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Chromatic aberrations

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Arc-en-ciel

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Primary, secondary and teriary colors

They went thataway

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Downfall and outflow

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Sharper than needles: post-solstice sunset over Norwegian sea

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Consumed walnut, outgrown collar

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Lotus leaf in distress

 

The inconstant weed

       Life is Juicy

Life begins in the waters—
Not the deep, but the borders of land:
The stagnants that nourish the sterile earth
Like a juicy gland.

Life is the seed of the marriage
Of liquid and solid events.
In the coves, in the swamps, in mysterious pools …

–Leonard Bernstein 1947

 

Sluggish currents and lazy winds mold a soft carpet into fantastical forms…

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A great part of the surface water feeding Farrar Pond enters through what some call Beaver Brook (or Beaver Dam Brook), which drains the wide marshes south and east of Baker Bridge, skirts the Fields of St. Anne’s and Mount Misery, and empties due south of Fairhaven Bay. En route, it rests in two small ponds excavated and dammed by the DeNormandie family in the 1950s. As relatively (and sometimes very) fast-moving water

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slows into sunlight,

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a seasonal dusting of duckweed (of which there are several genera and species) emerges. Where nutrients are concentrated (as here, draining eutrophic marshes and fertile farmland), wind or water may pile the tiny plants into a dense mat inches deep on the surface,

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from which dipping branch-tips emerge festooned:

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Nutrients are the key. Just fifty steps away, this isolated pool—wet most of most years, but perhaps still best described as “vernal”—exhibits  peripheral and submerged mosses, several kinds of algae and other aquatic or water-loving plants, but no duckweed:

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Seeding (via actual seeds or, more commonly, vegetative propagation) by one or more duckweed species seems inevitable; though the pool may be too small and tree-bound for ducks to land, despite vigilant oversight

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diverse mammals, reptiles and amphibians undoubtedly traverse the intervening ridge. But this is a glacial outwash plain, highly permeable and only lightly capped with fertile soil even ten millennia post-glacier. So absent a nutrient-rich inflow, soluble minerals needed for plant life are quickly lost to sub-surface outflows, and replaced only slowly by rotting vegetation and occasional imports:

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The visible life-cycle of duckweeds differs from that of most pond plants. This rootless drifter overwinters at the bottom as seeds or free dormant buds (turions). Developing sprouts from either contain air pockets (aerenchyma) that loft them to the surface for the duration of the growing season. As winter looms, new seeds and turions are sent below for safekeeping.

In between though, propagation largely takes a somewhat unusual path. Each tiny plant has a region of meristematic tissue, which generates daughter cells asexually. These grow and detach to create new adult plants. As with aphids that are born pregnant, this enables rapid and efficient reproduction; numbers can double in just a couple of days. In a small artificial pool, inoculated from the big pond years ago by both bucket and carapace,

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the first new plants begin to float up amid the tangled algae of a desiccated mid-spring:

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May 10th

In a few weeks, larger patches

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June 2nd

spread and thicken

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enough to provide open concealment for amphibians,

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June 4th

while clearings persist to encourage bottom-rooted plants to emerge:

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June 5th

The carpet continues to expand sideways until coverage is complete, except where disturbed by rain gathered into larger drops by overhanging branches (left side of this image),

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June 15th

sweeping by lilies when their stems or pads are disturbed by wind and indelicate swimmers,

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or the plashing entry of frogs from their perches on pad or bank, whether chasing airborne bugs, startled by approaching humans or just moving efficiently from place to place,

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(detail)

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while lighter

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(note pendant roots)

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“But we came to skate, not to hike!”

or more lissome creatures leave smaller footprints:

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When the single layer  can expand no further laterally, and subsurface light remains adequate, the mat thickens, still floating high enough not to clog the intake of this important piece of hydraulic equipment

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and spilling over to the disadvantage of other floating plants (some of which shed it more easily than others):

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Yet as the tiny hordes poise to overcome all, their glory begins to dim. First in occasional spots,

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July 3rd

then in larger patches, the plants bleach and die:

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July 5th

Parallel decline of the larger genera

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July 5th

bespeaks temporary challenge to the pond’s health, occasioned by intense light and heat around solstice-time, and lack of rainfall to cool and stir the water, bringing needed nutrients down and up to the vital surface. Some of the corpses sink or decay; others serve as softened food for still-herbivorous tadpoles

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July 12th

until almost none remain:

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No unnatural catastrophe, this disappearance is the natural result of genetic programming. Unlike species (periodic cicadas and synchronous bamboos, e.g.) that flourish and disappear on a precise clock to achieve sequential predator satiation and starvation and ensure their own survival, duckweeds simply have a limited potential for asexual budding—in the range of a dozen generations. (Our own somatic cells, by contrast, are about four times as durable.) The heavy mats in the Beaver Brook feeder pond represent not only multiple populations that may have evolved divergently over hundreds or thousands of years, but also multiple species. So they will expand in overlapping cycles and without visible interruption. But like rare blood types on Pacific Islands settled by single canoe voyages—or, more dramatically, achromatopsia on Pingelap—the duckweeds in this one little pool have suffered a genetic bottleneck: just a handful of cultivars to start, most died off or eaten or otherwise extinguished over the years, leaving just a few lineages with limited coverage. A salutary warning to proponents of crop, livestock or human monoculture…

But not all those who wander are lost, and in just a couple of weeks, the cycle begins again, to be repeated perhaps twice more before deep autumn

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July 26th

—and again, with variations, in seasons to follow.

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And having writ…

 

 

Shocks that phloem is heir to

The sap that sweetens our pancakes, preserves dinosaur blood in resined insects, and provides chewing gum, optical cement and incense evolved to serve many of the same purposes as our own blood and lymph, and a few besides. Injuries to bark and deeper layers lead to spillage of the vital fluid which (as with us) acts to flush away contaminants before “clotting” by various mechanisms to close the wound. (–Except in case of the most extreme literal shocks, which can leave perfectly dry wood scattered all about or aflame.)

The assaults that lead to grievous trunkily harm are diverse, including all sorts of mechanical impacts, incision, abrasion, avulsion, snow load and other bark-biting events, here wind flexion from nor’easters

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Albizia julibrissin, north side

and sun-scald/frost cracking from winter thaws

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Prunus (subhirtella?), southwest side

(here shown in cross-section after felling a year later due to excessively healthy growth despite the damage),

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not to mention collision with cars and lawnmowers, and attacks from bucks rubbing terrain- and status-marking scent from scalp glands

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Juniperus virginiana

(a particular issue with fragrant-wrapped magnolias), diverse smaller nibblings and peckings, down to micro-invaders like the dread phytophthora family. Our native Eastern red cedar, shown above and here,

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Not good for gin

provides not only berries for the cedar waxwing, but a higher-calorie food for sapsuckers that drill, depart, and return in time to harvest the amber ooze,

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leaving dry holes in sometimes-neat array:

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Thin-skinned species, including many within the lovely and fruitful genus Prunus, often exhibit a gelatinous “gummosis”

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Prunus virginiana

—recovery from which depends on both nature and depth of attack: in this case minor cambium scrapes that will heal, in others the result of and/or entry point for fungal infection. P. spinosa (blackthorn, or sloe), for example, is prone to this nasty-looking gall,

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Good for gin, if the plums survive

which the prudent will prune and burn or discard where it cannot release millions of spores to infect other specimens. A more menacing ’50s B-movie view of the same blob:

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Both economic and ecologic consequences can be significant. Where a desirable (hence oft-planted) species hosts—in obligate sequence or facultative dispersion—a disease fatal to an even more-valuable species, the former may be banned by statute:

White pine blister rust is not a serious disease of currants and gooseberries; however, it is a very serious disease of white pines (Pinus strobus). Currants and gooseberries serve as an alternate host for the rust fungus that causes white pine blister rust. Therefore, planting currants and gooseberries in areas where white pines are present can lead to serious losses of white pines. … White pine blister rust causes significant damage in pine forests by forming cankers on the branches of white pines. These cankers ultimately kill the trees. … To protect white pine forests, several states have enacted laws concerning planting of black currants.

This restriction does not apply equally to all Ribes species and cultivars, or in all parts of all states. (For an interesting resume of the relevant history in Massachusetts, including a list of towns with active bans, see this article.) It is a salutary reminder of interdependence and co-origination generally, and in particular of the risks we engender through inattention to an ever-so-broadly shared genetic heritage.

Some cankers may appear benign, and even attractive, in their earlier stages, like cedar apple rust, Gymnosporangium juniperivirginianae. With our area rich in both cultivated and “wild” apples, this pest finds an ample supply of both its alternately required hosts, and produces more or less harmless perennial galls like this:

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When spring rains arrive, spore-bearing “telial horns” are produced, of size, shape and profusion scaled to the originating gall: from minute

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to cute

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to monstrous:

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Here depleted, having killed twig but not tree,

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and apparently nibbled by creatures unknown:

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They live among us…

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Study in aqua, maroon, green and orange