Skip to content

Conservation

Native plants pushed out by introduced species as cities grow

by Colin Ricketts 18 Mar 2011
Native plants pushed out by introduced species as cities grow

Cities have shaped modern human civilisation but how have plants reacted to the urbanising tide of history?

Ecologists in Indianapolis have tried to answer that question by using dried 70-year-old plant specimens.

Dr Rebecca Dolan, director of the Friesner Herbarium at Butler University, has led the study, the results of which are published in the British Ecological Society's Journal of Ecology.

Dr Dolan and her team looked at a collection of 2,800 dried plants which had been collected around their city before 1940 and compared these with specimens found at 16 sites between 1996 and 2006.

While the number of species in the city has remained constant at around 700, the team found many changes in the make up of the city's flora. Many non-native plants have been introduced and flourished in the city in the past 70 years, while native plants have been declining at a rate of 2.4 species-a-year.

Dr Dolan said: ''This study shows that our flora is becoming less distinctive.''

Gone are the beautiful pink rose family member, Queen-of-the-prairie and the Virginia bunchflower, a lily with striking stalks of white flowers.

In their place are plants introduced by man often with unintended consequences as Dr Dolan explained.

''Japanese knotweed was brought to our area as an ornamental. It spreads readily by seed and by root sprouts, forming thickets that choke out native species,'' she said.

''Amur bush honeysuckle was once promoted by the USDA's Soil Conservation Service for erosion control and wildlife food, but we now know it does neither. Instead, it has spread and become a pest plant, covering the banks of many of the city's streams and woodland edges, and land managers spend a lot of money eradicating it.''

As there is no sign of a reversal of the trend for a greater proportion of the population to live in cities urban wildlife is growing in importance says Dolan, warning: ''A clear message for the future is to be careful when planting non-native material, especially in great numbers, due to the likelihood of introduced non-native plants becoming pests.''


Trending Eco-Friendly Clothing

Prev Post
Next Post

Eco-Friendly Shop

Women's Clothing

Eco-Friendly Clothing for Women Our online shop offers a wide range of sustainable women’s clothing products, including t-shirts, hoodies, vests, sweaters, shorts, and...
Shop Now

Men's Clothing

Eco-Friendly Clothing for Men Our online shop offers a wide range of sustainable men’s clothing products, including t-shirts, hoodies, vests, sweaters, shorts, and...
Shop Now

Kids Clothing

Eco-Friendly Clothes for Kids Our online shop offers a wide range of sustainable kids clothing products, including t-shirts, hoodies and jumpers. Our garments...
Shop Now
Someone recently bought a
[time] ago, from [location]

Thanks for subscribing!

This email has been registered!

Shop the look

Choose Options

Earth Times
Sign up for exclusive updates, new arrivals & insider only discounts

Recently Viewed

Edit Option
Back In Stock Notification
this is just a warning
Login
Shopping Cart
0 items

Before you leave...

Take 20% off your first order

20% off

Enter the code below at checkout to get 20% off your first order

CODESALE20

Continue Shopping