  We present the 12CO(1-0) and 13CO(2-1) line maps obtained observing with the
SEST a $\sim 1\degr \times 1\degr$ region of the Vela Molecular Ridge, Cloud D.
This cloud is part of an intermediate-mass star forming region that is
relatively close to the Sun. Our observations reveal, over a wide range of
spatial scales (from $\sim 0.1$ to a few parsecs), a variety of dense
structures such as arcs, filaments and clumps, that are in many cases
associated with far-IR point-like sources, recognized as young stellar objects
and embedded star clusters. The velocity field analysis highlights the presence
of possible expanding shells, extending over several parsecs, probably related
to the star forming activity of the cloud. Furthermore, the analysis of the
line shapes in the vicinity of the far-IR sources allowed the detection of 13
molecular outflows. Considering a hierarchical scenario for the gas structure,
a cloud decomposition was obtained for both spectral lines by means of the
CLUMPFIND algorithm. The CLUMPFIND output has been discussed critically and a
method is proposed to reasonably correct the list of the identified clumps. We
find that the corresponding mass spectrum shows a spectral index $\alpha\sim1.3
\div 2.0$ and the derived clump masses are below the corresponding virial
masses. The mass-radius and velocity dispersion-radius relationships are also
briefly discussed for the recovered clump population.
