It may well be snowing where you live, but if you're in the Northern Hemisphere, spring isn't far off. Spring means flowers. And what is a flower to a microbiologist? It's a niche.
Yes, flowers are a microbial habitat like any other, and though they start out with few microbial members, these communities quickly acquire a broad range of microbial types and progress through a classical succession of different groups. In mBio this week, Shade et al. describe the unexpectedly great microbial diversity of apple blossoms, communities marked by the consistent presence of groups that are well-known for their abilities to withstand environmental stress.
Shade et al. used tag pyrosequencing of 16S genes to make a community-level assessment of blossoms from six different apple trees, half of which were sprayed with streptomycin after the blossoms emerged. (Alarmingly, streptomycin is often used to control fire blight in apples, a disease caused by Erwinia amylovora, a bacterium that infects the fruit at the flower stage.) The flower communities were rich and diverse, but exhibited a bump in diversity within the first couple days after opening. This makes sense, since the flower would be low on bacteria (and possibly low on resources for those bacteria) before opening to the world. And streptomycin didn't seem to impact diversity or dynamics in these communities either way: even flowers that had been sprayed with streptomycin were home to rich, ever-changing bacteria communities.
Click on teh source link to read more on mBio's blog, mBiosphere.