Seedlings of Leucaena leucocephala (Lam.) de Wit. were planted in the field at The Agricultural Experiments Station of the college of Agriculture, King Saud University, Riyadh, Saudi Arabia in October 1995. Spacing between rows or trees within row was either 0.70 or 1.40 or 2.10 meter. The trees were pruned after two years of planting. Two trees from each plot were felled at time of pruning and...

The relationship between quadratic mean diameter and tree density appeared curvilinear on a log-log scale, based on data from direct-seeded slash pine (Pinus elliottii var. elliottii Engelm.) stands. The self-thinning trajectory followed a straight line for high tree density levels and then turned away from this line as tree density decreased. A system of equations was developed to model the re...

BACKGROUND AND AIMS Tree diameter, tree height and canopy closure have been described by previous meta-analyses as being important characteristics in roost selection by cavity-roosting bats. However, size and direction of effects for these characteristics varied greatly among studies, also referred to as heterogeneity. Potential sources of heterogeneity have not been investigated in previous me...

The effects of urban conditions on tree growth have been investigated in an increasing number of studies over the last decades, emphasizing the harsh environment of cities. Urban trees often grow in highly paved, compacted sites with consequently less soil moisture, higher soil temperatures, and greater vapor pressure deficits. However, there is still a knowledge gap regarding the impact of har...

This paper describes increment cores (a useful tool in forestry and wood technology) and their uses which include age determination, growth increment, specific gravity determination, fiber length measurements, fibril angle measurements, cell measurements, and pathological investigations. Also described is the use and care of the increment borer which is essential in obtaining good cores. A caut...

I review the present status of liquid mirror telescopes. In a nutshell: LMTs do work and several have been built and used. Extensive interferometric tests of liquid mirrors (the largest one having a diameter of 2.5 meters ) show diffraction limited performance. A large quantity of astronomical data have been taken at the NASA 3-m LMT and are currently being analyzed. Finally, I shall address th...

Gravitropism is necessary for plants to control the orientation of their axes while they grow in height. In woody plants, stem re-orientations are costly because they are achieved through diameter growth. The functional diversity of gravitropism was studied to check if the mechanisms involved and their efficiency may contribute to the differentiation of height growth strategies between forest t...

for maintaining of zagros forests role in wild life, water and soil conservation, the suitable solutions and methods for assessing the existing conditions and planning for management of this forests should be given. to detection of suitable sampling method to study tree diameter at breath height in the northern zagros forest, blake forest, in baneeh region, kurdistan province, and west of iran ...

Wood specific gravity (SG) has long been used by foresters as an index for wood properties. More recently, SG has been widely used by ecologists as a plant functional trait and as a key variable in estimates of biomass. However, sampling wood to determine SG can be problematic; at present, the most common method is sampling with an increment borer to extract a bark-to-pith core—a difficult task...