Relationships between leaf pigment content and spectral reflectance across a wide range of species, leaf structures and developmental stages

https://pubag.nal.usda.gov/download/26536/PDF

Estimating Corn Leaf Chlorophyll Concentration from Leaf and Canopy Reflectance

Leaf structure and function are shown to result in distinctive variations in the absorption and reflection of solar radiation from plant canopies. The leaf properties that determine the radiation-interception characteristics of plant canopies are directly linked to photosynthesis, stomatal resistance and evapotranspiration and can be inferred from measurements of reflected solar energy. The effects of off-nadir viewing and atmospheric constituents, coupled with the need to measure changing surface conditions, emphasize the need for multitemporal measurements of reflected radiation if primary production is to be estimated.

https://www.tandfonline.com/doi/pdf/10.1080/01431168608948944

Satellite remote sensing of primary production

Hyperspectral Vegetation Indices and Their Relationships with Agricultural Crop Characteristics

We evaluated the response of the Earth land biomes to drought by correlating a drought index with three global indicators of vegetation activity and growth: vegetation indices from satellite imagery, tree-ring growth series, and Aboveground Net Primary Production (ANPP) records. Arid and humid biomes are both affected by drought, and we suggest that the persistence of the water deficit (i.e., the drought time-scale) could be playing a key role in determining the sensitivity of land biomes to drought. We found that arid biomes respond to drought at short time-scales; that is, there is a rapid vegetation reaction as soon as water deficits below normal conditions occur. This may be due to the fact that plant species of arid regions have mechanisms allowing them to rapidly adapt to changing water availability. Humid biomes also respond to drought at short time-scales, but in this case the physiological mechanisms likely differ from those operating in arid biomes, as plants usually have a poor adaptability to water shortage. On the contrary, semiarid and subhumid biomes respond to drought at long time-scales, probably because plants are able to withstand water deficits, but they lack the rapid response of arid biomes to drought. These results are consistent among three vegetation parameters analyzed and across different land biomes, showing that the response of vegetation to drought depends on characteristic drought time-scales for each biome. Understanding the dominant time-scales at which drought most influences vegetation might help assessing the resistance and resilience of vegetation and improving our knowledge of vegetation vulnerability to climate change.

https://www.pnas.org/content/pnas/110/1/52.full.pdf

Response of vegetation to drought time-scales across global land biomes

https://pubag.nal.usda.gov/download/37948/PDF

Edward B. Knipling

Papers

Physical and physiological basis for the reflectance of visible and near-infrared radiation from vegetation