If this first weekend of spring finds you enjoying a Davis park or plaza, thank Mark Francis.

While it takes planners, citizens, developers, engineers and builders to turn an empty lot into an outdoor living room, its ultimate success or failure depends largely on the strength of its design. Francis, a UC Davis professor of landscape architecture, has been the creative genius behind many of Davis' favorite community spaces, both downtown and elsewhere, including Arroyo Park in West Davis and Mace Ranch Park in East Davis.

"I have seen the city of Davis as a laboratory to test my research findings in real-world places," Francis says. "I am especially interested in how to create spaces that lead to memorable experiences."

Dateline spent the noon hour recently walking through some of these outdoor living rooms while Francis told their stories and pointed out design details that make them work. We began on campus, where visiting middle-school kids were milling on the Shields Library front porch.

Campus planner Bob Segar has new designs for the Quad District, including a gallery of trees to better link the Quad to Shields Library.

Mark Francis: Bob has a wonderful vision for the campus. I worked with him on a study of the Quad District, with my students, in the early 1990s. We did behavior mapping — recording which people did what where and when — to make recommendations to enliven the public areas of the central part of the campus.

One recommendation was that the campus decentralize food services; that's why we now have local coffee kiosks. And we introduced the idea of moveable chairs — very radical. Everybody thought they'd get stolen. So I put $30 plastic chairs from Longs on the lawn by Walker Hall. They lasted for years. Today we have moveable furniture on the Silo patio and elsewhere.

Now we've reached 3rd and B, the entry to Central Park. What got you started on this design?

When I came to Davis in 1980 from City University of New York, there was only one restaurant where you could eat outside. That told me we desperately needed more and better public space.

There already was the Farmers Market, alongside the small, historic Central Park bounded by 4th, 5th, C and D streets. Next to it was a big gravel parking lot, slated to become a shopping center. But I said, Davis is at about 35,000 population now; we're going to double soon, and we will need more open space. In the existing park there was the 1930s sycamore grove, and it was the town's most sacred place; when the community needed to gather, that's where they came. I wondered, could we spread that energy south?

And we did. The whole community came together and built a park instead of a shopping center. It's part living room, part outdoor market, part civic meadow. And look at it! Behind us is the Teen Center, where kids hang out on the steps. Next to it is the public garden, where elderly people and others like to come. So, by design, you bring the young and old together.

Over there, a high-school group using the lawn as an outdoor classroom. If it were warmer, children would be playing in the fountain in the plaza, which they call the Davis Beach.

And at the far end is the homeless place. That's a key question: Do you design the homeless in or out? My view is you design them in, as long as they don't run off the other users. That's the kind of democratic space this is.

The Farmers Market was the hardest part of the design. In its old location, it had a 30-foot center aisle; I wanted to make it half the size with twice the people. That gives you a very crowded, very lively space. If you see your neighbor — the one on your street you don't talk to — you have to say hello to them.

Now we've walked over to the E Street Plaza, outside Baskin Robbins Ice Cream. There's a clock fountain, a big paved courtyard, and benches.

And very few people.

This is where you once wanted to create a town square.

That failed because the downtown merchants felt they could not give up any parking spaces. So the center of gravity, the community gathering place, shifted — first to the new Central Park, later to Davis Commons. And then the merchants said, "Hey, where's our park?" So we did the E Street Plaza. But I feel it is largely too little, too late.

As we head to Davis Commons, tell us which project you are most proud of.

It's still coming to life: the Davis Greenway. Once we had made all these lively green spaces around the city, I thought the most interesting question remaining was: How do we tie them all together? I did a concept plan based on the design of a bicycle wheel. The rim is a contiguous path around Davis, where you could run a marathon without any contact with roads or traffic. The spokes are the green streets and greenbelts that tie us together. Today that concept is the heart of the City of Davis General Plan and it's about 60 percent complete.

We've reached Davis Commons. There are toddlers running on the lawn. People eat lunch on the patios (where, yes, the chairs and tables are moveable).

The design of this project began when the university still owned the land, and it owes a lot to Bob Segar and Chancellor Larry Vanderhoef. They were brave enough to rethink traditional development and say, "Rather than putting the parking lot in front, we'll put a public space in the front." And they chose to sell the property to a developer who was equally innovative, Mark Friedman.

The overarching idea here was: How could you use the space without feeling you had to buy something — make it a true public space? We included elements, like the seat walls around the lawn, where you could feel comfortable just spending the afternoon and hanging out.

You know, when I started designing public spaces in Davis, I thought of them as mixed-use places. But that has changed. Now I think of them as mixed-life spaces. Here, you can sit and read a book in the garden, eat, hear music and let your kids run around without being held onto — something unique in public life today. I am now using these lessons we learned in Davis to design much larger parks and public spaces in Indianapolis, Milan, Italy and South Korea.