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According to the USDA Forest Service, an invasive species is defined as “a species that is non-native to the ecosystem under consideration and whose introduction causes or is likely to cause economic or environmental harm or harm to human health.” Invasive species, along with habitat loss and pollution, are the most severe threats to biodiversity and ecosystem function. Why are they such a problem? One factor that my colleague, Lenny Farlee, points to is that people don’t know they have a problem. That is, they are all around us, and most folks don’t even know it. People must first be able to recognize invasive species from non-invasive species. One of the more recent invaders is tree-of-heaven (Ailanthus altissima).

Don’t be fooled by the name. They are far from heaven for us. It’s actually been around for a couple hundred years. However, only over the past 10-20 years ​has it really begun to expand its range. This pattern is very typical of invasive species invasion. Mid-summer is one of the best times to identify and control this tree. Ohio State produced a publication on control methods, and this is linked at the end of this article. I want to focus on identification here.

Tree-of-heaven may be confused with similar-sized sumacs or even black walnut to the untrained eye. Because tree-of-heaven can grow very rapidly, they will often have several feet between branching along the main trunk. Some have also described the strong odor from tree-of-heaven similar to rotting peanuts. For most folks, the leaflets and fruit are the easiest features to go by. Each leaflet has one or more glandular lobes or teeth near the base. This is the best feature to differentiate it from similar species of similar size. On older trees, numerous fruit clusters will begin to form towards the end of June and will be present throughout most of July or longer. Black walnuts and other native trees with compound leaves lack these seed clusters.

Resources
Controlling Non-Native Invasive Plants in Ohio Forests: Ailanthus
Indiana Invasive Species Council

Dr. Brian MacGowan, Extension Wildlife Specialist
Department of Forestry & Natural Resources, Purdue University

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Spring time brings a cacophony of frog calls around ponds and wetlands, but as spring slowly transitions into summer, the warmer temperatures signal the breeding season for many of our native reptiles. One of the oldest and most primitive reptile groups are the turtles. These ancient reptiles have remained relatively unchanged for 225 million years. There are currently ~300 species of turtles worldwide, and 18 species are found in Indiana. Most turtles in Indiana are associated with water, particularly waters that provide a variety of food items, basking sites and adjacent upland habitats. While Indiana is home to a diversity of turtle species, many are declining in number across their range. There are many factors contributing to these declines, but one that is particularly important this time of year is road mortality.

Why do you see so many turtles crossing the road in late spring and early summer (May-June)? This is the time of year when most of our turtles are searching for adequate nesting sites. Unlike amphibians that generally lay their eggs directly in the water, female turtles search for nesting spots in open, unshaded areas where the soil is not muddy or subject to flooding. Nests are often located on the nearest spot of land providing these conditions, but females of some species may travel 1-2 kilometers in search of a suitable net site.

Unfortunately, many of the upland sites are separated from ponds, lakes and streams by roads (Figure 1). As the females leave the ponds to lay eggs, they are forced to cross busy roads and may suffer incredibly high mortality rates (Figure 2). Females are more prone to road mortality than males (which are not required to leave the water to lay eggs), resulting in some populations consisting of nearly all male turtles. Increased female mortality lowers population growth rates (once the female is killed, so are the eggs she was carrying). To further complicate matters, turtles are long-lived species (up to 100 years), and females may not reach sexual maturity for 8-25 years.

What can you do to help? Increase vigilance and slow down when driving, especially in areas where roads intersect ponds and adjacent uplands. If you encounter an injured turtle that needs medical attention, call the Indiana DNR at 800-893-4116 or 317-232-4080 during business hours, 765-473-9722 (northern half of Indiana) or 812-837-9536 (southern half of Indiana) after hours or visit wildlifehotline.info.

For more information on turtles:
The Turtles of Indiana
The Education Store (Search keywords for more information)

Rod Williams, Associate Professor of Wildlife Science
Department of Forestry and Natural Resources, Purdue​ University

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