Longitudinal distribution of Mimagoniates microlepis and Hoplias malabaricus was analyzed in a coastal stream system in Southeast Brazil. Six sites were sampled by electrofishing in seven months, from July 94 to July 95. Densities of M. microlepis, and H. malabaricus and its prey (Poecilia vivipara, Deuterodon sp. and Astyanax janeiroensis) were estimated by the Zippin method; environmental var...

In this study, a semi-empirical model that was originally developed for stem volume estimation is used for aboveground biomass (AGB) estimation of a spruce dominated alpine forest. The reference AGB of the available sample plots is calculated from forest inventory data by means of biomass expansion factors. Furthermore, the semi-empirical model is extended by three different canopy transparency...

We evaluate the potential of deriving a vegetation leaf area index (LAI) from small footprint airborne laser scanning data. Based on findings from large area histograms of discrete laser returns for two contrasting plots, LAI is estimated from the fraction of first to last and single returns inside the canopy. The canopy returns are classified using thresholding of LIDAR raw data heights subtra...

This discussion paper is/has been under review for the journal Geoscientific Model Development (GMD). Please refer to the corresponding final paper in GMD if available. Abstract Cities impact both local climate, through urban heat islands, and global climate, because they are an area of heavy greenhouse gas release into the atmosphere due to heating, air conditioning and traffic. Including more...

Green leaf area index (LAI) measures the amount of foliage in a vegetation canopy and strongly influences many ecological processes, including the fraction of photosynthetically active radiation (FPAR) absorbed by the canopy. Since these two variables are required in most modeling studies of vegetation and climate, they are operationally derived from measurements of the Moderate Resolution Imag...

Monitoring the components of crop canopies with remote sensing can help us understand the within-canopy variation in spectral properties and resolve the sources of uncertainties in the spectroscopic estimation of crop foliar chemistry. To date, the spectral properties of leaves and panicles in crop canopies and the shadow effects on their spectral variation remain poorly understood due to the i...

Under natural sunlight illumination, the chlorophyll fluorescence emitted by the vegetation represents less than 3% of the reflected light in the near infrared part of the spectrum. This small amount is difficult to quantify except at certain wavelengths, where the solar spectrum is attenuated (Fraunhofer lines). An instrument measuring the in-filling of the atmospheric oxygen absorption band a...

February 2009 109 continued on page 110 Introduction Elevation data are an important component in the visualization and analysis of geographic information. The creation and display of 3D models representing bare earth, vegetation, and surface structures have become a major focus of light detection and ranging (lidar) remote sensing research in the past few years. Lidar is an active sensor that ...

Questions: How do fire frequency, tree canopy cover, and their interactions influence cover of grasses, forbs and understorey woody plants in oak savannas and woodlands? Location: Minnesota, USA. Methods: We measured plant functional group cover and tree canopy cover on permanent plots within a long-term prescribed fire frequency experiment and used hierarchical linear modeling to assess plant ...