ENVIRONMENT

Industrial wastelands sound like grim places but many of them are refuges for fascinating plants. (Guardian)

Exotic flowers thrive in nutrient-poor soils, but what are nutrients? Use our resources to find out.

Teachers, scroll down for a quick list of key resources in our Teachers’ Toolkit.

Delicate stonewort is not a land plant. It’s actually a type of green algae found in muddy freshwater ecosystems such as estuaries and marshes. Photograph by Christian Fischer, courtesy Wikimedia. CC-BY-SA-3.0

This pyramidal orchid grows in the Rough Bank conservation area in the southwestern county of Gloucestershire, England. Photograph by Andrew Smith, courtesy Wikimedia. CC-BY-SA-2.0

Isn’t this pretty? It’s an early marsh orchid, one of the more common species in Harlech, a town in northwestern Wales. Photograph by Natalie S., courtesy Wikimedia. CC-BY-SA-4.0

This southern marsh orchid is blooming on a golf course in Harlech, Wales. Photograph by Natalie S., courtesy Wikimedia. CC-BY-SA-4.0

These gorgeous bee orchids grow naturally in the Aller Brook Local Nature Reserve, in the southwestern county of Devon, England. Bee orchids have a wide range, from Ireland in the west to Iran in the east. Photograph by Derek Harper, courtesy Wikimedia. CC-BY-SA-2.0

The false fox-sedge is a flowering plant that is familiar throughout northern Europe and as far east as China and central Asia. Photograph by AnRo0002, courtesy Wikimedia. Public domain.

• The super-short Guardian article offers some encouraging news about the ecology of brownfields. What are brownfields?
  • Brownfields describe property previously used for industrial purposes and possibly contaminated with toxic waste.
  • In the U.S., the Environmental Protection Agency’s Brownfields program “provides grants and technical assistance to communities, states, tribes, and other stakeholders, giving them the resources they need to prevent, assess, safely clean up, and sustainably reuse brownfields.” Learn more about the program here, and search for brownfields near you using their handy state- and region-based map.

• One of the common characteristics of brownfield sites is their nutrient-poor soil. What is a nutrient? Use our easy encyclopedic entry for some help.
  • Nutrients are chemical substances found in every living thing on Earth. They are necessary to the lives of people, plants, animals, and all other organisms.
  • Plants usually absorb nutrients from soil and water. The most important nutrients for plants are often grouped together by the acronym CHNOPS (shnahps). The letters stand for the elements’ chemical abbreviations:
    • C (carbon)
    • H (hydrogen)
    • N (nitrogen)
    • O (oxygen)
    • P (phosphorus)
    • S (sulfur)
    • Other important nutrients are calcium (Ca) and magnesium (Mg).

• Read through the super-short Guardian article. What are some of its examples of industrial activities contributing to nutrient-poor soils?
  • Runoff and waste from a former sewage-processing plant contributed to one area’s calcareous soil. Calcareous simply means “chalky,” and chalky soils do not contain many nutrients.
  • Runoff and waste from a sodium carbonate factory contributed to another area’s alkaline soil. (Sodium carbonate is a major component of glass manufacturing.) Alkaline soil is a type of clay (soil) that contains salts (alkalis). Alkaline soil is notoriously nutrient-poor and for that reason is considered one of the most difficult soils to develop for agriculture.
  • Finally, tons of fly ash from coal-fired power plants were dumped in pits along the Thames estuary. Fly ash contributed to an extremely alkaline freshwater marsh ecosystem.

• With such poor soil, how do orchids obtain nutrients they need to survive?
  • Orchids are strange plants that don’t have a traditional root system.
    • Many orchids are epiphytes, meaning they grow on another plant (usually a tree or shrub), not in soil. In fact, immersion in soil may smother delicate orchid roots. These orchids obtain water and nutrients from air, precipitation, and the debris that collects around them.
    • Some orchids are tubers, meaning they have enlarged structures used for collecting and storing nutrients.

• What other plants have adapted to nutrient-poor soils?
  • A lot!
    • Many succulents, such as cacti, are able to collect and store scarce water and nutrients for long periods of time.
    • Rain forests are some of the planet’s most important carbon sinks, but most nutrients (including carbon) are part of the vegetation itself, not the soil. Rain forest soil is notoriously poor.
    • Some of our favorite plants that have adapted to nutrient-poor soils are carnivorous plants, such as Venus flytraps and sundews. These plants obtain nutrients through the decaying bodies of their insect prey.

• Many brownfield sites have been converted into lovely local parks. Contact your local EPA representative to see if any parks were once brownfield sites—they might be great places for bioblitzes!

TEACHERS’ TOOLKIT

Guardian: From the wasteland a rich carpet of orchids

Nat Geo: What is a nutrient?

Nat Geo: Do-It-Yourself Bioblitz