Spaceborne potential for examining taiga-tundra ecotone form and vulnerability

Area of Science:

• Ecology
• Remote Sensing
• Forestry

Background:

• The taiga-tundra ecotone (TTE) exhibits subtle, heterogeneous structural changes across circumpolar regions.
• Ecotone form, defined by forest structure patterns, is influenced by local conditions and drives ecotone dynamics.

Purpose of the Study:

• To analyze forest structure at the patch-scale within the TTE using spaceborne data.
• To assess both vertical and horizontal components of ecotone form.
• To evaluate the potential of high-resolution spaceborne imagery (HRSI) for mapping and understanding TTE form.

Main Methods:

• Mapping forest patches in northern Siberia using a multi-resolution suite of spaceborne data.
• Examining the uncertainty of forest patch height estimates derived from spaceborne data.
• Analyzing uncertainty in relation to a conceptual model of general ecotone forms.

Main Results:

• Spaceborne data, particularly HRSI, offers opportunities to improve patch-scale forest height estimates.
• A significant uncertainty (centered at ~40%) was found in relative maximum height estimations.
• This height uncertainty constrains the ability to differentiate forest patches and identify TTE forms.

Conclusions:

• Reducing uncertainty in spaceborne height estimates is crucial for accurately depicting TTE form.
• Improved TTE form depiction can help explain variable forest responses to climate change.
• Addressing uncertainty may reveal the vulnerability of TTE portions to forest structure alterations.