What was the role of the Franciscans in changing the economy ...?

Question

of California from a hunter-gatherer economy to an agricultural economy?

Answer 1

Negligible.

The major impetus for economic development came later, first with the factory farms (sorry, ranches) that grew huge herds of cattle for hides to be shipped back to Spain,

http://www.mountainvalleyranch.com/calif...

and then with all the farmers who came out to grow food for the gold miners.

By comparison, the Cistercians in Europe did a much better job of economic development - introducing large scale water power in the middle ages, long before the Americas were colonized.

http://en.wikipedia.org/wiki/Cistercians