Understanding Forest Health with Remote Sensing-Part II—A Review of Approaches and Data Models

摘要: Stress in forest ecosystems (FES) occurs as a result of land-use intensification, disturbances, resource limitations or unsustainable management, causing changes health (FH) at various scales from the local to global scale. Reactions such stress depend on phylogeny species communities and characteristics their impacting drivers processes. There are many approaches monitor indicators FH using in-situ inventory experimental studies, but they generally limited sample points small areas, well being time- labour-intensive. Long-term monitoring based inventories provides valuable information about trends FH. However, abrupt short-term cannot sufficiently be assessed through usually have repetition periods multiple years. Furthermore, numerous monitored surveys expert judgement. Remote sensing (RS) technologies offer means an effective, repetitive comparative way. This paper reviews techniques that currently used for monitoring, including close-range RS, airborne satellite approaches. The implementation optical, RADAR LiDAR RS-techniques assess spectral traits/spectral trait variations (ST/STV) is described detail. We found ST/STV can record RS. Therefore, approach framework develop standardized concept RS applicable future programs. It only linking we will able improve our understanding relationship between stressors, associated responses order robust indicators.