GIS in bio controllers for invasive plant control

Compiled for GIS I: INTRO GEOG INFO SCIENCE (GEOG_560_400_F2021), Oregon State University, by Lee Baldwin

 

Introduction: Behind habitat destruction, biological invasion is the second leading cause of extinction. Biological invasion is when species that are not native to an ecosystem establish themselves in a new host ecosystem to the detriment of native species. For my degree project, I intend to use the fungus Verticillium albo-atrum, as an experimental bio control agent to manage invasive plants in the Watson Woods Riparian Preserve, located in Prescott, Arizona. This is a bibliography that contains information that will be beneficial to GIS applications to this experiment and the realm of invasive plant management within Arizona. 

 

Lien, Aaron M., Baldwin, Elizabeth, Franklin, Kim, & Lien, Aaron M. (2021). Collective Action and Invasive Species Governance in Southern Arizona. Rangeland Ecology & Management., 74(1), 151–164. https://doi.org/10.1016/j.rama.2020.10.004

 

As anthropogenic actions continue to alter ecosystems all around the world, ecosystem policy and management struggle to keep up with monitoring the causes and effects of meddling with the environment. One such problem is invasive species management, in which invasive species must be tracked from their point of origin, their spread and growth in their invaded environments, the impacts they have in their host ecosystems, and how to manage (and possible combat) them. One example of an invasive species in Arizona is buffelgrass. In this article, Baldwin and Lein et al discuss how different agencies and individuals evaluate the situation of buffelgrass invasion in Pima county, within the Sonoran-desert of southern Arizona. Their results utilize a topographical GIS map to analyze the landscape, policy actor agencies, their responsibilities, and amount of land managed to review how effective they were at managing buffelgrass and under what terms in regards to the lands they were managing along with what the missions of each agency were. While the effects and degrees of severity varied between agency and region, the conclusion alluded that buffelgrass is concern in the region and that collective action and coordination is necessary to properly manage it. In order to manage invasive plants in Arizona, understanding and coordinating roles between appropriate actors is necessary.

 

Wickert, K. L., Eric S O’Neal, Davis, D. D., & Kasson, M. T. (2017). Seed production, viability, and reproductive limits of the invasive ailanthus altissima (tree-of-heaven) within invaded environments. Forests, 8(7) doi:http://dx.doi.org/10.3390/f8070226

 

Ailanthus Altissima, also known as the “tree-of-heaven”, is an ornamental plant from China that has been imported to the U.S for aesthetic purposes, but has since proliferated into a pesky biological invader that is disrupting the habitats that it has invaded. In this article, Wickert et al studies the reproduction capabilities of tree of heaven by analyzing their average seed production, seed viability, and dispersal in order to predict their growth and distribution in their invaded habitats. This is crucial information in managing their invasion because it explains how the tree’s high and early reproduction success has been the main factor in their invasion, and what the limits of their reproduction are. By understanding the factors behind their invasion, management plans can be implemented to curb the conditions that are favorable to their growth; in this instance removing the trees before they start germinating seeds would be an effective step in managing these invaders.

 

Jeanmarie A. Haney, Jeanmarie A., Turner, Dale S., Springer, Abe E., Stromberg, Juliet C., Stevens, Lawrence E., Pearthee, Phillip A., Suplee, V., (2008)“Ecological Implications of Verde River Flows”, The Nature Conservancy, https://azconservation.org/dl/TNCAZ_VerdeRiver_Ecological_Flows.pdf

 

In this extensive report of the Verde River, the ecology of the Verde River watershed is studied in terms of the impacts that the river flow has on the ecosystem that it supports. This study goes into extensive detail about the geomorphology of the Verde River, using spatial and geographic analysis and data to study the effects of stream flows and water levels of the Verde River have on the economies, ecosystems, and pathway of the river. This is important in terms of invasive species management because invasive plants can also impact the river. Certain invasive plants, such as tamarisk, absorb more water than native plants which diminishes water levels and impacts river flows. By focusing control efforts on key points on the river banks (utilizing GIS mapping), reduction of impact by invasive species on river flow can be optimized for greatest effect.

 

Fred Phillips Consulting, (2011), “Verde River Cooperative Invasive Plant Management Plan” Fred Phillips Consulting, https://verderiver.org/wp-content/uploads/2017/12/verde-river-cooperative-invasive-plant-management-plan.pdf

 

Because the Verde River flows throw many regions of Arizona, the watershed is managed between several agencies and organizations. This cooperative management plan made for land owners and managers outlines versatile strategies and actions that can be taken for invasive species control. This plan also includes the implications of invasive species within the Verde River watershed and why it is important to act decisively. The plan also sets criteria for prioritizing a site, which utilizes DBMS that catalog conditions of vulnerability to invasive plants in particular areas against identified invasive plants.

 

Limbrunner, J., Sheer, D., Herberger, M., Cohen, M., Henderson, J., Raucher, B., (2011) “Policy Options for Water Management in the Verde Valley, Arizona”, The Nature Conservancy, https://cwagaz.org/images/Reports/Verde/WaterMgmtVV.pdf

 

This study by the Nature Conservancy explores the plans for managing the watersheds along the Verde River. Geographic data modeling along with water consumption from the river (with consumer categories listed, including agricultural, municipal, and residential uses) are used to make scenarios that depict results varying from levels of management intensity and from which policy actors. This study also details the cost of ecological restoration efforts, in which invasive species are a listed factor. This study concludes that the Verde River supports a diverse economy, ecosystem, and community that will take cooperation and consensus-centered management is vital to the river’s sustainable use. The study also concludes the likely scenario of mid-range growth in the near future which will lead to further withdrawals of water from the Verde River, and that decisive management is going to be necessary to stop over-exploitation of this vital resource.

 

US Forest Service, 2014, “Field Guide for Managing Tree-of-heaven in the Southwest”, USDA, https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5410131.pdf

 

This guide from the US Forest Service provides a quick overview of Tree-of-Heaven, it’s invasion of the Southwest, and suggested management procedures on controlling their invasion. Most of the recommendations include physical removal and coordination with landowners in order to keep the trees from spreading too quickly. The guide also lists chemical and bio control agents that can kill the invasive trees, as well as what the risks or uncertain factors are. The guide also lists species of fungi that are known to kill the host plants that they infect, but research with them is still be conducted in order to be considered for a prescribed method of management. This presents an opportunity to experiment with these fungi as potential bio controllers of tree-of-heaven, with the benefits of such possibly excluding the implications of using conventional herbicides and being a more natural approach to integrated pest management.

 

Weston, J. D., McClaran, M. P., Whittle, R. K., Black, C. W., & Fehmi, J. S. (2019). Satellite patches, patch expansion, and doubling time as decision metrics for invasion control: Pennisetum ciliare expansion in southwestern Arizona. Invasive Plant Science and Management, 12(1), 36–42. https://doi.org/10.1017/inp.2019.3

 

Studying the dispersal patterns of invasive species is also crucial to their control because it allows managers to predict their growth. This allows for predicting their intrusion into vulnerable areas and what can hinder their growth. In this study done by the University of Arizona, Weston et al analyzes the plant distributions of invasive species such as buffelgrass and discover that most of the invasive plants in southwestern Arizona grow by a satellite dispersion pattern, as opposed to random dispersion on an invaded front. Modeling also demonstrated how invasive plant growth rates slow down when managers focus on satellite concentrations of invasive plants. Patch size was also found to be an insignificant factor in terms of expansion rate. Meta-studies confirmed instead that the growth of patch sizes depend on environmental factors.

Büyüktahtakin, I. E., Feng, Z., Olsson, A. D., Frisvold, G., & Szidarovszky, F. (2014). Invasive species control optimization as a dynamic spatial process:: An application to buffelgrass (pennisetum ciliare) in arizona. Invasive Plant Science and Management, 7(1), 132-146. Retrieved from http://proxy.library.oregonstate.edu/login?url=https://www.proquest.com/scholarly-journals/invasive-species-control-optimization-as-dynamic/docview/1515640425/se-2?accountid=13013

 

Using effective raster cell data along with spatial analysis in a GIS application is an effective way of modeling the spread of invasive species, and buffelgrass is one example of a particularly aggressive spreading plant with a spread that can be charted. By modeling it’s spread, not only can the location of buffelgrass patches be predicted, but the treatment costs, damages, ecosystem carrying capacity, and risk to natural resources can also be determined. This interactive study proved several rules and strategies to buffelgrass control and removal. Rapid response teams that urgently remove new infestations is critical to keeping them from spreading. The amount of labor for removal efforts (in hours) along with risk scenarios for delays in treatment are also factored into this study, which shows that more labor hours with less delay in treatment yields more effective removal of buffelgrass.

 

Jason M. Stevens and Jeffrey S. Fehmi “Competitive Effect of Two Nonnative Grasses on a Native Grass in Southern Arizona,” Invasive Plant Science and Management 2(4), 379-385, (1 October 2009). https://doi-org.ezproxy.proxy.library.oregonstate.edu/10.1614/IPSM-09-022.1

 

One of the identifying criteria for invasive species is their competition with native species. In this case study, the invasive species of buffelgrass was compared against native Arizona Cottontop in terms of growth when they were place in close proximity of each other. Another feature of invasive species that goes beyond competition with native species that was discussed in this article was vulnerability to other disasters; in the case of buffelgrass a stronger susceptibility to wildfires (this also applies to the invasive woody plant tamarisk/salt cedar). When buffelgrass is grown within 5 centimeters of Arizona Cottontop, the native grass was shown to have a decrease in biomass due to competition with the invasive buffelgrass for resources such as water, nutrients, and sunlight. However, this study was conducted only in the first year of growth when both plants were planted at the same time, so long-term competition was not evaluated. However, given that rapid and early growth of invasive plants is a common component in the overrun of infested habitats, it can be concluded that long term competition between invasive buffelgrass and native Arizona Cottontop would favor the buffelgrass, or at least make native grasses harder to grow.

 

Wallace, C., Walker, J., Skirvin, S., Patrick-Birdwell, C., Weltzin, J., & Raichle, H. (2016). Mapping Presence and Predicting Phenological Status of Invasive Buffelgrass in Southern Arizona Using MODIS, Climate and Citizen Science Observation Data. Remote Sensing (Basel, Switzerland), 8(7), 524. https://doi.org/10.3390/rs8070524

 

Another factor behind buffelgrass invasion that makes it harder to manage is the variance in their growing periods. Herbicide treatments are most effective when buffelgrass is growing the fastest (due to absorption of nutrients that intake more herbicide and kill that plant), yet their growing periods and lifecycle can be altered in their new environments when compared to their original habitats (buffelgrass originated in Africa). By using remote sensing data and using GIS software to chart buffelgrass density in their invaded habitats in the Saguaro Desert in Arizona, this study demonstrated how buffelgrass growth periods and locations and be utilized for optimal herbicide treatment. The best results concluded at least 50% green buffelgrass was most reactive to the herbicidal treatments. Satellite-based MODIS-NVDI data was used to monitor the chlorophyll levels of buffelgrass to determine how “green” it was, with the most green indicating the most rapid growth.

 

Ignace, Danielle D., and Peter Chesson. “Removing an Invader: Evidence for Forces Reassembling a Chihuahuan Desert Ecosystem.” Ecology, vol. 95, no. 11, Wiley, 2014, pp. 3203–12, http://www.jstor.org/stable/43495234.

 

Another factor in invasive species control (and also a factor affected by biological invasion) is the biodiversity of native species. In an experiment involving introduction and removal of invasive species and monitoring the growth of native plants over several years. The invasive plant experiment with was E. cicutarium compared to the growth of native plants in Chihuahua desert in southeastern Arizona. Spatial data revealed that the timing of removal of these invasive plants was variable and therefore irrelevant in terms of invasive species removal, but overall species richness of native plants increased with the removal of E. cicutarium. One exception was the rare plant A. nuttallanius, which increased in density and abundance due to codependency on E. cicutarium.

 

Stromberg, Juliet C., et al. “Altered Stream-Flow Regimes and Invasive Plant Species: The Tamarix Case.” Global Ecology and Biogeography, vol. 16, no. 3, Wiley, 2007, pp. 381–93, http://www.jstor.org/stable/4139429.

 

As climate change continues to alter ecosystem regimes around the world, ecologists look into how the shifting climate may make ecosystems more vulnerable to invasive species that favor the altered climate conditions over the native species. In the Gila and Lower Colorado drainage basins of Arizona, Stromberg et al experiment on how the invasive tamarix species developed compared to native cottonwood trees. The variable of this experiment factored into account how altered stream flows, largely altered from climate change and droughts, could play a significant role in plant development. Methods for this experiment involved charting stream flows and moist habitats. The results found that cottonwood trees were the dominant species in floodplains due to the abundance of water near the surface in earlier climate regimes. However, due to altered stream flows and droughts, invasive tamarix species became the new dominant plants as their deeper roots had access to deeper groundwater.

 

Cerasale, David J., and Christopher G. Guglielmo. “An Integrative Assessment of the Effects of Tamarisk on Stopover Ecology of a Long-Distance Migrant Along the San Pedro River, Arizona – Una Evaluación Integral de Los Efectos Del Tamarisco Sobre La Ecología de Las Paradas Migratorias de Un Migrante de Distancias Largas a Lo Largo Del Río San Pedro, Arizona.” The Auk, vol. 127, no. 3, American Ornithological Society, 2010, pp. 636–46, https://doi.org/10.1525/auk.2010.09124.

 

Invasive plants don’t only disrupt the ecology of native plants in the ecosystems they infest, but they also disrupt the ecosystems of animals that depend on native plant species. One example of this is how the invasive plant Salt Cedar (Tamarisk) affects migratory birds that nest in riparian habitats, in this case along the San Pedro River in Arizona. Plasma metabolite profiling was used to measure the refueling performance of avian species as they nested in the area.

For this study, locations of tamarisk and (native) cottonwood clusters were charted along the banks of the San Pedro River. The results of the experiment concluded that the avian migrants had more access to food in cottonwood habitats than in tamarisk. However, nesting in tamarisk was also slightly higher than in cottonwoods. This produced mixed results as to how invasive plants influence migratory bird populations.

 

Keeley, Jon E. “Fire Management Impacts on Invasive Plants in the Western United States.” Conservation Biology, vol. 20, no. 2, [Wiley, Society for Conservation Biology], 2006, pp. 375–84, http://www.jstor.org/stable/3591345.

 

One of the reasons why invasive plants pose a significant fire hazard in dry climates is that they proliferate across areas prone to droughts and fire, then die off leaving enough dry wood fuel to exacerbate fire conditions. One fire management tactic is to use native, longer-lived species that have adapted to the area, then use controlled burns to remove invasive plants before they grow out of control, thus removing the fuel source from a potential wildfire while protecting native species. In this review by Jon Keely, he analyzes how controlled burns have played a crucial role in reducing invasive species in grasslands and managing wildfires. Controlling wildfires is crucial to managing invasive species because opportunistic invasive plants can quickly spread in an area cleared by wildfire before native plants have a chance to start regrowth. This rapid growth and die off then creates fuel for more wildfire frequency and intensity, thus demonstrating how invasive plants can alter the fire risk of the habitats they invade.

 

Bateman, H.L., Merritt, D.M., Glenn, E.P. et al. Indirect effects of biocontrol of an invasive riparian plant (Tamarix) alters habitat and reduces herpetofauna abundance. Biol Invasions 17, 87–97 (2015). https://doi-org.ezproxy.proxy.library.oregonstate.edu/10.1007/s10530-014-0707-0

 

In the ongoing fight against invasive species, several alternatives are being explored. One potentially interesting method is the use of bio control agents; other species that compete with invasive species but not with native ones in order to reduce and control invasive species presence. This method potentially yields more ecosystem-based approaches that don’t carry the risks or costs of high-intensity management or chemical agent affects to non-target species (ie, the use of glyphosate and its impact on other plant life). In the case for tamarisk removal, one candidate is the tamarisk leaf beetle Diorhabda carinulata that was introduced to the Mojave Desert in Nevada and the Virgin River in Arizona in 2006 to help manage salt cedar control. The leaf beetle defoliates the salt cedar trees, reducing their growth and proliferation in invaded habitats. Data analyses used ANOVA and NDVI comparisons to determine significant defoliation due to leaf beetle introduction. The results were mixed as the leaf beetle was also shown to impact the food system of native lizards and other animals that live in riparian habitats. Therefore, the use of lead beetles as a bio control agent was recommended to be used at the discretion of natural resource managers for site-specific areas where the beetle would be more effective.

 

Bateman, H.L, and Ostoja, S.M., (2012), “Invasive woody plants affect the composition of native lizard and small mammal communities in riparian woodlands”, Animal Conservation, Volume 15, Issue 3, retrieved from: https://zslpublications-onlinelibrary-wiley-com.ezproxy.proxy.library.oregonstate.edu/doi/full/10.1111/j.1469-1795.2011.00517.x

 

One method that resource managers use to (broadly) categorize invasive plants is woody plants vs herbaceous plants, largely due to its simplicity to identify and prescribe treatment methods. One easily identified woody invasive plant is tamarisk, also known as salt cedar. In an experiment done by Bateman et al on the Virgin River in Arizona, the effect of tamarisk invasions on native animal communities was analyzed. The results showed that while overall impact on abundant animal species was minimal, the impact or rarer animals was more pronounced as the rarer animal species were more vulnerable to disruptions posed by the invasive salt cedar.

 

Fradin, E. F., & Thomma, B. P. H. J. (2006). Physiology and molecular aspects of Verticillium wilt diseases caused by V. dahliae and V. albo-atrum. Molecular Plant Pathology, 7(2), 71–86. https://doi.org/10.1111/j.1364-3703.2006.00323.x

 

This research article contains information about the Verticillium fungi. This is important to my project because V. albo-atrum is the strain of Verticillium fungus that I intend to use as a bio control agent to manage the outbreak of tree of heaven and salt cedar. This article breaks down its information into the categories of Verticillium introduction to hosts, the symptoms and ranges of its infection, its pathogenicity, and the potential resistance of plants to infection from the fungus. One potential problem this could have for my project is that there are no known fungicidal treatments for verticillium infection (though there are some prevention treatments), so an outbreak could potentially harm some non-target species as well. Fortunately, there are some alternative treatment methods if the fungus does need to be contained, and this article provides useful information for it.

 

Thank you for taking the time to review my bibliography! If you have any comments, please feel free to leave them below in the comment section. I appreciate any feedback.