The following information was provided by our partners at the University of Georgia’s Center for Invasive Species and Ecosystem Health (see EDDMapS for more information). EDDMapS provides online data management services and is one of several data providers to the Great Lakes Early Detection Network. To see a full list of data providers, please visit our website.
A key component of EDDMapS is providing images in digital format Being able to use photographs to identify the species adds validity to the data collected and entered into EDDMapS. This module addresses general photography topics, including types of photographs, tips for taking quality photographs, and an introduction to digital photography. Information on uploading images is addressed in the “How To EDDMapS” section.
Nearly all field guides and identification keys rely on illustrations because seeing
a picture or drawing of an organism greatly aids in the correct identification. These pictures may be of the whole organism or simply a specific characteristic or feature important for distinguishing that organism. For instance, a picture of an exotic plant infesting a natural area can help demonstrate the invasive potential of that plant. This type of picture can lend credibility to statements made by the photographer or user of the image. Familiarize yourself with the characteristics commonly needed for identification like the glandular notches of tree-of-heaven and take several pictures of the subject’s diagnostic characteristics to ensure that identification is possible. Good photographs can also add validity to documentation of certain events,
such as the first occurrence of a species in a county. Herbarium records have the highest validity , so consider collecting an herbarium specimen for the first reported occurrence of an invasive species in a region or county. The following section briefly explains basic techniques and gives tips for taking useful photographs. To fully understand your camera’s options, refer to the user manual.
Frame the subject for the intended purpose. Panoramic photographs give context to the subject, for example showing the extent of an infestation. Midrange shots illustrate the presence and effects of specific species and close-ups provide details for identification of a species of interest.
Attention is naturally drawn to the area of the photograph that is in focus. For landscape scale photographs, most of the scene should be in focus. For subjects closer in, the photographer should be sure the most important part of the photograph is in focus. For plants you can focus on the entire plant or simply the area of interest. Many digital cameras do this automatically for you.
The type, direction and intensity of the light can affect the color and texture of an image. Hard light on a sunny day or from a direct flash emphasizes shadows, highlights, and textures. Soft light in early morning, late evening or cloudy days minimizes shadows and highlights and brings out color and detail. The direction of a light source will also influence the photograph. Front light (the light source is in front of the subject) highlights colors while eliminating shadows and textures. Backlight creates silhouettes or illuminates translucent subjects. Sidelight highlights both texture and color of a subject.
Backgrounds which contrast to the main colors of the subject help make the subject stand out in the photograph, while backgrounds similar to the main colors of the subject make the subject blend in more. A busy background can be distracting and make viewing the subject difficult. Try changing the background by changing the angle of the camera or by placing something behind the subject. It can be as simple as a white or black sheet of paper behind a leaf to help it stand out more clearly.
Digital cameras are recommended for collecting data for EDDMapS. Because of the large storage capacity of digital cameras, you can take several pictures of each subject and simply choose the best images to upload with your data. Digital cameras also allow you to easily upload images from your computer directly to EDDMapS. There are two basic types of digital cameras: point & shoot and single-lens reflex (SLR). Point & shoot digital cameras are essentially automatic, with limited ability to adjust settings. The advantages of point & shoot cameras are their lower cost (compared to SLR cameras), small size, and light weight. SLR digital cameras are more expensive and larger, but offer the photographer a suite of automatic settings in addition to the manual setting and through-lens focusing and framing. With SLR cameras, interchangeable lenses enhance zoom and macro features. Zoom lenses allow the photographer to take “close-up” photographs at a greater distance from the subject. This is advantageous when the subject is an animal that might become scared or leave if approached. Lenses with adjustable zooms also allow for easy manipulation of the framing of a photograph. Wide-angle lenses provide a wide field of view and can be very useful for landscape photography. Macro lenses allow for close up photography and can be used to capture small subjects or minute details necessary for identification. Images should be taken at the largest size and best quality settings available on your camera. Send the least edited, least compressed file available.
JPEG uses a compression scheme that degrades the image each time it is saved: consequently, it is important to avoid repeatedly editing and saving the file before submission. If editing, cropping, or enhancing the JPEG photo using image editing software (such as Adobe Photoshop) is necessary, perform all operations in one editing session and save the edited image at the highest quality (least compressed) possible. Retain a copy of the original file from the digital camera in case the editing process has to be repeated.
The EDDMapS web form allows as many as five images to be uploaded with each record entered. Examples of possible subjects for plants include the following:
• Site view showing extent of infestation, one invasive plant or many
• Flower shape, size, color and arrangement
• Leaf shape and arrangement (opposite, alternate or whorled attachment)
• Fruit shape, size, color and arrangement
• Bark, trunk or stem
• Roots, rhizomes or stolons
As you can see there are more than five possible characteristics to choose from, so pick the five which are most helpful in identifying the plant you are working with. Invasive privets (Ligustrum spp.) have many characteristics in common with native swamp privet (Forestiera spp.); however, the position of the flower or fruit can help easily distinguish between them.
• To reduce shake, use a tripod when possible
• Take multiple photographs of the same subject and choose the best for uploading with your data
• Look for the unique features of an invasive species, such as pointed rhizomes on cogongrass or glandular notches at the base of tree-of-heaven leaflets.
• Position yourself so the sun is over your shoulder to get the best light (Front lit image) for sharper details
• Automatic settings on digital cameras work very well for most situations
• Digital cameras usually have a macro setting for close-ups
Remember the images you submit will be used to validate your report to EDDMapS. Good images can make all the difference in your entry being given the highest validation.