Enter to win seeds from some of our favorite native plants!

As we enter a new year, we'd love to get your feedback on how we're doing here at the Natural Capital. As a little incentive, we'll select three responses at random to receive some seeds from some of our favorite native plants: cardinal flower, rose mallow, and Joe Pye weed. Start them in your yard, or scatter them in a wild place you visit. Just answer the 7 questions below, and be sure to click the "done" button when you're done. (If you don't see a survey below, click here.)

LOOK FOR: Hemlock Trees (While You Still Can)

Eastern Hemlock (Tsuga canadensis) is a majestic tree sometimes called the "redwood of the East." They can form tranquil evergreen groves in the understory, but really, they're just waiting for their big break. When a tree falls and opens a spot in the canopy, hemlocks will shoot up -- eventually reaching heights of 80 or even 100 feet over their 350 year lifespan. In the second-growth forests of the DC area, though, you'll see only scattered trees, and they're rarely taller than 15 or 20 feet tall.

Because they're evergreen, this is a great time of year to look for hemlocks, when other trees have lost their leaves. The needles of hemlock will help you distinguish this tree from other evergreens in our area: they are flat, about 3/4 of an inch long, and grow in a plane off the twigs. The overall form of hemlocks can also be distinctive:  branches grow horizontally from the trunk, but are floppy on the ends as the twigs haven't hardened up yet. Up close, you may notice very small cones on the trees -- they look like pine cones, but much smaller.

The genus name, Tsuga, is a Japanese word supposedly meaning "mother tree." Unfortunately the relationship between North American and Japanese hemlocks is not so nurturing. Around 1911, some imported hemlocks bound for a Japanese garden in Richmond came bearing an insect known as the hemlock woolly adelgid (uh-DELL-jid). This relative of the aphid is just a minor pest in Japan, where it's got several predators and the trees have some natural resistance. For our local Tsuga canadensis, though, infestation by the woolly adelgid is usually fatal within 4 to 10 years.

It wasn't until the 1980's that people started noticing that the adelgid had spread from ornamental plantings in Richmond to native trees in York River State Park and Shenandoah National Park. By the mid-90's, the adelgid had spread to Connecticut and Massachusetts, and it is now considered established throughout the hemlock's eastern range, from Maine to Alabama. Experiments are being done with the release of adelgid-eating beetles from Japan, but results don't seem very promising, and many stands of hemlock have already been lost. (To see some of the destruction to old growth hemlock groves, see this video from the Charlotte Observer.)

There are two morals to this story. First, garden with native plants, so that you don't unwittingly import a pest that will devastate an entire species. Second, get out there and appreciate what we've got, while you can.

In the wild: We're not aware of any really large hemlocks in the DC area (do let us know!) but there are still some small hemlocks scattered in our local forests. The most we've noticed are at Scott's Run Nature Preserve in McLean -- they grow right along several of the trails there (like the one shown here).

In your yard: It's probably better not to bother planting hemlocks unless and until someone figures out how to control the adelgids. Too bad, because they're beautiful trees.

Like the photos in this post? Mouse over for credits; a click takes you to the photographer on Flickr.

Keep Winter Cold - CCAN's Polar Bear Plunge

On the morning of January 23, at least 350 people will jump into the Chesapeake Bay in Annapolis to raise money and awareness for the need to stop global climate change. The Polar Bear Plunge Team asks:

What if winter were no longer cold?  What if there was little or no snow for skiing, no hard frosts to kill off insect pests or bring out the sap of a maple tree to make that delicious syrup?  How would polar bears and other animals that need the cold survive?

With climate change legislation pending in the Senate, this is an important opportunity to draw attention to alarming signs of global warming. Climate scientists report that arctic sea ice is melting faster than predicted, and that the top of the world could be free or nearly free of summer sea ice by 2013 or even earlier. This would mean almost certain extinction for polar bears - and a potentially catastrophic jolt for global climate patterns.

And so, once a year, we take this chance to get up close and personal with what winter feels like -- while we still can. Matt's taking the plunge. Will you join him, or sponsor him? The polar bears could use your help.

Need more inspiration? Check out this video from last year's plunge: