Terrain transition

I've got a little bit of a problem. I can't get the terrain transition to look realistic... Which can be a bit of a pain in the ass. Can someone out there please give me a little bit of advice. For example a jungle moving into a grassland which in turn moves into a desert. I'm looking for ways to do this other than using cliffs or rivers. Thanks. Sorry if this post comes out warped but i'm typing off my phone.

Tiles. Tiles are key IMO. If you are going from jungle to grass land you have to have an area in the middle that is pretty much half and half of tiles and doodads. Then each one goes a little into the other.

Also there are deserts that end abruptly.
http://www.piersallison.co.uk/images.../walls_end.jpg

I can't be completely sure but I'd assume that humans had some sort of part to play in that.

But for the OP, as Gilles said you'll want to use tiles to help do this. This might be stretching it but if you've taken biology you might remember something about how much organic matter was living in the ground. Stuff like sand had very little and was generally lighter, while heavy organic matter was darker and moister, like soil you'd find in a garden.

What I'm getting at is that as you transition from a desert to a forest use a variety of tiles that move from sandy desert tiles, to a neutral kind of dirt, to something more earthy. Put some sparse shrubs inbetween this area, you won't want to put too much, just enough to give it a barren feeling that this type of transition might have.

Yeh I probally wrote to much on that but I felt like getting technical for some reason.

Thanks :) I neva really thought my bio would come in useful to map makin. I'll give different tiles a try and see what comes out looking best.

[quote=DungeonM]I can't be completely sure but I'd assume that humans had some sort of part to play in that.[quote]
Yeah, I know. I couldn't find a picture that was natural. Although I have seen them. I know they happen naturally.