Survival of the fittest—that's how retail and fashion experts are describing the coming months. The spring runway shows in New York, Milan, and Paris have ended, and retail buyers have placed their bets for next season. Now, more than ever, their decisions about spring inventory could determine which stores make it through the downturn and which shut their doors.

The pressure is causing anxiety through all levels of the retail chain. "All of a sudden, there is a fear factor that we had not seen in several years—maybe ever—in our business," says Carol Hoffman, executive vice president of the Donegar Group, a retail and fashion analysis firm.

So far, lower-price chains have felt the tightest squeeze. The 59-year-old department-store chain Mervyns announced last week that it would liquidate its $2.5 billion business after failing to find a buyer, Steve & Barry's filed for bankruptcy then was sold, and the Boscov's department-store company has filed for bankruptcy protection. Overall, the Standard & Poor's retail index has lost more than 40 percent of its value since October 2007.

While higher-end brethren have survived, their numbers aren't pretty either. This month, Neiman Marcus reported a 15.8 percent decrease in sales for stores open more than a year. Saks and Nordstrom were down nearly 10 percent.

With stats like this, several major retailers declined to comment on their spring buying. "People are playing it very close to the vest," explains John Mincarelli, professor of fashion merchandising at the Fashion Institute of Technology.

But behind closed doors, many are testing inventory strategies to survive, and maybe even rebound, in the spring. Some boutiques are focusing on items that appeal to customers emotionally, rather than wardrobe basics. Buyers for retailers are cherry-picking more sparingly from designers' collections. And across the spectrum, retailers are holding back spending to protect themselves from softening demand—and potentially to benefit from last-minute deals on merchandise.

Many retailers have reduced the amount of inventory they buy in advance, says Mincarelli, who also consults for companies such as Macy's. Ordinarily, a store might place orders for 95 percent of its expected spring sales, but this year that number has dropped to more like 80 percent.

The next big question is how to allocate those dwindling dollars. In strong economic times, retailers could afford to be dazzled by runway shows—such as the ones that earned high praise in Paris this year—and buy accordingly. But these days, budgets reign supreme.