Yellow chevron markings at end of runway, what do they mean? In this YouTube video (link starts video at time of interest), the pilot appears to land in the area marked by the large yellow chevrons, in what appears to me (a layperson) to be a taxi way.



What are the meaning of the yellow markings? Under what conditions can a landing be made before this point?
Those are not chevrons but arrowheads used to mark the start of the runway. So, yes, he did land on the taxiway. 



Source: FAA Airfield Standards Quick Reference

He does land slightly before the runway threshold. He even says he is going to land short. Since there was nothing on the taxiway leading to the runway then it seems there is no problem doing that. 



screenshot from Google maps of KYKM runway 22 threshold

For comparison, chevrons mark either stopways or blast pads and look like this:


same source as first image

They may include an EMAS bed, so touching down there would not be a good idea.