[R] Generating a point pattern

[abunn@mymail.msu.montana.edu]

I have a stem map of trees that are different from CSR at distances of 10-15 meters on a hectare plot. There are about 100 stems per ha.

I want to generate a point pattern that replicates this for a model. So, about 100 trees in a 100 x 100 space that are clustered at distances from 10-15 meters.

Is this possible in R? Is there something similar to make.pattern in S+? I've been messing with splancs but since I don't want a cluster process (at least I don't think I do), I'm a bit lost.