Scrat is right that `soft` woods do deteriorate faster in warmer Southern waters BUT there are varying `factors` such as the thickness, type, green (fresh cut) vs dried, depth, water Ph, and overall fertility (almost any wood rots faster in a swamp than when placed in a just dug gravel pit), bottom type and several other factors. Some cedars have 1/2 the original trunk still there in 10 years, mulberry, osage, ect. But having that THICK cover for minnows and juvenile fish shallow can be critical for juvenile game and pan fish too. The PVC is the longest lasting, least `dense`(more open) AND is much deeper on the other hand where it tends to attract BIG predators...and also keep in mind that some predators seem to favor certain types of sets (lines or groups set all at 1 depth vs our preferred shallow to deep (a varied depth will almost always ensure SOMETHING will be on at least the deep end of it at least part of the time ); or that seems to be the case except on every 3rd Tuesday...unless one would do detailed study over a very wide variety of waters, in various depths, with different cover types, AND then be able to do daily observations there is much we probably may never know the `full` impact that adding cover actually has. We are like men trying to study icebergs from above the water when 7/8th of the thing is underwater and out of our vision. BUT, more important, we KNOW from sonar, reading, SNAGGING, ect that they WORK at least somewhat...add to the knowledge base here, sir...