An official website of the United States government
Abstract ContextThe > 25,000 km2Flint Hills ecoregion in eastern Kansas and northeastern Oklahoma, USA, is an economically and ecologically important area encompassing the largest remaining tallgrass prairie ecosystem in North America. Prescribed fires are used routinely to control invasive woody species and improve forage production for the beef-cattle industry. However, burning releases harmful pollutants that, at times, contribute to air quality problems for communities across a multi-state area. ObjectivesEstablish a modeling framework for synthesizing long-term ecological data in support of Flint Hills tallgrass prairie management goals for identifying how much, where, and when rangeland burning can be conducted to maximize ecological and economic benefits while minimizing regional air quality impacts. MethodsWe used EPA’s VELMA ecohydrology model to synthesize long-term experimental data at the 35 km2Konza Prairie Biological Station (KPBS) describing the effects of climate, fire, grazing, topography, and soil moisture and nutrient dynamics on tallgrass prairie productivity and fuel loads; and to spatially extrapolate that synthesis to estimate grassland productivity and fuel loads across the nearly 1000 times larger Flint Hills ecoregion to support prescribed burning smoke trajectory modeling using the State of Kansas implementation of the U.S. Forest Service BlueSky framework. ResultsVELMA provided a performance-tested synthesis of KPBS data from field observations and experiments, thereby establishing a tool for regionally simulating the combined effects of climate, fire, grazing, topography, soil moisture, and nutrients on tallgrass prairie productivity and fuel loads. VELMA’s extrapolation of that synthesis allowed difficult-to-quantify fuel loads to be mapped across the Flint Hills to support environmental decision making, such as forecasting when, where, and how prescribed burning will have the least impact on downwind population centers. ConclusionsOur regional spatial and temporal extrapolation of VELMA’s KPBS data synthesis posits that the effects of integrated ecohydrological processes operate similarly across tallgrass prairie spatial scales. Based on multi-scale performance tests of the VELMA-BlueSky toolset, our multi-institution team is confident that it can assist stakeholders and decision makers in realistically exploring tallgrass prairie management options for balancing air quality, tallgrass prairie sustainability, and associated economic benefits for the Flint Hills ecoregion and downwind communities.
more »
« less
This content will become publicly available on December 1, 2027
Fire frequency drives tradeoffs among conservation priorities in tallgrass prairie
Abstract BackgroundDisturbance is a natural part of all ecosystems and often creates a balance of resistance-resilience among taxa. Grassland ecosystems, and in particular tallgrass prairie, are model systems for studying the outcomes of disturbance regime shifts because they are disturbance-dependent (i.e., maintained by fire, grazing, or climate). The effects of changing disturbance regimes, such as fire frequency in mesic grasslands, are often assessed based on one or a few taxa. However, to support diverse management goals, land managers must consider the effects of their choices on many taxa. In this study, we addressed this gap using a meta-analysis of 37 studies from tallgrass prairie to assess the effects of different fire frequencies on arthropods, birds, plants, small mammals, and soil properties (referred to here as ecological factors) and the interactive effects of fire frequency and grazing, another important disturbance. ResultsAs expected, the abundance and diversity of taxa were affected by different fire frequencies. However, the directionality of the change varied among taxonomic groups, indicating that there is no “one-size-fits-all” fire-management strategy in tallgrass prairie. Annual fires promoted small mammal abundance but decreased plant abundance and diversity. Meanwhile, intermediate fire frequencies promoted plant abundance but at the cost of plant diversity, arthropod abundance, and soil total carbon and nitrogen. Grazing promoted plant abundance while reducing arthropod and obligate grassland-bird abundance. ConclusionsOur study revealed research gaps, with critical data missing from small mammals, birds, soil properties, and eastern tallgrass prairie. However, quantifying the differential responses of ecological factors to fire frequency, as we did here, can inform tallgrass prairie management strategies, providing an example of the potential for land managers to manipulate disturbance frequencies to meet diverse management goals. We outline the important tradeoffs associated with management strategies using fire frequency and highlight the potential for fire to be used in unison with grazing to create a more heterogeneous landscape conducive to tallgrass prairie. Multi-taxonomic syntheses like this one are needed for land managers and ecologists to harness the power of prescribed fire in order to increase grassland sustainability and health worldwide.
more »
« less
- Award ID(s):
- 2425352
- PAR ID:
- 10686793
- Publisher / Repository:
- Springer Nature
- Date Published:
- Journal Name:
- Fire Ecology
- Volume:
- 22
- Issue:
- 1
- ISSN:
- 1933-9747
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Microbial communities display biogeographical patterns that are driven by local environmental conditions and dispersal limitation, but the relative importance of underlying dispersal mechanisms and their consequences on community structure are not well described. High dispersal rates can cause soil microbial communities to become more homogenous across space and therefore it is important to identify factors that promote dispersal. This study experimentally manipulated microbial dispersal within different land management treatments at a native tallgrass prairie site, by changing the relative openness of soil to dispersal and by simulating vector dispersal via bison dung addition. We deployed experimental soil bags with mesh open or closed to dispersal, and placed bison dung over a subset of these bags, to areas with three different land managements: active bison grazing and annual fire, annual fire but no bison grazing, and no bison grazing with infrequent fire. We expected microbial dispersal to be highest in grazed and burned environments, and that the addition of dung would consistently increase overall microbial richness and lead to homogenization of communities over time. Results show that dispersal rates, as the accumulation of taxa over the course of the 3-month experiment, increase taxonomic richness similarly in all land management treatments. Additionally, bison dung seems to be serving as a dispersal and homogenization vector, based on the consistently higher taxon richness and increased community similarity across contrasting grazing and fire treatments when dung is added. This finding also points to microbial dispersal as an important function that herbivores perform in grassland ecosystems, and in turn, as a function that was lost at a continental scale following bison extermination across the Great Plains of North America in the nineteenth century. This study is the first to detect that dispersal and vector dispersal by grazing mammals promote grassland soil microbial diversity and affect microbial community composition.more » « less
-
Blubaugh, Carmen (Ed.)Abstract Ecosystem restoration is a critical component of land management, countering the loss of native biodiversity. Restoration efforts are enhanced by reintroducing naturally occurring ecosystem processes, including disturbances that may impact species characteristics such as niche position or niche size. In grasslands, grazing and fire affect plant diversity and habitat complexity, which potentially influence insect dietary behaviors and thus their contributions to functions like seed and arthropod predation. Using carbon and nitrogen stable isotopes, we characterized variation in the dietary niche of six ground beetle species (Coleoptera: Carabidae) in response to grazing by reintroduced bison and prescribed fire disturbances in twenty tallgrass prairies. Management disturbances did not affect activity density for most beetle species and mean trophic position was mostly unaffected. However, five of six species exhibited increased trophic niche area and breadth with disturbances, indicating a switch to a more generalist diet that incorporated a wider range of food items. The combination of bison and fire impacts may increase vegetation patchiness and heterogeneity, driving these diet changes. Morphological traits and microhabitat preferences might mediate response to disturbances and the resulting heterogeneity. Combining prescribed fire and grazing, which increases plant diversity and vegetation structural diversity, may help beetle communities establish over time and support the ecological functions to which these insects contribute.more » « less
-
Abstract AimGlobal change factors, such as warming, heatwaves, droughts and land‐use changes, are intensifying fire regimes (defined here as increasing frequency or severity of fires) in many ecosystems worldwide. A large body of local‐scale research has shown that such intensified fire regimes can greatly impact on ecosystem structure and function through altering plant communities. Here, we aim to find general patterns of plant responses to intensified fire regimes across climates, habitats and fire regimes at the global scale. LocationWorldwide. Time periodStudies published 1962–2023. Major taxa studiedWoody plants, herbs and bryophytes. MethodsWe carried out a global systematic review and meta‐analysis of the response of plant abundance, diversity and fitness to increased fire frequency or severity. To assess the context dependency of those responses, we tested the effect of the following variables: fire regime component (fire frequency or severity), time since the last fire, fire type (wildfire or prescribed fire), historical fire regime type (surface or crown fire), plant life form (woody plant, herb or bryophyte), habitat type and climate. ResultsIntensified fire regimes reduced overall plant abundance (Hedges'd = −0.24), diversity (d = −0.27), and fitness (d = −0.69). Generally, adverse effects of intensified fire regimes on plants were stronger due to increased severity than frequency, in wildfires compared to prescribed fires, and at shorter times since fire. Adverse effects were also stronger for woody plants than for herbs, and in conifer and mixed forests than in open ecosystems (e.g. grasslands and shrublands). Main conclusionsIntensified fire regimes can substantially alter plant communities in many ecosystems worldwide. Plant responses are influenced by the specific fire regime component that is changing and by the biotic and abiotic conditions.more » « less
-
Abstract Bison have long been considered a keystone species of North American prairies, increasing plant and animal diversity through a number of unique behaviors. One such behavior is wallowing, in which the repeated rolling of bison in the same spot leads to the formation of small, shallow, oval depressions called wallows. The objective of this study was to characterize spatial and physical attributes of bison wallows at the Konza Prairie Biological Station, a tallgrass prairie preserve in northeastern Kansas. We used aerial imagery from two different years (2011 and 2019) to assess the abundance and spatial distribution of these wallows in relation to fire frequency, elevation, and slope. We also recorded physical characteristics (2020) for a randomly selected subset of wallows and analyzed these data in relation to the same landscape features. Results from the analysis of the aerial images indicated that wallows were more abundant in areas characterized by combinations of more frequent burning, higher elevations, and little or no slope. In the 2020 physical measurements, we found that wallows were smaller in areas burned more often and shallower at higher elevations, particularly when located on grazing lawns. Terrestrial plants were found in approximately 72.1% of the wallows that were physically sampled, and their prevalence increased with increasing slope. We found some quantity of aquatic plants in approximately 7.1% of the sampled wallows. The probability of finding aquatic vegetation in wallows was higher on grazing lawns and in areas burned less frequently, particularly every 20 years. This study enhances the understanding of the distribution of wallows and their physical characteristics as a type of disturbance that could alter relationships within grassland communities.more » « less
