The first thing you might try is investigating the response of the daisy population to an increase in the incoming solar radiation. You do this by increasing the solar fraction by 0.1 at a time until the daisies die out. You must reset between each computation.

Now try a different value for the albedo of the white daisies say 0.6 and see what happens.[Note than when you reset the albedo will be reset also]

Try the effect of reducing the solar constant.

You might want to try the effect of changing some of the other parameters, though it is not so easy to see their effect.