Finding the tree line: quantitative derivation of forest cover estimates
Abstract- Human activities and climate change are affecting the current position of our ecosystem boundaries and it is expected that the boreal northern tree line will shift to the north due to milder climate at high latitude. This change in extent of the boreal forest will affect greatly the carbon...
| Main Authors: | , , , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.141.4691 http://www.isprs.org/publications/related/ISRSE/html/papers/742.pdf |
| Summary: | Abstract- Human activities and climate change are affecting the current position of our ecosystem boundaries and it is expected that the boreal northern tree line will shift to the north due to milder climate at high latitude. This change in extent of the boreal forest will affect greatly the carbon cycle and sustainable development of the north. To be able to assess these changes, field measurements using digital hemispherical photography were acquired to quantitatively estimate vegetation characteristics such as leaf area index (LAI) and canopy crown closure in the Yukon and Northwest Territories of Canada during the summer of 2004. Crown closure is used in this study as a quantitative measure to assess forest presence/absence based on a given forest definition. Empirical relationships are derived using LANDSAT ETM+ images that were normalized with coarse resolution SPOT-VGT data. The best results are found when linear combination of bands for the broadleaf species and linear combination of exponential relationships for the coniferous species are used. The crown closure maps from LANDSAT images are then used to calibrate low-resolution forest cover maps from NOAA-AVHRR and SPOT-VGT data. 1. |
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