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Posts tagged: Big Bend National Park

A Model for Managing a Weed’s Mischief

This post is part of the Science Tuesday feature series on the USDA blog. Check back each week as we showcase stories and news from the USDA’s rich science and research portfolio.

– Marcia Wood, Agricultural Research Service Information Staff

Along streams and irrigation canals in 16 states, a wily weed called giant reed, or Arundo donax, can grow a remarkable three to six inches a day. This intruder develops dense stands that can crowd out native plants like cottonwoods and willows, and can block water flow to farms and cities.

In research designed to stop arundo’s advance, Agricultural Research Service ecologist David F. Spencer and co-investigators have developed a computerized, science-based animation that shows precisely how a real-world arundo plant grows. The animation—apparently a first for an invasive weed—is intended for researchers, streamkeepers, students and others.

Click here to view the animation.

During this brief clip, a reality based “virtual arundo” goes through its first year of growth, emerging from a single, thick, underground stem, or rhizome, to reach its maximum height of about 30 feet.

The animation is derived from studies led by Spencer. In some of those studies, thousands of digitized measurements were taken by magnetic sensors of dozens of giant reed plants. Using commercially available software, the measurements were analyzed to create a computer-based model of the giant reed’s growth, with optional 3-D animation.

Researchers can use the animations to gauge—and see on-screen—the predicted effects of tactics to control arundo. For example, the model could help scientists determine the best times in the weed’s growth to unleash helpful insects that attack arundo’s leaves, stems or rhizomes.

In northern California, technician Greg Ksander (left) and ecologist David Spencer collect a leaf sample from giant reed (Arundo donax).
In northern California, technician Greg Ksander (left) and ecologist David Spencer collect a leaf sample from giant reed (Arundo donax).

Aerial view of Arundo near Big Bend National Park, Texas.
Aerial view of Arundo near Big Bend National Park, Texas.