In the southwest corner of Circle Ranch in the deep, steppe-shrub desert, we have a stock tank which we call “Lobo” because it was the last place that the Mexican wolf was seen in Hudspeth County before being hunted out.
When we bought the ranch, it was grazed around a few catchment water tanks, as it had been for over 100 years. Set-stocking around these few fixed points had created large dead zones in what had previously been grassland. Shown here is the dead zone below the tank. March 2009.
Here we have brought about 1,000 animals into this area, delivering significant impact to the dead zone. Pictured at right is a winter picture of an area with remnant grass plants and brush. Note the plants are pretty thinned out. April 2009.
The interior of Lobo Tank shows the animal impact in and around the water. It looks pretty bad after this kind of use and at this time of year, but the animals were there in large numbers for only 10 days. April 2009.
Another herd was run in the winter of 2009 and the early months of 2010. Then, in the summer of 2010, rain came to Circle Ranch. The rainfall was almost the perfect amount at the perfect time. Nevertheless, as seen in this picture, plant response in the dead zone was poor. Why? Plants cannot take root in dead, uncovered soil that contains no organic material, which prevents the soil from holding water. April 2010.
On the other hand, as can be seen from this picture also taken in August 2010, there has been tremendous plant growth in those awful looking areas on the dead zones’ flanks. Plant growth occurred where the remnant plants received high intensity animal impact for a short period time followed by complete rest allowing plant recover. Of course, the recovery only occurred if it rained.
I conclude that cattle can really help if there something left alive, but there are dead zones where animal impact alone does not work.
The same area shown in the middle of September 2010. A big rain had fallen within the preceding 24 hours. Note that the ground is completely dry except for those low spots and there is almost no sprouting of forbs or grass, despite the tremendous animal impact and moisture.
On Saturday 17, 2010, same day as above, in this spot, we dug a test hole to see what kind of water penetration we had. As can be seen, there is probably not more than two inches of water penetration, and that is only partial, despite a heavy rain and runoff measured not in inches, but cubic feet per minute!
Another picture of the same area. Note the tremendous growth on each flank of the runoff area and that most of this area has very little runoff. There is a small amount of forb germination near and below the tank. The plants in the distance are creosote. September 2010.
Another picture of the flank to the right and the draw to the left showing the wonderful growth after heavy animal impact the previous winter.
The area below is pretty much plant free.
September 2011. We did not run cattle in the winter of 2011 (or the next winter of 2012), because in the winter of 2009-10 we severely “peeled” the ranch and we didn’t have enough old growth grass to create litter. We were also concerned that by “peeling the grass,” we had harmed the quail, whose numbers had declined precipitously in 2009-10.
However in that winter of 2010-11 we sub-soiled using a Yeomans Plow, on Keyline contours. As everyone remembers, 2011 was the worst drought year in Texas history. Now look at the plant response in the sub-soiled area during the state’s worst drought. Note that the flanks have had almost no growth, reflecting low rainfall, but there is considerable growth in the runoff area.
September 2011: The same area showing the weed bloom. These emerged during in the worst drought in recorded Texas history. Note that there is almost no grass growth in either flank and, unlike previous photos, the dead zone is actually the area producing the most new growth. This is the result of sub-soiling this area to encourage water penetration, so that the water that did fall here was far more effective than the same amount of water falling on the flanks.
Another picture of the sub-soiled area showing pretty good growth where the sub-soiling has occurred and very little growth on the flanks. This picture was taken September 2011.
August 7, 2012. Remember, as of this date we had last run cattle in 2009-10 and we had no cattle in 2010-11 or 2011-12. I’m speaking here of winter grazing starting in September and ending in June. Each winter grazing period spans two calendar years even though it’s only 210 days. In this picture, taken at the end of the summer of 2012, further response can be seen in the sub-soiled areas. This is the second year of the Great Drought although it is not as severe as the year before. In the background, you can see the east flank of this area. It is very dry even though it has established plants; however, it hasn’t been sub-soiled.
This picture was also taken in August 2012, during the second year of the Great Drought. There is some growth in the sub-soiled area, but it is frankly disappointing after two full growing seasons of recovery and deferral.
Beginning in September 2012 and continuing through May 2013, we ran 420- cows and their calves.
August 30, 2013. Because of water problems, these cattle stayed in this location for 20 days, so there was significant animal impact of the subsoiled area, and of the surrounding areas. Then in June, July and August we had excellent rains in the desert, so the grazing and subsoiling came together with timely moisture. Here is the plant growth.
It is apparent we will need to sub-soil the road and move it because the road is now the “leak in the bucket” that will be formed as the plants in the middle connect the flanks on either side. Once this happens, the water will back into the foreground whereupon I predict we will see an accelerated recovery of both forbs and grass. We now have weeds creating litter to protect and cool the soil, and roots in the ground to trap water and add organic material. This encourages plant succession.
The green weed in the foreground is probably African Rue or Peganum harmala (though it might be a relative, Mexican Rue). African Rue was first planted in the United States in 1928 in New Mexico by a farmer wanting to manufacture the dye “Iranian red” from its seeds. Since then, it has spread to Arizona, California, Montana, Nevada, Oregon, Texas and Washington. Because it is so drought tolerant, African rue can survive in the salt-desert shrub lands of the western U.S. in spots where nothing else can grow. This ability to survive where other plants cannot is confused as “invasion,” and it is generally taken as scientific fact that “alien and/or invasive” plants and animals are doing “harm”.
What is actually happening is both simple and good. Nature abhors a vacuum: When human impact causes plants or animals to disappear, something else shows up as nature tries to heal herself. While these “invaders” may be “aliens,” just as often they are “natives”.
It turns out that, usually, whatever increases biodiversity and species richness benefits everything. “Alien” or “invasive” plants and animals seldom “invade” but usually just fill up empty niches, like that dead zone, where human impact has made it impossible for natives to grow anymore. Far from doing “harm,” “aliens” and “invaders” usually are restoring biodiversity, which helps plants, animals, soil-life and habitat. I predict the native plants will displace the African (or Mexican) Rue as habitat recovers. Rue will subside back into a richer, more diverse plant community.
This is what happens with other “aggressive aliens” like thistle and tumbleweed, which also have a reputation as “harmful invaders.” They are actually great rescue plants. Dense thistle stands restore the fertility, structure and permeability of degraded soils with their deep taproots; they are an important seed and bug source for quail and other birds.
I have put the words “alien,” “invasive,” “aggressive,” “native,” and “harm” in quotes as these emotionally charged terms are commonly used to promote the idea of an “invasive species crisis.” As the terms themselves are not scientifically defined, they can mean many different things. Together they are used to promote the growing use of poisons, both herbicides and pesticides to fight the “invaders.”
Forty years ago, the emerging environmental movement was focused on the effects of poisons, bulldozers, chainsaws and rifles on habitat and wildlife. Today, the second-most discussed issue after climate change are invasive species and the “solutions” are poison, bulldozers, chainsaws and rifles!
African Rue seed looks to me to be ideal for small birds like quail and dove.
I appreciate our friend, Gary Fuentes at NRCS, identifying Peganum harmala, which neither of us had seen before.
August 30, 2013. As can be seen both flanks of this area have also responded very well.
August 30, 2013. That’s the inside of the tank. This demonstrates that animals don’t harm plants around these tanks if grazing periods are short and recovery periods are long. Weed seed from animal impact and subsoiling made this a great dove spot this year!
At Circle Ranch, our primary habitat tool is animal impact from large grazers. These are cattle when we run our herds, but also bighorn sheep, elk, llamas, deer, pronghorn, burros, etc.
But animal impact can’t fix everything. There is no way that this eroded gully, an old road bed now 20 feet deep and 150 feet wide killing an entire valley, can be grazed back to health and restored to water function. And furthermore, like the dead zones pictured above, there’s nothing in there for animals to eat in order to hold them for these grazing periods. To address the situation, we are building a dam not to impound water (although it will hold water and assist in recharging water wells), but to back water up and spill it out onto the grasslands. August 2013.
And it has to rain… which eventually it will! It would be unrealistic to expect that planned grazing, sub-soiling, gully-diversions or any other range practice will work in the absence of rain. The question is: Can we make our rain and water cycle more effective? Can we make more water soak into the soil instead of running off, as is happening in the upper pictures of this series? If 10 inches of rain falls and eight inches runs off or evaporates immediately as is happening in the pictures above, the effective rainfall is two inches. But if only five inches of rain falls and 80 percent of the rain soaks up, the effective rainfall has doubled to four inches in a drought! Even in periods of reduced rainfall, a more effective water cycle means higher effective rainfall. And a less effective water cycle – the almost universal result of conventional grazing practices and destocking – means that we are creating drought even if there is pretty good rain.
Humans create drought, not because they change how much rain falls out of the sky but because they change how much rain can be absorbed by the land: This insight is necessary to effectively address the problem of damaged water function.
Another necessary insight is that we cannot restore the land, plants, animals and water function without restoring biodiversity.
And finally, we cannot restore biodiversity by attacking biodiversity.