Beware the Desert Invaders: Border Walls and Buffelgrass

Scroll this

This is the fourth post in the series Learning from and with Invasive Species: pluralities, refractions, futures, a 4 part series of pieces edited by Estraven Lupino-Smith concerned with how humans choose to relate to species perceived to be “out-of-place” as shaped by ontologies, socioeconomic context, place-based histories, and desires of knowing and belonging to the world. By drawing attention to invasivity as historical production and the fickleness of its adoption, the series takes up discussions around invasion ecology and its relationship to the politics of land, labor, resources, selfhood, and place-making.

Defensive walls are a non-native species, one that has thrived in the Western Hemisphere but that was originally, like the peach and the dandelion, imported.

Excerpt from Ian Volner’s The Great Great Wall

Buffelgrass has the potential to turn what maybe attracts you and others to this region–some of the iconic cacti and the biodiversity that surrounds them–into basically an African grassland. It’s a wonderful place in Africa but doesn’t really belong here.

Interview with Debbie Colodner, Dir. Of Conservation Ed. & Science, AZ-Sonora Desert Museum

Organ Pipe Cactus National Monument (OPCNM), Hia-Ced O’odham homeland, lies athwart the international boundary between Arizona, United States and Sonora, Mexico; a stretch of land geopoliticized as the “borderlands”. In 2020, the Trump administration constructed parts of The Wall through these borderlands, as a show of protection against supposed migrant invasion. The wall segment through OPCNM halves O’odham territory with a “steel scar” (Jordahl, 2021) 30 miles long and 30 feet tall: border imperialism manifest (Ellis, 2007).

Sonoran Desert ecologists reckon with “desert invaders” of a different ilk: Buffelgrass, an introduced plant whose weedy behaviour spells disaster for protected Sonoran Desert ecosystems. Although it might be assumed that The Wall would help control this threat by providing an impassable membrane, preventing the spread of Buffelgrass internationally. However, rather than help contain Buffelgrass, border construction has most likely worsened its spread. Below, I highlight how the twin spread of border walls and buffelgrass through the US-Mexico borderlands are interwoven with ongoing histories of settler-colonization and racialization.

Cenchrus ciliaris, Buffelgrass. Photo courtesy of Mark Marathon.

Buffelgrass was introduced to Arizona by the US Soil Conservation Service in the 1930s as a food source for cattle. The seeds’ high wing load and barbed bristles allow them to move rapidly along disturbed paths like roadways. From there, buffelgrass permeates the desert by wind to settle new areas, germinating in disturbed soil and emerging in dense clumps. Its tendencies to dry out in droughts and greening up quickly after rain allows it to outcompete native plants for resources, “naturally colonizing” Sonoran Desert ecosystems (Burquez et. al, 1996). Though its rapid, dense growth does make for robust pastoral feed, it greatly increases the probability of wildfires against which native species have negligible protective adaptations (Marshall et al., 2011). Fire can therefore “convert a rich desert ecosystem into a barren buffelgrass grassland” (AZ-Sonora Desert Museum). Accordingly, US officials categorize buffelgrass as a “noxious weed” (USDA, 2014), subjecting it to robust eradication efforts that include hand-pulling and spraying pesticides. Just a few miles south in Sonora, Mexico however, buffelgrass is still freely planted as sustenance for cattle. The border is therefore decisive in buffelgrass management, not only because it helps distinguish where the grass is legal/illegal, but also because it serves as a threshold for the US attempts to eradicate the ecological threat.

Buffelgrass’s varying legal status across the border shows how belonging and unbelonging—indeed the unfixed category of “nature” itself—are socially produced, geographically and historically contingent categories. In the US, buffelgrass was once not only legal but purposely cultivated. In the 1930s and ‘40s, the US Department of Agriculture (USDA) initially imported buffelgrass from Kenya to Arizona-Sonora to control erosion and sustain a booming cattle industry (Cox et. Al, 1988b). This cattle industry also begot the introduction of barbed wire fences, which transformed and divided the borderlands (Razac, 2000). Both imported to support the booming cattle industry transforming the frontera, the spread of buffelgrass and the extension of border fences are intimately intertwined.

Cenchrus ciliaris (Buffelgrass). Courtesy of Forest and Kim Starr.

By way of example, first federal border fence built between Arizona-Sonora (1949) was constructed as a cooperation between the National Parks Service and the Boundary Commission to control cattle (for which buffelgrass was initially introduced) from grazing and spreading disease into Organ Pipe Cactus National Monument, Hia-Ced O’odham ancestral territory. However, the cattle-wire fence impeded the Hia-Ced O’odham from moving through their territories with ease, contributing to the state of diaspora that the Hia-Ced O’odham survive in today (Martinez, 2013). This introduction of non-native plants (like buffelgrass), animals, and their associated corrals, aided settler colonial expansion by transforming ecologies in ways that worked to sever indigenous relationships with their lands. In this context, imperialism functions ecologically (Crosby, 1986). Following Kyle P. Whyte’s work (2018) conceptualizing settler-colonialism as a form of ecological domination that, violently disrupts human relationships with the environment, the spread of Buffelgrass and the spatialities of The Wall are related ecological developments of settler-colonial dispossession that “loop” from the past through the present. Indeed, the cattle wire fence that originally demarked Organ Pipe in 1949 was not fully replaced until Trump’s wall construction in 2019.

Since it offers a material barrier between where buffelgrass is controlled and uncontrolled, some have suggested that Trump’s wall could help prevent the spread of Buffelgrass internationally. In my interview with Rijk Morawe, Chief of Natural and Cultural Resources Management at Organ Pipe Cactus National Monument, he implied that buffelgrass is spread by people moving through the park, itself a function of borderland migration:

We being a border park next to Mexico they don’t have the same constraints and restrictions that we have and so it is problematic. Especially around the village of Sonoita and when we have vehicles on our side that get the seed into them or whatever they can transport the seed and if we have people that are moving through the landscape, those folks can capture the seed and it can be transported through the landscape as well, so it’s a big issue for us.

Rijk Morawe, Chief of Natural and Cultural Resources Management at Organ Pipe Cactus National Monument

Morawe suggested that despite its negative environmental impacts (including habitat fragmentation, erosion, groundwater draining, bulldozing of vegetation, and more) the wall could have one ecological upside. That is, its barriers may keep migration and border patrol activity closer to the boundary, preventing buffelgrass seeds from spreading inland. He did not mention that the reason people were travelling through the park in the first place is that barriers had already been strategically built through areas of traditional migration during the Clinton, Bush, and Obama administrations, funneling clandestine migrants into more remote and environmentally sensitive areas, sometimes resulting in death. Nevertheless, the idea that the border wall may lessen the spread of buffelgrass has also been shared by others, though in more overtly racist ways that frame Mexicans as invaders. In these cases, the ecological is the stage upon which race is demarcated and performed (Sundberg & Kaiserman, 2015).

Despite speculation that Trump walls could help contain buffelgrass, border construction has most likely worsened the spread. This is because border wall segments are flanked by border roads, disturbed pathways along which construction and Border Patrol vehicles ferry buffelgrass along the boundary. From there, as I wrote above, the seeds can travel inland by wind. The extent to which patrol vehicles threaten buffelgrass suppression is evidenced by comments on DHS’s proposed environmental remediation plan, a quarter of which demand invasive species control (such as washing border patrol tire treads) for buffelgrass.

Walls purportedly installed to defend against invasion instead exacerbate the violences surrounding illegalized (more-than) human migrations. In the case of buffelgrass, Trump border wall segments have worsened the issue by forging disturbed pathways upon which border patrol and construction vehicles ferry seeds. Since many of Trump’s border wall segments were built without environmental assessments and funded with money illegally re-routed from the Department of Defense, the Department of Homeland Security (DHS) is embarking on environmental remediation of these segments of The Wall. Border walls must not be re-framed as tools for conserving land which, naturally, knows no bounds.


“Buffelgrass.” Arizona-Sonora Desert Museum.

Burquez, Alberto, A. Martínez-Yrízar, Mark Miller, Karla Rojas, M. A. Quintana, and David Yetman. “Mexican grasslands and the changing aridlands of Mexico: an overview and a case study in northwestern Mexico.” The future of arid grasslands: identifying issues, seeking solutions (B. Tellman, DM Finch, C. Edminster, and R. Hamre, editors). United States Department of Agriculture, Forest Service, Fort Collins, Colorado (1996): 21-32.

Cox, Jerry R., J. H. Fourie, N. F. G. Rethman, and D. G. Wilcox. “The influence of climate and soils on the distribution of four African grasses.” (1988).

Crosby, Alfred W. Ecological imperialism: the biological expansion of Europe, 900-1900. Cambridge University Press, 1986.

Jordahl, Laiken. Borderlands Campaigner at Center for Biological Diversity, 2021. Interview with the author.

Ellis, R. J. “‘East Is West’: Interhemispheric American Studies and the Transnational Turn.” REAL 23, no. 1 (2007): 163.

Marshall, V. M., M. M. Lewis, and B. Ostendorf. “Buffel grass (Cenchrus ciliaris) as an invader and threat to biodiversity in arid environments: a review.” Journal of Arid Environments 78 (2012): 1-12.

Martínez, David. “Hiding in the shadows of history: revitalizing Hia-Ced O’odham peoplehood.” Journal of the Southwest (2013): 131-173.

Morawe, Rijk. Chief of Natural and Cultural Resources Management at Organ Pipe Cactus National Monument. Interview with the author.

Razac, Olivier. 2000. Barbed Wire: A political history. The New Press: New York.

Whyte, Kyle Powys. “On resilient parasitisms, or why I’m skeptical of Indigenous/settler reconciliation.” Journal of Global Ethics 14, no. 2 (2018): 277-289.

Feature Image: Border Wall between USA and Mexico, here under construction south of Ajo, Arizona. Courtesy of Gillfoto, Wikimedia Commons
The following two tabs change content below.

Gabrielle Wolf

Latest posts by Gabrielle Wolf (see all)

NiCHE encourages comments and constructive discussion of our articles. We reserve the right to delete comments that fail to meet our guidelines including comments under aliases, or that contain spam, harassment, or attacks on an individual.