The Rimrock Report
THE UNIVERSITY OF ARIZONA,
SCHOOL OF NATURAL RESOURCES AND THE ENVIRONMENT
July 2014
Volume 7, Issue 3
Grass
There is not a sprig of grass that shoots
uninteresting to me. Thomas Jefferson
rd
Thomas Jefferson; 3 President of the United States, primary author of the Declaration
of Independence, diplomat, statesman, inventor … range nerd. Who knew? Actually
that should not be a big revelation. At least not to Rimrock Regulars. Y’all are pretty
sharp, as opposed to being in the half of the class that makes the top half possible. Most
of you will remember that Jefferson lived on a plantation called Monticello in Virginia
and that he instructed Lewis and Clark to document the flora and fauna they
encountered in their search for a northwest passage. But I still find it interesting that
Thomas Jefferson found grass interesting. Maybe range folks are not that “out there”
after all. Maybe we are in good company. At this point I will resist the temptation to
say something about him not being the only US president that was interested in grass
and just stick to the subject. Grass. As we have discussed in this space before, most of
us in this country if we think about grass at all, probably take it for granted. It is
something to play sports on, or a good place for a
picnic (as long as there are no ticks, chiggers,
ants, or other little critters in it). We mow it,
water it, fertilize it, and mow it again. The
average person is probably vaguely aware that
cows eat grass. Some could answer correctly that
grass is a plant and a few might know that plants
use carbon dioxide and give off oxygen. Fewer
still could tell you what photosynthesis is unless
that is an “app” that I am not aware of. Grass, just
plain old everyday grass. What’s the big deal?
Ranchers know what the big deal is; range cons
know, soil scientists know, hydrologists know.
But if I were a natural resources grad student and
some pinheaded professor on the final exam
asked me to write a “tweet” that would
communicate the essence of grass to a 30something urban professional in Boston or a
congressional staffer in DC… how would I
Sideoats Grama, V Bar V Ranch
say that in 140 characters ? Well how about…
Inside this issue:
Grass
2-3
Chris’ Hot Topic of
Range
4-6
Plant of the “Week”
7-9
10
Open Range
Coordinator Position
Better Rangeland
Photos Workshop
11-14
View from the Rim
15
Just Me Talking
15
“grass…the
original
green
technology
…”
The Rimrock Report
Grass...continued
Grass, the original green technology. Solar powered renewable resource. Catches rain, occupies wind, holds
soil. Food, fuel, fiber, and fun.
Derived in the early 15th century from the Old English word “graes” it comes from the same root word as
“grow”. Grasses are a diverse family, ranging from wheat and corn to bamboo. Table 1 illustrates the
taxonomic classification of grass.
According to the NRCS Plant
Table 1. Taxonomic classification hierarchy for a grass species.
Database website, the family
Kingdom
Plantae
Poaceae has 324 genera. Some
Sub-kingdom
Tracheobionta
genera have only one species. For
Superdivision
Spermatophyta
instance, Blepharoneuron contains
Division
Magnoliaphyta
only B. tricolepsis (Pine
Class
Liliopsida
Dropseed), Western Wheatgrass is
the only example of Pascopyrum
Subclass
Commelinidae
(P. smithii). Others such as
Order
Cyperales
Bouteloua, named for two Spanish
Family
Poaceae
botanists, contain many different
Genus
Aristida
species (25). Notable among these
Species
arizonica
would be my favorite, B.
Common
Arizona Three-awn
curtipendula (Sideoats Grama), as
well as Blue Grama (B. gracillis),
Black Grama (B. eriopida) and Santa Rita Mountain Grama (B. eludens). Santa Rita Mountain Grama is
found in southeast Arizona and the bootheel of New Mexico (Figure 1) and is considered a threatened
species. Festuca is another highly populated genus (85). Our own Arizona Fescue (F. arizonicus) is among 6
species named for states, i.e. F. californicus, idahoensis, hawaiiensis, and the not so obvious versuta (Texas)
and brevissima (Alaska). How would you like to find F. aloha in your quadrat?
As alluded to above, providing food for herbivores is one of
the most important functions of grass, but there are many
others. Did you know for instance that there are medicinal
uses for grass? Don’t get ahead of me. Seriously, several
Native American cultures used Vanilla Grass (Hierochloe
odorata) as a cold remedy. Ashes from Little Bluestem
(Schizachyrium scoparium) were used to relieve
indigestion… Roots of Blue Grama (Bouteloua gracilis)
were chewed and then used to treat the wound in castrated
colts.. (... and I am not recommending you use these, this is
just for information purposes...). Did you know that Bamboo
is a grass and is one of the most popular building materials
in Asia. You can even make clothes and bedding out of it.
And if you recycle it through a Giant Panda, or elephant,
etc... you can get paper. Don’t believe me? Check out this
website.
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Volume 7, Issue 3
Grass...continued
Need more Jeopardy study material? Crammin’ for Cash Cab? Here we go:

Switchgrass (Panicum virgatum) is one of the primary feedstock sources of cellulosic ethanol production.
Here are a couple different viewpoints on that:
http://www.scientificamerican.com/article/grass-makes-better-ethanol-than-corn/
http://www.popularmechanics.com/science/energy/debunking-myths-about-nuclear-fuel-coal-wind-solar-2

One school of thought on the origin of the term
“grass roots” is that it originated in 1876 in a book
about the Black Hills: “gold is found almost
everywhere, in the bars, in the gravel and sand of
the beds, even in the 'grass roots’ ”. It has of course
been used most often since then as a reference to
political movements which start at local levels.
There are approximately 24,000 lbs/acre of roots in
typical tallgrass prairie.
Pioneers made sod houses by cutting bricks of soil
held together by grass roots.
In general, Bamboo is the world’s fastest growing
grass, sometimes as much as 4 feet per day.
Indian Ricegrass, House Rock Valley
Marsh is grassland under water.
Albedo is the % of light reflected rather than absorbed. Green grass (0.25) has a higher albedo than bare
soil (0.17). Fresh asphalt has an albedo value of 0.04 compared to fresh snow which has a value of 0.800.90.
Curly Mesquite (Hilaria belangeri) and Vine Mesquite (Panicum obtusum) are not trees, they are grasses.
It is a myth that grass seeds found in the Egyptian Pyramids have been planted and germinated.
In 2012, Americans produced approximately 251 million tons of municipal solid waste. Of this amount,
13.5 % was from yard trimmings. This is enough dry matter to feed all the mature beef cows in the US for
a month.
Sedges have edges, rushes are round, grasses are hollow
from the top to the ground. There are several interesting
versions of this little rhyme, I will let you look them up
if you are interested...
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Had enough yet? Yeah, I think we have made the point.
Grass is pretty important. So here is just one more shot. A
few weeks ago I was out looking at forest/range restoration
sites with Steve Campbell, Navajo County Extension
Director, and we were standing in a former dog-hair pine
thicket/soon to be savannah, talking about ecosystem health
in general when he said “Trees get the glory, but grass holds
the world together”. Ranks right up there with Jefferson.
Page 3
Foxtail Barley, Mingus Mountain
The Rimrock Report
Chris’ Hot Topic of Range
One of the most exciting things about
Rangeland Ecology is how dynamic it is.
There is no simple answer to any
question, and land management is a
practice of balancing art with science.
Vegetation dynamics are influenced by
variables such as soil type, precipitation,
invasive species, and fire. One variable
that is often ignored is atmospheric
Carbon Dioxide (CO2).
When atmospheric CO2 is mentioned, it
is most often in association with
influences on temperature and
potentially resulting global issues such
as melting glaciers and rising oceans.
What is typically not mentioned is the
direct impact CO2 has on plant growth.
It is all about photosynthesis, the process
in which a plant converts CO2 and light
into energy. Photosynthesis was covered
in detail by Doug’s January Rimrock
article titled, “The effects of global
warming and rotational grazing on wolf
predation of feral horses.” Don’t let that
title fool you, that article really was all
about photosynthesis.
Carbon Dioxide (Wikipedia)
In short, there are three main pathways
of photosynthesis; C3, C4, and CAM.
C3 is the primitive ancestral form of
photosynthesis, developed some 2500
million years ago (MYA) in
cyanobacteria and ruled the world when
plants first took to land 450 MYA. At
the time the atmospheric concentration
of CO2 was high enough that simple
diffusion was plenty to keep the engine
of photosynthesis running smoothly and
efficiently. C3 is a decent system, as far
as primitive systems go, and the
majority of today’s plants still use it.
C3 dominated forest circa 400 MYA (Edward Riou)
Page 4
Volume 7, Issue 3
Chris’ Hot Topic of Range...continued
Well time continued ticking by; pine
trees evolved in the Carboniferous age,
Pangea came and went, flowering plants
evolved during the Triassic, the K-T
meteor caused a mass extinction, etc.
Throughout this time CO2 fluctuated, but
stayed relatively high (Figure 1). Then
around 30 MYA CO2 levels started
falling dramatically; decreasing to a low
of 200 Parts Per Million (PPM) some 10
MYA (Figure 2). When CO2 drops
below 500 PPM some C3 plants start to
become carbon stressed since CO2
diffusion is slower at lower CO2
concentrations. The plant compensates
by keeping leaf pores open longer, but
that increases water loss. Higher oxygen
(O2) concentrations relative to CO2 is also Figure 1: Estimated atmospheric CO2 for the past 600 million Years (Figure by
Robert A. Rohde; Global Warming Art project )
problematic since O2 interferes with
photosynthesis. Thus as CO2 decreased,
strong selective pressure was created to
find a more efficient form of
photosynthesis. This was the introduction
of C4 photosynthesis, a shiny new and
improved photosynthetic pathway that
independently evolved over 60 times
across dozens of flowering plant taxa.
Today our rangelands tend to be a mix of
C3 (cool season) and C4 (warm season)
plants. The competitive dynamics
between the two vary, but basically
revolve around efficiency and the water
loss with less efficient photosynthesis.
C3 dominated rangelands tend to be in
areas with more reliable rainfall, cooler
temperatures, and higher relative
humidity while C4 dominated grasslands
tend to be in areas that experience
frequent drought conditions and higher
temperatures (Figure 3).
At least that’s how these plant
Figure 2: Estimated atmospheric CO2 for the past 65 million years ( Geoff
Zeiss ; IIPC AR5)
Page 5
The Rimrock Report
Chris’ Hot Topic of Range...continued
Figure 3: Left: C3 Bluebunch Wheatgrass dominated rangeland in Oregon. Right: C4 Blue Grama dominated rangeland in
Arizona.
associations have been recorded in the past. The future is less certain. In 1900 atmospheric CO2 was at 300
PPM; last year we hit a record 400 PPM (Figure 4). What does a 40% increase in atmospheric CO2 mean?
That’s a difficult question to answer. Typically it means faster plant growth with C3 becoming more efficient.
However, less predictable precipitation and increased temperatures will still favor C4 photosynthesis. So
exactly how C3 vs C4
dynamics play out will
depend on local conditions,
but it may not mirror the past
nearly as much as we would
like. Also, the increased
vegetation growth does sound
nice, but nitrogen and other
essential minerals are not
increasing. An increased
carbon to nitrogen ratio
means more abundant but
less nutritious forage. For
livestock operations this may
possibly increase the need for
protein supplementation.
Figure 4: Atmospheric CO2 for the past 1000 years (Etheridge et al. 1998)
So the future is still relatively
unknown and hard to predict, but it is fascinating seeing it all play out. As atmospheric CO2 continues to
exponentially increase, we can expect more pronounced changes in vegetation dynamics and a greater
departure from historic plant communities. Will C4 plants still hold their own as we move away from the
conditions that evoked its evolution? Will C3 plants retake land lost in the last few million years, or will the
changing climate and increased climatic variability make C4 the most important plant type of the future? Hard
to say, but as land managers we are on the front lines of this brave new world. Exciting times!
Page 6
Volume 7, Issue 3
Plant of the “week” by Guest Writer Doug Tolleson
Three-awns
You might be a range nerd if you don’t lump three-awns. But I have to admit that I do most of the time. Threeawns often fall into that type of plant that just end up as one big group. Like annuals, prickly pear, cholla…. I
started wondering why. I know some of them look a lot alike. Kind of like tobosa/galleta or one-seed vs. Utah
juniper. But a lot of them don’t really look alike and we still tend to lump them. We tend not to go to the effort
of learning the species name. It could be that most are not considered good livestock or wildlife feed. Many
have stringy leaves and those famous awns, not very palatable. They are not always found on the most
productive sites. So, they become “ARIST” or “Aristida” or “3awns” on our monitoring forms. But really, what could be that
hard about it?
Let’s take a couple of species found here in Arizona and
compare them. Figure 1 contains examples of Purple Three-Awn
(Aristida purpurea) and Arizona Three-Awn (Aristida
arizonica). They don’t look anything alike, right? Let’s consult a
plant key and see how different they are.
Ok, I am looking at Arizona Flora (Kearney and Peebles) ... are
they annual? no, perennial... so far - so good. Next... column of
the awn distinctly twisted, 3-5 mm long, panicle narrow, the
branches appressed, floriferous nearly to the base... arizonica.
Or, panicle branches very slender, more or less flexuous, lemma
conspicuously scabrous in lines, awns terete at base... purpurea.
No sweat. Well maybe we should consult our glossary of
botanical terms.
Appressed: Pressed closely, but not fused; e.g. leaves
against a stem.
Awn: Fine bristle-like appendage; e.g. terminating or on
the back of glumes and/or lemmas of some grass
spikelets.
Bract: Modified leaf associated with flower or
inflorescence, differing in shape, size or color from other
leaves.
Figure 1. Aristida purpurea (top), courtesy of
Matt Lavin – Wikipedia Commons, and Aristida
arizonica (bottom), courtesy of Western New
Mexico University.
Flexuous: Zig-zagging, bent alternately in different directions, often referring to a stem.
Floriferous: Having or producing many flowers.
Page 7
The Rimrock Report
Plant of the “week” ...continued
Glume: Bracts subtending the floret(s) of a sedge, or similar plant; in grasses forming the lowermost
organs of a spikelet.
Lemma: The lower of 2 bracts enclosing a grass flower.
Panicle: A compound raceme; an indeterminate inflorescence in which the flowers are borne on
branches of the main axis or on further branches of these.
Raceme: An indeterminate inflorescence in which the main axis produces a series of flowers on lateral
stalks, the oldest at the base and the youngest at the top; cf. spike.
Scabrous: Rough to the touch with short hard emergences or hairs.
Spikelet: A unit of the inflorescence especially in grasses, sedges and some other monocotyledons,
consisting of one to many flowers and associated bracts (glumes).
Terete: Circular in cross-section; more or less cylindrical.
Did that help? In Blue Collar Plant language that would be basically: arizonica has a narrow seedhead with
branches on the main stem axis that are flattened against the stem and with flowers all along the stem... and
purpurea has slender sort of zig-zag branches in the seed head and the outside of the flowers feel rough. Got
it?
I am sure you have caught on by now that three –awns do have distinguishing characteristics, but they may
not be that obvious to a lot of us and if multiple species fall within a similar functional group, we will likely
continue lumping them in the field. But three-awns still perform a lot of the important functions that grass is
famous for. They produce oxygen, intercept precipitation, hold soil in place, make good quail nests, burn well,
etc… and there are a lot of them. Aristida has 120 records
on the NRCS plants database. Distribution of the genus
includes the 48 contiguous states plus HI, USVI, and PR.
I’ll bet Thomas Jefferson would find three-awns
interesting. So, I decided to give three-awns some respect
and talk more about some of the individual species. Here
are a few interesting facts:

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Arizona three-awn (A. arizonica) has mature leaf
blades that are flat and curling. Often found in piñonjuniper sites. Note; it is sometimes mistaken for (A.
purpurea).
California three-awn (A. californica) is also known as
Aristida purpurea, Courtesy of Yavapai County Native and
Mohave three-awn and it likes dry sandy habitats.
Naturalized Plants.
Page 8
Volume 7, Issue 3
Plant of the “week” …..continued
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Purple three-awn (A. purpurea) is a
widespread species and has several integrating
varieties. e.g. Fendlers (A. fendleriana) and
Wrights (A. wrightii) three-awns.
Santa Rita three-awn is a variety of California
three-awn, i.e. var. glabrata Vasey.
Other common names include: wiregrass,
speargrass, and needlegrass.
Mainly found in semi-arid to arid regions and
abundance can indicate disturbed or
deteriorated range, sometimes due to heavy
grazing.
The awns can get into wool and eyes and cause
damage to livestock.
So next time you are out monitoring and come
across a three-awn, maybe you could take a little
time to find out which one it is. Or if it is 100o or it
is cold and the wind is blowing straight sideways;
you could just call it ARIST and keep going... and
figure it out next time.
Aristida purpurea, seeds with 3 awns. Courtesy of University of
Arizona Health Sciences Center.
Aristida purpurea-dominated roadside in Yavapai County.
Courtesy of one University of Arizona Extension Specialist who
really needs to go to a photography workshop.
Page 9
The Rimrock Report
Position Announcement: Program Coordinator
V Bar V Ranch Experiment Station, University of Arizona, School of Natural Resources and the
Environment.
Salary Range $29,443-$35,552 annually
Available ~ Sept 2014, application period will open soon
The successful candidate will work closely with the Rangeland Management Specialist at the V Bar V Ranch
Experiment Station to develop and deliver extension programming. This person will assume responsibility for
Range Rocks!, an outdoor-oriented youth education program primarily focused on rangeland ecology and
management. Subject matter may include grazing animal nutrition, ecological monitoring, or application of
technology in agriculture and natural resources. Educational activities coordinated by the incumbent will take
place in both indoor and outdoor “classrooms”. Students in this extension program learn hands-on “real life”
skills; in the field as much as possible. The Program Coordinator will be expected to work both independently
and within a team setting including collaboration with University of Arizona extension personnel and other
area educators. Familiarity with rangeland ecology and management and outdoor experiential learning is
required. The ability to work outdoors in a variety of weather conditions is a necessity. This person will be
responsible for developing and delivering lesson plans, maintaining project documentation, and should be
competent in basic word processing, graphic presentation, and spreadsheet software as well as social media
applications. Experience with distance education including video production is desired. Other activities will
include contributing to a quarterly range-oriented newsletter, The Rimrock Report, as well as helping to
organize and evaluate workshops, field days, and other University of Arizona outreach activities. B.S. degree
in rangeland/natural resources or environmental science, and two years experience is required, an M.S. is
preferred. The Camp Verde/Cottonwood/Sedona area is approximately 1.5 hrs north of Phoenix, 1 hr south of
Flagstaff and 1 hr east of Prescott. The area has a small town atmosphere with good shopping, educational,
medical, cultural, and recreational opportunities.
Interested individuals should contact:
Doug Tolleson Rangeland Management Specialist, V Bar V Ranch
2830 N. Commonwealth Drive Suite 103
Camp Verde, AZ 86322
928-554-8999
dougt@cals.arizona.edu
http://cals.arizona.edu/vbarv/rangeprogram/
Page 10
Volume 7, Issue 3
Better Photos-Better Rangelands Workshop
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The Rimrock Report
Better Photos-Better Rangelands Workshop...continued
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Volume 7, Issue 3
Better Photos-Better Rangelands Workshop...continued
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The Rimrock Report
Better Photos-Better Rangelands Workshop...continued
Page 14
The view from the Rim
I think July 4th is a great time to hear more from Thomas Jefferson.
 No occupation is so delightful to me as the culture of the earth, and no culture
comparable to that of the garden.
 In matters of style, swim with the current; in matters of principle, stand like a
rock.
 He who knows best knows how little he knows.
 One man with courage is a majority.
Picture courtesy of www.whitehouse.gov/about/
presidents/thomasjefferson
The University of Arizona
School of Natural Resources and the Environment
V Bar V Ranch
2830 N. Commonwealth Drive Suite 103
Camp Verde, AZ 86322
Phone: 928-554-8991
Fax: 928-554-8996
Cell: 928-821-3222
E-mail: dougt@cals.arizona.edu
Web: http://cals.arizona.edu/aes/vbarv/
Note: Please email me if you would like to be added to the
“mailing” list for this newsletter.
Just me talking...
Where to start? As I write, I am sitting under the ramada by Lemke Lake at Mingus Springs, now known as James 4-H
Camp. Another NRCWAY is in the books, everybody is heading down the mountain and I am taking advantage of a
little peace and quiet and cool weather. This year’s theme was range and forestry. Several students are talking about
careers in range, most want to come back next year, nobody went to the ER. We have three great candidates for SRM
high school youth forum. Overall, a great camp. Good job Kim, Susan, Mary, Jeff, John, Andrew, Chris and all the
others who made it so. Things are happening around the V Bar V Range Program too. We have been getting papers
published (see June issues of Rangelands, and Stewardship) and others submitted (keep an eye out in Rangelands). We
are working on more. We have received another grant from Western Center for Risk Management Education to continue
our drought scenario workshops. We will be part of a collaborative group doing a drought/adaptive grazing management
education project on the Tonto NF. And we are working on proposals to keep the Arizona Cooperative Rangeland
Monitoring Program going with BLM. Chris and I have been monitoring cow body condition and diet quality on the
ranch, along with utilization and production. We are working with Mike Crimmins to do a pilot study comparing
precipitation monitoring with old and new technology on a few area ranches. The Extension Centennial celebration for
northern Arizona will be at the ranch (Mahan Park) later this month (24th). That will be a great opportunity to look back
at what Extension has accomplished here in Arizona. The Arizona Section SRM is meeting with Navajo County
Extension to talk about and tour range/forest restoration efforts in the Show Low area on August 14-15. Then on
Saturday the 16th we will have our photography workshop. Ranch Explorers will be at Mahan Park on August 22nd. Last
but not least, we are looking for someone to join our team and work with the Range Rocks! program as well as plug into
our other extension range education activities (see job announcement in this issue). We should be hiring several new
extension folks in Arizona this coming year, so keep an eye on the UA Human Resources website as well as our
facebook page. Well that is probably about enough. I am trying to stay focused. I plan to shift gears now and get back to
working on the literature review for a journal paper… but the breeze is blowing and bass are jumping like crazy in the
pond. Dang, that was a big one…
Till next time,,
Doug
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