scholarly journals Thermal Tolerance of Gloomy Scale (Hemiptera: Diaspididae) in the Eastern United States

2020 ◽  
Vol 49 (1) ◽  
pp. 104-114 ◽  
Author(s):  
Michael G Just ◽  
Steven D Frank

Abstract An insect species’ geographic distribution is probably delimited in part by physiological tolerances of environmental temperatures. Gloomy scale (Melanaspis tenebricosa (Comstock)) is a native insect herbivore in eastern U.S. forests. In eastern U.S. cities, where temperatures are warmer than nearby natural areas, M. tenebricosa is a primary pest of red maple (Acer rubrum L.; Sapindales: Sapindaceae) With warming, M. tenebricosa may spread to new cities or become pestilent in forests. To better understand current and future M. tenebricosa distribution boundaries, we examined M. tenebricosa thermal tolerance under laboratory conditions. We selected five hot and five cold experimental temperatures representative of locations in the known M. tenebricosa distribution. We built models to predict scale mortality based on duration of exposure to warm or cold experimental temperatures. We then used these models to estimate upper and lower lethal durations, i.e., temperature exposure durations that result in 50% mortality. We tested the thermal tolerance for M. tenebricosa populations from northern, mid, and southern locations of the species’ known distribution. Scales were more heat and cold tolerant of temperatures representative of the midlatitudes of their distribution where their densities are the greatest. Moreover, the scale population from the northern distribution boundary could tolerate cold temperatures from the northern boundary for twice as long as the population collected near the southern boundary. Our results suggest that as the climate warms the M. tenebricosa distribution may expand poleward, but experience a contraction at its southern boundary.

2020 ◽  
Vol 50 (11) ◽  
pp. 1215-1227
Author(s):  
Don C. Radcliffe ◽  
Stephen N. Matthews ◽  
David M. Hix

Shade-tolerant mesophytic tree species tend to dominate the understories of present-day oak–hickory and mixed-hardwood forests in the eastern United States. We quantified the sapling density associations with abiotic and biotic variables for three important mesophytic species: red maple (Acer rubrum L.), sugar maple (Acer saccharum Marsh.), and American beech (Fagus grandifolia Ehrh.) in southeastern Ohio. In this study, we sampled 165 permanent plots in oak-dominated, topographically diverse, mature (>90 years old), second-growth forests following a time span of 21–25 years (1993–1995 and 2016–2018) between samples on the Athens and Marietta units of the Wayne National Forest. Our models showed that sugar maple was strongly associated with high pH soils and red maple was strongly associated with low pH soils. Additionally, red maple was associated with upper slope positions and older stands, while American beech was associated with lower slopes, northeasterly aspects, and northeast-facing upper slopes. Basal area of competing species, solum depth, and management unit were not significantly related to sapling density for our focal species. American beech sapling density doubled between the two sampling periods, while densities of both maple species declined by half. Our results will help scientists and managers by providing insight into potential future composition of currently oak-dominated forests in areas without active management intervention.


2010 ◽  
Vol 40 (4) ◽  
pp. 716-726 ◽  
Author(s):  
Heather D. Alexander ◽  
Mary A. Arthur

Fire suppression has facilitated the spread of red maple ( Acer rubrum L.), a fire-sensitive, yet highly adaptable species, in historically oak-dominated forests of the eastern United States. Here, we address whether a shift from upland oaks to red maple could influence forest hydrology and nutrient availability because of species-specific effects on precipitation distribution and inorganic nitrogen (N) cycling. In eastern Kentucky, we measured seasonal variations in red maple, chestnut oak ( Quercus montana Willd.), and scarlet oak ( Quercus coccinea Münchh.) throughfall and stemflow quantity and quality following discrete precipitation events, and we assessed net N mineralization rates in underlying soils over a 2-year period (2006–2008). Throughfall was 3%–9% lower underneath red maple than both oaks, but red maple generated 2–3× more stemflow. Consequently, NH4+ throughfall deposition was less under red maple than chestnut oak, whereas stemflow-derived nutrient inputs were substantially larger for red maple than both oaks. Soils underlying red maple had 5–13× greater winter net nitrification rates than soils under both oaks and 20%–30% greater rates of seasonal net ammonification than soils under chestnut oak. These findings suggest a spatial redistribution of water and nutrients via precipitation as red maple dominance increases and point to stemflow as an important mechanism that may foster red maple competitive success, further bolstering the mesophication process in the United States.


2009 ◽  
Vol 39 (8) ◽  
pp. 1444-1452 ◽  
Author(s):  
Songlin Fei ◽  
Kim C. Steiner

Red maple ( Acer rubrum L.) is becoming increasingly dominant in forest stands throughout the eastern United States. To investigate the reasons for the increase, we examined the development of red maple and oak ( Quercus spp.) seedlings and stump sprouts following the harvest of oak-dominated stands. Within 7 years after harvest, red maple seedlings were present in far greater numbers and captured more growing space than all oaks combined. Growing space occupied by red maple stump sprouts exceeded oak sprouts by a ratio of 3.5:1. Through stump sprouts alone, red maple fully recaptured the amount of growing space it had previously occupied in the overstory 7 years after harvest. Results from similar but older stands show that red maple dominance is sustained into the third decade of stand development. Red maple surpassed all oaks combined in rapid site capture through both seed-origin and sprout-origin regeneration. Red maple’s superior ability to regenerate by sprouts is particularly favored by timber harvesting following a history of management and disturbance regimes that permit the accumulation of suppressed small-diameter red maple stems. Among the events and processes that promote stand conversion, timber harvesting may be the major proximal cause of the widespread, increasing dominance of red maple.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Michael G Just ◽  
Adam G Dale ◽  
Steven D Frank

Abstract Gloomy scale, Melanaspis tenebricosa (Comstock), is native to the eastern United States and feeds on deciduous trees. In natural areas, it is a background herbivore that typically remains at low densities. Gloomy scale generally responds positively to warming with greater egg production, size, survival, and abundance. In urban areas, which are warmer than surrounding natural areas, gloomy scale is pestiferous on planted trees, particularly red maple (Acer rubrum L.; Sapindales: Sapindaceae) but other native maples as well. They live on the bark and damage host trees by feeding from plant cells and tissues, which deprives the trees of energy and nutrients, reducing the trees’ growth and overall health. Gloomy scales are likely to expand their range beyond the Southeast and become pestilent in new areas with continued climatic warming and urbanization. Here we present a review of the biology, ecology, response to environmental conditions, host range and damage, and management of gloomy scale.


Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 136
Author(s):  
Brice B. Hanberry

Forest classifications by disturbance permit designation of multiple types of both old growth forests and shorter-lived forests, which auto-replace under severe disturbance, and also identification of loss of the disturbance type and associated forest. Historically, fire and flooding disturbance regimes, or conversely, infrequent disturbance, produced unique forests such as disturbance-independent forests of American beech (Fagus grandifolia), eastern hemlock (Tsuga canadensis), and sugar maple (Acer saccharum) in the Eastern United States. However, disturbance has changed to primarily frequent mechanical overstory disturbance, resulting in novel forests. To demonstrate the transition to no-analog forests after disturbance change, I compared historical tree surveys (ca. 1837 to 1857) to current surveys in the Northern Lower Peninsula of Michigan. To establish widespread disturbance change effects, I also located where beech and hemlock are currently most abundant throughout the Eastern US compared to historical distribution of beech–hemlock forests. In the Northern Lower Peninsula of Michigan, beech and hemlock historically were about 30% of all trees, but currently, beech and hemlock are 2% of all trees. Red maple (Acer rubrum) increased from 1% to 11% of all trees and aspen (Populus) increased from 2% to 13% of all trees. The squared-chord difference between historical and current surveys was 0.40, or dissimilar forests. Areas with ≥20% beech and hemlock or ≥15% of either species decreased from about 52 million to 6 million hectares, with current distribution restricted to the Northeastern US. Current forests are dissimilar to historical forests, and this transition appears to be driven by disturbance regimes without historical analogs. Disturbance change may provide perspective in forest management for climate change.


2020 ◽  
Vol 52 (3) ◽  
pp. 292-297
Author(s):  
Tara Lee Bal ◽  
Katherine Elizabeth Schneider ◽  
Dana L. Richter

2004 ◽  
Vol 52 (6) ◽  
pp. 757 ◽  
Author(s):  
M. B. Dickinson ◽  
J. Jolliff ◽  
A. S. Bova

Hyperbolic temperature exposures (in which the rate of temperature rise increases with time) and an analytical solution to a rate-process model were used to characterise the impairment of respiration in samples containing both phloem (live bark) and vascular-cambium tissue during exposures to temperatures such as those experienced by the vascular cambium in tree stems heated by forest fires. Tissue impairment was characterised for red maple (Acer rubrum), chestnut oak (Quercus prinus), Douglas fir (Pseudotsuga menziesii), and ponderosa pine (Pinus ponderosa) samples. The estimated temperature dependence of the model’s rate parameter (described by the Arrhenius equation) was a function of the temperature regime to which tissues were exposed. Temperatures rising hyperbolically from near ambient (30°C) to 65°C produced rate parameters for the deciduous species that were similar at 60°C to those from the literature, estimated by using fixed temperature exposures. In contrast, samples from all species showed low rates of impairment, conifer samples more so than deciduous, after exposure to regimes in which temperatures rose hyperbolically between 50 and 60°C. A hypersensitive response could explain an early lag in tissue-impairment rates that apparently caused the differences among heating regimes. A simulation based on stem vascular-cambium temperature regimes measured during fires shows how temperature-dependent impairment rates can be used to predict tissue necrosis in fires. To our knowledge, hyperbolic temperature exposures have not been used to characterise plant tissue thermal tolerance and, given certain caveats, could provide more realistic data more efficiently than fixed-temperature exposures.


1972 ◽  
Vol 50 (8) ◽  
pp. 1783-1784 ◽  
Author(s):  
John P. Rier ◽  
Alex L. Shigo

Fluorescence microscopy was used to show that during 34 days after the wounding of red maple, Acer rubrum, callose accumulated in the phloem, new xylary tissues formed, and plugs formed in vessels to 10 cm above and below the wounds.


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