What’s going on outside the Portal site?

by

The 20-hectare Portal research site has been studied for over 30 years now – and we’re still learning new things! But every additional year brings up new insights and new questions about the ecology happening in that patch of the desert. Why did certain species disappear? Where did new species come from? How important are changes in the weather to the persistence of species? Are there important trade-offs in rodent survival strategy (i.e., competition vs. dispersal)? How important are plant dynamics to rodent species composition (or vice versa)? What might we be missing by only focusing on rodents and plants?

Image

The Portal research site, and fencing around a rodent trapping plot.

One major question we’ve been thinking about more lately is the connection of the 20-hectares patch of desert that we study (Portal) to the surrounding desert. Since we know that rodents species come and go throughout the years, and they must be coming and going to somewhere else, we decided to venture outside our usual trapping grids for a few days to see what’s going on outside the Portal site.

October 12-17, a subset of the Ernest and White labs (Morgan, Glenda, Ken, Erica, and myself) travelled to do the usual monthly rodent-trapping and to trap 12 additional “outside” areas within walking distance of the site. We tried to trap in areas that might have different characteristics, because locations with different vegetation or topography could support different rodent species than we might expect at the Portal site. Our sites included two cattle tanks, some arroyos, areas grazed by cattle, and an area that used to be a study site for Peter Waser (he studies banner-tailed kangaroo rats), and has been cleared of shrubs.

Image

Cattle tanks collect rainwater, but are actually dry most of the year. This one looked like a mini-grassland.

To learn about the rodents that might occur outside of Portal, in each site we set a rodent trapping grid approximately the same size as a Portal plot (50 meters x 50 meters) and sampled the vegetation by counting the plants along an X-shaped transect. We marked our rodent trap location with pink flagging tape, which was a great idea, because otherwise it would have taken *forever* to find and pick up our traps the following morning. It turns out that walking in a straight line in the desert without a guide is really hard!Image

 

The portal crew setting out rodent traps. See the pink flagging?

We didn’t do our usual plant-survey at Portal this fall, and mid-October is a bit late in the season, but we were able to confidently identify most of what we saw, even if the plant was already going to seed. Most of the crew was new to plant transect work, but I think they were convinced that counting plants isn’t that bad, at least until we came to our final riparian area, which was full of catclaw acacia (Acacia greggii). “Cat-claw” acacia is as horrible as it sounds… like thousands of tiny, angry kittens clawing at your clothes, face, and hands. Except that these angry kittens leave the tips of their claws in your skin. Yes, we left with plenty of battle scars!

Image

The white line down the center of the photo is the transect tape for our vegetation survey. The green stuff is a thicket of cat claw acacia. Worst. Transect. Ever.

Overall, the trip was a success, and I think that everyone had a good time. Research is exciting and fun when it’s done right! I left wishing we could spend more time exploring the desert around Portal and learning more about the natural environmental gradients that might be an important part of what’s driving observations at our site. So many ecological studies are done at small spatial and temporal scales, but understanding species dynamics and connectance across a landscape is an important challenge for ecologists. Hopefully, our mini-exploration was just a first step in beginning to understand our research in the larger context of the Chihuahuan desert landscape.

Advertisements

Tags: , , , , ,

5 Responses to “What’s going on outside the Portal site?”

  1. BAlvarius Says:

    It will be interesting to hear the results of the expanded survey around the Portal Project. A larger landscape view may indeed provide more insights into short term changes in diversity at the site.

  2. DiAnn Says:

    This sure was not a easy project for you to do! It will be interesting to see the project results.

  3. sarahsupp Says:

    Thanks! The expanded survey was definitely informative for me. Stay tuned for a series of posts that will talk about some of our findings from the off-site survey!

  4. Do macroecological patterns respond to altered species interactions? [Research Summary] « Jabberwocky Ecology | Weecology's Blog Says:

    […] used 15 years of data from the Portal Project, our lab’s long-term research site in southeastern Arizona, to evaluate the response of the […]

  5. exhibition banner stands Says:

    The buildings, however, were not the concrete jungles you find in some modern
    cities but beautiful architectures, each designed differently from the
    others. We need others opinion for anything that is circulated through a selected mass of people.
    I had done the same thing learning to survive, to succeed.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


%d bloggers like this: