Shrubland resilience varies across soil types: implications for operationalizing resilience in ecological restoration

Wonkka, Carissa L.; West, Jason B.; Rogers, William E.

doi:10.1890/15-0066.1

Cited by 8 publications

(10 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some have proposed using prescribed fires during heatwave and drought conditions (sometimes referred to as “extreme fire”) to prevent or reverse expansion by woody species, thereby increasing the dominance of grasses and other herbaceous species (Smit et al., ; Twidwell et al., b; Twidwell, Rogers, et al., ). To date, the ability of these “extreme fires” to favor grasses has only been tested in a few locations and has sometimes reversed woody plant expansion (Smit et al., ; Twidwell et al., a; Wonkka et al., ). Nevertheless, our results suggest that “extreme fires” can sometimes have unintended consequences, such as declines in grass cover and related ecosystem services (e.g., forage production and carbon storage).…”

Section: Discussionmentioning

confidence: 99%

“…However, in mesic grasslands, many experimental and observational studies find community structure either resistant to drought and heatwaves or initially altered, followed by quick recovery (Fuhlendorf & Smeins, ; Hoover et al., ; Isbell et al., ; Kreyling, Wenigmann, Beierkuhnlein, & Jentsch, ; Tilman & Downing, ; Vanderweide & Hartnett, ; Weaver, ; but see De Boeck et al., ). Few studies in grasslands, however, have assessed the community responses to the combined impacts of climate extremes and disturbance events, such as wildfire (Smit, Asner, Govender, Vaughn, & van Wilgen, ; Twidwell, West, et al., ; Wonkka, Twidwell, West, & Roger, ).…”

Section: Introductionmentioning

confidence: 99%

“…Instead, prescribed fires are more common and are generally conducted when many plants are still dormant and fires are easier to control (Mohler & Goodin, ), resulting in lower intensity fires (Choczynska & Johnson, ; Gibson, Hartnett, & Merrill, ). Wildfires in the growing season, in contrast, can have high fire intensities and occur after plants have broken dormancy (Smit et al., ; Twidwell et al., b; Wonkka et al., ).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The combined effects of an extreme heatwave and wildfire on tallgrass prairie vegetation

Ratajczak

Churchill

Ladwig

et al. 2019

J Vegetation Science

View full text Add to dashboard Cite

Questions: Climate extremes are predicted to become more common in many ecosystems. Climate extremes can promote and interact with disturbances, but the combined effects of climate extremes and disturbances have not been quantified in many ecosystems. In this study, we ask whether the dual impact of a climate extreme and concomitant disturbance (wildfire) has a greater affect than a climate extreme alone. Location: Tallgrass prairie in the Konza Prairie Biological Station, northeasternKansas, USA. Methods:We quantified the response of a tallgrass prairie plant community to a 2year climate extreme of low growing-season precipitation and high temperatures. In the first year of the climate extreme, a subset of plots was burned by a growing-season wildfire. This natural experiment allowed us to compare community responses to a climate extreme with and without wildfire.Results: In plots exposed to the climate extreme but not wildfire, community structure, diversity, and composition showed minor to insignificant changes, such as a 20% reduction in grass cover and a slight increase in species diversity. Plots exposed to both the climate extreme and wildfire underwent larger changes, including an 80% reduction in grass cover, 50% increase in forb cover, and increased plant diversity. Two years after the climate extreme, structural shifts in burned plots showed little sign of recovery, indicating a potentially lasting shift in plant community structure. Conclusions:Our results suggest that community responses to climate extremes need to account for climate-related disturbances -in this case, high temperatures, drought and wildfire. This response diverged from our expectation that heat, drought, and an additional fire would favor grasses. Although growing-season wildfires in tallgrass prairie have been rare in recent decades, they will likely become more common with climate change, potentially leading to changes in grassland structure. K E Y W O R D Sclimate change, climate extremes, drought, fire, pulses, regime shifts, resilience 688 | Journal of Vegetation Science RATAJCZAK eT Al.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The combined effects of an extreme heatwave and wildfire on tallgrass prairie vegetation

Ratajczak

Churchill

Ladwig

et al. 2019

J Vegetation Science

View full text Add to dashboard Cite

show abstract

“…, ; Wonkka et al . ). Thus, shifts to shrub and tree dominance in our study region exhibit two key features of a state transition: a threshold relationship between state and a driver variable (shrub cover vs. fire frequency) and hysteresis once woody plants are established (Twidwell et al .…”

Section: Introductionmentioning

confidence: 97%

Changes in spatial variance during a grassland to shrubland state transition

et al. 2016

View full text Add to dashboard Cite

1. State transitions are changes in ecosystem structure and self-reinforcing feedbacks that are initiated when an exogenous driver variable crosses a threshold. Reversing state transitions is difficult and costly. While some state transitions are relatively rapid, many take years to decades. Outside of theoretical models, very little is known about slower state transitions and how they unfold in time and space. 2. We quantified changes in spatial variance as a mesic grassland ecosystem shifts to a shrub-dominated state, using long-term experiments and simulations that maintain grasslands with annual fires or initiate a state transition to shrub dominance by decreasing fire frequency. 3. In the experiments, the susceptibility to state transitions varied substantially in space. In the less frequent fire treatment, some plots became shrub-dominated around year 20 and grass extirpations began in year 25, but a third of the plots were still grass-dominated in year 37. Variable rates of state transition resulted in increasing spatial variance of grass cover over time, whereas shrub cover variance decreased. In the annually burned treatment, grasses remained dominant and the spatial variance of grass cover declined. 4. In a separate experiment, less frequent fires were maintained for 23 years and then switched to annual fires. The switch to annual fires occurred shortly after grass variance started to increase and a majority of these plots quickly returned to a grass dominated state. 5. In simulations, spatial variance remained low and average grass cover was high under frequent fires. If fire frequency decreased below a threshold, the ecosystem transitioned to shrubland, with a transient increase in the spatial variance of grass cover during the transition between states. 6. Synthesis. Spatial variability in the rate and susceptibility to state transitions is indicative of a system with a patchy spatial structure, high spatial heterogeneity and low connectivity between patches. Increases in spatial variance can serve as an indication that some patches have begun a state transition and that management interventions are needed to avoid widespread transitions. This is one of the first empirical examples where altering management after an increase in spatial variance prevented state transitions. Supporting InformationAdditional Supporting Information may be found in the online version of this article:Appendix S1. Information about long-term data set and its analysis.Appendix S2. Description of spatial interactions and noise in the simulation model.

show abstract

“…Its past condition, although possibly dominated by native species, displayed limited resilience since the perturbation resulted in a state change to shrubland and the system did not recover to grassland. Thus, contrary to common usage, resilience may not always imply strong ecosystem health and high biodiversity (Suding et al ; Zellmer & Gunderson ), and restoration may be necessary to overcome the resilience of the current, less desirable state (Wonkka et al ).…”

Section: Managing For Resilience: the Importance Of Conceptual Framewmentioning

confidence: 99%

Operationalizing resilience for conservation objectives: the 4S's

Aslan

Petersen

Shiels³

et al. 2018

Restoration Ecology

View full text Add to dashboard Cite

Although resilience thinking is increasingly popular and attractive among restoration practitioners, it carries an abstract quality that hinders effective application. Because resilience and its components are defined differently in social and ecological contexts, individual managers or stakeholders may disagree on the definition of a system's state, occurrence of a state change, preferred state characteristics, and appropriate methods to achieve success. Nevertheless, incentives and mandates often force managers to demonstrate how their work enhances resilience. Unclear or conflicting definitions can lead to ineffective or even detrimental decision-making in the name of resilience; essentially, any convenient action can be touted as resilience-enhancing in this case. We contend that any successful resilience management project must clearly identify up-front the stressors of concern, state traits, scales of appropriate management, and success indicators (the 4S's) relevant to the management targets. We propose a deliberate process for determining these components in advance of resilience management for conservation. Our recommendations were inspired and informed by two case studies wherein different definitions of stressors, state, scales, and success would result in very different management choices, with potentially serious consequences for biodiversity targets. Conceptual Implications• Resilience management attempts to align abstract concepts with real-world challenges, and different perspectives may yield very different decisions. • A priori identification of the ecological and social characteristics of a particular system is essential to ensure that stakeholders are in agreement about focal system state, scale, stressors, and success. • A proactive approach to defining resilience in a particular system should occur prior to management implementation so that success can be understood and recognized.

show abstract

Shrubland resilience varies across soil types: implications for operationalizing resilience in ecological restoration

Cited by 8 publications

References 23 publications

The combined effects of an extreme heatwave and wildfire on tallgrass prairie vegetation

The combined effects of an extreme heatwave and wildfire on tallgrass prairie vegetation

Changes in spatial variance during a grassland to shrubland state transition

Operationalizing resilience for conservation objectives: the 4S's

Contact Info

Product

Resources

About