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Seasonal closures – when, where and why?

December 1, 2018

Roughly half of Pitkin County’s open space lands are closed seasonally or, in a few cases, entirely, for the protection of wildlife.

Wintertime closures typically start in December, when snows begin to accumulate and temperatures drop.  While black bears hibernate, other large mammals must forage and move about through deepening snow, taxing their energy reserves during the harshest months of the year.  In addition, the females are often pregnant with young that will be born in the spring or early summer, adding to the challenge of finding enough to eat as shrubs and grasses disappear beneath the snow.  The absence of humans means elk, deer, bighorn sheep and other species don’t have to expend energy unnecessarily in reaction to human presence.


Welcoming in the new (water) year from the ground on down

October 26, 2018

A schematic of the elevations and ecosystem types for the iRON stations. Two stations are located at North Star Nature Preserve, which is why there are only 8 elevation points for the 9 total stations. Image Credit: Ellie Barber.

As the leaves changed last month, the colors welcomed in a new year — a new water year. In order to include even early season snowpack in hydrological planning, a water year differs from a calendar year by running from October through September instead of from January to December. This allows water that fell snow as snow in early winter to be included in the same year as the spring streamflows it drives. Having a water year that begins in October makes sense from a soil perspective as well: this fall’s soil moisture plays an important role in next year’s water supply.

The amount of water held in the soil is called soil moisture, and it is vital in shaping local ecology and fire risk, as well as in determining how much water we receive as runoff during a (more…)

North Star’s fen – an ancient ecosystem

October 1, 2018

The average person might call it a swamp.  The average rancher might want to drain it.  But a fen, like the one at North Star Nature Preserve, an open space property near Aspen, is actually an “old-growth” wetland that can be thousands of years old.

A fen is a groundwater-fed wetland with saturated organic soils commonly known as peat.  Fens develop when the rate of plant growth exceeds the rate of decomposition of plant litter. The result is the accumulation of organic matter, i.e. peat.  

Here’s what the 2018 Wetland Fen Assessment & Floristic Inventory of North Star Nature Preserve has to say on the subject:

“Fens are rare and ecologically significant wetlands in Colorado and the Rocky Mountains and are colloquially known as ‘old-growth’ wetlands because they can be thousands of years old.  They are ancient ecosystems 8,000 to 12,000 years old.  Even though they occupy a small percentage of the landscape, they provide important headwater quality functions, including carbon storage, wildlife habitat and biodiversity.”