management practices can affect the yield, maturity, and fiber quality of cotton. one practice used to increase yield has been to adjust the spacing between cotton rows. typically cotton is planted in row spaced 70-100 cm apart. ultra narrow row cotton production has been proposed as an economical means to increase yields and reduce production costs. a field study was conducted to assess the ef...

Second-order closure models for the canopy sublayer (CSL) employ a set of closure schemes developed for ‘free-air’ flow equations and then add extra terms to account for canopy related processes. Much of the current research thrust in CSL closure has focused on these canopy modifications. Instead of offering new closure formulations here, we propose a new mixing length model that accounts for b...

BACKGROUND AND AIMS The light availability on a temperate, deciduous-forest floor varies greatly, reflecting the seasonal leaf dynamics of the canopy trees. The growth and/or reproductive activity of understorey plants should be influenced by the length of the high-irradiance period from snowmelt to canopy closure. The aim of the present study was to clarify how spring-blooming species regulate...

Simultaneous triaxial sonic anemometer velocity measurements vertically arrayed at six levels within and above a uniform pine forest were used to examine two parameterization schemes for the triple-velocity correlation tensor employed in higher-order closure models. These parameterizations are the gradient-diffusion approximation typically used in second-order closure models, and the full budge...

This study attempts to find a new and better approach to estimate forest LAI in fully closed canopy condition. Although there have been many previous studies to estimate LAI using optical remote sensor data, there are not enough evidences whether the red and near-IR reflectance are still effective to estimate forest LAI in closed canopy situation. In this study, we have conducted a simple corre...

We proposed the hydraulic limitation hypothesis (HLH) as a mechanism to explain universal patterns in tree height, and tree and stand biomass growth: height growth slows down as trees grow taller, maximum height is lower for trees of the same species on resource-poor sites and annual wood production declines after canopy closure for even-aged forests. Our review of 51 studies that measured one ...

The objective of this study is to test the feasibility of nation-wide medium footprint airborne laser scanning (ALS) data for derivation of forest parameters. The comparison of canopy closure as one important parameter for many forest functions derived from ALS data and aerial photo interpretation was conducted. The present study was carried out in the framework of the Swiss National Forest Inv...