Sunday, March 29, 2009

Ecosystem on a Log and Scarab Beetles - Field Photos

I wanted to share couple of interesting snapshots taken during the past week – well the snapshots themselves aren’t all that great, but what is depicted in them is pretty cool.

First, a section of an old log that now serving as a microcosm of biodiversity:

The fallen log is of the species Pinus elliottii (Slash Pine), as you can see from the photo, a new P. elliottii sapling has sprouted mid span. The sapling’s roots haven’t penetrated the base of the log and are fully contained within the rotting wood.

And if you take yet a slightly closer look,

You’ll notice that near the base of the sapling several other species of plants, grasses and mosses (including this week’s Wetland Plant of the Week - L. lucida) have made the log home. Though it’s difficult to see from the above images, there are also several ants, spiders and chiggers using the plants as habitat.

Using the fallen pine log for nutrients and structural support is interesting enough, but the story gets even better!

What is truly remarkable is that if you take a look to the right of the log in the first photo, you’ll notice a clearing of the foliage associated with a slight topographical depression. This depression actually functions as a waterway during periods of seasonal flooding!

Taking a look at the surrounding trees,

you’d find water stain lines more than a foot in elevation above the ground surface.

Considering that this entire site is less than five miles from the Gulf of Mexico and letting my imagination run a little wild (but not too much), I can easily envision a scenario in which such a log-microcosm serves as a platform in “rafting” plants and animals to far off places, thereby driving Natural Selection via a founding effect… It even has a ready made sail - the leaves of the pine sapling!

The other snapshot I felt deserved posting was a couple of Scarab Beetles (Family Scarabaeidae) battling for the privilege of rolling dung.

Being a still photo as opposed to a video, you may not be able to read the whole story in the above image, but what’s happening is that three "Tumblebugs" (Canthon spp.) are maneuvering a well-rounded ball of dung.

Male Scarab beetles proactively assist the females in collecting dung to be used for nest building. In exchange for help with rolling the dung balls back to the burrow, males may receive the opportunity to mate with the female, who will in turn lay a single egg on the dung ball.

Rolling the dung helps compact the material into a more stable base for larval development and at the same time provides a method for the most fit males to demonstrate their paternal skills in hopes of wining the affections of a potential mate.

In the picture above two males, both vying for an opportunity to mate, are attempting to impress the female – unfortunately for her, their back-and-forth rolling has landed her on her back under the ball of dung! She can just be made out under the upper left corner of the dung ball.

No comments:

Post a Comment