Autumn Begins

bears digging, some unusual flowers, and a lovely purple mushroom

On yet another gray, wet day, some friends went up the Eaglecrest Road in early September, frequently stepping off the road to make way for big equipment. Some headed for the Nest, while I and some others searched for the rare white-petalled variety of dwarf fireweed (a.k.a. river beauty). Sadly, it was done flowering—as was almost everything else. There were a few laggard monkshoods, yellow rattle-box, and groundsels, and I saw some delayed salmonberries just ripening. Deer cabbage leaves shone with yellows and golds. It was really autumn at Eaglecrest.

White fireweed. Photo by Kerry Howard

I was interested to hear reports of a Clark’s nutcracker in the area, and there were several bird-watchers on the road, hoping to spot it for themselves. This bird is normally found in montane conifer forests from central BC southward, but I’m told it occasionally ranges north to the southern Yukon and is very rarely seen in our coastal conifers.

Marsh felwort. Photo by David Bergeson

Looking back to our so-called summer: a trip to Crow Point and the Boy Scout beach in mid-August found the little gentian called marsh felwort in its usual place near the trail on flat, gravelly soils. Five pointed petals make bluish or lavender stars that usually appear in August. This little annual plant occurs widely in the northern hemisphere. In the spruce groves there were fairy rings of white mushrooms and a clump of giant purple mushrooms known as purple (or violet) corts. Corts belong to a multi-species complex in the genus Cortinarius and form mycorrhizal associations with the roots of spruces and other trees. Also, around one big spruce tree, I saw a palatial squirrel midden with numerous entrances, one of the most impressive middens I’ve even seen. A lot of spruce cones were demolished to make a pile that size.

Photo by Jennifer Shapland

Both brown and black bears frequent these meadows, and I recently saw tracks of both species. We often see bear diggings here. Usually the bears have been digging roots of Angelica lucida (‘seawatch’), occasionally also eating the lower stems and leaf stalks. But this time, there was one area where bears had concentrated on digging up beach lovage; dozens of holes were marked by the discarded reddish leaf stalks. When the roots of these perennial plants are eaten, presumably the population of those species is reduced, thus reducing their future availability as bear food—unless the plants set enough seed before the roots were eaten, and the seeds germinate well, to establish a new generation of those species in the area. Also, a few side shoots and root fragments survived the digs and can regenerate full plants, but would this be enough to replace those eaten?

Another August hike took us—squelching all the way—to Cropley Lake in hopes of finding a blue gentian in flower and the yellow fireweed. Success! Also known as yellow willowherb, it usually grows along damp creek-sides and in montane meadows. It looks very different from the common pink-flowered fireweed, which is now classified in a different genus altogether. We also enjoyed some stands of the deep, rich purple monkshood flowers. There were hundreds of fringed grass of Parnassus flowers; in a previous essay, I related the history of how it may have got its name.

Yellow fireweed. Photo by Anne Sutton

At the very end of August, I went with a friend to the first meadow on the Spaulding trail. All across this meadow, we found many small diggings in the moss, leaving no evidence of who made them or what might have been taken. We found the seed heads of the strange little wetland plant called Scheuchzeria (sometimes called pod-grass). Widespread in the northern hemisphere, it has is currently classified in its own taxonomic family, and I have found very little information about its ecology and behavior.

A brief stop on a log for a snack provided a lucky sight of two chickadees: After conversing with each other in a nearby pine (no doubt about the odd lumps on the log), one by one they came down to a fruiting skunk cabbage. On each visit, the bird plucked one seed off the club-shaped infructescence, leaving a little empty pit, and flew off, but quickly returned. Jays and other critters sample these seeds too, sometimes leaving big bare patches, but it was good to see these little guys in action.

Dredge islands

…there’s so much to be learned!

Gastineau Channel rounds the north end of Douglas Island with a short stretch that is roughly east-west. On the north side of this part of the channel lie islands mostly made of the material dredged from the channel in the 1950s; actually, they are islands only at high tides. One island is apparently a rocky outcrop that may have been a real island. Post-glacial uplift has raised the islands well above the reach of the tides, so that they now support a diversified community of plants. Most of them are now capped with stands of vigorously growing spruces and cottonwoods.

After careful consultation of the tide tables, we set out to explore the eastern series of islands, on a nice low tide. Although I’d previously visited the westernmost islands, this was new terrain for me. We waded through wide expanses of tall grass and crossed several tidal sloughs where dowitchers and yellowlegs foraged and mallards loafed on the banks.

A characteristic of most of the islands we visited was what might be called a lichen barrens—a habitat quite reminiscent of recently deglaciated lands. Not really barren at all, they are wonderfully rich in lichens, mosses, and a few small flowering plants. They are generally surrounded by a ring of trees, lending them a feeling of seclusion. As we reveled in their diversity and beauty, we also wondered why they are there—why didn’t the trees grow there too?

We were pleased to find abundant meadow rue on some islands but much less happy to find a big stand of hemp-nettle. This prickly plant is an invasive weed from Eurasia. There was evidence of the passage of some large creature through the grasses and herbs, and eventually we found several scat piles that told us the creature was a deer.

mary-on-the-trails

Perhaps the most intriguing observations came from fireweed. The flowering stage was different on every island: flowers just opening on this island but nearly finished on another, with intermediate stages on still other islands. One bumblebee was flying busily, but two very wet bees rested, each nestled in an open flower. Bumblebee workers often sleep outside the nest, wherever they happen to be. These bees were so wet that we wondered if they had died as they slept, but we did not disturb them to find out.

On one island we noted some swollen buds on several fireweed stems. These flowers had not opened and all the sexual parts were present; no pollinator could have visited. Nevertheless, the fruits (or pods) below the flowers were well developed. The pods contained lots of the white fluff that we see on each seed when the pod opens and the seeds become airborne, but no seeds were visible. Why did the pod develop if no pollination had occurred?

The swollen buds frequently contained tiny insect larvae about one millimeter long. If no larva was detectable, then the female parts of the flower were often mutilated and deformed. Do these larvae somehow prevent the flower from opening and cause the pod to develop anyhow? There is much to be learned here!

Recent sightings

…a collection of small discoveries from recent walks.

Along the road to the Eagle’s Nest and Pittman Ridge, there was a small stand of fireweed that stood out from the rest. The petals were white, while the narrow sepals showing between the petals were the usual vivid pink. A very showy display.

White-petal-fireweed-2-Kerry
Photo by Kerry Howard

At Point Louisa, on a moderately low tide, the rocky shores and pools held the usual assortment of sea stars, chitons, anemones, and urchins. I was entertained by a couple of urchins: in one pool, the urchin sat in a clam-shell bowl that was a perfect fit. And in the next pool, another urchin wore a sizable clam shell as a hat, which covered the urchin completely, to the very tips of its spines—another perfect fit. Urchins often bear stones or bits of shell on their spines, possibly for camouflage or, in some places, perhaps protection from UV light.

A stroll on Eagle Beach brought a surprise—two woolly-bear caterpillars (Lophocampa maculata). One marched steadily along the sand, struggling a bit over small divots of loose sand, but persevering. The other one trudged rapidly up toward the rye grass, made a ninety-degree turn and scurried along for several yards, and then made another right-angle turn back down toward the damp sand near the water’s edge. Both explorers visited milkwort and goose-tongue plants but did not seem to eat anything. According to various sources, these caterpillars customarily eat the leaves of poplar, willow, and alder, so it was a puzzle just why they were down on the beach. If they were looking for a place to pupate, this wasn’t it!

Along a short stretch of the Treadwell Ditch trail we found a series of piles of red bunchberries. Each berry had been opened, and the single fat seed extracted. Surely the work of a rodent—a squirrel or maybe a mouse. In contrast to that pattern of consumption, on Gold Ridge we found some patches of bunchberry in which the berries had been systematically pecked open, removing bits of fruit pulp but leaving the seeds intact. Birds, no doubt, but which? There are very few reports in the natural history literature of birds eating bunchberries.

Skunk cabbage fruiting stalks are starting to fall over and ‘melt’ into puddles of ooze containing lots of seeds. When I first arrived in Juneau, many years ago, I found some of these things that had just fallen over and started to take up water (before the oozy stage). At that earlier stage, each seed was surrounded by a jelly coat, and I (being new in the area and quite ignorant of local matters) took the aggregations of jelly-coated seeds to be frog eggs. But what were those ‘eggs’ doing in the middle of the forest??? Ah well, I learned! On a recent walk, I found the remnants of a skunk cabbage fruiting stalk, with the central pith intact, indentations showing where the seeds had been, and no seeds on the ground. The pithy center had been plucked clean by a seed-predator, such as a squirrel, or a jay, or a flock of chickadees, or…who knows?

Gold Ridge provided several additional observations of interest: A tangle of brush suddenly shook vigorously, drawing our attention. In the middle of the tangle, a red squirrel harvested a cluster of the devil’s club berries and made off with it. We often see devil’s club seeds dispersed by bear scats, but this was the first time (that I can recall) I’d seen a squirrel presumably intent on having the seeds for lunch. Farther up the trail, we surprised a well-grown ptarmigan chick, and stopped to watch. The chick was apparently not too sure what to do: it ran up the trail a little way, came back, turned around and ran up several yards, came back, and finally took off up the trail and into the brush. I was charmed by the fluttering of the white feather over its legs—like lacey pantalettes.

Time out for tea and crumpets at a rocky viewpoint, with marmots whistling on all sides (a couple of illegally off-leash dogs had just gone up the trail). Time, then, to examine our immediate surroundings more closely. Here’s a patch of trailing raspberry, in the subalpine zone, not its usual forest habitat. The pretty little rosettes of pussytoes leaves; the tiny, now-empty, artistic seed capsules of white mountain heather; a lonely purple flower of the miniscule moss gentian. The odd growth pattern of the alpine harebell, with the single flower borne on a stem that seems to emerge from underneath a low rosette of leaves.

A nearby stand of copperbush was covered with immature fruits of a curious shape, rather like small green pumpkins with curved handles on top. I was reminded of the stones used for the game of curling. A few laggard copperbush flowers attracted some bumblebees, who did not linger long.

Hmmm….pumpkins and curling stones, pantalettes, and who knows what else might we find!?

Around Cropley Lake

“Elysian fields” of Eaglecrest

Ambling up from Eaglecrest to Cropley Lake at the end of July, we passed from summer back into spring. Near the lodge, the tall blueberries were ripe, attracting batteries of pickers with buckets. Just a few hundred feet higher, the low-growing bog blueberries sported their tightly closed pink buds. By the lake, flowers were still blooming while at the lower elevations, the same species had set seed. The tiny white gentian, however, dotted the meadows almost everywhere.

We found several stands of the pretty shrub called copperbush. It’s related to blueberries, but you wouldn’t know it from appearances. The flowers look entirely different: they have spreading, coppery petals instead of the pendant, pinkish-white bells of the blueberries, and the fruit is a dry capsule, not a succulent berry.

I don’t know how long Cropley Lake has been there; a small pond may have occupied the bowl originally. One drainage was blocked by a dike, decades ago, judging by the size of the spruce trees on its crest. A dam was built across another drainage, and the overflow from the dam feeds a small pool, which drains down-valley to help create Fish Creek.

We sat on the boulders just below the dam, watching the miniature Dolly Varden foraging on surface insects. They ranged in size from four to eight inches or so. Many of them had colorful orange fins, and we guessed that these were males. They could be mature individuals, despite their diminutive size.

The resident Dolly Varden in Cropley lake were undoubtedly introduced by humans many years ago. Resident Dolly Varden, which live their whole lives in fresh water, mature at a small size. A tiny female may produce only a few dozen eggs. If some of their offspring get washed downstream to the sea, they may survive and adopt an anadromous life style: growing to a large body size and re-entering fresh water to spawn. But return to Cropley Lake can’t happen; there is at least one barrier falls.

The dollies we saw in the pond below the dam may be in for a hard time, come winter. The pond must often freeze right down to the bottom, or nearly so. In past springs, I’ve sometimes seen several dead dollies here, with no living individuals in sight.

On the other side of Cropley Lake, we found a stand of creamy-flowered plants growing near a seep. They looked rather like fireweed, except for the flowers. I think I once knew them, but–as with so many things—the knowledge had faded. However, our handy plant guide told us that they are indeed yellow fireweed, more of a habitat specialist than our common pink species.

I was pleased to find numerous butterwort plants, a.k.a. bog violet. The purple flower is vaguely violet-like, but the nectar spur at the back of the flower is much longer and the face of the flower is distinguishable upon close inspection. Butterworts are insectivorous plants; their flat yellowish leaves are sticky traps for insects, which are then digested by the plant. The insects are a good source of nitrogen for plants growing in boggy, nutrient-poor soils.

butterwort-by-bob-armstrong
Butterwort. Photo by Bob Armstrong

We also inspected the stems of the little iris relative with the ponderous name of sticky false asphodel. The flower stem is covered with sticky hairs that trap miniscule insects. Some years ago, we did experiments to see if this plant could be insectivorous, putting chemically labeled fruit flies on the sticky stem and then testing for presence of the label in the plant’s seeds and roots. No luck. There may be another function of the sticky hairs that remains to be discovered.

For those interested in the names of things: the true asphodel is an Old World lily (not an iris) and it was the flower of the Elysian Fields in Homer’s Odyssey. These fields were the meadows where dwelt the souls of the dead. (The name ‘asphodel’ was also strangely corrupted into ‘daffodil’, a totally different plant.) The famous Parisian avenue called Champs Élysées means Elysian Fields, presumably referring to the gardens that once flanked it and not to a collection of dead souls!

Apical dominance

which leader will lead?

Did you ever wonder how it happens that spruce trees typically have such nice, conical tops? The uppermost shoot, called the leader, produces a particular hormone that suppresses growth in the branches below, most effectively in the branches nearest the leader. The effect dwindles to negligible on the lowermost branches. Voilá! –a conical top to the tree.

If the leader is damaged—chewed by a porcupine, or invaded by an insect, or cut off, the next-lower branches rapidly start to grow, and the damaged tree-top may now display two or three new leaders, until one of them might eventually take over. The dominance of the leader at the apex is disrupted, allowing lower branches to grow more. A similar but usually smaller effect may occur on the end of branches.

The effect of that suppressive hormone is countered by another hormone, one that encourages growth. The balance between the two hormones differs among species of plants, so not all plants grow with conical tops. But one can see the same phenomenon in other trees: for example, look at the cottonwood trees that have been decapitated to prevent them from growing up into the power lines. The remaining branches grow well and begin to reach upward more than before the top was removed.

The strength of apical dominance and the effects of release from that dominance vary among species, although very few general patterns have been discerned (such as effects of habitat, geography, climate, or life history). And the evolutionary pressures that govern both the strength of apical dominance and the effects of its release have been little studied. So I’ll just present a few examples here, to illustrate some of the variation and complexities.

Herbivory, by grazing and browsing animals, often crops off the tops of a plant, ending the dominance effect and leading to branching, which frequently increases the production of flowers and fruits (this is why gardeners commonly pinch off the tops and ends of branches, making a plant bushier and potentially more fruitful). But this begs the obvious question: if branchi-ness is good for the reproductive output of the plant, why was apical dominance so strong, suppressing the branches? Presumably, there are other advantages associated with apical dominance. For example, if the plant allocates resources not to branches but to good vertical growth, this can be advantageous by reaching more light and increasing the survival of the plant, which would eventually lead to greater lifetime reproduction. That option might over-ride the advantages of short-term increased fruit production in most circumstances. Nevertheless, the ability to respond to release, if herbivory occurs, is itself a useful trait. In other words, the evolutionary fitness of a plant may be better with strong apical dominance in the absence of herbivory, but better with release when herbivory occurs.

The club moss (Lycopodium) grows along the ground, sending up short vertical shoots. If the main upright shoot dies, dominance is reduced, and lateral spread increases. The horizontal growth then eventually reaches a new location and a new upright shoot forms there. A living, dominating shoot is successfully exploiting a good site, but when it fails and releases lateral growth, the individual plant as a whole may survive by reaching a new site. In short, the dominance is advantageous in certain circumstances but not in all.

In a species of fireweed (Epilobium in some taxonomies), strong apical dominance leads to good seed production and good seed dispersal (by wind) in areas where competition for light is severe, giving an advantage to good vertical growth and reduced branching. However, this only works where soil nutrients are sufficient to support such growth; in poor sites, which cannot support good growth, the potential advantages of apical dominance may be negated. Again, the advantage of apical dominance is seen in certain circumstances, in this case related to resources.

The relationship between resource availability and the effects of apical dominance are seen also in bearberry (Arctostaphylos uva-ursi). Here (in contrast to fireweed), apical dominance is weak in rich habitats, the plants are much-branched, and the plant is exploiting its present location to the fullest possible extent. In resource-poor habitats, apical dominance is strong, as the plant allocates its limited nutrients to growing in situ: release from apical dominance, perhaps by herbivory, leads to increased branching, increasing the chances of the plant stretching out to find a better site.

These few examples serve to emphasize that multiple factors interact to determine the strength of apical dominance and the consequences of release from that dominance. No wonder that researchers have yet to find general patterns in the ecology of apical dominance. The physiology is well understood; now to learn the whys and wherefores!