Changes in Vegetation

About this map

The vegetation in the LA region is likely to face 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 with a measure called NDVI (Normalized Difference Vegetation Index), an indicator of vegetation health or greenness.

The map on the left depicts recent NDVI conditions during the peak of summer. 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).

In the map on the right, you can observe the difference between NDVI in summer 2000 and summer 2020. 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: Didan, K. (2015). MOD13Q1 MODIS/Terra Vegetation Indices 16-Day L3 Global 250m SIN Grid V006 [Data set]. NASA EOSDIS Land Processes DAAC. Accessed 2023-02-15 from