The relationship between ice thickness and northern hardwood tree damage during ice storms

2001 ◽  
Vol 31 (10) ◽  
pp. 1758-1767 ◽  
Author(s):  
Olga J Proulx ◽  
David F Greene
Keyword(s):  
Tree Mortality ◽  
Return Time ◽  
Ice Thickness ◽  
Tree Damage ◽  
Northern Hardwood ◽  
Canopy Tree ◽  
Ice Storms ◽  
Ice Accumulation ◽  
Primary Determinant ◽  
Damage Type

The response of four tree species, Acer saccharum Marsh., Acer rubrum L., Populus tremuloides Michx., and Betula populifolia Marsh., to ice storm damage was studied in the northern hardwood forest of southern Quebec. The focus of the study was the impact of ice accretion on trees as a function of damage type and species at the stand and regional scales along a gradient of ice accumulation ranging from 2 to 88 mm radial thickness and to assess the role of the combined effect of ice and wind stress. Further, we estimate the return time for death resulting from ice storms in these forests. The study showed that the magnitude of ice accumulation was the primary determinant of tree damage (measured as the mean percentage of individual tree canopy removed) and that tree size was the primary determinant of damage type (bending, snapping, or substantial branch loss). Stand position (edge versus interior) did not influence susceptibility to damage. The research demonstrated that edge and slope trees bent or snapped in the direction dictated by crown asymmetry. We have no evidence that the modest winds during this icing event played a major role. Lastly, we couple the return time for a given ice thickness with the probability of severe damage to argue that (i) canopy tree mortality from icing is primarily due to glaze accumulations of moderate rarity (around 12–35 mm of ice) rather than extraordinary events such as 1998 and (ii) ice storms are likely the greatest single source of canopy tree mortality in the hardwood forests of southern Quebec with an estimated return time for death of about 250 years.

scholarly journals Quantitative Ice Accretion Information from the Automated Surface Observing System

2007 ◽  
Vol 46 (9) ◽  
pp. 1423-1437 ◽  
Author(s):  
Charles C. Ryerson ◽  
Allan C. Ramsay
Keyword(s):  
United States ◽  
The United States ◽  
Ice Thickness ◽  
Ice Storm ◽  
Design Standards ◽  
Ice Storms ◽  
Ice Accumulation ◽  
Direct Measurements ◽  
Improved Design ◽  
Precipitation Events

Abstract Freezing precipitation is a persistent winter weather problem that costs the United States millions of dollars annually. Costs and infrastructure disruption may be greatly reduced by ice-storm warnings issued by the National Weather Service (NWS), and by the development of climatologies that allow improved design of infrastructure elements. However, neither the NWS nor developers of climatologies have had direct measurements of ice-storm accumulations as a basis for issuing warnings and developing storm design standards. This paper describes the development of an aviation routine/special weather report (METAR/SPECI) remark that will report quantitative ice thickness at over 650 locations during ice storms using new algorithms developed for the Automated Surface Observing System (ASOS). Characteristics of the ASOS icing sensor, a field program to develop the algorithms, tests of accuracy, application of the algorithms, and sources of error are described, as is the implementation of an ice-thickness METAR/SPECI remark. The algorithms will potentially allow freezing precipitation events to be tracked with regard to ice accumulation in near–real time as they progress across the United States.

Spatial characteristics of canopy disturbances in riparian old-growth hemlock – northern hardwood forests, Adirondack Mountains, New York, USA

2010 ◽  
Vol 40 (1) ◽  
pp. 13-25 ◽  
Author(s):  
Miranda T. Curzon ◽  
William S. Keeton
Keyword(s):  
New York ◽  
Linear Regression Analysis ◽  
Gap Dynamics ◽  
Adirondack Mountains ◽  
Old Growth ◽  
Tree Damage ◽  
Northern Hardwood ◽  
Gap Fraction ◽  
Successional Forests ◽  
Damage Type

Gap dynamics in temperate, late-successional forests influence important riparian functions, including organic matter recruitment and light environments over streams. However, controls on gap dynamics specific to riparian forests are poorly understood. We hypothesized that (i) gaps are larger and more frequent nearer streams, (ii) gaps cluster at within-stand scales, and (iii) tree damage type and gap fraction vary among riparian landforms. All gaps within four 6–9 ha plots in riparian old-growth eastern hemlock ( Tsuga canadensis (L.) Carrière) – northern hardwood forest in the Adirondack Mountains, New York, USA, were mapped and measured. We recorded species, damage type, and diameter at breast height for gapmakers and dominant perimeter trees. Spatial distribution was assessed with Ripley’s K. Spatial autocorrelation in gap area and tree damage type were assessed using Moran’s I. Linear regression analysis defined relationships between proximity to streams and gap area and frequency. Expanded gap fraction ranged from 28.3% to 47.6%. Gaps were randomly distributed at scales ≤25 m and clustered at scales of 63–122 m. Distribution patterns were not consistent at other scales. Convergent and divergent landforms significantly influenced gap fraction, tree damage type, and species distributions. Positive correlations between convergent topography and gap area suggest an interaction between low-order riparian landforms and gap formation dynamics in late-successional forests.

scholarly journals Forest carbon sink neutralized by pervasive growth-lifespan trade-offs

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
R. J. W. Brienen ◽  
L. Caldwell ◽  
L. Duchesne ◽  
S. Voelker ◽  
J. Barichivich ◽  
...  
Keyword(s):  
Tree Growth ◽  
Tree Mortality ◽  
Carbon Sink ◽  
Growth Stimulation ◽  
Forest Carbon ◽  
System Model ◽  
Earth System ◽  
Canopy Tree ◽  
Trade Offs ◽  
Almost All

Abstract Land vegetation is currently taking up large amounts of atmospheric CO2, possibly due to tree growth stimulation. Extant models predict that this growth stimulation will continue to cause a net carbon uptake this century. However, there are indications that increased growth rates may shorten trees′ lifespan and thus recent increases in forest carbon stocks may be transient due to lagged increases in mortality. Here we show that growth-lifespan trade-offs are indeed near universal, occurring across almost all species and climates. This trade-off is directly linked to faster growth reducing tree lifespan, and not due to covariance with climate or environment. Thus, current tree growth stimulation will, inevitably, result in a lagged increase in canopy tree mortality, as is indeed widely observed, and eventually neutralise carbon gains due to growth stimulation. Results from a strongly data-based forest simulator confirm these expectations. Extant Earth system model projections of global forest carbon sink persistence are likely too optimistic, increasing the need to curb greenhouse gas emissions.

Variation in canopy gap formation among developmental stages of northern hardwood stands

1996 ◽  
Vol 26 (10) ◽  
pp. 1875-1892 ◽  
Author(s):  
Sally E. Dahir ◽  
Craig G. Lorimer
Keyword(s):  
Sugar Maple ◽  
Tree Mortality ◽  
Developmental Stages ◽  
Turnover Time ◽  
Gap Formation ◽  
Old Growth ◽  
Northern Hardwood ◽  
Hardwood Species ◽  
Shade Tolerant Species ◽  
Mature Stands

Trends in gap dynamics among pole, mature, and old-growth northern hardwood stands were investigated on eight sites in the Porcupine Mountains of western upper Michigan. Recent gaps (created between 1981 and 1992) were identified using permanent plot records of tree mortality, while older gaps (1940–1981) were identified using stand reconstruction techniques. Although canopy gaps were somewhat more numerous in pole and mature stands, gaps were <25% as large as those in old-growth stands because of smaller gap-maker size, and the proportion of stand area turned over in gaps was only about half as large. Gap makers in younger stands generally had mean relative diameters (ratio of gap-maker DBH to mean DBH of canopy trees) <1.0 and were disproportionately from minor species such as eastern hophornbeam (Ostryavirginiana (Mill.) K. Koch). Gap makers in old-growth stands had mean relative diameters >1.5 and were predominantly from the dominant canopy species. Even in old-growth forests, most gaps were small (mean 44 m2) and created by single trees. Based on the identity of the tallest gap tree in each gap, nearly all shade-tolerant and midtolerant species have been successful in capturing gaps, but gap capture rates for some species were significantly different from their relative density in the upper canopy. The tallest gap trees of shade-tolerant species were often formerly overtopped trees, averaging more than 60% of the mean canopy height and having mean ages of 65–149 years. Canopy turnover times, based on gap formation rates over a 50-year period, were estimated to average 128 years for old-growth stands dominated by sugar maple (Acersaccharum Marsh.) and 192 years for old-growth stands dominated by hemlock (Tsugacanadensis (L.) Carrière). While these estimates of turnover time are substantially shorter than maximum tree ages observed on these sites, they agree closely with independent data on mean canopy residence time for trees that die at the average gap-maker size of 51 cm DBH. The data support previous hypothetical explanations of the apparent discrepancy between canopy turnover times of <130 years for hardwood species and the frequent occurrence of trees exceeding 250 years of age.

scholarly journals A STUDY INTO ICE BUILD-UP AND MELTING ON VERTICAL COOLED PIPES

2016 ◽  
Vol 52 (3) ◽  
Author(s):  
Y. Zasiadko ◽  
O. Pylypenko ◽  
A. Forsiuk ◽  
R. Gryshchenko
Keyword(s):  
Thermal Energy ◽  
Experimental Unit ◽  
Ice Thickness ◽  
Ice Melting ◽  
Empirical Correlations ◽  
Time Intervals ◽  
Ice Accumulation ◽  
Time Periods ◽  
Semi Empirical

The use of cold accumulators based on the principle of ice build up on the cooled surfaces during off-peak periods and ice melting during on-peak periods is an effective method of electricity bills reduction. Within comparatively short periods of on-peak demand a noticeable amount of thermal energy related to ice melting is to be released, it becomes clear that not only sizing of ice accumulators based on balance calculations is actual, but also the determination of time periods of ice accumulation becomes critical. This work presents experimental unit for obtaining data on the ice build-up on the vertical cooled pipes and later on to continuously register data on the ice thickness diminishing at the regimes of ice melting when cooling of pipe stops. The data for ice build-up and melting for some regimes have been presented and analyzed. The data form the base for deriving semi-empirical correlations allowing to determine a time intervals necessary to generate of ice layers of a given thickness.

A review of biodiversity outcomes from possum-focused pest control in New Zealand

2016 ◽  
Vol 43 (3) ◽  
pp. 228 ◽  
Author(s):  
Andrea E. Byrom ◽  
John Innes ◽  
Rachelle N. Binny
Keyword(s):  
New Zealand ◽  
Pest Control ◽  
Tree Mortality ◽  
Meta Analysis ◽  
Rattus Rattus ◽  
Return Time ◽  
Evidence Base ◽  
Fruit Production ◽  
Invasive Pest ◽  
Biodiversity Indicators

Worldwide, introduced vertebrate pests impact primary production, native biodiversity, and human health. In New Zealand, extensive pest control (~10 million ha) is undertaken to protect native biota and to prevent losses to the primary sector from wildlife vectors of bovine tuberculosis (TB), primarily possums (Trichosurus vulpecula). Control is conducted by TBfree New Zealand and by conservation agencies. Remote, forested terrain is treated using the toxin 1080 via aerial delivery in bait with a return time of ~5 years. Ground-based control is conducted annually using traps and/or poison bait. Possums are controlled to very low abundance by these operations. Aerial 1080 is effective against another forest-dwelling vertebrate pest, the ship rat (Rattus rattus). Possum control has reduced TB rates, but collateral benefits for native biodiversity have not been quantified, making it difficult to demonstrate a return on investment. We review information from 47 accounts of responses of native biota to possum control. Of these, 60% quantified responses to aerial 1080; the remainder were ground-based. Possum control benefited vegetation by increasing foliage and fruit production, and by reducing tree mortality. Controlling ship rats and possums together improved bird populations, but rats recovered rapidly and long-term outcomes for rat-vulnerable birds are unknown.Large-bodied invertebrates also benefited from extensive pest control. We conducted a meta-analysis of 84 response measures from 35 of these 47 studies in order to provide a quantitative assessment of these findings. The analysis demonstrated that both ground and aerial control of this invasive pest in New Zealand has provided substantial collateral benefits for native biota. Few studies have taken advantage of decades of extensive pest control in New Zealand to monitor ecosystem-level outcomes, which have received only short-term attention thus far. Non-treatment experimental controls and replicate sites that enable validated assessments of outcomes for native biota are vital. Future studies would benefit from a standardised set of biodiversity indicators from a range of taxonomic and functional groupings, and from standardising experimental designs so individual studies can contribute to future meta-analyses, to strengthen the evidence base for the impacts of invasive pests on native biota in New Zealand and worldwide.

A Comparison of Low-Cost Collector Configurations for Quantifying Ice Accretion

2020 ◽  
Vol 59 (9) ◽  
pp. 1429-1442
Author(s):  
John L. Campbell ◽  
Lindsey E. Rustad ◽  
Sarah Garlick ◽  
Noah Newman ◽  
John S. Stanovick ◽  
...  
Keyword(s):  
Low Cost ◽  
Weather Conditions ◽  
Ice Thickness ◽  
Ice Accretion ◽  
Hubbard Brook Experimental Forest ◽  
Ice Storms ◽  
Weather Events ◽  
Different Types ◽  
Different Diameters ◽  
Economic And Social Impacts

AbstractIce storms are important winter weather events that can have substantial environmental, economic, and social impacts. Mapping and assessment of damage after these events could be improved by making ice accretion measurements at a greater number of sites than is currently available. There is a need for low-cost collectors that can be distributed broadly in volunteer observation networks; however, use of low-cost collectors necessitates understanding of how collector characteristics and configurations influence measurements of ice accretion. A study was conducted at the Hubbard Brook Experimental Forest in New Hampshire that involved spraying water over passive ice collectors during freezing conditions to simulate ice storms of different intensity. The collectors consisted of plates composed of four different materials and installed horizontally; two different types of wires strung horizontally; and rods of three different materials, with three different diameters, and installed at three different inclinations. Results showed that planar ice thickness on plates was 2.5–3 times as great as the radial ice thickness on rods or wires, which is consistent with expectations based on theory and empirical evidence from previous studies. Rods mounted on an angle rather than horizontally reduced the formation of icicles and enabled more consistent measurements. Results such as these provide much needed information for comparing ice accretion data. Understanding of relationships among collector configurations could be refined further by collecting data from natural ice storms under a broader range of weather conditions.

A novel ice storm manipulation experiment in a northern hardwood forest

2012 ◽  
Vol 42 (10) ◽  
pp. 1810-1818 ◽  
Author(s):  
Lindsey E. Rustad ◽  
John L. Campbell
Keyword(s):  
United States ◽  
Forest Canopy ◽  
Forest Ecosystems ◽  
Hardwood Forest ◽  
Canopy Openness ◽  
Northern Hardwood Forest ◽  
Ice Storm ◽  
Northeastern United States ◽  
Northern Hardwood ◽  
Ice Storms

Ice storms are an important natural disturbance within forest ecosystems of the northeastern United States. Current models suggest that the frequency and severity of ice storms may increase in the coming decades in response to changes in climate. Because of the stochastic nature of ice storms and difficulties in predicting their occurrence, most past investigations of the ecological effects of ice storms across this region have been based on case studies following major storms. Here we report on a novel alternative approach where a glaze ice event was created experimentally under controlled conditions at the Hubbard Brook Experimental Forest, New Hampshire, USA. Water was sprayed over a northern hardwood forest canopy during February 2011, resulting in 7–12 mm radial ice thickness. Although this is below the minimum cutoff for ice storm warnings (13 mm of ice) issued by the US National Weather Service for the northeastern United States, this glaze ice treatment resulted in significant canopy damage, with 142 and 218 g C·m–2 of fine and coarse woody debris (respectively) deposited on the forest floor, a significant increase in leaf-on canopy openness, and increases in qualitative damage assessments following the treatment. This study demonstrates the feasibility of a relatively simple approach to simulating an ice storm and underscores the potency of this type of extreme event in shaping the future structure and function of northern hardwood forest ecosystems.

Elevated mortality of residual trees following single-tree felling in northern hardwood forests

2006 ◽  
Vol 36 (5) ◽  
pp. 1255-1265 ◽  
Author(s):  
John P Caspersen
Keyword(s):  
Tree Mortality ◽  
Community Dynamics ◽  
Stand Structure ◽  
Hardwood Forests ◽  
Natural Mortality ◽  
Northern Hardwood Forests ◽  
Substantial Impact ◽  
Northern Hardwood ◽  
Single Tree

In this paper, I examine tree mortality in northern hardwood forests subjected to single-tree felling. Mortality risk was estimated as a function of growth prior to harvest and time since harvest. This allowed me to separately quantify mortality due to (1) natural processes, (2) intentional felling, and (3) stress and (or) felling damage (postcut mortality). The long-term rate of mortality due to natural causes was 1.5% per year. The intentional felling of trees increased the average mortality to 3.1%, and postcut mortality of residual trees increased the average an additional 0.2%–3.3% (the latter reflects both the direct negative effects of harvesting and the indirect positive effect of releasing residual trees from suppression). Thus, from a population-level perspective, the increased mortality caused by stress and (or) felling damage to residual trees was small compared to that caused by both natural mortality and tree felling. However, the long-term population average obscures more dramatic (though transient) effects of felling on small trees (DBH <10 cm), for which mortality rates increased by as much as 5% immediately after felling. This increase is several times greater than the natural mortality rate for small trees and may therefore have a substantial impact on stand structure and community dynamics.

scholarly journals Predicting individual tree mortality in northern hardwood stands under uneven-aged management in southern Québec, Canada

2008 ◽  
Vol 65 (2) ◽  
pp. 205-205 ◽  
Author(s):  
Mathieu Fortin ◽  
Steve Bédard ◽  
Josianne DeBlois ◽  
Sébastien Meunier
Keyword(s):  
Tree Mortality ◽  
Individual Tree ◽  
Northern Hardwood
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