Black Oak Trees Research Articles

Rise and Fall of an Oak Gall Wasp (Hymenoptera: Cynipidae) Outbreak in Massachusetts.

The recently described oak gall wasp Zapatella davisae Buffington & Melika (Hymenoptera: Cynipidae) has caused extensive damage and mortality to black oak trees, Quercus velutina L. (Fagales: Fagaceae), in coastal parts of New England, United States. Like many newly described and/or newly introduced species, it is unclear how long populations of Z. davisae have existed in this region. However, as this species forms galls on the woody-tissue of its host, it may be possible to obtain historical information about changes in its population size by examining the presence of galls in relation to annual growth nodes. Here, we explore the utility of this approach to determine population size changes in Z. davisae densities on Nantucket, Martha's Vineyard, and Cape Cod, Massachusetts, through dissection of black oak branches. In addition, we calculated parasitism rates during the years of study and obtained morphological and molecular identifications for the parasitoids associated with Z. davisae. Our results show significant changes in population sizes, with higher levels of parasitism at sites on Martha's Vineyard and Cape Cod compared to sites on Nantucket. In addition, morphological examinations, in combination with DNA sequencing, identified the associated parasitoids as five species in the genus Sycophila Walker (Hymenoptera: Eurytomidae). We comment that considerable morphological variation within several of these recovered species was observed, present the first record of males for a species from which only females have been described, and suggest that future work is required to clarify the species boundaries for this important parasitoid group.

Simple method for direct crown base height estimation of individual conifer trees using airborne LiDAR data

Crown base height (CBH) is an essential tree biophysical parameter for many applications in forest management, forest fuel treatment, wildfire modeling, ecosystem modeling and global climate change studies. Accurate and automatic estimation of CBH for individual trees is still a challenging task. Airborne light detection and ranging (LiDAR) provides reliable and promising data for estimating CBH. Various methods have been developed to calculate CBH indirectly using regression-based means from airborne LiDAR data and field measurements. However, little attention has been paid to directly calculate CBH at the individual tree scale in mixed-species forests without field measurements. In this study, we propose a new method for directly estimating individual-tree CBH from airborne LiDAR data. Our method involves two main strategies: 1) removing noise and understory vegetation for each tree; and 2) estimating CBH by generating percentile ranking profile for each tree and using a spline curve to identify its inflection points. These two strategies lend our method the advantages of no requirement of field measurements and being efficient and effective in mixed-species forests. The proposed method was applied to a mixed conifer forest in the Sierra Nevada, California and was validated by field measurements. The results showed that our method can directly estimate CBH at individual tree level with a root-mean-squared error of 1.62 m, a coefficient of determination of 0.88 and a relative bias of 3.36%. Furthermore, we systematically analyzed the accuracies among different height groups and tree species by comparing with field measurements. Our results implied that taller trees had relatively higher uncertainties than shorter trees. Our findings also show that the accuracy for CBH estimation was the highest for black oak trees, with an RMSE of 0.52 m. The conifer species results were also good with uniformly high R2 ranging from 0.82 to 0.93. In general, our method has demonstrated high accuracy for individual tree CBH estimation and strong potential for applications in mixed species over large areas.

Life History and Potential Hosts of Zapatella davisae (Hymenoptera: Cynipidae), a Recent Invader on Black Oak in the Northeastern United States

Abstract Quercus velutina (Black Oak) is a dominant deciduous tree in Cape Cod, Martha's Vineyard, and Nantucket, MA. In recent years, Black Oak trees in these regions have experienced severe canopy loss due to the infestation of a stem-gall wasp, Zapatella davisae. In addition to infestations first documented in the Cape Cod region in 2012, Zapatella davisae has been present in Long Island, NY, since the 1990s. We investigated the life cycle of Z. davisae, specifically emergence patterns and timing of development. We evaluated differences in the severity of the infestations in Long Island and Cape Cod. We also identified towns in Cape Cod that contained Z. davisae infestations to better estimate the geographic extent of the infestation in the region. We found that Zapatella davisae completes 1 generation per year and emerges throughout the month of May. The severity of the infestation was the greatest in Cape Cod, an indication that something is controlling the population in Long Island. We concluded tha...

Yeasts associated with the curculionid beetle Xyloterinus politus: Candida xyloterini sp. nov., Candida palmyrensis sp. nov. and three common ambrosia yeasts

Seven yeast strains were isolated from the body surface and galleries of Xyloterinus politus, the ambrosia beetle that attacks black oak trees. Based on rDNA sequence comparisons and other taxonomic characteristics, five of the strains were identified as members of the species Saccharomycopsis microspora, Wickerhamomyces hampshirensis and Candida mycetangii, which have been reported previously as being associated with insects. The remaining two yeast strains were proposed as representatives of two novel species, Candida xyloterini sp. nov. (type strain ATCC 62898(T)=CBS 11547(T)) and Candida palmyrensis sp. nov. (type strain ATCC 62899(T)=CBS 11546(T)). C. xyloterini sp. nov. is a close sister taxon to Ogataea dorogensis and assimilates methanol as a sole carbon source but lacks ascospores. On the other hand, C. palmyrensis sp. nov. is phylogenetically distinct from any other ambrosia yeast reported so far. The species was placed near Candida sophiae-reginae and Candida beechii based on DNA sequence analyses, but neither of these were close sister taxa to C. palmyrensis sp. nov.

Multispectral and Biogeochemical Evaluation for Possible Smelter and Power Plant Emission Effects on Trees in a Missouri Conservation Area and Illinois Nature Preserve

Stack emission and deposition of heavy metals from industrial sites continues to be an environmental concern, and the effects of it on particular ecosystems need to be further investigated. This has become more practicable with recent advancements in information gathering systems and analysis techniques, like those afforded by remote sensors and GIS. The intent of this research was to determine the utility of Landsat multispectral imagery, biogeochemical sampling of black oak trees, and hyperspectral scanning of leaf reflectance for the purpose of assessing forests at the Magnolia Hollow Conservation Area in Missouri and the Fults Hill Nature Preserve in Illinois, both located downwind from a lead smelter facility and a coal fired power plant. Vegetation index models using multiband images were derived to characterize tree health status at the time of leaf sample collection, and change detection analysis was conducted to quantify temporal variations over a 13 year period. Multivariate statistics were used to identify relationships between spectral reflectance, biogeochemistry, and forest attributes. Preliminary results have found relatively high concentrations of several metals (e.g., Hg and Cd) accumulated in leaf tissue. These may be sufficient enough to induce discernible contamination effects in specific reflectance wavelength regions, and change detection has revealed that there is a notable difference in forest coverage that has occurred at these areas during the timeframe assessed.

Description of Komagataella phaffii sp. nov. and the transfer of Pichia pseudopastoris to the methylotrophic yeast genus Komagataella

The new methanol-assimilating yeast species Komagataella phaffii Kurtzman sp. nov. (type strain NRRL Y-7556(T)=CBS 2612(T)) is described. Of the four known strains of this species, two were isolated from black oak trees in California, USA, one from an Emory oak in Arizona, USA, and one from an unidentified source in Mexico. The species forms hat-shaped ascospores in deliquescent asci and appears to be homothallic. Analysis of nucleotide sequences from domains D1/D2 of large-subunit (26S) rDNA separates the new species from Komagataella pastoris, the type species of the genus, and from Pichia pseudopastoris, which is here renamed Komagataella pseudopastoris (Dlauchy, Tornai-Lehoczki, Fulop & Peter) Kurtzman comb. nov. (type strain NRRL Y-27603(T)=CBS 9187(T)=NCAIM Y 01541(T)). On the basis of D1/D2 26S rDNA sequence analysis, the three species now assigned to the genus Komagataella represent a clade that is phylogenetically isolated from other ascomycetous yeast genera.

Control of Black Oak and Tanoak in the Sierra Cascade Range

Abstract Broadcast, directed, and stem injection herbicide techniques were applied to 3- to 8-year-old black oak (Quercus kelloggii) and 3-year-old tanoak (Lithocarpus densiflorus) clumps (directed applications only). Broadcast applications of imazapyr at all rates to black oak and directed applications of imazapyr to tanoak performed better with the addition of an adjuvant compared to treatments without the adjuvant. However, even with an adjuvant, broadcast treatments of imazapyr at or below 560 g acid equivalent (ae/ha) only suppressed black oak growth and did not provide long-term control. Directed applications of imazapyr gave excellent control of both black oak (0.43–2.17% ae plus Sylgard) and tanoak (0.14–1.13% ae plus Hasten) clumps. Imazapyr was more effective than basal bark treatments with triclopyr (8.9% ae), and tank-mixing imazapyr with glyphosate did not improve the level of control. Stem injection treatment of black oak trees or clumps with imazapyr was very effective with nearly all rates and hack intervals, but late summer or fall applications gave greater suppression of basal re-sprouts compared to spring and early summer treatments. These results demonstrate that imazapyr is a very effective and versatile tool for the control of black oak and tanoak clumps and black oak trees. West. J. Appl. For. 19(4):268–276.

Uptake and mobility of uranium in black oaks: implications for biomonitoring depleted uranium-contaminated groundwater

In a preliminary study, the uptake and the mobility of uranium (U) by black oak trees ( Quercus velutina) were assessed by measuring the isotopic composition of tree rings in two mature oak trees in a heavy metal contaminated bog in Concord, MA. The bog is adjacent to a nuclear industrial facility that has been processing depleted uranium (DU) since 1959. Over the past 40 years, DU has been leaking from an onsite holding basin and cooling pond down gradient to the bog where the oaks are located. Because DU has no source outside the nuclear industry, contamination from the industrial facility is readily discernable from uptake of natural U by measuring isotopic compositions. Isotope ratio analysis confirms the occurrence of DU in bark, sapwood and heartwood tree rings dating back to 1937, pre-dating the introduction of DU at the site by at least 20 years. Isotope dilution analysis indicates high concentrations of U (>3 ppb) in sapwood that drop rapidly to relatively constant concentrations (0.3–0.4 ppb) in heartwood. These data indicate that once incorporated into tree cells, U is mobile, possibly by diffusion through the tree wood. Concentrations of U in sapwood are approximately equal to average U concentrations in groundwater onsite over the past 10 years, suggesting that oak trees can be used as present-day bioindicators of U-contaminated groundwater. We suggest that regional sampling of oak bark and sapwood is a reasonable, inexpensive alternative to drilling wells to monitor shallow groundwater U contamination.

INFLUENCE OF TREE DIAMETER, ASPECT, AND MONTH KILLED ON THE BEHAVIOUR OF SCOLYTIDS INFESTING BLACK OAKS

AbstractThe scolytids, M. mali, M. fasciatum, X. saxeseni, X. ferrugineus, and X. xylographus, were attracted consistently to black oak trees killed each month from March to August, 1974. More beetles were attracted to larger diameter trees and most were trapped on the north aspect. The beetles showed no trends for attraction for trees killed in different months.

EFFECTS OF PRUNING THE ROOTS OF GAS‐INJURED TREES

TRE.ES IN the vicinity of illuminating gas leaks in the soil may die rapidly, as indicated by a sudden wilting and drying of all the foliage, or they may succumb more or less gradually over one or more years. This latter type of injury may first involve uppermost twigs, the branches on one side, or a large branch or two, while -the remainder of the tree appears to be unaffected. Such unequal injury to the top of a tree frequently results in a tree of little value. In other cases, the damage may be minimized by judicious pruning. When one side or a few branches are killed, questions arise as to the manner in which this localization of injury occurs and whether a practice such as root pruning would be a benefit. Stone in the bulletin by Start, Stone, and Fernald (1908) stated that if symptoms of gas poisoning were discovered in only one root, and the poisoning has not extended to the tree trunk, amputation of the root is the best remedy. He also claimed that the cutting of tree roots under a roadbed when regrading was done or curbing was placed saved many trees from iiijury by gas. Fernow (1910) also recommended root pruning for trees detected in the early stages of gas poisoning. To secure evidence of the effect of root pruning as a means of aiding gas-injured trees, small oak trees were subjected to illuminating gas in water until definite symptoms of injury were produced. The most affected distal portions of the tap and fibrous roots were then pruned off, the trees were repotted in soil, and the appearance of the tops and roots was observed during the following two years. EXPERIMENTAL. -A fairly uniform group of thirty, twoand three-year-old red and black oak trees that had been grown in pots was divided into three lots of ten trees each. The roots were washed free of soil and placed in gassing chambers consisting of clean, one-gallon cans, such as are used for varnish. Holes were cut in one side to admit the roots of ten trees. The foliaged tops were sealed off from the roots by plastic clay molded around the stems. The roots stood in' 3 cm. of water into which measured volumes of illuminating gas were passed. Coke oven gas of the New Haven Gas Light Company was used. A complete analysis of this gas was given in a previous paper (Deuber, 1936). The content of illhminants was 3.00 per cent, carbon monoxide 8.70 per cent, and hydrocyanic acid was absent, according to the factory analyses. One cubic foot of this gas was passed into tlle water of the gassing chamber containing the first lot of trees; 17.2 cubic feet of gas during four hours into the water of the second lot; and 24.5 cubic feet in seven hours to the third lot together with a flow of 0.58 cubic feet of gas per hour for the next four