Landscape dynamics are the “big picture” of changes in the growing season, vegetation, and surface water. The length and warmth of the growing season control the amount of plant matter, which is the energy supply for all other biological processes and crucial for wildlife. Major changes in vegetation are likely to benefit some species and harm others. A long-term increase in shrubs in the arctic has already been observed. Formation and drainage of ponds and lakes, which are important habitat for many species, are natural processes that may be accelerated by climate change.
Remote sensing provides valuable tools for monitoring landscape patterns and dynamics. Our long-term monitoring program includes 4 different projects that utilize remote sensing to follow landscape change:
Analysis of trends in surface greenness as measured from satellites. Satellites have been measuring the amount of sunlight reflected from the earth in different wavelengths (colors) for over 20 years. We can compute an index of the earth’s greenness from these measurements and determine the length of the growing season and its peak greenness.
Analysis of trends in greenness and snow cover measured by remote automated cameras at weather stations. These photographs provide a close-up view of changes in the seasons that can be linked directly to weather data.
We will analyze changes in vegetation and other land surface features visible on high-resolution aerial photographs. We have a set of detailed aerial photographs taken on a 20-km grid across the Arctic Network. On these photographs we can measure things like shrub cover, tree cover, and area of small ponds caused by thawing permafrost. We plan to repeat these photographs every 10 years and compare the dates to get a network-wide view of changes over time.
We will analyze the change in area of lakes and ponds using satellite images. Water levels in lakes and ponds in permafrost regions can change rapidly and lakes often drain entirely. These changes can be tracked using inexpensive moderate-resolution satellite imagery.
