“Divergent responses of butterflies and bees to burning and grazing management in tallgrass prairies” #grassland #rxfire #pollinators @julia_leone @usgs

“Divergent responses of butterflies and bees to burning and grazing management in tallgrass prairies”

This open access article was published Dec. 4, 2022, in the journal Ecology and Evolution. Access the article via the permanent web address (DOI) (https://doi.org/10.1002/ece3.9532)

Abstract

Butterflies and bees contribute significantly to grassland biodiversity and play important roles as pollinators and herbivores. Grassland conservation and management must be seen through the lens of insect conservation and management if these species are to thrive. In North America, grasslands are a product of climate and natural disturbances such as fire and grazing. These natural disturbances have changed considerably since European colonization and subsequent landscape fragmentation.

The aim of this study was to better understand the impacts of fire and grazing management on butterfly and bee communities in tallgrass prairie, enabling land managers and conservationists to better protect and manage remnant prairie. We examined butterfly and bee abundance, species richness, and diversity in Minnesota tallgrass prairies managed by grazing or fire. In 2016 and 2017, we surveyed butterflies, bees, vegetation, and surrounding land use at 20 remnant prairies (10 burned and 10 grazed) with known management histories.

Butterfly and bee abundance at our study sites were significantly negatively correlated. Butterfly abundance, but not species richness, was higher in burned than grazed prairies, and prairie-associated grass-feeding butterflies were more abundant at sites with higher plant species richness. Bee abundance was unrelated to management type but was higher at sites with sandier soils; bee species richness was positively associated with forb frequency.

These findings highlight the challenges of designing management plans tailored to wide groups of pollinators and the potential pitfalls of using one group of pollinators as indicators for another. They also point to the importance of a mosaic of management practices across the prairie landscape.

Keywords: grassland insect conservation; grassland management; ground-nesting bees; pollinator conservation; prairie butterflies; prescribed fire

Citation

Leone, Julia. B., Nora P. Pennarola, Jennifer L. Larson, Karen Oberhauser, and Diane L. Larson. “Divergent responses of butterflies and bees to burning and grazing management in tallgrass prairies.” Ecology and Evolution, 12, e9532 (2022).

“An Assessment of Prairie Management Practices for Maintaining Habitat Quality for the Endangered Poweshiek Skipperling Butterfly in Canada” #rxfire #pollinators @J_Henault @NCC_CNC

“An Assessment of Prairie Management Practices for Maintaining Habitat Quality for the Endangered Poweshiek Skipperling Butterfly in Canada”

This article was published in August 2022 in the journal The American Midland Naturalist. Access the article via the permanent web address (DOI) (https://doi.org/10.1674/0003-0031-188.1.74)

Abstract

The Poweshiek skipperling (Oarisma poweshiek) was once a common prairie butterfly in central North America, but is now critically endangered in Canada and the United States. The Poweshiek skipperling is confined to the largest remaining tall grass prairie in Canada, which is currently managed using grazing and fire to maintain prairie habitat and prevent forest and shrub encroachment. To support re-introduction, restocking, and recovery of this critically endangered species, it is necessary to understand the habitat conditions preferred by skipperlings. By surveying prairie sites with Poweshiek skipperling across age and treatment categories (1–2 y since burn, 4–6 y since burn, >15 y since burn, and grazing), we identified commonly-used nectar plants and recorded physical variables known to influence plant diversity. We measured soil variables, including macronutrients, compaction, pH, texture, and moisture content, and used multivariate statistics to test for significant differences in site characteristics and plant community across treatments. For each site, we captured plant diversity, abundance, and cover, as well as total plant biomass. We found the oldest burn sites had the fewest skipperlings. Intermediate burn sites and lightly grazed sites contained the most skipperlings. In 95% of nectaring observations, adult skipperlings were feeding on Black-eyed Susan (Rudbeckia hirta), upland white aster (Solidago ptarmicoides), and Self-heal (Prunella vulgaris). Characteristics in the physical components of sites and plant communities did not significantly differ across treatment types for most variables with the exception of the oldest burns, which showed significantly higher levels of soil compaction, live biomass, bare ground, less flowering species during the flight period, less flowering stems, and increased presence of nonnative and invasive species. Poweshiek skipperling is at high risk of imminent extirpation, and we recommend that the management regimes be adjusted to plan for a consistent supply of habitat conditions and plant species composition exemplified by our intermediate burn sites. We suggest fire return intervals of 4–6 y using patch burns in combination with grazing, permitted at times that minimize the impact on immature stages of Poweshiek skipperling. This management is needed to provide suitable habitat conditions to maintain the current population and allow for successful restocking and recovery.

Citation:

Dupont-Morozoff, Jaimée, Richard Westwood, and Justis Henault. "An Assessment of Prairie Management Practices for Maintaining Habitat Quality for the Endangered Poweshiek Skipperling Butterfly in Canada." The American Midland Naturalist 188, no. 1 (2022): 74-101.

“The Impact of Fire on Nectar Quality and Quantity for Insect Pollinator Communities” #rxfire #pollinators #grassland @emilygeest

“The Impact of Fire on Nectar Quality and Quantity for Insect Pollinator Communities”

This article was published April 2022 in the journal The American Midland Naturalist.

Access the article through the permanent web address (DOI) (https://doi.org/10.1674/0003-0031-187.2.268)

Abstract

Grassland insect pollinators have undergone population declines due to habitat loss and degradation. Patch-burning is a management method used to reduce woody plant encroachment and maintain grassland habitats. However, the impacts of fire on the quality and quantity of floral resources (nectar volume, total sugar, and sucrose concentration) available to insect pollinators are understudied. Evaluating how time since last fire and season of fire impact nectar quality and quantity is vital to understanding the overall impact of fire on insect pollinator communities. For this study, 10 flowering forb species (Asclepias viridis, Baptisia alba, Cirsium undulatum, Desmodium canadense, Monarda citriodora, Monarda fistulosa, Oenothera speciosa, Penstemon tubaeflorus, Ruellia humilis, Spiranthes cernua) were selected in The Nature Conservancy's Joseph H. William's Tallgrass Prairie Preserve in an area managed with patch-burning and cattle grazing. Study sites were burned in spring 2018, summer 2018, summer 2019, and spring 2020, with three replicates of each treatment (for 12 total burn units). In each unit, we collected nectar from flowering individuals of each plant species with microcapillary tubes to measure standing crop or the nectar in flowers at any given time that is available to insect pollinators. Total volume of nectar and sucrose concentration were recorded, and total mg of sugar was calculated. Desmodium canadense flowering individuals were only located in units burned the previous spring, whereas P. tubaeflorus flowering individuals were only located in units burned the previous summer. For the eight remaining species, total volume of nectar, total mg of sugar, and sucrose concentration varied with different burn regimens for different species. Cirsium undulatum inflorescences with crab spiders (Thomisidae) had higher volumes of nectar and higher amounts of sugar available. This study highlights how a patch-burn approach with different fire return intervals may benefit insect pollinators at the community level by providing a wide range of nectar qualities and quantities to support insect pollinators with different nutritional needs.

Citation

Geest, Emily A., and Kristen A. Baum. "The Impact of Fire on Nectar Quality and Quantity for Insect Pollinator Communities." The American Midland Naturalist 187, no. 2 (2022): 268-278.

“Effects of patch-burn grazing and rotational grazing on grassland bird abundance, species richness, and diversity in native grassland pastures of the Midsouth” USA #rxfire #grassland #birds

“Effects of patch-burn grazing and rotational grazing on grassland bird abundance, species richness, and diversity in native grassland pastures of the Midsouth USA”

This article was published February 2022 in the journal Agriculture, Ecosystems, and the Environment. Access the article through the permanent web address (DOI) https://doi.org/10.1016/j.agee.2021.107710

Abstract

Declines in native warm season grasslands have been linked to grassland bird population decline due to habitat loss including conversion to non-native grasses. Rotational grazing (ROT) and patch-burn grazing (PBG) are two possible tools to restore native warm-season grasses (NWSG) on working-lands in the Mid-South USA and thus aid in the recovery of grassland bird populations. This project compares ROT, PBG, and before treatment implementation to assess their effects on grassland-associated bird species. At three research sites between KY and TN, 14–10 ha NWSG pastures were established and randomly assigned 7 pastures each to ROT and PBG treatment and monitored avian relative abundance during the breeding season from 2014 to 2017. Avian call count data and vegetation characteristics were collected in 2014 and treated as a before treatment year. Following 2014, ROT and PBG treatments were implemented across each respective research site. We used the open N-mixture model framework to estimate avian relative abundance related to year, treatments, research site, and landscape and within-field variables. Avian species richness and diversity were calculated for each treatment, research site, and year. Landscape variables, within-field variables, and research sites exerted more influence on relative abundance than ROT or PBG. Grassland-associated bird species relative abundance and species richness/diversity were affected by habitat disturbances (both ROT and PBG) but varied by species and site. Field sparrows [Spizella pusilla] had the highest increase in relative abundance (9.68 ± 1.24 birds/point count location or 1.77 ha) while northern cardinals [Cardinalis cardinalis] exhibited a significant decrease in relative abundance (3.44 ± 1.54 birds/point count location) following treatment implementation on specific research sites. Species diversity and richness did not differ between ROT and PBG treatments. However, a site and year difference were observed for both estimates. Using ROT and/or PBG to create habitat disturbances can alter within-field variables (i.e., vegetation height) which, taken into context with landscape variables, could impact grassland bird populations and diversity depending on grassland bird species habitat requirements. Our research provided the baseline information for ROT and PBG impacts on grassland birds in the east/southeastern USA. However, we believe future research should focus on breeding and annual fecundity to better understand how populations will change over time and how working lands conservation might aid this conservation effort without a reduction in livestock productivity.

Keywords: Patch-burn grazing; Rotational grazing; Grassland; Birds; Conservation; Prescribed burning; Native warm-season grasses

Citation

Lituma, Christopher M., Byron R. Buckley, Patrick D. Keyser, Elizabeth Holcomb, Ray Smith, John Morgan, and Roger D. Applegate. "Effects of patch-burn grazing and rotational grazing on grassland bird abundance, species richness, and diversity in native grassland pastures of the Midsouth USA." Agriculture, Ecosystems & Environment 324 (2022): 107710.

“Silvicultural options for open forest management in eastern North America” #rxfire #oak @usfs_nrs @usfs_rmrs

“Silvicultural options for open forest management in eastern North America”

This article was published October 15, 2020 in the journal Forest Ecology and Management.

The complete article can be accessed for free through the US Forest Service Treesearch database - https://www.fs.usda.gov/research/treesearch/60466.

Highlights

•Open forests differ from closed forests, and should be managed differently.
•Open forest silviculture focuses more on groundflora management than trees.
•Most traditional silvicultural tools can be used to manage open forests.
•Open forest silviculture is not intended to optimize yield or tree recruitment.

Abstract

Fire-sustained open oak and pine forests were once widespread across eastern North America, but are now comparatively scarce. To regain the goods and services of these open forests, managers are increasingly looking to restore them with the silvicultural systems and tools best suited to meet their objectives. Hence, we synthesized a number of research efforts and case studies from open pine, mixedwood, and oak-dominated forests in eastern North America to demonstrate the silvicultural options available and recognized knowledge gaps. The silvicultural treatment options and tools available are very similar to those applied in closed-canopy forests, even if the objectives are fundamentally different. For instance, while conventional practices in naturally regenerated forests concentrate on managing closed tree canopies to increase periodic yields and encourage new tree recruitment, open forest silviculture focuses on the maintenance of a vertically simple and understocked canopy to facilitate a robust herbaceous groundflora and limit woody plant regeneration. To achieve and sustain this understocked condition, open forest management applies multiple tools (e.g., prescribed fire, periodic harvests or deadenings, and herbicide use and planting if and when needed) along with other understory enhancement and maintenance treatments. This review demonstrates that while we have learned much about open forest silviculture over the decades, many information gaps and challenges for managers remain.

Keywords: Southern pine; Prescribed fire; Ground flora; Oak; Timber management; Restoration; Wildlife management

Citation

Bragg, Don C., Brice B. Hanberry, Todd F. Hutchinson, Steven B. Jack, and John M. Kabrick. "Silvicultural options for open forest management in eastern North America." Forest Ecology and Management 474 (2020): 118383.

“Fire in Eastern Oaks – A Primer” #oak #rxfire @oakfirescience @usfs_nrs @dendroguy

“Fire in Eastern Oaks – A Primer”

This General Technical Review was published in June 2022. This publication can be accessed for free through the USDA Treesearch database (https://www.fs.usda.gov/treesearch/pubs/64520)

Abstract

This publication provides an introduction to the concepts that are important to understanding fire in the ecology and management of oak forests in the eastern United States. Fire historically was common in eastern oak forests and woodlands but perceptions of fire changed and suppression became the norm. Research has demonstrated how fire-maintained woodlands and savannas are occupied by plant and wildlife species that require more open conditions than that in closed-canopy forests. Fire is essential to maintaining oak forests. In addition to favoring oaks, fire creates an environment that allows regeneration of other tree species and stimulates germination of a diverse assemblage of herbaceous plants in the understory.

Keywords: prescribed fire; oak management; wildfire; forest community

Citation

Stambaugh, Michael C.; Dey, Daniel C.; Marschall, Joseph M.; Harper, Craig A. 2022. Fire in eastern oak forests - a primer. NRS-INF-39-22. Madison, WI: U.S. Department of Agriculture, Forest Service, Northern Research Station. 15 p. https://doi.org/10.2737/NRS-INF-39-22.

Pre-print “Intentions of Landowners in South-central USA towards Active Management of Ecosystem for Deer Habitat Management”

“Intentions of Landowners in South-central USA towards Active Management of Ecosystem for Deer Habitat Management”

This pre-print was submitted to the journal Environmental Management in October 2022. Access the pre-print through the permanent web address (DOI) (https://doi.org/10.21203/rs.3.rs-2170264/v1)

Abstract

Active management such as prescribed fire and thinning can restore the savanna and prairie ecosystem to maintain a full suite of ecosystem services and creates a suitable habitat for wildlife such as white-tailed deer (Odocoileus virginianus). Active management, however, comes with the cost of management and acceptance of management tools. The south-central transitional ecoregion is increasing in woody plant dominance due to the exclusion of fire and other anthropogenic factors which otherwise was a mixture of forest, savanna, and tallgrass prairie. Deer hunting is a vital source of revenue generation to offset the landowner’s management cost in the region. We studied Oklahoma landowners’ perceptions regarding active and sustainable management of forest and rangeland for deer habitat using two established theories of reasoned action and planned behavior as well as expanded theories adding moral norms. We analyzed mailed survey data using structural equation modeling. We found that subjective norms and perceived behavior control significantly affected deer hunting intention when moral norms were introduced into the model. Attitudes independently significantly affected intentions of deer hunting but have negative relations with the intentions. The study suggested that landowners have positive social pressure and were interested in active management but associated financial burden and risk could be shaping negative attitudes.

Keywords: Theory of Planned Behavior; Theory of Reasoned Action; Moral Norms; Prescribed Fire; White-tailed Deer (Odocoileus virginianus)

"Neighbours consistently influence tree growth and survival in a frequently burned open oak landscape" #rxfire #oak #lter @cedarcreekesr @oakfirescience

"Neighbours consistently influence tree growth and survival in a frequently burned open oak landscape"

This open-access article was published May 18, 2022 in Journal of Ecology.  Access the article through the permanent web address (DOI)  (https://doi.org/10.1111/1365-2745.13906)

Abstract

Successful management of fire-prone woody ecosystems is challenging and requires knowledge of the spatial arrangement of the trees and how the tree distribution patterns influence the nature and consequences of subsequent fires.

In open tree landscapes, trees are often aggregated, and the ability of trees within the clumps to survive fires plays a significant role in determining subsequent landscape dynamics. If positive interactions exist among neighbouring trees, this will help maintain the patterns of clumped trees. However, the tree-aggregated landscape will continue to exist only if the positive neighbour interactions persist consistently over time. In cases where disturbances are episodic, detecting these interactions is only possible through long-term studies.

Data reported here are from a 25-year study involving the annual tree censusing of a large grid-plot in a frequently burned open oak landscape dominated by Quercus macrocarpa and Quercus ellipsoidallis. The results showed that while having neighbours reduced tree growth, neighbours consistently facilitated survival, irrespective as to whether the neighbours were conspecifics or heterospecifics. Trees of all sizes in close proximity to neighbours were considerably more likely to survive fire throughout the study. This neighbour facilitation is likely the result of a reduction of both herbaceous and woody fuel within clumps.

Synthesis.

This is the first study to document consistent neighbour facilitation among trees experiencing repeated stressors over an extended time period. Our findings support the literature documenting positive neighbour effects among plants in stressful and highly disturbed environments, in accordance with the stress-gradient hypothesis. While aggregated tree regeneration is typically viewed as the primary cause for the development of tree clumps in fire-prone ecosystems, our study showed that aggregated tree survival, by itself, can also be an important driver of post-fire tree clumping. Our results support the growing literature emphasizing the importance of landscape heterogeneity as a driver of resilience in fire-prone tree ecosystems, and the value of maintaining or creating this heterogeneity during forest management.

Citation

Davis, M. A., & Condit, R. (2022). Neighbours consistently influence tree growth and survival in a frequently burned open oak landscape. Journal of Ecology, 110, 1802– 1812.

“Delayed Tree Mortality After Prescribed Fires in Mixed Oak Forests in Northwestern Ohio” #rxfire #savanna #oak @oakopenings @mymetroparks @foresters

“Delayed Tree Mortality After Prescribed Fires in Mixed Oak Forests in Northwestern Ohio”

This open access article was published July 5, 2021 in the journal Forest Science. Access the article through the permanent web address (DOI) (https://doi.org/10.1093/forsci/fxab022)

Abstract

Delayed tree mortality can contribute to variability in fire effects in forests, but its prevalence is not well understood in eastern North American oak forests where a management goal is using prescribed fire to shape forest density and composition. To assess potential delayed mortality after prescribed fires, we tracked the fates of 690 trees of four species in burned and 542 trees in unburned oak forests in northwestern Ohio, USA, and modeled survival using tree diameter and bole char.

Delayed mortality, occurring 3–4 growing seasons after fire and in addition to initial mortality (1–2 growing seasons after fire), varied with species and tree diameter. Compared to initial mortality, delayed mortality resulted in eleven times more small-diameter (1–13 cm) red maple (Acer rubrum) dying after fire. White oak (Quercus alba), 1–25 cm in diameter, also incurred delayed mortality (five-times increase in dead trees). Neither sassafras (Sassafras albidum) nor black oak (Quercus velutina) displayed delayed mortality. Background tree mortality in unburned sites was minimal (0.4% per year across species). Logistic regression to model canopy survival selected only stem diameter for burned red maple trees, whereas both diameter and bole char related to survival in other species.

Results suggest that (1) monitoring postfire tree mortality in oak forests should extend for at least four growing seasons to detect delayed mortality in some species, and that (2) single surface fires may eventually reduce encroaching red maple in oak forests more than initial postfire years indicate.

Keywords: Acer rubrum; burns; hardwoods; Sassafras albidum; Quercus alba; Quercus velutina; survival models

Citation

Abella, Scott R., LaRae A. Sprow, and Timothy A. Schetter. "Delayed Tree Mortality After Prescribed Fires in Mixed Oak Forests in Northwestern Ohio." Forest Science 67, no. 4 (2021): 412-418.

A Brief Update and Overview of the New Science Blog #FireEcology #RxFire

The "New Science Blog" exists to increase the rate at which relevant science is shared with practitioners and researchers in the Upper Midwest.

Curating the blog:

The blog is curated to meet our major goal of sharing applied science with practitioners.

Papers shared via the blog are selected for their potential relevance to fire practitioners, land managers, ecologists, researchers, and policy makers in the region.

Your feedback about whether we were too narrow or too broad with our first selections will help us modify how we determine which papers to share.

How we find new publications:

The primary way we find new publications is through Google Scholar. Google Scholar alerts notify us when new fire science publications have been published for the tallgrass prairie and oak savanna ecosystems; for example, Google Scholar alerts notify us of papers that include both the phrase "tallgrass prairie" and "fire."

You can easily create your own advanced searches and get updates in your inbox using the "Create alert" icon at the bottom of the left-hand menu on Google Scholar (scholar.google.com).

Other common ways we hear about new publications are through pre-publication presentations at conferences, updates on Twitter, and directly from authors.

The types of publications we tend to share:

Readers can expect to see an emphasis on papers that compare restoration and management techniques that incorporate prescribed fire (for example, research published in Restoration Ecology, Ecological Restoration, Fire Ecology, Conservation Biology, Ecosphere). Studies of fire effects on taxa and other natural history papers also provide valuable information to land stewards and wildlife biologists (journals such as American Midland Naturalist [RIP], Natural Areas Journal, and Biodiversity Conservation).

We will also share papers that provide examples of fire ecology research methods that can be applied to management challenges in the TPOS region even if the study was not conducted here.

Some or our readers have interest in papers that share interesting perspectives on fire ecology, wildfire, and prescribed fire, whether or not the information can be directly applied. You can expect to see about 5-10 percent of posts here sharing new peer-reviewed papers that address national policy, issues that affect public opinion about prescribed fire (like smoke), and fire science that is otherwise nationally or internationally notable.

There are multiple options to follow the New Science Blog:

There are a couple of ways to access the New Science Blog.

The blog is linked to the "Just New Papers" Twitter account (@strictlyfiresci), which posts automatically as this blog is updated. [If you're reading this, chances are you came here via Twitter.]

As information technology scholars have long noted, one weakness of Twitter is that  "not every user may have something worthwhile to tweet" (Information Systems: A Manager’s Guide to Harnessing Technology, 2010). While the future of Twitter has become more precarious at approximately the same time this blog has been ramping up, there are other ways recieve updates from the New Science blog.

An alternative way is to subscribe via RSS, a tool familiar to Gen X and Elder Millennials. Believe it or not, there are still some ways to do this, but it's now a niche technology. IYKYK - http://www.tposfirescience.org/new-science/rss.xml

The third way, and the simplest for those who aren't interested in Twitter, is to watch for research round ups in the TPOS newsletter (join here).

References

"Twitter and the Rise of Microblogging," in Information Systems: A Manager’s Guide to Harnessing Technology, 2011, https://open.lib.umn.edu/informationsystems/chapter/7-5-twitter-and-the-rise-of-microblogging/. Accessed Nov. 8, 2022.