Introducing SEGA!

Near one of our sites, Red Mountain provides dramatic visual evidence to some of the unique edaphic conditions that exists on the Colorado Plateau 

It is with great excitement that I am writing to inform you all of the successful launch of our project on the Southwest Experimental Garden Array (SEGA).

The army of blue grama ready for dispersal to field sites

Perhaps you recall a mention of a project that uses six sites across an elevation gradient with unique soils to test a variety of plant responses to changing environmental conditions and the importance of both soil and soil biota in those changes.

Well, we started by growing Bouteloua gracilis (Blue grama) from two Pinion Juniper Sites. We used soil and soil organisms from each of these sites as well as soil and soil organisms from the transplant sites. These transplant sites include a Pinion Juniper site (2 degrees Centigrade warmer), a desert grass land (three degrees centigrade warmer), and two Ponderosa Pine sites ( 2 and three degrees centigrade cooler). In summary, plants are either grown in all home soil environments (both physical soil and soil biota from the home site), home soil, but soil biota from the transplant site, soil from the transplant site and soil biota from the home site, and lastly all away (soil and soil biota from the transplant site).

The San Francisco Peaks stand through the haze of a June Wildfire above our plots at the Arboretum at Flagstaff. 

Now that these treatment combinations have been planted in the field, we will be able to test a variety of questions related to climate change, plant migration, and plant-soil interactions. For example, if a plant is to migrate to a new site as a result of climate change or human management action, is the plant hindered by growing in a novel soil environment? Can this hinderance be alleviated by the plant migrating with its natal soil biota? Perhaps the plant is actually released from native pathogens by moving to a novel soil type and experiences enhanced growth. In addition, we can test how plants may respond to a changing climate. Since we are using an elevational gradient to simulate warming, our transplant also experience drying, however, active irrigation and weather instruments allow us to add water to simply examine a warming effect. This is important because while most climate models agree on temperature trends in the Southwest, there is far less clarity on future precipitation regimes.

This project will help us understand how plants may respond to global change on the leading edge, core, and tailing edge of their distribution, and how soil may confound these predictions, thus filling several gaps in the literature. In addition to Blue grama, we are also in progress of preparing a parallel and similar experiment that focuses on Pinus ponderosa (Ponderosa Pine) that will be launched this Fall.

Katarina collects the first data set in the field with the Arboretum greenhouse and SEGA weather station in the background.

So far, we have put in thousands of man hours to sterilizing soil and preparing sites, to see plants in the ground is a very rewarded climax of the project. Data is already showing us that some soil environments are very detrimental to plant growth and both populations o Blue grama display home soil and soil biota advantage. Furthermore, home team soil biota provide an advantage for plants growing in unfavorable soil types.

This is visual assessment of some of our treatment effects, The circled plant on the left is growing in soil and soil biota from a novel site while the circled plant on the right is growing in soil and soil biota from its site of origin. One can clearly see the "home team advantage" in the much larger plant on the right. Now that these plants are in the real world we can observe if the home team advantage persists in novel climatic environments

This project has been made possible by many helping hands. We could not have done this without our fellow lab mates, past and present, the volunteers that have come out in the field with us from friends, to fellow students and even high school students from Flagstaff Highschool! Thanks to everyone!

Students from Flagstaff High School help Install the precipitation gauge at one of the SEGA sites. 

Stay tuned for more progress updates and data! These data will be presented at the Ecological Society of American Annual meeting and the Conference for Research on the Colorado Plateau! Hope to see some of you there!
Cheers,
Michael

Not far from multiple SEGA sites is the isolated portion of the North Rim of the Grand Canyon. Here, a Pinion  Pine snag reminds us of the importance of understanding plant response to drought as a storm brings early spring moisture to the Rainbow Rim