196 



Ifiaj 1952 



INTERlilDUNTAIN FOREST AND RAjROS Eff^^IjvIENT STATION 

 ? i ^ U. S. Department (jf Agricultu^e""^----^ 



^ Forest Service OgdeiiJ^"l^t^l\' 'A 



Reed W. Baile^^, Director ' ■ V.v,'>^ 



Research Note No. 3 / * •952 



* f i, <T7i n ,^ 



^ ■" 



■■■'■> Of g 



RODBNI DAi./IAG£ IK FONDEROSA PINE PL Al^I^ 



Alvin K, Wilson, Forester 



Initial establishrnent of ponderosa pine (P inus p onderosa ) stands, 

 by both natural and artificial raeans, is inade difficult by infrequent 

 seed years, low precipitation, and plant competition. These difficulties 

 are aggravated by the feeding of the snavshoe hare (L epus aj.ier ic-inu s) 

 and the v^/estern porcupine ( Erethizon epixa nt hum) which t^nces the form 

 of bark and branch removal from the steras of surviving seedlings and 

 small saplings up to 6 feet in height thus disfiguring, weakening, or 

 killing the trees. Both rodents are present on all sites where ponderosa 

 pine is likely to be planted, or is found in natural stands, in the 

 Interraountain region. Feeding by the hare tends to be most frequent 

 where snowbrush ( Geanothus velutinus ) provides cover against pi'-edators. 

 Porcupines will locate the scattered valdlings and planted stock even 

 in large burns v>;hen they are grov.'ing several miles fraa the margin of 

 timber. 



To determine the extent and nature of feeding by both rodents, 

 examinations v^ere made by running randomly located 0.5 chain strips 

 through each of two 10-year old plantations some 6 miles apart in the 

 Boise Basin of south central Idaho. Trees were tallied by tivo height 

 classes (under 3 feet and over 3 feet) and three condition classes, no 

 feeding, damaged (but not girdled) , and girdled. Few stems exceeded 

 6 feet in height. Table 1 shows the percentages damaged f"nd girdled by 

 feeding. 



Table 1. — Percentage of seedlings and small saplings by conditio n 

 classes and tlie number of trees examined in tvjo 10-year 

 old -olantatious in central Idaho 



Not Fe d _ on No. trees 



fed on Damaged Gird led examined 



Percent Pe rcen t Percent 



Granite Greek 79.3 18.4 2.3 87 



Elk Creek 76.9 18. 9 4.2 353 



