Thursday, August 30, 2012

Lichens: Like’em or leave’em


I’ve noticed lichens before on rocks, trees and high alpine ridges before but didn’t look closely at them until recently. Peter Nelson, a lichenologist who studied lichens in Gates of the Arctic National Park this summer, hosted a lichen walk one evening in Bettles, Alaska and enthusiastically shared his knowledge of lichens, rattling off latin names without skipping a beat and pointing out lichens easily missed. 

Foliose lichen
Lichens are in a category by themselves. They are not like trees, mosses or even mushrooms. Lichens are a combination of fungi and algae on a microscopic level--not a fungus with alga growing on the outside. Separately, the fungus and alga would look completely different than the form created when they grow together as a lichen. The fungus isn’t the typical cap and gill mushroom one might first think of, but instead a type of cup fungus.

Basically, the fungus is the house in which the alga creates food. Alga photosynthesize and provide the fungus with carbohydrates, vitamins and proteins. In return, the fungus shelters the alga and protects it from the sun and predators. The physical manifestation of this relationship is the lichen. 

Unlike other plants, lichens do not derive any nutrition from the substrate on which they grow, such as soil or tree bark. They are a completely self-contained because the algae creates all the food the fungi needs. That is why lichens can grow on rocks. 

Crustose lichen growing on rocks
Lichens will actually be one of the first species to colonize an area, such as after a glacier retreats or after a fire, because they don’t rely on anything outside of themselves to grow (besides sunlight, water and air for photosynthesis). Their growth on gravestones has allowed scientists to calculate their rate of growth because the earliest date of growth is written in stone. This growth rate can then be used to determine when the earliest time a glacier could have retreated from an area or to date an archeological site. 

Even though lichens grow relatively slowly, they can survive thousands of years if left undisturbed. Amazingly, lichens can completely dry out and not die. With the next rain, dew or snow melt they will rehydrate and keep growing. 

On alpine ridges, lichens commonly grow on the ground and on rocks
This dryness is evident when walking on a high alpine ridge as they crunch underfoot. This breaks up the lichen, but all is not lost--each of the fragments will grow into a new lichen. And if the powdery substance found on those crushed lichens sticks to your boot for a few steps or a few miles, you will help the lichen spread. That powdery substance is composed of tiny chunks of fungi/algae combinations ready to colonize a new area. The powder will also stick in the hooves of several of the animals that eat it, such as caribou, deer, elk, pronghorn antelope and Dall sheep. Lichen powder can also be spread when flying squirrels and birds utilize pieces of lichens for nesting material. 

The different fungi and algae combinations produce the different lichens. Even without knowing the names, you’ll be able to differentiate the three main groups of lichens--foliose (leaf-like), fruticose (shrub-like) and crustose (paint- or stain-like). Rocks are often dotted with different colored crustose lichens. The green or black ‘old man’s beard’ dangling from old tree branches is a fruticose lichen. Foliose lichen is often found on the ground and tree bark. 

Foliose and fruticose lichens
Some areas are extremely lichen-rich, such as the location I went to on the lichen walk. Within a one square-foot area, we counted 13 different lichens that included some from each lichen group, which I thought was an impressive amount of diversity for a small area in the arctic. As Peter was eagerly rambling off the different names of the lichens, his enthusiasm sparked a new interest that will have me down on my hands and knees examining lichens a little more closely. 

A diverse array of lichens can grow in a small area
Note: Published in the Bonners Ferry Herald on August 30, 2012. 


Thursday, August 23, 2012

Autumn arrives early in the Arctic


I walked towards the water-filled gravel pit early one morning last week, a sound filled the air that I hadn’t heard since spring--the honking of Canada geese. Canada geese don’t spend the summer in Bettles, Alaska, they only pass through on their way to the North Slope in the spring and then again in the fall on their way south. This only means one thing--autumn is here.

Even though it seems early I shouldn’t be surprised, signs of autumn are everywhere. The fireweed finished blooming earlier than I could remember and a fair number of seed pods have already burst open with fluffy seeds. 

Seed pods on the fireweed are already opening 
Two weeks ago a few random willow and aspen leaves started turning yellow but I dismissed it since every year a few leaves turn before all the others. Once more leaves starting turning and even falling off, I reckoned that autumn had come early. Every day I see more yellow and orange leaves that I didn’t notice the day before. 

Leaves beginning to turn color on the banks of the Koyukuk River in Bettles, Alaska
Even the blueberry brush is turning red. The rainy summer kept the blueberry season short with a meager crop. Those picking blueberries were lucky to find them before the birds and bears devoured them all. 

With the early start on fall, the low-bush cranberries are ready and they seem to be plentiful this year. They are best after a hard frost and the closest we’ve been is 31 degrees Fahrenheit on August 9. Even before a frost, they are still quite tasty--even for the bears. I came across a pile of fresh pink bear scat still containing whole cranberries the other evening. They too are preparing for fall. 

Low-bush cranberries among reindeer lichen
With all the recent rains, mushrooms are poking out of the ground like jack-in-the-boxes. They pop up one day and the next day they are gone--harvested by squirrels. The squirrels waste no time in packing them off and caching them for winter. 

Another sign of fall is the arrival of the sandhill cranes headed south. A group of three starting hanging around after the first Canada geese arrived. Like the geese, they migrate through in the spring and fall. Now every morning, the sound of sandhill cranes and flocks of geese congregating on the airport fill the crisp morning air.

Autumn in the boreal forest 
Along with that cool, crisp morning air comes a welcomed smell of fall--wood smoke. As the smoke rises from the chimneys, I can’t help to think of the colder, snowier months ahead and making sure the woodshed is full come November. 

While it can snow any month of the year in the Arctic, the first snow that sticks truly signals that summer is over. While it did snow high in the mountains earlier this month, it wasn’t visible from Bettles. Once the first snow blankets the peaks of the Brooks Range, summer is definitely over and winter is only a few weeks away. 

Autumn is a short season in the Arctic, sandwiched between summer and winter. It usually goes fast and before long all the leaves will litter the ground, the snow line will have crept down the mountains into Bettles, and all the cranes and geese will be well on their way to warmer wintering grounds. 

Note: Published in the Bonners Ferry Herald on August 23, 2012. 

Thursday, August 16, 2012

Pondering the puzzle bark of the ponderosa pine


One of the first conifers I learned to identify after moving to Boundary County was the majestic ponderosa pine, mainly because of the bark. I had never seen a tree with such unique bark. The first time I found a ponderosa pine, I spent quite a bit of time flaking off the puzzle-shaped pieces of bark with a pocket knife and seeing what different patterns and shades of orange were revealed. 

The orange-colored bark of older ponderosa pine brightens up the woods on a wintery day 
I later learned that only the older ponderosa pine had the characteristic orange-colored bark while the younger trees had dark brown to black bark, with a young tree being less than 100 to 120 years of age. Another difference between young and old ponderosa lies within the tree. Young ponderosa, called bull pine, have coarse, knotty wood while old ponderosa, called western yellow pine, have clear, even-grained wood. Ponderosa pine are also called yellow pine, rock pine, yellow bellies and P-pine.

No matter what ponderosa pine are called, there is no other type of forest like a ponderosa pine forest. The openness of a ponderosa pine stand creates a park-like setting, except the ground is littered with long ponderosa pine needles and pinecones instead of grass. Ponderosa pines have long (5 to 8 inch) needles in bundles of three and egg-shaped cones armed with sharp prickles on the end of each cone scale. 

Long needles of the ponderosa pine 
I tend to gravitate towards open ponderosa pine ridges because of their openness and the ability to see farther, especially while looking for shed antlers. These open stands are often found on dry, south-facing slopes or ridges because they are able to grow in drier soils. The ability to survive on less than 12 inches of annual precipitation enables the ponderosa pine to extend from British Columbia to Mexico and east of the Cascade crest into the Black Hills of South Dakota. On road trips through the Southwest US, I’ve been surprised to find ponderosa pine stands on high plateaus of northern Arizona and red-rock valleys in Utah. The open stands remind me of home, especially on hot summer days when they smell like parched earth. 
Open stands of ponderosa pine create a park-like setting
Ponderosa pine are able to thrive in the drier areas because of their extensive taproots that penetrate deep into ground to access water. Studies have found that a three-inch tall, year-old tree can develop a taproot nearly two feet long, while a four-year-old tree that averages a foot in height can have a taproot nearly five feet long. Now imagine how deep the taproot on a 120 foot high ponderosa pine penetrates the earth. 

Ponderosa pine need an extensive root system to supply moisture to the long tufts of needles and to support the massive trunks that old trees can produce. When a ponderosa pine attains an age of 400 to 500 years of age, it can be upwards of four to five feet in diameter and over 120 feet high. The largest ponderosa pine in Idaho is six feet in diameter and 182 feet tall while the largest ponderosa pine in the country is seven-and-a-half feet in diameter and 240 feet tall.

Ponderosa trees this big were considered ‘old’ when Lewis and Clark first described them on their expedition in 1804. Shortly after, botanical explorer David Douglas named these majestic trees ponderosa pine because of their great size. I wonder if when they first discovered the tree they too were fascinated by the puzzle-shaped pieces of bark? 

Note: Published in the Bonners Ferry Herald on August 16, 2012. 

Thursday, August 9, 2012

How can a weed smell so sweet?


Do you remember the first time you smelled the pleasant aroma of alpine fir, labrador tea or cottonwood sap? I won’t forgot the first time I smelled crushed alpine fir needles along the Clifty Mountain trail. Certain smells trigger memories and I’m amazed at what smells can trigger childhood memories, like campfire smoke and pineapple weed--yes, pineapple weed. 

Pineapple weed is the common name for that hardy plant that often grows in gravel driveways and smells like sweet pineapple when crushed. Walk on or mow over a patch of pineapple weed and the air is filled with a pineapple-like aroma. How can a weed smell so sweet? 
The flower heads are composed of tiny, densely packed flowers that smell like pineapple when crushed
Typically less than a foot tall, the fern-like leaves give way to egg-shaped, yellow-green heads that have a rough resemblance to pineapple. However, the common name is derived from the pineapple-like smell emitted when the flower heads or leaves are crushed. Pineapple weed is also known by the less descriptive name of disc mayweed. 

Prior to flowering, pineapple weed can be confused with mayweed chamomile because they look almost identical but mayweed chamomile doesn’t smell sweet like pineapple weed when crushed. Upon flowering, mayweed chamomile can be differentiated because it has white petals around the yellow-green flower heads. 

Pineapple weed is a hardy plant, occupying the poorest, most compact soils of gravel driveways, roadsides and other disturbed areas. Pineapple weed seems to grow where other plants don’t, minimizing competition. It can be a nuisance in fields, gardens and pastures. The tiny (one to two millimeter) seed created by each flower head easily sticks into tire treads and rubber soles of shoes that transport it to new destinations. I’ve found pineapple weed in my driveway in Bonners Ferry, Idaho, my hometown in Minnesota and in Bettles, Alaska--a wide range of conditions to thrive in. 

Pineapple weed thrives in the poorest soils, especially gravel driveways
Pineapple weed is believed to be native to the Pacific Northwest or brought to the Pacific Northwest by people who migrated from northeast Asia prior to European settlement of North America. During their exploration, Lewis and Clark didn’t find specimens of pineapple weed until they were camped at Camp Chopunnish in Idaho County, Idaho on June 9, 1806. Now, pineapple weed grows in every state except Texas, Alabama, Georgia, Florida and Hawaii and is found across most of Canada. Pineapple weed even grows in Greenland. 

With little competition in gravel driveways, the pineapple weed’s fibrous roots can spread out and absorb the little moisture that falls on driveways in Arizona or the inundating spring rains of north Idaho. They flower early, often as early as May in northern regions, and continue into September. 

Just as the aroma of wood smoke coming from a campfire reminds me of childhood camping trips, the smell of pineapple weed reminds me of picking flower heads from the gravel outside my parent’s barn as a kid and inhaling the wonderful, sweet smell of pineapple on a hot, summer afternoon. 

Note: Published in the Bonners Ferry Herald on August 9, 2012. 


Thursday, August 2, 2012

White-tailed deer a far ranging species


Grazing in fields in early morning, seeking shelter in the woods during mid-day, browsing in city parks in the evening and crossing highways at night, the signature white tail of the white-tailed deer is well known. From the fields of the Kootenai Valley to the oak forests of the Appalachian Mountains, the white-tailed deer seems to be everywhere. They thrive in every state except Alaska, Hawaii, California, Utah, and Nevada. They range northward into all the Canadian provinces except Newfoundland, Labrador and Prince Edward Island, and even inhabit the southern reaches of the Yukon and Northwest Territories. They range southward into Mexico, Central America and South America. 

White-tailed doe and fawn on edge of canola field
The hardwood forests of Indiana are vastly different from the forests of northern British Columbia but the adaptability of the white-tailed deer allows it to survive in both. The white-tailed deer is one of the few mammals that occupies such a wide range of latitudes and diverse habitats--mainly because they are opportunistic feeders. They feed on agricultural crops, grasses, shrubs, fruit, berries, apples, acorns and mushrooms. 

Agricultural fields are a bed and breakfast to white-tailed deer--breakfast being the crop of choice and bed being the vegetative cover along field edges. A nearby irrigation ditch makes it complete. White-tailed deer followed the advancement of agriculture across the continent and expanded its range in the process. What once was prairie filled with unpalatable grasses became a buffet of lush green crops. 

White-tailed deer in the Kootenai Valley
Logging, often associated with clearing fields, also enabled the expansion of their range. Old-growth forest doesn’t provide much forage within reach of deer whereas early successional habitats created by harvesting, thinning and burning provide ample fresh growth at ground level for several decades. 

Logging and agriculture also create boundaries between two vegetative types (such as a field and forest), which attracts white-tailed deer because of the vegetative diversity and availability of cover. Likewise, woodlands near cities provide the cover deer need to sleep along with easy access to a wide array of gardens, ornamental shrubs and fruit trees for food. 

Fields near forests offer food with nearby cover
Not only are white-tailed deer adaptable in what they eat and where they live but also in their behavior. Depending on the habitat, group size and migration can vary, such as smaller herds occupying forested habitats. Some white-tailed deer migrate between fawning areas and wintering ranges, while others do not. 

The most adaptable of the white-tailed deer are the yearling bucks--they are the pioneers of the species. Every year 40 to 50 percent of the yearling bucks leave the herd around November--not because of population density or availability of food but because of hormonal changes associated with the rut. 

White-tailed bucks in vegetative cover at a field's edge
If yearling bucks wander into new habitat, a viable population won’t be established until young does join them. Unlike yearling bucks, young does won’t leave the herd until it overpopulates the area. Therefore, new habitats won’t show population growth until nearby populations are on the upswing. 

The overabundance of white-tailed deer in an area is one of the most challenging problems facing wildlife managers, as well as gardeners, farmers, fruit tree owners, and vehicle drivers because they seem to be everywhere. 

Note: Published in the Bonners Ferry Herald on August 2, 2012.