Rhiannon

The replica is only a couple of miles from Seahenge, but, as you observe, it's not in exactly the same environment. However, the main observable difference is that none of the original timbers fell or leant, so the builders may have taken greater care in packing the bases than did Time Team. Perhaps, we might say 'they knew what they were doing'!

Maybe they were aware of how rapidly the wood might decay, and I imagine the timbers of the replica have considerable life left in them. My feeling is that left to itself the replica will simply collapse as the timbers fall over. The only permanent component may well be the upturned tree trunk. After all, that turned out to be the truly enduring feature.