Forest dynamics at Minnesota's prairie-forest border driven by invasive buckthorn (Rhamnus cathartica) and native bur oak (Quercus macrocarpa)1

2012 ◽  
Vol 139 (3) ◽  
pp. 311-322 ◽  
Author(s):  
Peter H. Wyckoff ◽  
Ruth Greiman ◽  
Anthony Krueger ◽  
Logan Luce
2011 ◽  
Vol 41 (10) ◽  
pp. 1981-1992 ◽  
Author(s):  
Lisa A. Schulte ◽  
Erik C. Mottl ◽  
Brian J. Palik

Oak forests throughout North America are declining due to changes in disturbance regimes that have led to increased competition from other tree and shrub species. We evaluated associations between oak regeneration, the occurrence of two common invasive shrubs (common buckthorn ( Rhamnus cathartica L.) and Tartarian honeysuckle ( Lonicera tatarica L.)), and forest edges in oak forests in a portion of the midwestern United States where bur ( Quercus macrocarpa Michx.), red ( Quercus rubra L.), and white oak ( Quercus alba L.) were historically dominant. We found poor recruitment of oaks in comparison to other, more shade-tolerant tree species. Results further revealed a strong stand-scale association between bur oak, open canopy conditions, high soil nutrient levels, and the presence of common buckthorn and Tartarian honeysuckle; these same site characteristics were disassociated with red and white oak. Within red and white oak stands, however, the presence of the invasive shrubs was more pronounced near forest edges. While oak recruitment is hampered throughout stands, our research suggests that predominant constraints may vary based on soil and light gradients found along forest edges.


Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 739-743 ◽  
Author(s):  
Wayne K. McNeil ◽  
Jimmy F. Stritzke ◽  
Eddie Basler

Seedlings of winged elm (Ulmus dataMichx.), bur oak (Quercus macrocarpaMichx.), black walnut (Juglans nigraL.), eastern redcedar (Juniperus virginianaL.), and loblolly pine (Pinus taedaL.) were treated in nutrient solution with ring-labeled14C-tebuthiuron {N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N′-dimethylurea} or14C-hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione]. Four hours later,14C was detected in all sections of winged elm treated with14C-tebuthiuron and14C-hexazinone. Root absorption of the tebuthiuron label by the other species occurred in the order: loblolly pine > bur oak > black walnut = eastern redcedar. The sequence of14C-hexazinone absorption was: loblolly pine > black walnut ≥ bur oak = eastern redcedar. Foliar accumulation of the tebuthiuron label occurred in the order: bur oak > loblolly pine > eastern redcedar = black walnut, whereas the sequence with hexazinone was loblolly pine > bur oak > black walnut = eastern redcedar. The presence of the three metabolites of hexazinone in loblolly pine suggests that it may be resistant to hexazinone as a result of its ability to degrade hexazinone rather than its ability to limit uptake.


2020 ◽  
Vol 40 (3) ◽  
pp. 377-390 ◽  
Author(s):  
Beth Fallon ◽  
Anna Yang ◽  
Cathleen Lapadat ◽  
Isabella Armour ◽  
Jennifer Juzwik ◽  
...  

Abstract Hyperspectral reflectance tools have been used to detect multiple pathogens in agricultural settings and single sources of infection or broad declines in forest stands. However, differentiation of any one disease from other sources of tree stress is integral for stand and landscape-level applications in mixed species systems. We tested the ability of spectral models to differentiate oak wilt, a fatal disease in oaks caused by Bretziella fagacearum ``Bretz'', from among other mechanisms of decline. We subjected greenhouse-grown oak seedlings (Quercus ellipsoidalis ``E.J. Hill'' and Quercus macrocarpa ``Michx.'') to chronic drought or inoculation with the oak wilt fungus or bur oak blight fungus (Tubakia iowensis ``T.C. Harr. & D. McNew''). We measured leaf and canopy spectroscopic reflectance (400–2400 nm) and instantaneous photosynthetic and stomatal conductance rates, then used partial least-squares discriminant analysis to predict treatment from hyperspectral data. We detected oak wilt before symptom appearance, and classified the disease with high accuracy in symptomatic leaves. Classification accuracy from spectra increased with declines in photosynthetic function in oak wilt-inoculated plants. Wavelengths diagnostic of oak wilt were only found in non-visible spectral regions and are associated with water status, non-structural carbohydrates and photosynthetic mechanisms. We show that hyperspectral models can differentiate oak wilt from other causes of tree decline and that detection is correlated with biological mechanisms of oak wilt infection and disease progression. We also show that within the canopy, symptom heterogeneity can reduce detection, but that symptomatic leaves and tree canopies are suitable for highly accurate diagnosis. Remote application of hyperspectral tools can be used for specific detection of disease across a multi-species forest stand exhibiting multiple stress symptoms.


1951 ◽  
Vol 83 (4) ◽  
pp. 106-106
Author(s):  
Clifford J. Dennis

Apparently, the male of Cyrtolobus griseus Van Duzee (Stud. N.A. Memb. 90.16, 1908) has never been described. The following is a description of a male which is here designated the allotype. This specimen was collected in the University of Wisconsin Arboretum, Madison, July 21, 1950 from bur oak (Quercus macrocarpa Michx.). The allotype is in the author's collection.


1929 ◽  
Vol 61 (6) ◽  
pp. 125-130
Author(s):  
W. V. Balduf

In an earlier volume (I) the writer presented observations on the bionomics of the parasites and inquilines from the galls of Disholcaspis mamma (Walsh) on a bur oak (Quercus macrocarpa) near Urbana, Illinois. Not less than fifteen species of Hymenoptera were then associated with that gall. In the last two years this gall and its several inhabitants were rare or lacking there, but the leaf galls of Neuroterus verrucarum O.S. and N. niger Gillette were abundant on the same tree. The larvae of the latter cynipids are heavily parasitized by a chalcid, Tetrastichus verrucarii Balduf of the family Tetrastichidae. Observations on the habits and stages of the parasite and its hosts are given below. These records incidentally extend the known hymenopterous fauna of the above tree by four or more species.


2019 ◽  
Vol 49 (9) ◽  
pp. 1060-1068
Author(s):  
A. Mosseler ◽  
J.E. Major ◽  
D. McPhee

Ten-year-old bur oak (Quercus macrocarpa Michx.) saplings established on the exposed, infertile, treeless barrens of a former coal mine site in New Brunswick, Canada, were harvested to assess the effects of subsequent coppicing on regrowth parameters and biomass production. Two years after harvesting, coppice height growth exceeded that of the original 10-year-old saplings by 20%. Mean stem numbers were 1.2 and 6.7 for 10-year-old and coppiced trees, respectively. Mean dry mass recovered after 2 years with 214, 112, and 207 g for 10-year-old saplings and the 1- and 2-year-old coppices, respectively. Site quality of the broken shale rock overburden was similar across four of the five sites, with the exception that one site had twice the soil nitrogen (N) at 0.123% than the other four site types, which had an average of 0.064% N. This high N site had 2.3-fold the productivity of the mean for the other four sites. Mean coppice stem height showed the strongest predictive relationship to total coppice dry mass when compared with the greatest stem height, greatest or mean stem basal diameter, or coppice stem number. The most dramatic result of this bur oak coppicing experiment was the rapid recovery of height growth, biomass production, and observable stem quality within coppices over the 2-year period following harvesting of the original, 10-year-old saplings.


2002 ◽  
Vol 58 (2) ◽  
pp. 103-111 ◽  
Author(s):  
Scott St. George ◽  
Erik Nielsen

AbstractA record of estimated annual (prior August to current July) precipitation derived from a regional bur oak (Quercus macrocarpa Michx.) tree-ring chronology indicates that southern Manitoba's hydroclimate has been relatively stable over the last 200 yr. Although this stability was interrupted briefly by pronounced wet intervals in the late A.D. 1820s and 1850s, hydroclimatic conditions since permanent Euro-Canadian settlement were much less variable and persistent than those prior to A.D. 1790. The reconstruction indicates that the Red River basin experienced extremely dry conditions between A.D. 1670 and 1775, with below-normal precipitation occurring approximately 2 years out of 3. Annual precipitation was estimated at more than two standard deviations below the mean during A.D. 1477, 1485, 1556, 1595, 1612, 1644, 1661, 1743, 1900, and 1980. Comparisons with limnological records from North Dakota and Minnesota suggest that multidecadal fluctuations in regional hydroclimate have been remarkably coherent across the northeastern Great Plains during the last 600 yr. However, individual dry years in the Red River basin were usually associated with larger scale drought across much of the North American interior.


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