Invasive Species Control Optimization as a Dynamic Spatial Process: An Application to Buffelgrass (Pennisetum ciliare) in Arizona

2014 ◽  
Vol 7 (1) ◽  
pp. 132-146 ◽  
Author(s):  
İ. Esra Büyüktahtakin ◽  
Zhuo Feng ◽  
Aaryn D. Olsson ◽  
George Frisvold ◽  
Ferenc Szidarovszky
Keyword(s):  
Invasive Species ◽  
Native Species ◽  
Spatial Competition ◽  
Control Strategies ◽  
Fire Risk ◽  
Spatial Process ◽  
Pennisetum Ciliare ◽  
Damage Indices ◽  
Invasive Species Control ◽  
Over Time

AbstractBuffelgrass (Pennisetum ciliare) is a fire-prone, African bunchgrass spreading rapidly across the southern Arizona desert. This article introduces a model that simulates buffelgrass spread over a gridded landscape over time to evaluate strategies to control this invasive species. Weed-carrying capacity, treatment costs, and damages vary across grid cells. Damage from buffelgrass depends on its density and proximity to valued resources. Damages include negative effects on native species (through spatial competition) and increased fire risk to land and buildings. We evaluate recommended “rule of thumb” control strategies in terms of their ability to prevent weed establishment in newly infested areas and to reduce damage indices over time. Two such strategies—potential damage weighting and consecutive year treatment—used in combination, provided significant improvements in long-term control over no control and over a strategy of minimizing current damages in each year. Results suggest specific recommendations for deploying rapid-response teams to prevent establishment in new areas. The long-run population size and spatial distribution of buffelgrass is sensitive to the priority given to protecting different resources. Land managers with different priorities may pursue quite different control strategies, posing a challenge for coordinating control across jurisdictions.

Targeting Vulnerable Life-Stages of Sericea Lespedeza (Lespedeza cuneata) with Prescribed Burns

2012 ◽  
Vol 5 (4) ◽  
pp. 487-493 ◽  
Author(s):  
Bryant M. Wong ◽  
Gregory R. Houseman ◽  
Sarah E. Hinman ◽  
Bryan L. Foster
Keyword(s):  
Invasive Species ◽  
Seedling Survival ◽  
Control Strategies ◽  
Abiotic Factors ◽  
Management Strategies ◽  
Effective Control ◽  
Life Stages ◽  
Lespedeza Cuneata ◽  
Sericea Lespedeza ◽  
Invasive Species Control

AbstractThere is growing interest in whether invasive species may be controlled by utilizing management strategies that target vulnerable life stages. We manipulated the timing of fire and measured its effects on sericea lespedeza germination and seedling survival. Although fire strongly decreased germination in the laboratory, fire increased germination under field conditions. Additionally, fire caused small decreases in seedling survival in the field. Therefore, controlled burns are likely to encourage spread of sericea lespedeza and are unlikely to effectively control this invasive species. Although targeting vulnerable life stages is a promising strategy for invasive species control, our results illustrate that system-specific studies may be needed to unravel potentially complex interactions between biotic and abiotic factors before effective control strategies can be devised.

scholarly journals Exploiting intraspecific competitive mechanisms to control invasive cane toads ( Rhinella marina )

2012 ◽  
Vol 279 (1742) ◽  
pp. 3436-3442 ◽  
Author(s):  
Michael R. Crossland ◽  
Takashi Haramura ◽  
Angela A. Salim ◽  
Robert J. Capon ◽  
Richard Shine
Keyword(s):  
Invasive Species ◽  
Communication Systems ◽  
Native Species ◽  
Negative Effects ◽  
Specific Chemical ◽  
Rhinella Marina ◽  
Invasive Species Control ◽  
Tropical Australia ◽  
Competitive Mechanisms ◽  
Species Specific

If invasive species use chemical weapons to suppress the viability of conspecifics, we may be able to exploit those species-specific chemical cues for selective control of the invader. Cane toads ( Rhinella marina ) are spreading through tropical Australia, with negative effects on native species. The tadpoles of cane toads eliminate intraspecific competitors by locating and consuming newly laid eggs. Our laboratory trials show that tadpoles find those eggs by searching for the powerful bufadienolide toxins (especially, bufogenins) that toads use to deter predators. Using those toxins as bait, funnel-traps placed in natural waterbodies achieved near-complete eradication of cane toad tadpoles with minimal collateral damage (because most native (non-target) species are repelled by the toads' toxins). More generally, communication systems that have evolved for intraspecific conflict provide novel opportunities for invasive-species control.

scholarly journals Functional diversity changes in native and alien urban flora over three centuries

2021 ◽  
Author(s):  
Marija Milanović ◽  
Ingolf Kühn ◽  
Petr Pyšek ◽  
Sonja Knapp
Keyword(s):  
Invasive Species ◽  
Alien Species ◽  
Functional Diversity ◽  
Functional Traits ◽  
Urban Areas ◽  
Native Species ◽  
Seed Mass ◽  
Ecological Niches ◽  
Alien Plant ◽  
Over Time

AbstractAlien species in urban areas have a large effect on overall species diversity. A suitable metric of flora’s response to environmental change is functional diversity (FD) that refers to the multivariate space of species’ trait compositions, reflecting their ecological niches. We studied how FD changed over 320 years of urbanization in the city of Halle (Saale), Germany. Selected functional traits (related to stress-tolerance, reproduction, competitiveness and phenology) were examined for the difference in FD between native and alien plant species, the latter specifically for archaeophytes, neophytes and invasive species. Functional diversity for each trait was calculated using Rao’s Q index followed by a linear model to test for changes in Rao’s Q over time between the groups. Over the 320 years, overall FD remained constant despite species turnover, but FD significantly increased for neophytes and invasive species compared to native species. Plant height was the only trait showing increase in FD as main effect, while for the other traits examined FD decreased over time. Considering invasive species separately, the majority of traits exhibit a significant increase in FD except for seed mass where it decreased. Finally, FD of multiple functional traits combined decreased over time. This can be due to homogenization of functional trait between native and alien species, as a consequence of habitats becoming more similar and subsequent habitat filtering. Our results demonstrate that during the last three centuries, urbanization influenced plant FD in various ways and may contribute to future uniformity of urban floras and greater invasiveness.

scholarly journals Mapping Rocky Mountain ridged mussel beds with preliminary identification of overlapping Eurasian watermilfoil within the Canadian range

2020 ◽  
Vol 42 ◽  
pp. 19-31
Author(s):  
Joy Wade ◽  
Craig Stephen ◽  
Colin Robertson
Keyword(s):  
Invasive Species ◽  
Native Species ◽  
Myriophyllum Spicatum ◽  
Rocky Mountain ◽  
Mussel Beds ◽  
Eurasian Watermilfoil ◽  
Potential Habitat ◽  
Preliminary Identification ◽  
Invasive Species Control ◽  
Species At Risk Act

The Rocky Mountain ridged mussel (Gonidea angulata) is a bivalve species whose Canadian range is limited to the Okanagan Valley, British Columbia. In 2019, conflicts between habitat protection for the mussel and potential habitat alteration to control the invasive Eurasian watermilfoil (Myriophyllum spicatum) (milfoil), led to a decision to maintain the status of the mussels as Special Concern under Canada’s Species at Risk Act (SARA) rather than classify it as Endangered. Milfoil control can cause direct mortality and/or burial of the mussels, but there had been no systematic study of the impacts of milfoil control on mussel beds. The purpose of this study was to address knowledge gaps by delineating known mussel beds and potential overlap with milfoil to provide information for management decisions that balance the needs of native species protection and invasive species control. Rocky Mountain ridged mussels in three reference locations were enumerated using snorkel surveys. The presence and distribution of milfoil was documented in relation to five sites within these three locations. Milfoil was encroaching on one site, causing some changes to the substrate. At other sites, the differences in the depth and distribution of the mussel and the milfoil could allow milfoil control without damaging the mussel beds. It is recommended that, before milfoil removal near known mussel beds be undertaken, a detailed site evaluation be conducted to determine potential impacts. This study suggests presumed impediments to co-managing the mussels and controlling an invasive species should not preclude classifying the mussels as Endangered and affording protections under SARA.

Secondary Invasion and Reinvasion after Russian-Olive Removal and Revegetation

2017 ◽  
Vol 10 (4) ◽  
pp. 340-349 ◽  
Author(s):  
Erin K. Espeland ◽  
Jennifer M. Muscha ◽  
Joseph Scianna ◽  
Robert Kilian ◽  
Natalie M. West ◽  
...  
Keyword(s):  
Invasive Species ◽  
Species Diversity ◽  
Native Species ◽  
Perennial Grass ◽  
First Year ◽  
Russian Olive ◽  
Secondary Invasion ◽  
Species Cover ◽  
Resistance To Invasion ◽  
Over Time

Russian-olive is a nitrogen-fixing tree invading riparian corridors in western North America. The premise of revegetation after weed removal is that revegetation is required to return native species to a removal site and that revegetation improves site resistance to invasion or reinvasion via competitive exclusion. Therefore, we expected that revegetation would reduce invasive species cover and increase native species cover compared with non-revegetated controls. Native understory species diversity increased with time since removal. We recorded 18.2 native species in 2012, and 28.2 native species in 2016. Out of 22 planted species, 2 did not establish. Diversity in revegetated plots did not differ from unplanted controls, likely because species spread quickly across plot boundaries. Native perennial grass, seeded species, and annual bromes increased over time, while nonnative forbs and native forbs decreased over time. Only invasive perennial grass cover responded to the revegetation treatment with cover much higher in controls compared with revegetated plots (25.7% vs. 7.7%); this was likely a response to a preplanting herbicide treatment. All categories of species diversity except invasive species diversity increased over time. Only 4% of Russian-olive stumps resprouted in the first year of removal, less than 1% resprouted 2 yr after removal. There was no Russian-olive emergence from seed in the removal year, and seed emergence varied exponentially among following years. Seeded native species did not have trouble establishing once adequate spring moisture occurred in the second growing season after Russian-olive removal, indicating that removal did not present substantial obstacles to successful revegetation. Follow-up control of Russian-olive is critical after initial treatment.

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