Category Archives: smells

Alder in bloom. Now a common sight in February.

On the lakeshore, a smell of springtime mud and wet leaves. Soil microbes are getting a boost from the unseasonably warm air and our noses are soaked in their festivities, an aroma-pulse of decomposition.

I push forefinger against thumb, then flick, I tap an alder catkin. A cloud of lime-yellow pollen drifts down to the lake water.


Smooth alder (also called hazel alder, Alnus serrulata)

Alders are monoecious, that is they have separate male and female flowers on the same plant. The male flowers mature before the females, preventing self-pollination.

Male flowers hang in pendulous catkins. They are furry, soft, floppy, cute. Like kittens, hence the name. From 16th century Dutchkatteken, a little cat.


Female flowers just before they mature and receive pollen.

Female flowers several days later. Their sticky surfaces are now covered by captured pollen.

Female flowers several days later. Their sticky surfaces are now covered by captured pollen.


Later in the year the female flowers will swell and harden into small cone-like strobili. These look like cones, but alder is a flowering plant, an angiosperm not a cone-bearing gymnosperm like a pine.

Last year's strobili, their seeds now either shed into the wind or stolen by birds.

Last year’s strobili, their seeds now either shed into the wind or stolen by birds.

A little early for flowering? Not any more. Plants are shifting their bloom and bud-break earlier as the climate warms. For example, a study in the Washington DC area found that over the last 30 years of the 20th century, alder moved its blooming date 11 days earlier. Most species are following suit, but not all at the same rate. Non-native species like privet, bittersweet, and multi-flora rose are less tied to native seasonal rhythms and so are better able to exploit the early springtime warmth.

Fog happens, and the woods rise into it.

The overlook at Green’s View offered an interesting prospect this morning. The hundred mile view was shortened by the enveloping cloud to less than one hundred feet.

fogThe fog penetrated the forest, hazing and graying views through the trees.

fog2The smell was deliciously tenebrous, seeping into the dim air from the darkness of the soil. Shrews and moles must inhale the same rich earthiness as they burrow.

Although we imagine springtime coming from elsewhere, a warm breeze blowing birds and warmth from the tropics, in reality most of the year’s new life rises from the musty earth, surging through layers of decay.

The first significant signs of this life have now appeared in Shakerag Hollow. Harbinger-of-spring (also called salt-and-pepper plant, Erigenia bulbosa, a carrot relative with an edible tuber) has raised hundreds of tiny blooms over the mountainside, each one standing barely taller than the upper surface of the leaf litter.

harbinger of spring1

harbinger of springFungi are also poking through, spreading their spores from colored cups.

cup1cuo2And the animal world is alive. Hairy woodpeckers call, perhaps starting their  breeding season. Orange centipedes lumber across the litter, seeking prey into which to sink their poisoned fangs. Spiders, although withdrawn in their hiding places, have their presence revealed by the foggy air. Every web is a bright cloud of droplets. In some places, funnel-web spiders had strewn the forest floor with dozens of newly constructed traps.

funnelLeaves of toothwort, spring beauty, bloodroot and trillium were unfurling, but their flowers were not yet emerged. Soon, though, the smouldering wet soil will blaze.

Microbial ecology: follow your nose

The arrival of tropical storm Lee has broken a month of drought. After weeks of heat and no rain, we’re getting a steady downpour that so far has lasted 24 hrs, with another day or so to come. Lee is an insistent fellow who may yet outstay his welcome.

One of the many benefits of the return of the rain is the reactivation of the microbes that have been in suspended animation in the dry soil. We can’t see them, but we can smell them. Their odors waft up to us as we walk — some are musty, some sharp, others are rounded and pleasant. The actinobacteria are particularly special. They smell of healthy, rich soil. These actinobacteria are a diverse group, some of whose members gave us chemicals that we use as antibiotics.

I’ve prepared an online experience of the richness of these creatures for you. Follow the instructions below: