performance to make more passes render in the same time. So you can try keeping the same noise limit, but lower GIvsAA from the default 16 to 8. Then render a few frames to see if there is any improvement.
-Use sharpen+blur in the VFB post processing to slightly blur the sharp edges (this is like adding some real life "imperfection" to your image)
-Enabling motion blur

[SHORT CUTS]

No Animation without motion blur, thats always enabled ;)
AA was my first guess too, i will try  to lower the GI vs AA Samples. Thanks for you reply, much appreciated.