The Effect of Nitrogen Fertilization, Rock Type, and Habitat Type on Individual Tree Mortality

An individual tree mortality model for nitrogen fertilized Douglas-fir (Pseudotsuga menziesii var. glauca [Beissn.] Franco) stands was developed using data from permanent research plots located throughout the inland Northwest. The proposed linear logistic model included the following independent variables: a dummy variable for the two habitat types, a set of dummy variables for the five rock types, a set of dummy variables for the three N fertilizer treatments, diameter at breast height, crown ratio, and crown competition factor. The results show that N fertilization, rock type, and habitat type significantly affect individual tree mortality. The probabilities of tree mortality on fertilized plots were greater than those on control plots and increased with increasing N fertilizer application rates. Trees growing on granitic and metasedimentary rocks had lower foliar potassium concentration and exhibited greater probabilities of mortality than did those growing on other rocks. The probabilities of mortality for trees growing on sedimentary rocks were very low. Moist sites had lower soil fertility and produced higher mortality rates than dry sites. Furthermore, the N fertilization response ratio, defined as the annual mortality probability of a fertilized tree over the annual mortality probability of a unfertilized tree with identical tree and stand characteristics, was estimated based on the mortality model. The response ratios were nearly constant (about 1.4) across a range of tree diameters for all rock types with the 224 kg N treatment. The response ratios were also nearly constant (about 2.1) across a range of tree diameters for all rock types with the 448 kg N treatment. Finally, the mortality prediction model passed a validation test on independent data not used in model development.

[1]  R. G. Buchman,et al.  A tree survival model with application to species of the Great Lakes region , 1983 .

[2]  Jerome K. Vanclay,et al.  Growth models for tropical forests: a synthesis of models and methods , 1995 .

[3]  David A. Hamilton,et al.  Modeling the probability of individual tree mortality , 1976 .

[4]  Gregory S. Biging,et al.  Using the non-parametric classifier CART to model forest tree mortality , 1998 .

[5]  David A. Hamilton,et al.  Extending the range of applicability of an individual tree mortality model. , 1990 .

[6]  S. Buol.  Soil Genesis and Classification , 1980 .

[7]  Nicholas L. Crookston,et al.  User's guide to the stand prognosis model / , 1982 .

[8]  John W. Moser,et al.  Dynamics of an Uneven-Aged Forest Stand , 1972 .

[9]  K. Lowell,et al.  Stand growth projection: simultaneous estimation of growth and mortality using a single probabilistic function , 1987 .

[10]  P. Harcombe,et al.  Tree Life Tables , 1987 .

[11]  R. Kobe,et al.  Intraspecific Variation in Sapling Mortality and Growth Predicts Geographic Variation in Forest Composition , 1996 .

[12]  Bahman Shafii,et al.  Effects of Nitrogen Fertilization on Growth of Grand Fir and Douglas-Fir Stands in Northern Idaho , 1989 .

[13]  M. R. Carter,et al.  Soil Sampling and Methods of Analysis , 1993 .

[14]  D. Binkley,et al.  Forest Nutrition Management , 1987, Forest Science.

[15]  Robert A. Monserud,et al.  Height Growth and Site Index Curves for Inland Douglas-fir Based on Stem Analysis Data and Forest Habitat Type , 1984 .

[16]  C. R. Hatch,et al.  The effect of habitat type and rock type on individual tree basal area growth response to nitrogen fertilization , 2000 .

[17]  H. Burkhart,et al.  Constraining individual tree diameter increment and survival models for loblolly pine plantations , 1997 .

[18]  William R. Wykoff,et al.  A Basal Area Increment Model for Individual Conifers in the Northern Rocky Mountains , 1990, Forest Science.

[19]  David A. Hamilton,et al.  A Logistic Model of Mortality in Thinned and Unthinned Mixed Conifer Stands of Northern Idaho , 1986, Forest Science.

[20]  K. Coates,et al.  Models of sapling mortality as a function of growth to characterize interspecific variation in shade tolerance of eight tree species of northwestern British Columbia , 1997 .

[21]  K. Cromack,et al.  Response of Douglas-fir to infection by Armillaria ostoyae after thinning or thinning plus fertilization , 1991 .

[22]  R. Monserud,et al.  Modeling individual tree mortality for Austrian forest species , 1999 .

[23]  L. Zhang,et al.  Effects of intermediate silvicultural treatments on the distribution of within-stand growth , 1994 .

[24]  J. Krajícek,et al.  Crown competition-a measure of density. , 1961 .

[25]  Clinton K. Williams,et al.  Forested plant associations of the Okanogan National Forest , 1983 .

[26]  Y. Lee,et al.  Predicting mortality for even-aged stands of lodgepole pine , 1971 .

[27]  Jerome K. Vanclay,et al.  Compatible Deterministic and Stochastic Predictions by Probabilistic Modeling of Individual Trees , 1991, Forest Science.

[28]  J. Marshall,et al.  Root chemistry of Douglas-fir seedlings grown under different nitrogen and potassium regimes , 1998 .

[29]  Robert A. Monserud,et al.  Simulation of forest tree mortality , 1976 .

[30]  G. Gertner,et al.  Modeling red pine tree survival with an artificial neural network , 1991 .

[31]  B. Smith,et al.  Forested plant associations of the Colville National Forest. Forest Service general technical report , 1995 .

[32]  J. Vanclay.  Mortality functions for north Queensland rainforests , 1991 .