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Horizontal and Vertical Stand Structure
Analysis of Uneven-Aged Pine-Juniper-Oak
Mixed Forest ecosystem in Northeastern
Mexic01
J. Jimenez2
o. Aguirre32
H. Kramer
Ahstract-A stand structure investigation was carried out in a
large uneven-aged mixed pine-juniper-oak stand, located in the
training forest ofthe forestry faculty of the Universidad Autonoma
de Nuevo Leon in the Sierra Madre Oriental, Nuevo Leon, Mexico.
The main objective of this research was to develop an adequate
stand structure analysis, which to complex conditions of Mexican
diverse, uneven-aged conifer-hardwood natural forests (Pinus
pseudostrobus, Juniperus flaccida, Quercus rysophylla, Q. canbyi,
Q. Zaceyi, Q. polymorpha, Arbutus xalapensis, Juglans mollis, Rhus
virens, Prunus serotina y Cercis canadensis).
The recommended inventory procedure was a combination of
total tree measurements and detailed investigations with the aid of
the "Structural Group of Four" as described by Fiildner (1995). The
data of the full enumeration were used to determine the abundance
(nlha) and dominance (gl,sfha) of individual tree species, as well as
a homogeneity indicator for total stand and different tree species.
Representative samples were used to estimate frequency of tree
species, diameter differentiation (TD) and height differentiation
(TH), as well as the mingling (DM) for total stand and the different
tree species. These procedures were used to estimate horizontal
structure.
With the aid of the heights of all sample-trees, the tree species
were distributed on three height zones (based on number and basal
area of the trees) to determine vertical structure analysis. In this
case Pinus pseudostrobus was found in the upper zone and the other
species were distributed in the second and third height zones.
This research emphasizes the importance of a detailed, horizontal and vertical stand structure analysis in forest ecosystem according to the tree species.
Ipaper presented at the North American Science Symposium: Toward a
Unified Framework for Inventorying and Monitoring Forest Ecosystem
Resources, Guadalajara, Mexico, November 1-6,1998.
2Facultad de Ciencias Forestales, U.A.N.L. Apartado Postal 41, Linares,
N.L., Mexico. e-mail: jjimenez@CCr.dsi.uanl.mx
3Forstliche Fakultat der Uiversitat Giittingen, Germany.
USDA Forest Service Proceedings RMRS-P-12. 1999
281