We present the ^ { 12 } CO ( 1-0 )  and ^ { 13 } CO ( 2-1 )  line maps obtained observing with the SEST a \sim 1 \arcdeg \times 1 \arcdeg 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 \sim 1.3 \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 .