To download an image, click the link to the preferred image. After the image has loaded into your browser: Mac: hold down mouse on image and choose "Save this image as". PC: right-click on image and choose "Save image as".
Have you checked out the Ohio Street Tree Evaluation? It contains high quality before-and-after photos over 20 years, and includes great data. http://www.dnr.state.oh.us/forestry/Urban/ostep/ostep.htm