Use of remote sensing technologies to improve forest inventories and management: Review

To effectively preserve forests sustainably, one must strike a balance between the ecological needs of healthy forest ecosystems and the demands of an expanding human population. The recent increase in demand for forest products, particularly those that indicate a long-term change in land use from forests to other purposes, protecting forested ecosystems from harvest and other disturbances is essential. The objectives of this review were explaining the current state of the art of each of remote sensing technologies, highlighting important research problems related to forest inventories, and sharing some thoughts on how operational readiness for these technologies could affect the techniques used in forest inventories. Airborne laser-scanning data are frequently collected at elevations between 500 to 3000 meters for forest inventory. The assessment of forest inventory features and the development of digital terrain models for bare earth are two common uses for these data. Applications like species identification based on crown shape would require higher pulse densities, or more than five pulses per square meter. Airborne point clouds are more regularly spaced and monitor the canopy from the top down, whereas terrestrial systems examine the canopy from the bottom up. Point clouds are used to illustrate stand structure in both terrestrial and aerial LiDAR (light detection and ranging in) systems. The use of remote sensing technologies to simulate forest inventory features in combination with additional auxiliary geospatial data sets is not a new phenomenon. The rapidly evolving instrument technology and short service life, which require calibration across instruments and acquisitions, as well as the relatively new state of the technology and operational costs, which effectively limit the number of acquisitions from the same area, are some of the many reasons for this.