NORTHEASTERN FOREST EXPERIMENT STATION 

Upper Darby , Pennsylvania 

No. 53 

1955 

Windthrow A Hazard 

In Virginia Pine Strip Cuttings 

The eye of Hurricane Hazel passed to the west of the 

Beltsville Experimental Forest in Maryland on the afternoon 

of October 15, 1954. Sustained wind velocities of 66 mph 

(from the SE), with maximum gusts of 98 mph, were recorded 

nearby. 

Some scattered trees 

throughout the Experimental Forest were broken 

off or blown down. The 

damage was studied on two 

compartments that had 

been logged by the. stripcutting method (table 1). 

The cut strips were three 

chains wide in Compartment A and two chains 

wide in Compartment B. 

The uncut strips were one 

chain wide, running generally NE and SW, 

The merchantable volume lost on Compartment A was 7.7 

percent of the pine on the uncut strips, and 2.2 percent of 

the hardwood. Figured on a per-acre basis, these losses on 

the uncut strips amounted to 153 cubic feet of pine and 14 

cubic feet of hardwood. The loss ratio on Compartment B was 

similar. 

More trees broke off than were blown over. This may 

have been due to the long drought before the stom, which 

resulted in a firm anchorage for the roots. Had the ground 

been wetter, a greater proportion of the trees might have 

blown down, Another factor that may have led to breakage 

was red rot it was noticed at the point of breakage in 14 

out of 85 pines. 

4 

Literature on the silvics and management of 

Virginia pine is scanty. 

But as the use of this 

species increases, so does 

interest in its management. The observations 

reported here are a small 

but possibly significant 

contribution to what we 

know. 

J 
Table 1.-Summary of wind damage done by Hurricane Hazel on uncut strips 

in recently cut Virginia pine-hardwoods 

-% Merchantable cubic-foot volumes to a 4-inch top. 

Study of storm damage was limited to the two predominant species, Virginia pine and pitch pine. Of the two, 

Virginia pine was more susceptible to damage. The storm 

damage can be summed up this way: 

Compartment 

Inches & Cu.ft. & Cu.ft. No. Cu.ft. 

Virginia pine 5-9 0.5 2.2 0.1 1.0 0.6 3.2 

A { 

9+ 2.1 53.9 1.9 54.9 4.0 108.8 

Pitch pine 5-9 .5 3.0 0 0 .5 3.0 

9+ 1.6 36.6 .1 1.7 1.7 38.3 

Hardwoods 5-9 0 0 0 0 0 0 

9+ .1 1.8 .7 12.0 .8 13.8 

Virginia pine 5-9 1.3 7.1 .6 3.8 1.9 10.9 

I 9+ 3.1 64.0 1.5 43.8 4.6 107.8 

Pitch pine 5-9 0 0 0 0 0 0 

9+ .4 8.7 O 0 .4 8.7 

Hardwoods 5-9. .3 .3 0 0 .3 .3 

9+ O, 0 .4 9.9 .4 9.9 

Average total loss -- 4.95 88.80 2.65 63.55 7.60 152.35 

Total 

losses 

- No. Cubic - No. Cubic 

trees feet trees feet 

Species 

Trees 

Pitch pine 

Before hurricane 532 9,667 363 6,204 

Volume 

Virginia pine 

Lost in hurricane 

Size 

class 

(d. b. h.) 

J 

The greatest volume losses of pine were in the larger 

size classes: 3.5 percent in the 5- to 9-inch d.b.h. classes 

and 8.3 percent in the trees 9 inches and larger. 

Though storms like Hurricane Hazel are spectacular 

and cause great damage, the cumulative effects of lesser 

storms cannot be overlooked. Such storms may qccur every 

45 Losses per acre due to-- 

Breakage 

Trees Volume 

Windthrow 

Trees Volume 
year, usually associated with summer thunder showers; and 

they are often ushered in with gusty winds that for brief 

periods may rise to 50 or 60 mph. 

A study of damage from these lesser storms was made 

on Compartment A. It showed (table 2) that cumulative losses 

from such storms over a 2-year period were nearly equal to 

the losses from the October 1954 hurricane. In these storms 

too, breakage losses exceeded windthrow~losses. 

Table 2.--Wind losses from Hurricane Hazel compared cith losses 

from smaller storms over 2-year period 

(1n number of trees per acre) 

One possible cause of'the wind losses on these two 

compartments may be the age of the stands. They average 

about 65 years old. The strip cutting method used here as 

part of a special study is normally used in younger stands, 

for harvesting pulpwood. Wind 10s ses in another compartment 

that average4 4.5 years old were less. 

U. S. Weather Bureau records indicate a possible frequency of severe storms in this area about once in 5 years. 

So the possibility of wind damage should be considered in 

managing forests that contain large proportions of Virginia 

pine in 'the Coastal Plain area. 

Species 

--RICHARD H. FENTON 

Virginia Pine-Hardwood Research Center 

Northeastern Forest Experiment Station 

Forest Service, U.S . Dept . Agriculture 

Virginia pine 2.59 2.00 3.76 0.82 

Pitch pine 2.00 .12 1.65 .12 

Total 4.59 2.12 5.41 0.94 

Prior 2-year period 

AGRICULTURE-FOREST SERVICE-UPPER DARBY 3 

Breakage 

Hurricane Hazel 

Breaka~e Windthrow Windthrow