Influence of weather at time of pollination on acorn production of Quercus alba and Quercus velutina

1999 ◽  
Vol 29 (12) ◽  
pp. 1817-1823 ◽  
Author(s):  
Robert A Cecich ◽  
Neal H Sullivan

Pistillate flower development and acorn production were observed in small populations of white oak (Quercus alba L.) and black oak (Quercus velutina Lam.) in central Missouri from 1990 to 1997. There were significant year-year differences in the size of flower crops for both species and significant tree-tree differences in black oak. About 7% of the white oak flowers matured into acorns; most flowers aborted by early July, just after fertilization. About 12% of the black oak flowers matured into acorns, but some individual trees never or rarely produced a mature acorn. The number of fertilized flowers in white oak and black oak in early July was positively correlated with acorn production. Over all trees and years, the number of flowers and acorns were significantly correlated. Acorn production varied in relation to weather variables during the time of pollination. Simple regression models were good predictors of white oak acorn production but not of black oak acorn production. Maximum temperature and the number of days with hail had negative effects on acorn production. The number of days of rain during the pollination period was positively correlated with flower survival in black oak but not with white oak.

The Condor ◽  
2006 ◽  
Vol 108 (2) ◽  
pp. 377-388 ◽  
Author(s):  
Jeffrey E. Moore ◽  
Robert K. Swihart

Abstract We assessed dietary preference of 14 captive Blue Jays (Cyanocitta cristata) for different food types under different conditions of availability. In four separate feeding trials, we provisioned jays with the following: Trial 1, two nuts each of white oak (Quercus alba), pin oak (Q. palustris), black oak (Q. velutina), northern red oak (Q. rubra), and shagbark hickory (Carya ovata); Trial 2, two small and two large red oak acorns; Trial 3, two germinating and two nongerminating white oak acorns; and Trial 4, one large red oak acorn, one large white oak acorn, and one shagbark hickory nut. We used discrete choice models to describe selection under conditions of changing choice sets. Blue Jays displayed a clear preference for pin oak and strong avoidance of red oak acorns when alternative foods were available. White oak and black oak acorns were selected intermediately. Shagbark hickory nuts were never used. Correlation coefficients suggested that preference was inversely related to seed size and the proportion of seed consisting of hard seed coat. In the absence of alternative food items, small red oak acorns were readily taken, whereas large red oak acorns were mostly avoided but still used by some birds. These results highlight the importance of considering food availability when making conclusions about preference, and lend support to the hypothesis that Blue Jays can be important dispersers of even less-preferred oak species. We discuss the potential as well as the limitations for Blue Jays to act as seed dispersers, with respect to postglacial range expansion of fagaceous tree species, and in the context of present-day dispersal in regions where forests are highly fragmented.


2009 ◽  
Vol 26 (3) ◽  
pp. 122-125 ◽  
Author(s):  
Benjamin A. Sands ◽  
Marc D. Abrams

Abstract In a 2004 clearcut of a former even-aged oak (Quercus) forest, we examined the number and maximum height of stump sprouts for three oak species in east-central Pennsylvania. The greatest number of sprouts was produced by black oak (Quercus velutina) and chestnut oak (Q.montana) as compared with white oak (Q. alba). Logistic regression showed that diameter of stumps was a significant factor in determining the probability of sprouting for black oak, and an inverse relationship between stump diameter and the number of sprouts per stump was foundfor all three species. The number of white oak sprouts peaked in the 10‐20-cm diameter class and declined on larger stumps. The number of black oak sprouts peaked in the 20‐50-cm classes, and trees in the 70‐80-cm class produced the fewest sprouts. The mean annual growthof the tallest sprout on each stump was greater for black oak and chestnut oak than white oak.


2011 ◽  
Vol 41 (12) ◽  
pp. 2359-2374 ◽  
Author(s):  
Patrick H. Brose

Timely development of newly germinated oak (Quercus spp.) seedlings into competitive-sized regeneration is an essential part of the oak regeneration process. The amount of sunlight reaching the forest floor partly governs this development, and foresters often use the shelterwood system to expose oak seedlings to varying degrees of insolation. To further understand the seedling development–sunlight–shelterwood relationships, I conducted a multiyear study at five locations in Pennsylvania. Each location had four stands either uncut or recently treated with one of three shelterwood harvest methods (preparatory cut, first removal cut, or final removal cut) resulting in four different levels of sunlight reaching the forest floor. In each stand, four 32 m2 plots were prepared, and each was planted with 400 acorns of black (Quercus velutina Lam.), chestnut (Quercus montana Willd.), northern red (Quercus rubra L.), or white oak (Quercus alba L.) and protected from wildlife. Germination success was universally high and for the next 8 years, I monitored seedling survival and measured seedling growth. The final and first removal cut treatments had higher seedling survival than the preparatory cut and uncut treatments. Oak seedling growth was positively related to sunlight availability; seedlings in the final removal cut grew the most, followed in descending order by those in the first removal cut, preparatory cut, and uncut treatments. These findings provide insight into the subtleties of regenerating oak forests with the shelterwood system.


2019 ◽  
Vol 66 (3) ◽  
pp. 371-381 ◽  
Author(s):  
Zachary J Hackworth ◽  
John M Lhotka ◽  
Jeffrey W Stringer

Abstract This study examined the influence of midstory removal applied 9 years prior to a shelterwood establishment cut on survival, growth, and competitive status of black oak (Quercus velutina Lam.), white oak (Quercus alba L.), and an oak competitor, red maple (Acer rubrum L.), immediately before and at 6 years following shelterwood cutting on intermediate productivity sites in the Central Hardwood Forest Region. We also examined height and density distributions of the regenerating cohort to quantify seedling establishment and to elucidate relative oak competitiveness at each time period. Although oak seedlings were taller 9 years after midstory removal than in undisturbed controls, the midstory removal treatment reduced the frequency of free-to-grow oaks (relative to understory competitors) and increased the size of red maple and relative density of large competitors. Height growth of all three species following establishment cutting was increased by prior midstory removal and dependent on seedling competitive position immediately before shelterwood establishment. Additionally, we observed increased seedling densities 6 years following shelterwood establishment cutting and greater white oak seedling establishment when midstory removal preceded the shelterwood treatment.


2012 ◽  
Vol 30 (1) ◽  
pp. 23-27
Author(s):  
J. Roger Harris ◽  
Lisa E. Richardson-Calfee

Growth rates of nursery-grown oaks (Quercus L.) vary considerably, and many oak species are not commonly grown because of slow growth when young. A method for rapid screening of young oak seedlings to predict potential growth in a production nursery was investigated. Acorns from single maternal trees of four Virginia-native oak species, Quercus montana Wild. (chestnut oak), Quercus palustris Münchh. (pin oak), Quercus velutina Lam. (black oak), and Quercus alba L. (white oak) were collected in Blacksburg, VA, in the fall of 1999 and subjected to stratification (moist-chilling) at 5C (41F). Single acorns were then planted in individual cells of 50-cell liner trays and grown in a heated greenhouse until individual seedlings had set first buds. Height at first budset was recorded for individual seedlings. Trees were then transplanted into 3.8 liter (#1) black plastic containers and grown outdoors in Blacksburg, VA, until June 2001, when they were transplanted to field soil. All trees were grown in the ground for three additional growing seasons, and final trunk diameters were measured in February 2004. Height at first budset was not related to trunk diameter at the end of the experiment for any species and was only weakly related to final height for black oak. Trunk diameter of seedlings when planted in field beds 1.5 years from seed was related to trunk diameter at the end of the experiment for all species, but little variation was explained by the relationship for chestnut oak or black oak. Plant height at field planting was not as predictive as trunk diameter for final trunk diameter, except for black oak. The utility of screening a group of oak seedlings at the liner stage for subsequent growth potential is species-specific. Screening white oak by trunk diameter appears especially promising.


Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Rachel E. Nation ◽  
Heather D. Alexander ◽  
Geoff Denny ◽  
Jennifer K. McDaniel ◽  
Alison K. Paulson

Abstract Background Prescribed fire is increasingly used to restore and maintain upland oak (Quercus L. spp.) ecosystems in the central and eastern US. However, little is known about how prescribed fire affects recently fallen acorns under different fine fuel loads, which can vary with stand composition and basal area, burn season, and fire frequency. We conducted plot-level (1 m2) burns in an upland oak stand in northern Mississippi, USA, during December 2018, using single (i.e., ambient), double, and triple fine fuel loads, representative of those in nearby unburned and recently fire-treated, closed-canopy stands. Pre burn, we placed 30 acorns each of white oak (Quercus alba L.) and Shumard oak (Quercus shumardii Buckley) ~1 cm below the litter surface in five plots of each fuel treatment. Immediately post burn, we planted unburned and burned acorns in a greenhouse. After ~50% of each species’ unburned acorns germinated, we measured percent germination and height, basal diameter, and leaf number of germinating seedlings weekly for 11 weeks. Then, we harvested seedlings to determine above- and belowground biomass. Results The single fuel treatment reduced acorn germination rates of both species to ~40% compared to ~88% in unburned acorns. When burned in double and triple fuel loads, acorns of both species had a <5% germination rate. There was no difference in basal diameter, leaf number, or biomass of seedlings from burned versus unburned acorns for either species. However, seedlings originating from burned acorns of both species were ~11% shorter than those from unburned acorns. Thus, both species responded similarly to fuel load treatments. Conclusions Acorns of both species exhibited greater survival with lower fine fuel loads, and consequently lower percent fuel consumption. Acorns germinating post fire generally produced seedlings with growth patterns similar to seedlings originating from unburned acorns. These findings indicate that regular, repeated prescribed fires or canopy reductions that limit fine fuel accumulation and create heterogeneous fuel beds are likely to increase acorn germination rates relative to unburned sites or those with recently introduced fire.


1872 ◽  
Vol 4 (7) ◽  
pp. 123-125
Author(s):  
V. T. Chambers
Keyword(s):  

It is necessary for me to correct a serious error into which I have fallen.At page 165, v. 3, I have described a larva mining the upper surface of leaves of the White Oak (Quercus alba), which seemed to me to answer the requirements of Dr. Clemens' Lithocollctis tubiferella, which also mines the leaves of Quercus alba. The larva was not removed from the mine, but viewed through the integument.


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