SESSION 2 Effects of Tephra Deposition from Eruption of Mt. St. Helens; G. Segura

Large-scale Defoliation by Gypsy Moth in Pennsylvania; J. Quimby

Hurricane Hugo Damage Assessment Using Permanent Plots; R. Sheffield

Impacts of Chernobyl Nuclear Disaster on Ukraine Forests; M. Kaletnik et al.

Hurricane Andrew Resource Assessment; M. Soukup & G. Davis

Inventory Techniques After Hurricane Events in Central Europe; H. Lohmann


                                Gerardo Segura
   Centro de Ecologia, UNAM, Apdo. Postal 70-275. 04510, Mexico D.F. Mexico


   Heavy tephra deposition from the May 18, 1980 eruption of Mt. St.  Helens
impacted large areas of old-growth forests of mixed conifer species in
southeast Washington causing short and long term effects on tree growth and
mortality.  Recent evaluations of the impacted area showed that long term
effects of tephra were relatively species specific causing severe decline and
mortality only to Abies amabilis.  Such impacts have been associated with the
prolonged retention of fine tephra in the foliage of this species.  Variations
in the nature, extent, and severity of growth losses and mortality were
addressed at three different levels of organization:  the landscape, the
stand, and the individual tree.  Site characteristics, stand structure and
history, amount of tephra deposited, growth and percent mortality, and crown
vigor were measured.  Intensity of decline and mortality and growth losses
were evaluated at the three levels of organization using discriminant
analysis, dendrochronology, time series analysis and stem analysis.

   Most damaged stands within the landscape were those that received the
largest amounts of fine tephra and that occurred at lower elevations where A.
amabilis tended to be a less dominant species.  Decline conditions and
reductions in radial growth were more severe, not only in stands that received
large amounts of tephra but also where other non-affected species (e.g.,
Pseudotsuga menziesii and Tsuga heterophylla) were more dominant.  These
species experienced significant increases in growth in stands where A.
amabilis suffered the most severe growth reductions, suggesting changes in the
competitive interactions among species and shifts of stand productivity to
non-affected species.  A large variability of decline conditions and patterns
of radial growth were also observed between individual A. amabilis trees in a
stand and within the crown and stem of individual trees.  Overall reductions
in growth along the stem of trees was related to the severity of crown damage.
Growth reductions were more pronounced in the lower portion of the bole,
particularly among trees showing severe crown decline.  An increase in growth
in the upper stem near the apex was common in most declining trees.  This area
coincided with a portion of the crown experiencing vigorous growth that has
probably maintained a positive carbohydrate balance and can be considered a
zone of recovery.



                                John W. Quimby
              Pennsylvania Department of Environmental Resources
            Bureau of Forestry, Division of Forest Pest Management
                               34 Airport Drive
                         Middleton, PA 17057-5021 USA


   Gypsy moth was intensively controlled up until 1968 when various economic
and environmental considerations make it impractical.  Since then, there has
been a series of epidemics of gypsy moth within the Commonwealth of
Pennsylvania that have caused a variety of impacts that have affected the
political, economic, and social fortunes in a variety of habitats,
physiographic provinces, and ecological settings.  The technological and
managerial tools have evolved during the last 25 years such that there are
a multitude of options available to the resource manager to confront,
ameliorate, and accommodate to gypsy moth epidemics.  The decision-making
process has become unique for each forest stand.  The paper addresses the
decision-making process and the informational basis behind that process.

   The text of this presentation 

HURRICANE HUGO--DAMAGE ASSESSMENT USING PERMANENT PLOT REMEASUREMENT Raymond M. Sheffield, Research Forester Forest Inventory and Analysis Southeastern Forest Experiment Station Asheville, North Carolina ABSTRACT Hurricane Hugo struck South Carolina in September 1989 causing extensive mortality and damage to forest stands in 23 counties. The storm significantly altered forest conditions, making many short and long-term forestry resource programs obsolete. The Forest Inventory and Analysis Research Work Unit at the Southeastern Forest Experiment Station used a network of 2,530 permanent plots in the damaged area to assess changes in the forest resouce due to the hurricane. Resource changes attributed to wind damage included tree mortality, salvage and cleanup efforts, and a host of damages to trees alive at the time of the inventory. This paper summarizes data collection and analytical procedures used in assessing the degree of damage inflicted upon the forest resources across more than 6.5 million acres of timberland. Damages recorded for each live tree facilitated the development of a needed classification system for assessing the relative degree of tree and stand-level losses. Damage is summarized in terms of lost volume, reduced stocking of viable growing stock, and acreage now needing treatment because of hurricance damage. Opportunities for followup research are discussed. The text of this presentation

HURRICANE ANDREW RESOURCE ASSESSMENT Mike Soukup (1) National Park Service, South Florida Research Center & Gary Davis National Park Service, Channel Islands National Park ABSTRACT Hurricane Andrew was a category four hurricane and one of the most intense storms ever recorded in Florida. The storm passed through three National Park Service areas with significant natural resources, Everglades National Park, Biscayne National Park, and Big Cypress National Preserve. Immediately after the storm a resource assessment was conducted by a 25 member multi- disciplinary team charged with determining storm impacts, ecological responses to the storm, and short and long term actions needed to protect threatened resources. This session will focus on the findings of the assessment team and the implementation of long term research and monitoring programs needed to prevent or track potential damage to park ecosystems. Actions already in place as a result of the assessment will be discussed. Relationships to pre-storm effects of human and natural disturbance on fragile natural systems will also be examined, including chronic habitat fragmentation, altered air and water resources, non-native species, and human disturbance. Address: Dr. Michael Soukup Everglades National Park 547 Alcazar Avenue Coral Cables, Florida 33134 THE IMPACTS OF THE CHERNOBYL NUCLEAR DISASTER ON THE FOREST VEGETATION OF THE POLISSYA REGION OF UKRAINE Dr. Mykolai Kaletnik, Dr. Peter Pasternak Ukrainian Ministry of Forestery Dr. Serhei Hrisivk Ukrainian State Agricultural University Yuriy Bihun School of Forest Resources Penn State University Univ. Park, PA 16802 USA ABSTRACT In the spring of 1986, the aftermath of the Chernobyl nuclear explosion left a substantial portion of the forested area of the Ukrainian Polissya region contaminated with radioactive fallout. Although less than 5% Ukraine is forested, nearly one-quarter (24.2%) of its woodlands (approx. 2,371,600 ha) are located in the Polissya region. Common pine (Pinus sylvestris) is the primary species with associated boreal hardwoods, birch (Betula sp.), aspen (Populus sp.), and alder (Alnus sp.) characteristic of this transition forest zone. Of the four oblasts (provinces) showing evidence of radioactive fallout, damage was concentrated primarily in two provinces: Kiev and Zhitomir. Weather patterns as well as the forests of the Polissya region of Ukraine and neighboring republic of Byelorus played a major role in ameliorating the radioactive atmospheric deposition on agricultural areas and urban centers. Impacts of the fallout have been monitored in forest zones since shortly after the catastrophic event, but detailed scientific studies on the effects on forest vegetation and forest soils were not initiated until 1990. Results and analysis from these preliminary studies are available. Patterns of fallout, interception of particulate matter by the forest canopy, and impact on understory flora were recorded. The migration, accumulation and persistence of radioactive materials in roots, boles, leaf litter and soils is reported. Radioactive deposition followed a mosaic pattern depending on the proximity to the center of the explosion and prevailing winds. In spite of the erratic distribution and the variable size of the contaminated units, the affected area was stratified into five levels or zones of contamination with corresponding management and utilization strategies for each zone. Entry into highly contaminated areas is restricted and the degree of contamination determines access which, in turn, dictates management activities for grazing, timber harvesting, foraging and hunting. The need for long-term monitoring and inventory methods is discussed. The text of this presentation

INVENTORY TECHNIQUES FOR FOREST MANAGEMENT AND PLANNING AFTER HURRICANE EVENTS IN CENTRAL EUROPE Dr. Helmut Lohmann (1) Director of the Department of Forest Planning (Forstplanungsanstalt) State Forest Management Administration, Saarland ABSTRACT In February 1990 hurricanes damaged large parts of forest stands in southwest Germany. In the state, the municipal and the privately owned forests of the state of Saarland, Germany, with a forest area of about 90,000 ha, more than 2.5 million cubic meters of wood of different kinds and sizes became broken by the storm events and had to be cut down as well as transported out of the forests. That was about eight times as much as the normal yearly harvesting rate. For getting the resultant problems optimally managed, different forest inventory techniques were applied immediately and a data analysis was carried out by the forest planning department. Especially the analysis of a permanently installed inventory system of regularly distributed inventory points (1x1 km-grid of points of inventory across the whole state) was very effective. In about a few weeks time a complete overview of the impacts of the hurricane events on the public and private forest could be given for direct management use. The paper describes the different applied terrestrial and aerial photographic inventory techniques as well as the main results of the analysis of the inventory data. Some model calculations about the ecological implications, the possible forest management problems and the financial impacts of the hurricane destruction are given. (1) Author address: Forstplanungsanstalt, Virchowstr. 7, D-6600 Saarbrucken, Germany, Tel. (681) 8597-323 The text of this presentation