Multi-decadal changes in tundra environments and ecosystems: synthesis of the International Polar Year-Back to the Future project (IPY-BTF).

Understanding the responses of tundra systems to global change has global implications. Most tundra regions lack sustained environmental monitoring and one of the only ways to document multi-decadal change is to resample historic research sites. The International Polar Year (IPY) provided a unique opportunity for such research through the Back to the Future (BTF) project (IPY project #512).

Four decades of plant community change in the Alpine tundra of southwest Yukon, Canada.

Repeat measurements from long-term plots provide precise data for studying plant community change. In 2010, we visited a remote location in Yukon, Canada, where a detailed survey of alpine tundra communities was conducted in 1968. Plant community composition was resurveyed on the same four slopes using the same methods as the original study.

Vegetation, Microtopography, and Depth of Active Layer on Different Exposures in Subarctic Alpine Tundra.

Four slopes with different exposures (southeast-, southwest-, east-, and north-facing), but with similar gradients, elevations, and rock type, were studies in the Ruby Mountains of southwest Yukon Territory, Canada, Vegetation was best developed on the southeast facing slope, was successively less on east- and southwest-facing slopes, and least on the northfacing slope. Solifluction lobes were present in varying degrees, and their development largely followed that of vegetation in that they were best developed on the southeast-facing slope and least well developed on the north- and southwest-facing slopes. The vegetation occurred in sharply delineated communities across the lobes on the southeast-facing slope, and the communities repeated themselves in predictable patterns.