Changes in Vegetation

About this map

LA’s vegetation is sure to be affected by warmer temperatures and lower precipitation, and this in turn will impact the animal species that rely on these plants for food and shelter. One of the ways that researchers examine plant health over a large region is NDVI (Normalized Difference Vegetation Index), a measure of vegetation greenness.

NDVI values can tell us about the density of vegetation (how much plant life is in an area) and/or how productive the plants are (more productive vegetation is actively photosynthesizing). The higher a region’s NDVI value, the more photosynthesis is occurring in that region. There are many sharp contrasts between high and low NDVI areas in Los Angeles (e.g. between the Angeles National Forest and Downtown LA).

By studying trends in NDVI over time, scientists can detect changes in vegetation health. Because plant health is closely linked to water availability, a decrease in NDVI can reveal the effects of drought on a landscape. 

Data source: NDVI generated from MOD13Q1 data, which was retrieved from the online MODIS Data Products, courtesy of the NASA EOSDIS Land Processes Distributed Active Archive Center (LP DAAC), USGS/Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota, modis.gsfc.nasa.gov/data/dataprod/mod13.php. NDVI statistics: Chunyu Dong, UCLA.