MAN-AGEMENT PLANS THE NATIONAL FORESTS 71 



Strip in case an adverse decision is lianded down by the supreme court. The 

 successful carrying out of tlie plan depends upon such acquisition/ 



The data used in the preparation of the plan have been obtained from various 

 sources. The topographic and type maps were made from timber reconnaissance 

 fiel.d work and are considered good. The estimates for cut-over land have been 

 built up on an average acre basis for each type. Field data were secured by 

 calipering large areas within each type. These estimates are considered relia- 

 ble. The estimates for the mature virgin stands were likewise arrived at on an 

 average acre basis. It was found by check estimates that the original recon- 

 naissance figures were worthless. Accordingly, a revision was made on the 

 basis mentioned. Growth and yield figures are based on Korstian's work and 

 on recent investigations. All available data have been included in a report, 

 "Growth and yield data for the important timber species in northern New 

 Mexico " on file in the oflfices of the supervisor and district forester. 



The plan will be sufl[ic'ent for a period of 10 years. At the expiration of the 

 decade (1933) it should be revised. 



2. PHYSIOGKAPHIC FEATUEES OF THE AEEA 



(a) Size and location. — The Rio Pueblo is one of the important tributaries 

 of the Rio Grande in northern New Mexico. The watershed is located in Taos 

 County, approximately 20 miles south of Taos on the west slope of the Sangre 

 de Cristo Range of the Rocky Mountains. The forested area of the watershed, 

 all within the Carson National Forest, the Santa Barbara grant, and the 

 disputed strip amounts to 110,385 acres. 



(&) Topography. — The topography is very rough. Elevations range from 

 7,500 to 13,000 feet above sea level,. The main drainage is to the west, with 

 many side tributaries cutting deep canyons in the mountain side. The entire 

 working circle is a series of canyons and ridges with comparatively small areas 

 of level or gently sloping land in the canyon bottoms or on the ridges. The 

 rou^h country makes this logging chance a most difficult one from the operator's 

 viewpoint. 



(c) Climate. — Because of the high elevation an abundance of rainfall is pre- 

 cipitated upon this area. No exact figures on annual rainfall are available, but 

 on the basis of the records of stations situated in somewhat similar localities 

 it is estimated that the Rio Pueblo country receives about 26 inches annually. 

 Most of the rain falls in summ^er during July and August. The snows com- 

 mence in October or November and cover the ground until April. Some drifts on 

 north slopes and in sheltered ravines do not disappear until July. Showers in 

 April, May, and June are not uncommon, so the fire danger during that period 

 is not so pronounced as is usual in the Southwest. 



Killing frosts sometimes occur as late as June 1 and as early as September 15. 



The area receives an abundance of rainfall but has a short growing season. 



((f) Soil. — In general, the soil is a shallow clay loam with a range from 

 slide rock to a deep clay in the canyon bottoms. 



3. FOEEST DESCEIPTION 



(a) Types present. — Elevations range from 7,500 feet on the west up to 

 13,000 feet on the south and east. Accordingly, all of the important timber 

 types in the southern Rocky Mountain region are present, namely. Western 

 yellow pine, from 7,500 to 9,000 feet ; Douglas fir, from 9,000 to 10,000 feet ; and 

 spruce, from 10,000 feet to timber line at 11,500 feet. 



Of the total productive timber area of 52,865 acres the pine type covers 

 11,987 acres, the Douglas fir type 17,889 acres, and the spruce type 22,989 acres. 



(6) Major silvical features. — With the exception of the yellow-pine type, in 

 v/hich groups of all ages occur, the forest is practically even aged. Within a 

 Douglas fir or spruce stand, however, there is an even distribution of diameter 

 classes, due to various degrees of suppression, which in effect gives the forest an 

 all-aged appearance. It has been observed in old cuttings that after the stand 

 has been opened by felling the larger trees a marked increase in growth takes 

 place in the formerly suppressed or partially suppressed trees. Therefore, in 



■^ Laws authorizing the exchange of national forest timber or land for these areas were 

 enacted in 1925 and 1926, respectively, following a decision against the United States in 

 the case of the disputed strip. 



