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

2021 ◽  
Author(s):  
Scott R Abella ◽  
LaRae A Sprow ◽  
Timothy A Schetter

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. Study Implications Delayed tree mortality, a poorly understood phenomenon in eastern North American oak forests, varied with species and stem diameter after prescribed fires in northwestern Ohio oak forests. Accompanied by minimal mortality of large oaks (>25 cm in diameter), single surface fires appear capable of reducing density of encroaching red maple stems, but these reductions may not appear for at least 3–4 growing seasons after fires.

1999 ◽  
Vol 23 (2) ◽  
pp. 88-93 ◽  
Author(s):  
Patrick Brose ◽  
David Van Lear

Abstract A study was initiated in 1994 to evaluate the degree of bole damage and crown decline residual overstory trees would experience because of prescribed burning of shelterwood stands. Three oak-dominated shelterwood stands, partially harvested 2 to 4 yr earlier, were divided into four treatments (unburned control, spring burn, summer burn, and winter burn). Fifteen permanent sampling points were systematically located in each 5 to 12 ac treatment area, and overstory trees were selected from these points with a 10 BAF prism. Before burning, each tree was evaluated for lower bole and crown condition and reevaluated two growing seasons after the fires. Hickory, oak, and yellow-poplar were largely unaffected by the winter and summer prescribed fires but displayed bole damage and crown decline following spring burning. American beech and red maple declined after all fire treatments. Fire damage to oak, hickory, and yellow-poplar was strongly associated to presence of logging slash near a tree's base. Directional felling or moving slash should minimize injury to these trees. This research will aid resource managers wishing to use prescribed fire in shelterwood stands to favor oak regeneration while minimizing damage to residual overstory oaks. South. J. Appl. For. 23(2):88-93.


2001 ◽  
Vol 10 (1) ◽  
pp. 91 ◽  
Author(s):  
David D. Neumann ◽  
Donald I. Dickmann

Beginning in 1991, periodic surface fires (frontal fire intensities <200 kW m–1) were introduced into a mixed red pine (Pinus resinosa Ait.) and white pine (P. strobus L.) plantation (dbh 16–60 cm). Replicated plots of 0.4–0.5 ha were either burned three times at biennial intervals (early May of 1991, 1993, and 1995), burned once (early May 1991), or not burned. Measurements were conducted during the 1994 and 1995 growing seasons. The pine overstory was largely unaffected by the fires. The understory on unburned plots contained 16 111 large seedlings (>1 m, ≤ 1.9 cm dbh) and 3944 saplings (2.0–5.9 cm dbh) per ha, consisting of 23 woody angiosperm taxa. Plots burned once contained 60% of the large seedlings, 7% of the saplings, and 6 fewer taxa than unburned plots. No large seedlings and few saplings were found in plots burned biennially. Cover of low (<1 m) woody and herbaceous vegetation in plots burned once or three times was twice that of unburned plots, even in the growing season immediately following the May 1995 re-burn. Recovery of low vegetative cover in the re-burned plots was rapid, exceeding that in once-burned or unburned plots by late summer following the burn. Species richness of low vegetation was 20–25% higher in burned than unburned plots, except in the year immediately following reburning. Taxa dominating this site following burning were Sassafras albidum (Nutt.) Nees, Rubus spp., Phytolacca americana L., and Dryopteris spinulosa (O.F. MÜll.) Watt. Restoration of low-intensity surface fires to ecosystems dominated by mature red pine or white pine is feasible, but major changes in understory structure and composition will occur.


1980 ◽  
Vol 4 (2) ◽  
pp. 73-76
Author(s):  
S. V. Kossuth ◽  
J. F. Young ◽  
J. E. Voeller ◽  
H. A. Holt

Abstract Eleven hardwood species were treated with seven herbicides during the spring, summer, fall, and winter seasons using a hypo-hatchet injector. Late spring to fall injections were most effective and winter injections least effective. Early spring injection tended to allow revegetation by outgrowth of lateral buds. Most of the herbicides were effective at the tested concentrations with injections of 1-2 ml/2.5 cm of stem diameter, with the best results from DOWCO 233, Krenite, Tordon 101-R and 2,4-D amine, respectively. Overall control ranged from 81 to 96 percent, depending on herbicide treatment. Multiple clumps of red maple stems were not well controlled by injecting just one stem.


2011 ◽  
Vol 28 (3) ◽  
pp. 161-165 ◽  
Author(s):  
Roger A. Williams ◽  
Yuhua Tao

Abstract A carbon management diagram for use in oak-hickory forests in southern Ohio has been developed to allow easier quantification of total forest carbon stock. The total carbon stock is positively correlated to basal area and average stand diameter but poorly correlated to the number of trees per acre. The total amount of carbon stored in these forests is going to be influenced by age and site quality to the extent that age and site influence basal area and the average tree size. Accordingly, not all stands considered to be fully to overstocked store the most carbon. Rather, it is a combination of basal area and average tree size that determines the total carbon stored, with the carbon stock in the forest increasing with an increase in both basal area and average tree diameter. Examples illustrating the use of the diagram are presented for two oak forests on oak site indexes 60 and 80. Both forests are overstocked at age 100 years, but the forest on site index 60 stores 77 tons/ac of total carbon compared with 103 tons/ac on site index 80.


2003 ◽  
Vol 27 (4) ◽  
pp. 264-268 ◽  
Author(s):  
Eric Heitzman

Abstract Since 1999, widespread and locally severe oak decline and mortality have occurred throughout the Ozark Mountains of northern Arkansas and southern Missouri. A contributing factor in the decline and mortality is an outbreak of the red oak borer [Enaphalodes rufulus (Haldeman) (Coleoptera: Cerambycidae)]. In northern Arkansas, a 2,150 ac mature oak forest severely affected by decline was selected as a case study to describe changes in species composition and stand structure and to assess regeneration potential of oaks and non-oak species. Mortality reduced total overstory basal area from 105 to 57 ft2/ac, and overstory density decreased from 156 to 89 trees/ac. Most dead and dying trees were northern red oak (Quercus rubra L.) and black oak (Q. velutina Lam.). Basal area and density of overstory red oaks were reduced from 51 to 11 ft2/ac and from 60 to 11 trees/ac, respectively. These trees died regardless of dbh class. Mortality was less common in white oak (Q. alba L.) and was generally limited to smaller trees. Understory trees and taller seedlings were predominantly red maple (Acer rubrum L.), flowering dogwood (Cornus florida L.), blackgum (Nyssa sylvatica Marsh.), and black cherry (Prunus serotina Ehrh.). Oaks less than 3 ft tall were abundant, but taller oak seedlings and saplings were uncommon. Tree mortality increased the proportion of white oak and hickories (Carya spp.) in the overstory, and stimulated a regeneration response of mostly non-oak species. South. J. Appl. For. 27(4):264–268.


2020 ◽  
Vol 50 (4) ◽  
pp. 371-379
Author(s):  
Salah Eddine Roula ◽  
Rachid T. Bouhraoua ◽  
Filipe X. Catry

Wildfires may have serious and long-lasting impacts in Mediterranean Basin oak forests. Although cork oak (Quercus suber L.) is usually considered a highly fire-resistant tree species, post-fire recovery is not guaranteed. We assessed the mortality and regeneration of 729 cork oak trees that burned and were cut in six sites with the objective of identifying the main factors affecting the short- to medium-term post-fire recovery. We used linear mixed models to investigate potential relationships among tree stump status at the end of the second and fifth growing seasons and several tree- and site-level variables. Overall tree mortality in the second year was 44% and was negatively affected by bark thickness and positively affected by root exposure, trunk injuries, and diameter, in decreasing order of importance. Between the second and fifth years, mortality increased to 53%, but this increase was only observed in sites with high grazing pressure. Grazing also had a strong negative impact on the growth of basal resprouts, thereby compromising tree recovery. The results give useful information on the need for application of adequate forest management practices (particularly avoiding debarking injuries, soil erosion, and grazing pressure) to increase the resilience of these ecosystems and reduce the negative economic and ecological impacts of wildfires.


1998 ◽  
Vol 28 (3) ◽  
pp. 331-339 ◽  
Author(s):  
Patrick H Brose ◽  
David H Van Lear

Effects of seasonal prescribed fires of varying intensities on density, mortality, stem form, height, and height growth of hardwood advance regeneration were investigated. Three mixed-hardwood stands on productive upland sites were cut using a shelterwood technique, each forming a block of spring burn, summer burn, winter burn, and control treatments. Advance regeneration was inventoried from permanent plots before and after burning. Fires top-killed nearly all hardwood regeneration, forcing the rootstocks to sprout. Fire treatments reduced densities of all hardwood species relative to not burning, with spring and summer fires causing greater density reduction than winter burning. Among species, oak (Quercus spp. L.) and hickory (Carya spp. Nutt.) were more resilient sprouters than yellow-poplar (Liriodendron tulipifera L.) and red maple (Acer rubrum L.), especially as fire intensity increased. All prescribed fires improved oak stem form and stimulated height growth of hickory and oak. Overall, prescribed fires improved oak advance regeneration with spring burning providing the most benefit. This approach of following a shelterwood harvest with prescribed fire may be a viable method of regenerating oak-dominated stands on productive upland sites.


2020 ◽  
Author(s):  
Maria Castellaneta ◽  
Angelo Rita ◽  
J. Julio Camarero ◽  
Michele Colangelo ◽  
Angelo Nolè ◽  
...  

&lt;p&gt;Several die-off episodes related to heat weaves and drought spells have evidenced the high vulnerability of Mediterranean oak forests. These events consisted in the loss in tree vitality and manifested as growths decline, elevated crown transparency (defoliation) and rising tree mortality rate. In this context, the changes in vegetation productivity and canopy greenness may represent valuable proxies to analyze how extreme climatic events trigger forest die-off. Such changes in vegetation status may be analyzed using remote-sensing data, specifically multi-temporal spectral information. For instance, the Normalized Difference Vegetation Index (NDVI) measures changes in vegetation greenness and is a proxy of changes in leaf area index (LAI), forest aboveground biomass and productivity. In this study, we analyzed the temporal patterns of vegetation in three Mediterranean oak forests showing recent die-off in response to the 2017 severe summer drought. For this purpose, we used an open-source platform (Google Earth Engine) to extract collections of MODIS NDVI time-series from 2000 to 2019. The analysis of both NDVI trends and anomalies were used to infer differential patterns of vegetation phenology among sites comparing plots where most trees were declining and showed high defoliation (test) versus plots were most trees were considered healthy (ctrl) and showed low or no defoliation. Here we discuss: i) the likely offset in NDVI time-series between test- versus ctrl- sites; and ii) the impact of summer droughts &amp;#160;on NDVI.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Keywords&lt;/strong&gt;: climate change, forest vulnerability, time series, remote sensing.&lt;/p&gt;


2006 ◽  
Vol 7 (1) ◽  
pp. 25 ◽  
Author(s):  
D. M. Benson ◽  
J. R. Sidebottom ◽  
J. Moody

Fungicides were evaluated for control of Phytophthora root rot for five growing seasons in two field plantings of Fraser fir (Abies fraseri) affected by Phytophthora cinnamomi in western North Carolina. At the first site, which had a fairly well-drained soil, treatment programs with Aliette (5 lb/100 gal, three applications per year), Subdue Maxx (3.7 fl oz/1.15 gal/1000 ft2, two applications per year), and Subdue GR (5.75 lb/1000 ft2, two applications per year) maintained low rates of mortality (< 10%) for three growing seasons, whereas tree mortality in the untreated plots reached 13 and 37% by the second and third growing seasons, respectively. At the second site, which was in a flood plain, disease did not develop during the first 2.5 years, even in untreated control plots. However, mortality increased rapidly following several high-rainfall events, but none of the fungicides had any effect on disease development. Apparently, at least under conditions not overly conducive to the disease, the fungicide treatment programs can delay the onset of high mortality rates caused by P. cinnamomi in Fraser fir for up to three growing seasons. Accepted for publication 23 February 2006. Published 31 March 2006.


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