In a 5-quart saucepan, heat the oil over medium-high heat. Add the sausage and cook, breaking up the meat with a wooden spoon into small pieces, until brown, about 5 minutes. Using a slotted spoon, remove the cooked sausage and reserve.
Add the barley and cook stirring constantly until lightly toasted, about 4 minutes. Add the broth, carrots, parsnips, zucchini, fennel, leeks, chard, cheese rind if using, bay leaf, 1 teaspoon salt and 1/2 teaspoon pepper. Bring the mixture to a boil. Reduce the heat to a simmer and cook, uncovered, until the barley is tender, about 35 minutes.
Remove the Parmesan rind and bay leaf, and discard. Season the soup with the remaining 1 teaspoon salt and 1/4 teaspoon pepper.
Ladle the soup into bowls and garnish with the cooked sausage and chopped chives.