نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 دانشیار، گروه مهندسی صنایع مبلمان، دانشکده منابع طبیعی و علوم زمین، دانشگاه شهرکرد، شهرکرد، ایران.
2 دانش آموخته کارشناسی ارشد، دانشکده منابع طبیعی و علوم زمین، دانشگاه شهرکرد
3 استادیار، گروه علوم جنگل، دانشکدۀ منابع طبیعی و علوم زمین، دانشگاه شهرکرد، شهرکرد
4 دانشیار، بخش تحقیقات جنگلها و مراتع، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان اصفهان، سازمان تحقیقات، آموزش و ترویج کشاورزی،
5 استادیار، گروه مهندسی صنایع مبلمان، دانشکده منابع طبیعی و علوم زمین، دانشگاه شهرکرد
6 دانشیار، گروه مهندسی محیط زیست، دانشکده منابع طبیعی و علوم زمین، دانشگاه شهرکرد، شهرکرد، ایران
7 دانشیار، گروه مهندسی طبیعت، دانشکده منابع طبیعی و علوم زمین، دانشگاه شهرکرد، شهرکرد، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Abstract
Background and Objective: Zagros forests are a vital ecosystem in Iran, with wild almond species serving as key ecological components. This study investigates the effect of habitat conditions on wood physical properties and fiber biophysical characteristics of Amygdalus elaeagnifolia in two distinct habitats (Choliche and Karebas) within Chaharmahal va Bakhtiari Province.
Materials and Methods: Wood samples were selectively harvested from healthy and same-aged trees at breast height, and properties such as dry density, critical basal density, swelling, shrinkage, and fiber characteristics (length, diameter, and cell wall thickness) were measured. In order to investigate the effect of habitat on the physical and biochemical characteristics of A. elaeagnifolia tree, the data were first evaluated for normality using the Kolmogorov-Smirnov test and for homogeneity of variances using the Levene test. If the assumption of normality and homogeneity of variances was confirmed, the means were compared with independent t-test. In cases where the assumptions required for the parametric test were violated, the non-parametric Mann-Whitney U test was used to compare the means. To analyze the relationships between variables, the Pearson correlation coefficient was used and the correlation matrix was presented as the basis for identifying the dominant axes of change. This matrix allowed for the examination of collinearity between traits and the determination of the set of co-ordinated variables. Also, to analyze the relationships between variables, principal component analysis (PCA) was used to reduce the dimensions of the data and identify the principal components.
Findings: The results of statistical tests showed that some physical and biochemical properties of the wood of A. elaeagnifolia tree are affected by habitat conditions. The differences observed in indices such as density and structural components of fibers between the two habitats confirm the effective role of environmental factors such as climate in determining the properties of wood. The above correlations indicate a direct dependence of mass on volume at all moisture levels and indicate that the mass changes of the samples are mainly a function of their volume changes, which is fully consistent with the physical behavior of wood. The correlation between dry density and wet density and wet mass indicates the relative stability of the wood structure in the transition from dry to wet conditions. The critical basal density showed a strong positive correlation with fiber diameter. This indicates that thicker fibers are usually accompanied by thicker cell walls, which leads to an increase in basal density (dry mass to wet volume). Shrinkage and swelling showed a positive and very strong correlation. This indicates that these two mechanical properties have a coherent behavior; that is, wood that contracts more when drying also shows more swelling when absorbing moisture. In the biometric properties, a positive and strong correlation is also observed between the variables (crown diameter and crown cross-sectional area and between collar diameter and shoot height), which indicates the simultaneous and proportional growth of different tree components. Principal component analysis (PCA) showed that the first two components explain a major part of the total variance of the data. The first component was mainly influenced by the mass, volume and density of the wood, while the second component was more associated with traits related to swelling, shrinkage and climatic factors. These results indicate that the separation of specimens and habitats is not based solely on a single characteristic, but rather on the simultaneous combination of fiber and physical traits.
Conclusion: Habitat conditions critically shape the physical and biophysical properties of A. elaeagnifolia wood. These insights support ecological assessments, conservation planning, and sustainable management of Zagros forest habitats.
کلیدواژهها [English]
)