Skip to content

Nature

From garbage tip to wildlife haven - new theory for Everglades tree islands

by Martin Leggett 22 Mar 2011
From garbage tip to wildlife haven - new theory for Everglades tree islands

Today the tree-islands of Florida's Everglades are natural havens for the some of the most spectacular of the swampland's denizens - alligators, panthers and rare birds. But five millenia ago, they may have been home to a very different community, as sites where prehistoric humans settled - and dumped their garbage. That's the story being coaxed from the analysis of rocks and soil sampled from some of the tree-islands by a team from Montreal's McGill University.

Tree-islands have long been a curiosity of the Everglades, where they punctuate the flat marshy landscape as circular areas of raise ground. Here trees have taken root, alligators nest and a diverse range of other wildlife take refuge. Previous research has found that the islands owe much of their long-term resilience to a layer of hardened limy rock. It was initially thought that the islands simply formed on natural protrusions of this carbonate bedrock.

Now, excavation and analysis, by a team that included Gail Chmura, a paleoecologist, has shown that underneath the rock is more soil - and layers of human refuse, which are known as middens. These layers contained discarded food remains, including bones, charcoal fragments, and broken pieces of clay pots, as well as shell tools. It is now thought that the accumulation of this material over hundreds of years built up the land, and provided the high ground that the trees subsequently colonized.

Chmura interprets this garbage-tip evidence positively, saying ''This goes to show that human disturbance in the environment doesn't always have a negative consequence.'' The research also suggests how the hard carbonate cap, known as the 'perched carbonate layer', may have formed. It seems that the the probing roots of the trees drew up groundwaters from the bedrock, laden with dissolved carbonates. These precipitated to form the rocky layer, together with phosphates from discarded bones.

This layer not only provides a firm footing it protects the underlying soil from periodic fires, so that plants and trees can easily regrow afterwards. However, the ecology of these man-formed islands are now under threat – from the actions of man once more. By cutting down trees, and drawing up water tables, the perched carbonate layer is at risk of being dissolved and loosened. This research may help Florida authorities to better manage these uniques features of the Everglades landscape.


Trending Eco-Friendly Clothing

Love My Planet Women's Relaxed Fit Hoodie
Earth
Quick Add
Close
Notify me
Notify me
Love My Planet Women's Relaxed Fit Hoodie
Love My Planet women's eco-friendly relaxed fit hoodieSize Guide Centimeters 8 10 12 14 16 18 Bust 84 88 92 97 103 108 Waist 66 70 75 80 85 91 Hips 91 95 99 104 109 116 Bust: Measure around the fullest part of...
£38.00
£38.00
Close
Notify me
Notify me
Penguins Hate Push-Ups Men's Pullover Hoodie
Earth
Quick Add
Close
Notify me
Notify me
Penguins Hate Push-Ups Men's Pullover Hoodie
Penguins Hate Push-Ups men's eco-friendly pullover HoodieSize Guide Centimeters XS S M L XL XXL Height 171 175 179 183 189 195 Chest 86 93 99 104 116 129 Waist 71 76 81 89 99 112 Chest: Measure all round your chest just below...
£38.00
£38.00
Close
Notify me
Notify me
Lightning Bolt Kids Long Sleeve T-Shirt
Earth
Quick Add
Close
Notify me
Notify me
Notify me
Lightning Bolt Kids Long Sleeve T-Shirt
Lightning Bolt kids eco-friendly long sleeve t-shirtSize Guide Centimeters 3-4yrs 5-6yrs 7-8yrs 9-10yrs 11-12yrs Height 98 112 125 136 147 Chest 60 66 70 75 84 Chest: Measure all around your chest just below your armpits. Height: Your natural height If you fall between...
£18.00
£18.00
Close
Notify me
Notify me
Notify me
Union Jack Tote Bag
Earth
Quick Add
Close
Notify me
Notify me
Union Jack Tote Bag
Union Jack eco-friendly colour tote bagProduct Specification Organic Cotton Tote Bag. Twill Weave (170gsm). 37 x 42 cm (7cm gusset.) Made in India / Designed on the Isle of Wight. Wash Cool, Hang Dry.
£16.00
£16.00
Close
Notify me
Notify me
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