Land Surface Phenology Monitoring

On This Page Navigation

Hogan in the shade of a large deciduous tree with trees turning yellow in fall. Steep canyon walls in the background.
Phenology relates to the timing of periodic plant and animal life cycle events, such as leaves changing color in the fall in Canyon de Chelly National Monument.

NPS

Landscape processes related to climate, geology and hydrology operate over a range of scales and influence the distribution, abundance and productivity of plants and animals. This, in turn, influences the development and maintenance of ecosystems. Phenology refers to the timing of periodic plant and animal life cycle events, such as spring greenup, flowering, and animal migration. It is an indicator of an ecosystem's response to environmental variables, most notably climate. Scientists measure and monitor phenology using remote sensing data, typically acquired from earth orbiting satellites. Phenological monitoring of vegetation allows us to examine the status and trends in the integrated vegetation response to climate variability and climate trends.

Snow cover extent, timing and duration are important factors that respond to changes in climate. They are related to other ecosystem processes, such as quantity and timing of soil moisture recharge, runoff, and streamflow. Changes in snow depth and duration ultimately affect growing season dynamics and net primary productivity in the region.

Scientists project that climate change will affect the western United States in a number of ways:

  • warmer temperatures
  • lower winter precipitation
  • a longer growing season with increased water stress

The effects of these changes in moisture availability are already being experienced in this region. Drought, associated insect outbreaks, and increased fire frequency and severity are evidence of this. Monitoring vegetation phenology may provide us with early indications of whether current vegetation can persist under these projected conditions, or whether there may be gradual or sudden vegetation type shifts.

Satellite image of New Mexico and surrounding states. The background is mostly brown with dark green areas that represent forests. White areas cover the central area of the image.
Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery of snow cover in New Mexico.

NASA

Monitoring Objectives

The Southern Colorado Plateau Network (SCPN) is using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data to monitor the phenology and condition of vegetation and snow cover in SCPN parks. All MODIS data used in this project are provided by NASA through the NASA Land Processes Distributed Active Archive Center (LP DAAC) at the USGS/Earth Resources Observation and Science (EROS) Center, Sioux Falls, South Dakota.

Monitoring objectives are

  • Determine annual status, interannual variability, and long-term trends in the timing of growing season start and end, and intensity of seasonal greenness.

  • Determine annual status, interannual variability, and long-term trends in the timing and duration of snow cover.

Vital Signs and Metrics

1. Growing season

  • Season start

  • Season end

2. Seasonal greenness

  • Spring peak greenness

  • Monsoon peak greenness

  • Season-long productivity

3. Snow cover

  • Snow cover extent

  • Snow cover duration

Monitored in These Parks



Monitoring Project Status

SCPN has MODIS satellite data covering SCPN parks from 2000 to the present. Currently, the network is working on addressing challenges in processing and analyzing MODIS data for arid ecosystems. The Satellite-based Vegetation Phenology and Condition, and Snow Cover Extent Monitoring Protocol for the Northern and Southern Colorado Plateau Networks was published in 2017.

Project Contact

Jodi Norris, Landscape and Quantitative Ecologist

Reports and Publications

Thoma, D., J. Norris, and P. Lauck. 2017.Satellite-based Vegetation Condition and Phenology, and Snow Cover Extent Monitoring Protocol for the Northern and Southern Colorado Plateau Networks. Natural Resource Report NPS/SCPN/NRR—2017/1533. National Park Service, Fort Collins, Colorado.

Last updated: November 19, 2018