Timberline (noun)

1. The upper boundary or limit of tree growth in an area, often due to environmental factors such as altitude or climate.
2. The line marking the boundary or limit of tree growth in an area.

Origin:

From timber + line.

Examples:

1. The timberline in the mountains marked the end of tree growth, with only tundra beyond that point.
2. The timberline was an important indicator of the type of environment present in an area, with forests below and tundra above.
3. The timberline was a popular spot for hikers, who were able to enjoy panoramic views from its heights.
4. The timberline was visible from a distance, marking the transition from lush forest to barren tundra.
5. The timberline was a unique and important ecosystem, providing habitat for a variety of wildlife and plant species.