Hi Cabus,
All species of CP which are now in collections were originally field collected at some point in time, in some shape or form. I am very conscious of stresses on ecosystems, but the biggest eventual threats to S.American CP are habitat destruction / environmental alteration. I feel that it is important to preserve representatives of all populations of plants in cultivation because that is all that we can do. Even if habitats are not destroyed, the impact man has on the environment is causing problems for many species and will inevitably lead to their decline / death. Right there in Brazil, the location of type Drosera graminifolia was polluted due to nearby mining activities and now this unique form would be entirely gone if it wasn't for the previous collection of seed. I also have a collection of Drosera communis which was destroyed as well. If I didn't receive material, these plants would be gone for good. I have sent some to most of my regular trading buddies as well as several others.
Plants collected from the field often do not survive the shock of being torn out of the ground and placed in an artificial environment, and it is obviously important to try to leave populations intact for the time being. I would welcome any SMALL quantities of seed you might be able to collect. However, I should also emphasize that, if you collect, it should be ONLY for a good cause and care should be taken not to stress the population. In other words, take very little and make sure the people you send seed to are able to keep that material alive indefinitely and make an effort to get it into other collections where it will be safe. We simply cannot rely on botanical gardens to preserve all CP, and we certainly can't rely on governments to put economic and other interests aside to protect our precious CP.
Please do not interpret this as overall encouragement to field collect. My interest is in preservation in cultivation. Once a plant is in cultivation and growing well, there should be no need to go back to the same location to collect more.
Matt