Nice images. Looking at the first two, it's a bit of a toss up; personally, I prefer the top image, because while there are some dark areas in the trees, and the sky doesn't stand out quite as much, the grass and ground-cover look much more natural. In the HDR version, especially around the trail, there's an unnatural orange caste to the dried grass areas.
My take is that it would have been better shot with a graduated neutral density (G-ND) filter to enhance the cloud/sky contrast, and perhaps, (depending on the time of day and sun's angle) a circular polarizer (CPOL) as well. This, followed by some selective levels/curves adjustments would have produced an overall more natural image.
The image looking over the Fraser Valley toward Mt. Baker would ahve been better composed if you'd moved the camera a bit to the right to eliminate the foreground area of blackberry and dried grass. This too might well have been improved by the use of a CPOL and/or G-ND filters. A slight levels tweak will clear up some of that haze.
The stump image is one for which there is not easy solution. Dappled light is a very, very difficult thing to work with. In this case, a CPOL would have helped to darken the sky somewhat and reduced the dynamic range of the image. Again however, I think some work in the pixel room will be required; selective levels and curves adjustments, and or a little dodging and burning.
With respect to the issue of composition, the concern I have with #1 is that there's very little of interest to immediately grab the eye. I understand that the cyclists are the subject, but they don't stand out enough. When you're shooting people or animals, always try and have them coming toward you rather than away from you. Additionally, I suspect that the path upon which they're riding would have been a good compositional element if you had been in front of the riders and framed the shot in such a way that the eye could follow the path through the middle of the image to each cyclist.
I actually like the composition of the stump shot very much, but the dappled light is so strong that it makes it difficult for the eye to see easily what's stump, and what's not.
When you're dealing with areas of complex lighting (such as the stump) or wide dynamic range (the cyclists) bracketing is your friend. Shoot 1/2 or 1/3 stop on either side of the 'optimum' exposure. This will give you a great deal more to work with, and you may find that while a highlight is blown in the 0EV, in -1EV image, it's fine, and you can tweak the shadows to get a good image.
Lastly, are you shooting RAW? If not, I would recommend it.
Hope that helps, don't hesitate to yell if I can offer any more assistance.