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Full-Text Articles in Forest Sciences

Effects Of Understory Vegetation And Litter On Plant Nitrogen (N), Phosphorus (P), N∶P Ratio And Their Relationships With Growth Rate Of Indigenous Seedlings In Subtropical Plantations, Jun Wang, Dafeng Hui, Hai Ren, Zhanfeng Liu, Long Yang Dec 2013

Effects Of Understory Vegetation And Litter On Plant Nitrogen (N), Phosphorus (P), N∶P Ratio And Their Relationships With Growth Rate Of Indigenous Seedlings In Subtropical Plantations, Jun Wang, Dafeng Hui, Hai Ren, Zhanfeng Liu, Long Yang

Biology Faculty Research

Establishing seedlings in subtropical plantations is very important for forest health, succession and management. Information on seedling nutrient concentrations is essential for both the selection of suitable indigenous tree species to accelerate succession of the established plantation and sustainable forest management. In this study, we investigated the concentrations of nitrogen ([N]), phosphorus ([P]), and N∶P ratio in leaves, stems and roots of seedlings of three indigenous tree species (Castanopsis chinensis, Michelia chapensis and Psychotria rubra) transplanted with removing or retaining understory vegetation and litter at two typical subtropical forest plantations (Eucalyptus plantation and native species plantation). We also measured the …


Low Mortality In Tall Tropical Trees, R. Q. Thomas, J. R. Kellner, D. B. Clark, D. R. Peart Apr 2013

Low Mortality In Tall Tropical Trees, R. Q. Thomas, J. R. Kellner, D. B. Clark, D. R. Peart

Dartmouth Scholarship

The dynamics of the tallest trees in tropical forests are of special interest due to their carbon content, canopy dominance, and the large canopy gaps created when they die. Known ecological mechanisms that may influence tall tree survival lead to conflicting predictions. Hydraulic stress and exposure to high winds and desiccation should increase death rates, yet the tallest trees have the greatest access to light and escape damage caused by falling boles and branches. The uncertainty in tall tree mortality rates has been difficult to address due to their low density, which makes mortality rates challenging to estimate accurately. Here, …


Evaluating Tree Height Using Pictometry® Hyperspatial Imagery, Daniel Unger, David Kulhavy, Matthew A. Wade Jan 2013

Evaluating Tree Height Using Pictometry® Hyperspatial Imagery, Daniel Unger, David Kulhavy, Matthew A. Wade

Faculty Publications

This study evaluated the use of Pictometry® hyperspatial 4-inch (10.2 centimeters) multispectral imagery to estimate height of baldcypress trees on the campus of Stephen F. Austin State University (SFASU), Nacogdoches, Texas. Actual tree heights of 60 baldcypress trees measured with a telescopic height pole were compared to Pictometry® estimated tree height. Linear correlation coefficients (r) and coefficient of determinations (R2) between actual tree height and Pictometry® estimated tree height for all 60 tress, and the shortest 30 and tallest 30 trees, were calculated. A paired t-test (alpha = 0.05) was calculated for all 60 tress, and the shortest 30 and …


Five Year Carbon Storage Analysis In The Gordon Natural Area, Joy Fritschle, Chad Hudson, Catherine Spahr, Andy Tamez Jan 2013

Five Year Carbon Storage Analysis In The Gordon Natural Area, Joy Fritschle, Chad Hudson, Catherine Spahr, Andy Tamez

Forest Carbon Storage Study Documents

The Gordon Natural Area (GNA) serves as a natural laboratory for a range of class research projects. In a Geography Field Methods course led by Dr. Fritschle, students established five permanent carbon-study plots in 2008. Since then, students have returned to these plots to measure the carbon stock of standing trees in five plots located along a topographic gradient: floodplain, ridge-top, lower mid-slope, mid-slope and upper mid-slope. Using U.S. Forest Service established guidelines, all trees greater than 5 cm and up to 73 cm in diameter at breast height (DBH) were measured and identified within each 40 m circular plot. …