TREE FOLIAGE CHARACTERISTICS 

 ASSOCIATED WITH THE RELEASE 

 OF WESTERN REDCEDAR 

 Literature Review 



Foliar nutrient concentrations can be mathematically 

 related to various forms of tree growth. Using multiple 

 regression techniques, Leyton and Armson (1955) 

 determined the critical threshold amounts of foliar 

 nitrogen and potassium for height growth of Scots pine 

 (Pinus sylvestris L.). The same methods were used to 

 estimate Japanese larch (Larix leptolepsis Murr.) height 

 growth as a function of foliar nutrient concentrations 

 (Leyton 1956). Foliar nutrient quantities can be used to 

 predict basal area, height, and volume growth of red 

 pine (Pinus resinosa Ait.) (Hoyle and Mader 1964). 

 Likewise, amounts of nutrients in leaf parts are related 

 to the height and volume growth of sycamore (Platanus 

 occidentalis L.) (Haines and others 1979). Using entire 

 tree populations, Stone and others (1958) used foliar 

 nutrient concentrations to predict stand volume. Foliar 

 concentrations of different nutrients can be used to 

 predict site index as demonstrated by Gagnon (1964) 

 and Radwan and DeBell (1980). 



Mathematical models predicting tree growth using 

 foliar nutrients can help identify amounts of foliar 

 nutrients that limit tree growth. The relationships of 

 tree growth to foliar nutrient concentrations have been 

 divided into a region of deficiency, a region of critical 

 amounts, and a region of luxury consumption (Barrows 

 1959; Richards and Bavege 1972; Everard 1973). 

 Leyton (1958), when investigating critical and nutrient 

 requirements for tree growth, found it easier to detect 

 critical nutrient amounts than to find optimum 

 amounts or to predict fertilizer response. 



Critical and deficient amounts of foliar nutrients for 

 fruit production have been thoroughly investigated 

 (Sprague 1964) and are continually being refined for 

 different crops and soils (Jones and others 1968; 

 Embleton and Jones 1966; Embleton and others 1971). 



Foliage nutrient concentrations for many eastern 

 conifer (Lowry and Avard 1968. 1969; White 1954), 

 and southern conifer (Wells and Metz 1963) populations 

 have been reported. Foliar nutrient concentrations for 

 northwest conifers have been reported by Tarrant and 

 others (1951), Daubenmire (1953), and Beaton and 

 others (1965). 



In addition to sampling the natural variation of foliar 

 nutrients of different species, more specific studies were 

 conducted on foliar nutrient deficiencies in conifers. 

 Van den Burg (1979) reported foliar deficiency levels for 

 nitrogen, phosphorus, potassium, magnesium, and 

 manganese in three spruce species. Likewise, Gessel 

 and others (1951) reported preliminary results that 

 identified foliar nutrient deficiencies for western 

 redcedar, and later Walker and others (1955) finalized 

 the mineral requirements for western redcedar. Powers 

 (1976) summarized the deficient and critical foliar 

 nutrient concentrations for conifers, hardwoods, and 

 field crops. 



Besides establishing deficiency levels of nutrients for 

 tree growth, many studies have also reported the foliar 

 symptoms of nutrient deficiencies. Foliar nutrient 



deficiencies of hardwoods have been described by 

 Ashby (1959). Ashby and Mika (1959), Hacskaylo and 

 Struthers (1959), Ike (1968), Phares and Finn (1972). 

 Smith (1976). Perala and Sucoff (1965), and Mader and 

 others (1969). Foliar symptoms of mineral deficiencies 

 of conifers have been described by Walker and others 

 (1955). White and Wright (1966), and Behan (1968). 



Methods 



DATA COLLECTION 



A sample of the most recent foliage was collected at a 

 height of 12 feet (3.7 m) and from the north side of 

 each western redcedar tree on the variable radius plots. 

 As the foliage was collected, its color was identified 

 using the Munsell color notation system (Munsell Color 

 Company 1952; Hamilton 1960). The foliage was kept 

 cold until it was chemically analyzed by the University 

 of Idaho College of Agriculture Plant and Soil Analytical 

 Laboratory. These chemical tests resulted in amounts 

 of 12 foliar nutrients for 601 western redcedar trees in 

 this study (table 8). 



IDENTIFYING SIGNIFICANT ASSOCIATIONS 



Regression analysis was used to identify the foliar 

 variables significantly associated with the release of 

 western redcedar. The dependent variable in the regres- 

 sion models was the difference between the DDS for 

 released trees and the predicted nonreleased DDS for 

 the same tree (DDS "released" - DDS "nonreleased"). 

 Twelve foliar variables were tested for association with 

 the dependent variable. The predicted diameter growth 

 of each tree was included in each regression model to 

 eliminate variation not related to the release response of 

 the sampled trees. The transformed diameter increment 

 for the 10 years after treatment was used as the > 

 dependent variable in the regression models. 



Foliar nutrient content was separated by foliar color 

 using discriminant analysis in which 1 1 Munsell foliar 

 colors and 12 foliar nutrients were used. 



Results 



The diameter-growth responses of 601 western 

 redeedars to release from overstory and surrounding 

 competition were related to foliar characteristics. 

 Amounts of phosphorous and manganese in foliage of 

 western redcedar had positive, significant relationships 

 with the differences between released diameter growths 

 and predicted nonreleased diameter growths. These 

 relationships were indicated by the positive significant 

 coefficients in the regression models for the phosphorus 

 and manganese variables (table 9). These coefficients 

 were evidence that western redcedar having foliage 

 with the greater amounts of manganese and phos- 

 phorus had greater diameter growth response to release 

 than western redcedar having foliage with smaller 

 amounts of manganese and phosphorus. 



Foliage concentrations of iron, sodium, potassium, 

 and sulfur had negative significant relationships with 

 the differences in diameter growths of released and 

 predicted nonreleased western redeedars. The negative 

 regression coefficients for foliar iron, sodium, 

 potassium, and sulfur indicated that the diameter incre- 

 ment of released trees with the higher concentrations of 



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