If you pitch environmental journalists, take a look at this post from the Green Media Toolshed about the importance of visuals with a story, and eight different types of visuals.
The tips come from journalists at the Society of Environmental Journalists convention. During a panel discussion called Visualizing your Stories, three award-winning environmental reporters shared their strategies for coming up with the perfect visual to help complete their story—and make it more attractive to their readership.
They mentioned a graphic for timelines, data trends over time, maps, comparative data, sequential events, report cards, explaining complicated processes, and multi-layers of data, such as showing the relation between income, race and pollution.
In my ebook, “How to Use Photos & Graphics in Your Publicity Campaign,” I quote a magane editor who says that a good visual can sometimes move a story from the back of the magazine to the front.