Fragments of Life

When zookeepers discovered that flamingos need a large flock in order to breed, it led to all kinds of creative approaches to fool the birds – mirrors, plastic yard ornaments, speakers playing bird-crowd sounds (now, zoos generally just keep more birds). I think of habitat loss and fragmentation like a flock of flamingos. There’s a certain amount required for the habitat to function properly. If the size is too small or divided, it will fail.

The Atlantic Longleaf Pine Ecosystem (a.k.a. pine barrens – a deceptive name considering the high amount of biodiversity) spanned over 35 million hectares (about the size of Germany) around the year 1500; today, only ~1 million hectares of pocket forests remain. (1)

Good news though! If habitat is restored, amphibians (including those pictured above plus Mabee’s salamander), among many other species, come back too. (2)

1. D.H. Van Lear et al. 2005. History and restoration of the longleaf pine-grassland
   ecosystem. Forest Ecology and Management 211:150–165
2. J. C. Mitchell. 2016. Restored Wetlands in Mid-Atlantic Agricultural Landscapes Enhance Species Richness of Amphibian Assemblages. Journal of Fish and Wildlife Management. 7(2) 490-498

Fight, Flight, or FREEZE

When a predator approaches, options are limited – especially if you’re a tadpole. The woodfrog tadpole (Rana sylvatica) is known to stop swimming and sink to the pond bottom, an action called “freezing behavior.”

In one study, researchers exposed woodfrog embryos to some water from a predator’s tank with or without an injured tadpole (1). When the embryos hatched, the ones that had smelled both the predator and injured relative showed very reduced activity (freezing behavior) if re-exposed to just predator-water.

In mice, freezing behavior is affected by the size and speed of an object. Video showing lab mice exposed to various dots indicates that small, slow objects trigger mice to freeze. When exposed to terrifying large dots, mice take off.

1. Mathis, A., M.C.O. Ferrari, N. Windel, F. Messier, and D.P. Chivers. 2008. Learning by embryos and the ghost of predation future. Proc Biol Sci. 275(1651): 2603-2607.

 

Pining for Carbon

The boreal forest, or taiga, extends across Canada and Russia. Conifers dominate this cold ecosystem. The evergreen needles allow the trees to photosynthesize all year.

While conifers grow well in the frigid taiga, they don’t decompose very quickly when a tree falls. In other habitats, trees that die release their carbon as they decay. The pines, firs, spruce, and larches of the taiga soak in carbon from the atmosphere, add that carbon to their mass, and hold it in their bodies even after they die. One study suggests that the boreal forest sequesters twice as much carbon as tropical forests and six times the amount held in temperate forests (1).

For now, the taiga is helping us combat climate change. As temperatures warm, though, stored carbon can break down and release into the atmosphere as carbon dioxide, exacerbating the issue. The more we limit carbon emissions now, the more the boreal forest can help us into the future.

1. https://www.borealbirds.org/sites/default/files/pubs/report-execsummary.pdf

Nuthatch & Friends

The nuthatch (Sitta carolinensis) has a lot of friends. It often teams up with chickadees and titmice. While larger flocks give greater protection from predators, more species diversity within the flock improves problem solving (1). Birds in diverse groups were able to get food from a new feeder faster.

1. Freeberg, T.M., S.K. Eppert, K.E. Sieving, and J.R. Lucas. 2017. Diversity in mixed species groups improves success in a novel feeder test in a wild songbird community. Scientific Reports. Volume 7, Article number: 43014.

Springtime Symbiosis: Trout Lilies and Superhero Ants

Trout Lilies (Erythronium americanum) pop up from the forest floor, tiny harbingers of warm weather to come. This little lily is a spring ephemeral – a flowering plant that takes advantage of that tiny window of time between the last frozen days of winter and the heyday of spring, when the forest canopy selfishly soaks up all the sun’s rays. During those few weeks, the Trout Lily breaks through a ceiling of dead leaves, and slurps up sun and nutrients to store for the rest of the year in its underground bulb. If that’s not enough, that brief time is also used to flower, produce seeds, and make sure the next generation is safely on its way. No wonder this little plant needs a rest for the remainder of the year!

Given the time limitation, the Trout Lily can’t mess around with seed distribution. It has to be done right and done quickly. Call in the ants.

Many spring ephemerals, like the Trout Lily, produce an incentive for ants to take their seeds, move them a distance away, and plant them in a safe, nutrient-rich location. Each seed has a dollop of yumminess on its outer surface, like icing on a seed-shaped cupcake (officially the “icing” is called an elaiosome, a mixture of fats and protein). Ants carry the seeds back to their nests, feed the yumminess to their larvae, and dispose of the seeds in a waste area which just happens to be a wonderfully fertile location for young seedlings to begin their lives.

Not only do ants spread seeds to new locations and give them a fertile spot to grow, they also protect the seeds from predators like mice. Ruhren and Dudash (1) placed seeds in four scenarios on the forest floor: (a) accessible to both ants and mice, (b & c) accessible to either mice or ants, and (d) inaccessible to mice and ants. The researchers found that ants secured the seeds before the mice, saving the little plants’ lives. In locales where these superhero ants have vanished, spring ephemeral populations drop 70% (2).

Want to learn more about the superhero ants (a.k.a. winnow ants)? Visit School of Ants.

1. Ruhren, S. and M. R. Dudash. 1996. Consequences of the Timing of seed release of Erythronium americanum (Liliaceae), a deciduous forest myrmecochore. American Journal of Botany 83(5):633-640.
2. Rodriguez-Cabal, M., K.L. Stuble, B. Guenard, R.R. Dunn, N.J. Sanders. 2012. Disruption of ant-seed dispersal mutualisms by the invasive Asian needle and (Pachycondyla chinensis). Biol. Invasions 14:557-565.

Phoenecia: Land of Purple… Snail Dye

“One of the costliest substances ever produced by man” was actually produced by sea snails (Hexaplex and Haustellum sp.). The Phoenicians (in modern-day Lebanon and Syria) harvested whelks and manufactured a reddish-purple dye called Tyrian Purple. Processing just one pound of the dye required millions of snails and cost almost $100,000 in today’s dollar. The color was prized by the Romans, who used the rare and expensive cloth to designate nobility. Romans named the land that produced the dye “Land of Purple,” or Phoenicia. (1)

As you can probably imagine, destroying millions of whelks for one pound of dye is pretty unsustainable. Over time, populations of the Mediterranean snail declined and were eventually extirpated from the region. The dye industry also collapsed. Even though other sources of purple dyes were found, they paled in comparison to Tyrian purple – literally, since Tyrian purple doesn’t fade in sunlight.

Today, many more species in the Mediterranean are facing extirpation. Almost every sea resource (like snails and other mollusks, turtles, crustaceans) in the area has plummeted to less than half its past population size. (2)

Nature can be an amazing provider, if respectfully and responsibly utilized. Populations of plants and animals produce more than could ever survive, so harvesting a certain number of individuals can actually help many species. But that “certain number” is important. Harvest too much, and the populations we rely upon decline. In harming other species, we ultimately harm our own – a lesson we could learn from the Phoenicians and the snails.

1. McCord, C.P. 1969. The Lowly Whelk and the Lofty Royal Purple Dye. Archives of Environmental Health: An International Journal 18(3) 379-385.
2. Lotze, H.K., M. Coll, and J.A. Dunne. 2011. Historical Changes in Marine Resources, Food-web Structure and Ecosystem Functioning in the Adriatic Sea, Mediterranean. Ecosystems. 14(2): 198-222.

Saving the Corpse Flower… and its friends

Deep inside the corpse flower are its developing fruits (painted in the sketch above). After 6-9 months, they’ll look like a column full of beautiful ripe tomatoes, tempting birds to eat them and distribute the seeds inside.

Unfortunately, both the corpse flower (Amorphophalus titanium) and its major seed distributor, the rhinoceros hornbill, are threatened by deforestation. Populations of the rhinoceros hornbill bird (Buceros rhinoceros) have declined by 72%. Other species, such as the orangutan and Sumatran tiger, are also suffering from this habitat loss.

What’s driving the deforestation? Many old growth forests in Sumatra have been cut to make way for palm oil plantations. Are the Sumatrans really eating that much palm oil? Nope. It’s you and me. So check your food labels – sometimes palm oil is listed under “vegetable oil” (if so, it must describe which plants). Look up eateries and food brands by using the Union of Concerned Scientists’ Palm Oil Scorecard – thankfully, Ben & Jerry’s has a good score!

The Corpse Flower, a Botanical Marvel

It’s rare to see a corpse flower bloom. If you ever have the opportunity, take it… especially if you get to visit Sumatra. Lucky for me, a corpse flower (Amorphophallus titanium) blossomed in the greenhouse next to my office last weekend at NC State University (https://cals.ncsu.edu/corpse-flower-at-nc-state/).

It took the corpse flower, dubbed Lupin, 13 years to save up enough energy to bloom.  It’ll probably be another five years before it does so again. So corpse flowers are rather special. Actually, fewer than 200 cultivars have been recorded since 1889. But now’s your opportunity. For some yet unknown reason, a bunch are flowering at once (1).

Lupin grew six feet tall in under two months! That tall, purple-grey phallic structure is called a spadix. At its base are about 700 vibrant orange and purple female flowers and thousands of male flowers (2). When the one giant petal (actually a bract known as a spathe) opens, the spadix releases a stench to attract carrion beetles and flies who pollinate all those female flowers.

So actually, the corpse flower isn’t a flower at all. It’s over a thousand flowers wrapped into one giant, stinky, gorgeous inflorescence.

1. http://www.sciencealert.com/no-one-really-knows-why-but-america-s-corpse-flowers-are-all-blooming-at-once
2. Gandawijaja, D, S. Idris, R. Nasution. 1983. Amorphophallus titanium Becc.: a Historical Review and Some Recent Observations. Ann. Bot. 51:269-278.

A Raspberry’s Worst Nightmare

With all the beautiful berries available now, I’ve been seeing more fruit flies hanging around the kitchen. Annoying? Yes. Ruining my strawberries? Nope. Fruit flies lay their eggs on damaged or rotting fruit. So they’re only interested in the pieces that are going bad. I’m ok with that.

But consider a fruit fly who lays her eggs on fresh fruit. She’d have the agricultural community freaking out. Just imagine the risk to berry crops. Actually, you don’t have to imagine because scientists have already done the calculations for you: it’s potentially $2.6 billion of risk (1).

Evolution has already dealt this stunning set of cards to Drosophila suzukii, the spotted-wing drosophila (2). The females have an ovipositor (the anatomical structure that deposits eggs) that looks like a serrated knife. Unlike the common fruit fly in your house, this species’ egg-laying parts can cut through the skins of raspberries, strawberries, blueberries, cherries, and grapes.

Want to learn more about the spotted-wing drosophila? IFAS at the University of Florida has a great info page on the little beastie (with horrifically gorgeous pictures, by Martin Hauser, of that ovipositor – if you haven’t seen fruit fly genitalia yet, you are missing out).

p.s. Thanks to Dr. Nadia Singh for introducing me to Drosophila suzukii.

1. Walsh, Douglas, M. Bolda, R. Goodhue, A. Dreves, J. Lee, D. Bruck, V. Walton, S. O’Neal, F. Zalom. 2011. Drosophila suzukii (Diptera: Drosophilidae): Invasive Pest of Ripening Soft Fruit Expanding its Geographic Range and Damage Potential. Journal of Integrated Pest Management. 2(1): G1-7.

2. Atallah, L. Teixeira, R. Salazar, G. Zaragoza, A. Kopp. 2014. The making of a pest: the evolution of a fruit-penetrating ovipositor in Drosophila suzukii and related species. Proceedings of the Royal Society B: Biological Sciences, 281 (1781)

Ecology of “The Force”

As Obi-Wan Kenobi explained, The Force is “an energy field created by all living things. It surrounds us and penetrates us; it binds the galaxy together.” These sage words constituted my first exposure to an ecological idea: Energy.

Jedi are no fools. Every drop of energy we use (and rely upon) comes from outer space. Solar energy reacts with carbon dioxide and water inside those wondrous Earthly chemists, plants, to build the most amazing molecule of all – sugar. Sugars combine to form building blocks of plant bodies and, when eaten by an animal, these components break apart to release energy. We use this energy to power our bodies.

Life forms even store energy by combining sugars into fats or oils. The oil saved up by an unfathomable number of plants, buried millions of years ago, power our machines today. We call these ancient plant oils “fossil fuels.” Breaking apart those molecules releases the energy (and carbon dioxide) made long, long ago.

In a sense, that energy does surround and penetrate us; it flows through us.

May the Fourth (be with you) is Star Wars Day. Enjoy it by appreciating the energy of all living things that bind us together.