Boreal Thermokarsts and Predaceous Diving Beetles

"Thermokarst" is a land surface characterised by very irregular surfaces 

of marshy hollows and small hummocks formed as ice-rich permafrost 

thaws, that occurs in Arctic areas, and on a smaller scale in mountainous 

areas such as the Himalayas and the Swiss Alps. These pitted surfaces 

resemble those formed by solution in some karst areas of limestone, which is 

how they came to have karst attached to their name without the presence 

of any limestone. Small domes that form on the surface due to frost heaving 

with the onset of winter are only temporary features. They then collapse 

with the arrival of next summer's thaw and leave a small surface 

depression. Some ice lenses grow and form larger surface hummocks, 

which last many years and sometimes become covered with grasses 

and sedges, until they begin to thaw. These domed surfaces eventually 

collapse either annually or after longer periods and form depressions 

which contribute to uneven surfaces. These are included within 

the general label of thermokarst.

--   Wikipedia

One of the most interesting natural areas in Fairbanks is Creamer's Field, a wildlife refuge that was created from the lands of a local dairy farm that, during its years of operation, was the largest individually owned dairy farm in Alaska.  It is home to thousands of migrating sandhill cranes, as well as a multitude of other wildlife and plant species.  For the visitor, miles of hiking trails through grasslands and boreal forest are supplemented with hiking and nature pamphlets and signs that help the visitor understand the flora, fauna and environment through which we walk.

Creamer's Field is only about five miles from our campground, so we decided to bicycle over.  The terrain in Fairbanks is flat because the city lies in the Tanana River valley, a wide plain made flat by glaciers and ancient wide rivers and lakes.  Locally, we only had to cross the lovely Chena River, a tributary of the Tanana:

The refuge facility repurposes the original farm buildings, and the old "Creamer's Dairy" sign still graces the former barn:

Here we have finally arrived at the visitor center, the former farmhouse and residence of Charles and Anna Creamer.

During the gold rush at the turn of the century, Belle and Charles Hinckley brought three cows and some horses from Nome up the Yukon and Tanana Rivers to the small outpost of Fairbanks to operate a dairy. They paid for their passage on the sternwheeler by selling milk to other passengers. On the last leg of the journey, they met and became friends with the Creamers, another pioneer family on their way to Fairbanks. Charles Hinckley's sister, Anna, later married Charlie Creamer in Fairbanks. In 1928 Charlie and Anna Creamer purchased the dairy from the Hinckleys and continued to develop, enlarge, and operate it until 1966, after which it was turned over to the State of Alaska for operation as a wildlife refuge.

Today, the various Creamer's Refuge habitats offer homes for a diversity of animals, but its special role is for stopovers and summer use of migratory birds. Even though some birds such as Canada Geese, Northern Pintail Ducks, and Golden Plovers stay for only a short time, they depend on Creamer's Refuge to feed and rest each spring and fall during their migration. Other birds such as Sandhill Cranes, Northern Shoveler Ducks, and Mallard Ducks may remain the whole summer. Visitors enjoy excellent bird watching spring through fall.

Creamer's Refuge appeals to other types of wildlife as well. Visitors frequently spot Moose meandering through the forest, Snowshoe Hares nibbling on willows, Red Squirrels chattering or a Red Fox pouncing on a variety of Voles living in the fields. Woodchucks (Groundhogs, Marmots) are frequently seen near the Farmhouse and Barns and have burrows near Jusilla Creek. The only amphibian in Interior Alaska, the Wood Frog, can be found breeding in the seasonal pond in the spring and later in the Boreal Forest. Any standing water becomes home to hungry hordes of mosquitoes as the summer progresses.

We got to know the mosquitoes intimately on our walk through the boreal forest.

The sandhill cranes are shy, and while there were hordes of them in the refuge, they wouldn't let us get near them.  The best photo we could get was of these majestic birds as they flew in groups from one part of the refuge to another:

To help nurture other birds, the refuge is dotted with hundreds of birdhouses, each numbered to permit ongoing census and research on their nesting and breeding activities:

The two prettiest flowers in the refuge were the numerous daylilies in the grasslands areas, and the pretty primroses throughout the wooded areas.  Here's a photo of some daylilies:

It would be easy to get lost in the refuge, were it not for the trail maps.  Here, David tries to find our route while Kathy, behind the camera, scouts from an observatory deck:

The first half of our outing was a hike through the grasslands.  Afterward, we stopped for lunch in a grove of trees, partly to take shelter from a brief rainshower.  We then walked to the boreal forest area, where most of the path was along a 1-mile boardwalk through a forest of birch and spruce:

The boreal forests ring the regions immediately south of the Arctic Circle in a vast expanse that easily rivals the rainforest regions of the world. The northern boreal eco-region accounts for about one third of this planet's total forest area. This broad circumpolar band runs through most of Canada, Russia and Scandinavia. In North America, the boreal eco-region extends from Alaska to Newfoundland, bordering the tundra to the north and touching the Great Lakes to the south.

Known in Russia as the taiga, the boreal forest constitutes one of the largest biomes in the world, covering some 12 million square kilometres. Overlying formerly glaciated areas and areas of patchy permafrost on both continents, the forest is mosaic of successional and subclimax plant communities sensitive to varying environmental conditions. It has relatively few species, being composed mainly of spruces, firs, and conifers, with a smattering of deciduous trees, mostly along waterways.

Long, severe winters and short summers are characteristic. Also characteristic of the boreal forest are innumerable water bodies: bogs, fens, marshes, shallow lakes, rivers and wetlands, mixed in among the forest and holding a vast amount of water.

Due to the presence of permafrost in this area, thermokarts are common.  If you want to know what thermokarsts are, we have conveniently included the definition at the beginning of this blog.

Did we mention the lovely primrose?

As we delved more deeply into the boreal forest, we crossed through wetlands.

Ten thousand years ago, if you stood in the boreal forest of Creamer's Field, you would have been standing at the edge of a river.  The long depression that is the boreal forest is all that remains today. After the river changed course, the old channel began to gradually fill in with dead plant material. This organic matter builds up because decay is slow in the cold, wet snows of the subarctic regions. As the depression continued to fill, new plants began to dominate the site.  Willows and alders are replacing grasses, sedges and rushes:

Here, Kathy reads the trail guide as we contemplate the wetlands of the boreal forest:

The ponds in this boreal forest, like the one pictured above, are examples of thermokarst ponds, which are home to tadpoles and an assortment of adult and larval insects.  Some of these larval insects, such as mayflies and mosquitoes, fly as adults and fill the air during the summer months. Each year, this bloom of insect life attracts thousands of fly-catchers, warblers and other insect-eating, migratory birds.  Hiding beneath the calla lilies of the ponds are insects such as mosquito larvae dragonfly nymphs, and predaceous diving beetles such as the photogenic little lady below:

This particular forest exhibits another phenomenon that is common in the subarctic regions of Alaska:  the impact on trees of heavy snows.  Notice the broken limbs and leaning trees in the photo below.  Like fire, water and ice, snow plays an active role in creating the forest structure.  In 1992, Fairbanks received a heavy snowfall early in September.  Helped by leaves still attached to the trees, the heavy wet snow accumulated beyond what many trees could handle.  Limbs broke, tops snapped, and trees were bent over.  Even though some trees are dying from the heavy snow, they are still an essential component of the forest because they provide habitat to a wide variety of animals.

Leaving the boreal forest trail, we returned to the grasslands and were greeted by a flock of Lesser Canada Geese, foraging and perhaps nesting in the deep grasses:

We thought the goose congregation was an appropriate salute to us as we worked our way back out of the refuge, found our bicycles, and planned our ride home.  While the mosquitoes were fierce in the woods, the rains were merciful and held off despite forecasts of precipitation.

We made it home without getting wet and warmed ourselves by the fireplace with samples of our favorite single malt scotches.  Kathy chose Lagavulin; David decided on Ardbeg.  Cheers!