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The Effect of Prescribed Fire and Deer Browsing on an Oakhickory Woodland of West-Central Illinois at the Alice L. Kibbe Field Station
Başlık:
The Effect of Prescribed Fire and Deer Browsing on an Oakhickory Woodland of West-Central Illinois at the Alice L. Kibbe Field Station
Yazar:
Rechkemmer, Will T., author.
ISBN:
9780438080928
Yazar Ek Girişi:
Fiziksel Tanımlama:
1 electronic resource (99 pages)
Genel Not:
Source: Masters Abstracts International, Volume: 57-06M(E).
Advisors: Sean E. Jenkins Committee members: James T. Lamer; Susan T. Meiers; Benjamin R. Wodika.
Özet:
Oak (Quercus L.) woodland and savanna complexes were the dominant ecosystems across much of eastern North America at European settlement. Native Americans burned oak ecosystems to promote forage for game and manipulate hunting grounds for thousands of years. Concomitantly, Native American fire use had significant effects on vegetation structure. Land use in the late 1800s and early 1900s has led Midwestern oak woodlands and savannas to be listed as critically endangered ecosystems. Oak and hickory ( Carya Nutt.) have several morphological and physiological adaptations that increase their fire tolerance, which has led to the widespread use of prescribed fire for restoration purposes. Additionally, White-tailed deer (Odocoileus virginiana Zimmerman) are a keystone herbivore and have been implicated as a limiting factor to oak regeneration.
I investigated the effects of prescribed fire and deer browsing at the Alice L. Kibbe Field Station in West-central Illinois. I used a randomly stratified design with four treatments: Unburned-Control (UC), Unburned-Exclosed (UE), Burned-Control (BC), and Burned-Exclosed (BE). We established 40 plots in 2013 (n = 10 per treatment). I sampled overstory and sapling metrics within 300 m2 plots and total seedling counts and ground flora within nested 100 m2 and 1 m2 plots using modified Daubenmire cover classes. Each plot was sampled consecutively from 2013--2017. Prescribed fires were conducted in April 2014 and 2017. I used mixed effect models to evaluate the effects of prescribed fire on overstory, sapling, and resprouting variables. For ground flora and seedlings I used mixed effect models to determine how exclosure and prescribed fire affected functional groups.
I found that prescribed fire reduced woodland structure by decreasing density of overstory ironwoods, total saplings and understory tree saplings. Oak and hickory resprouts made up a significant portion of resprouts (27%), but were uncommon as dead seedlings or saplings (5%), while mesic seedlings were more commonly top killed (25% of dead stems in 2017) than as resprouts (1% in 2017). The ground flora response was mainly directed by prescribed fire. Species richness and diversity increased after fire. Annuals, grasses, and sedge cover increased after fire, while shrub and vine cover decreased. Offsite hardwoods tended to have higher densities on exclosure units while old field species increased on unburned exclosure plots. My results demonstrate periodic, low intensity prescribed fire can be used for a number of woodland management goals. Prescribed fire reduced woodland structure while increasing diversity and cover of ground flora. Deer browsing may be having minimal effects on the ground layer at this site. Based on my results, primary objectives of managers in west-central Illinois should focus on restoring prescribed fire to these systems with less emphasis on herbivore management. If immediate increases in species diversity and hardwood regeneration are primary objectives, I recommend a combination of selective thinning and burning to increase light levels and reduce overstory structure that will favor heliophytic species. CHAPTER II: SPRING FLORA IN AN OAK-HICKORY WOODLAND OF WEST-CENTRAL ILLINOIS: EFFECTS OF LANDSCAPE POSITION, PRESCRIBED FIRE, AND WHITE-TAILED DEER BROWSING Prescribed fire use has increased and studies of its effects on woodland and grassland communities are widespread. Similarly, a growing body of literature exists on white-tailed deer browsing effects on spring flora and woodland communities. However, there is a paucity of literature on the combined effects of prescribed fire and white-tailed deer browsing on spring flora. I surveyed spring ephemeral flora in an oak-hickory woodland of West-central Illinois on previously established 1 m2 plots with four treatments: burned/exclosed, burned/not exclosed, unburned/exclosed, and unburned/not exclosed (n = 50 per treatment). I found that species richness, evenness, and diversity were higher on north facing slopes (P ? 0.002) and at lower slope positions (P ? 0.04). Dutchman's breeches cover was highest on north facing low slopes (P ? 0.04), while cover of wild blue phlox was marginally higher on exclosure plots (P = 0.10). Three species were indicators of north facing slopes (dutchman's breeches, violets, and cutleaf toothwort; P ? 0.003) while two species were indicators of south facing slopes (false rue anemone and violet wood sorrel; P ? 0.047). Spring beauty was associated (P = 0.009) with unburned exclosure plots suggesting deer may be having an impact on its cover. Overall, my research demonstrates that abiotic site factors may have more influence on spring flora than prescribed fire or deer herbivory at this site. Understanding the effects of environmental factors, along with management techniques and herbivory on spring flora contributes a greater understanding of management and ecology in oak-hickory woodlands, and can provide better insight to natural resource managers in the future. CHAPTER III: PAST LAND USE AFFECTS OAK REGENERATION AND MESOPHICATION OF AN OAK WOODLAND IN WEST-CENTRAL ILLINOIS Oak forests dominate eastern North America; however oak decline has been documented by numerous researchers, leading oak woodlands and savannas to be listed as critically endangered ecosystems. Oak woodland and savanna systems were maintained by periodic fire and grazing, however have become dense, closed canopied forests due to logging and fire suppression in the early 1900's. Within these systems, oak regeneration is low, and most regeneration is dominated by mesophytic species. Age structure and past disturbance effects on central Illinois oak woodlands have been understudied; therefore I conducted an age structure study of an oak woodland in West-central Illinois, by coring 750 individual trees, representing 20 species. I found that woodland composition prior to 1900 was dominated by post oak, shagbark hickory, and white oak. During this period, the study area was likely cattle pasture and after cattle grazing ceased in 1932, white oak, black oak, northern red oak, and white ash had peak recruitment, followed by a slow influx of mesophytic trees. Additionally, mesophytic tree recruitment showed stronger correlation to climate as compared with xerophytic hardwoods. My results support the disturbance reliance of oak woodland systems, and the necessity for intermittent periods without disturbance to promote regeneration. Without periodic disturbance, future oak woodlands may become dominated by mesophytic species, with oaks as a minor component.
Notlar:
School code: 6012
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Yer Numarası | Demirbaş Numarası | Shelf Location | Lokasyon / Statüsü / İade Tarihi |
---|---|---|---|
XX(692878.1) | 692878-1001 | Proquest E-Tez Koleksiyonu | Arıyor... |
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