In sample that is presented, the grammar is confusing. The sentence could be better punctuated or broken up into shorter sentences.
The subject is implied from the previous section which reads:
Hawaii's traditions are as diverse as its people.
So the subject is implied to be Hawaii's traditions
.
The sentence is written in the present tense, and often when people write in the present tense, one finds that people slip into a past tense.
To parse this sentence it might be easier to break it up into shorter sentences.
An inelegant example would be:
Hawaii's traditions are rooted in a native culture.
The traditions are passed from one generation to the next.
Over the years, these traditions have mixed with the traditions of
many people who have come from all over the world--people who
have made Hawaii home.
The point of this message is to say that Hawaii is a diverse, cosmopolitan place, and the people are easygoing and they get along with people from many different cultures.
Notice the tense shift
in the third sentence of my example. It would be possible to keep it in the present tense, but the tone would change.
Over the years, these traditions integrate with the traditions of
many people who come from various parts of the world--people who make
Hawaii home.