A botanist's field notes: excursions in all seasons

March 1, 2017

Last night’s thunderstorm emboldened the chorus frogs, who seem to have spread in the past week from a small stronghold along the southeast edge of the East Woods to much of the southeast corner. An inch of rain fell overnight, and the morning was foggy. I parked at P10 and walked through the burned woods, which are now completely cool. Last week sections of the forest were still smoking. There were pools of water along the edge of the trail even in this highest section of the woods. Across the interstate, through the oaks and partial fog, the office buildings and the cars and the lights were a different world. The chorus frogs could not have cared less.

After the warmth and excitement of last week, the drop in temperatures last Thursday and following had slowed everything down. When I left the house on Thursday, it was 50F, and I foolishly wore sandals. By that afternoon, it was rainy and 40F, and by nighttime it was nearly freezing. Over the weekend we had snow. But this morning is back to spring. There is a dusting of newly fallen leaves on the burned sections of the forest floor. I was hopeful that perhaps the marcescent oaks were actively dropping last year’s leaves. From what we know – based, I believe, on a single study of black oaks in Madison Wisconsin – marcescent oaks yield their leaves when secondary growth starts up beneath the bark, and the young cork forms an abscission layer where none had formed the previous year. But I suspect the fallen leaves had just been knocked down by the wind: the buds on the white and bur oaks I passed still appeared to be in winter, and beyond the woods in the oak collection, one of the marcescent young post oaks I have been watching still wore all its leaves.

I walked south of the oak collection hoping to hear a woodcock again. A deer startled and bounded off. I stopped at bur reed marsh to listen to an odd squeaking bird or frog at the edge of the pond. One moved close to the boardwalk. I thought at first of spring peepers, but that didn’t seem right. The call wasn’t as strident as I remember, but it had the rubbery squeeky precall of a frog. I wasn’t sure what else it could be. It might have been a shorebird of some kind… it reminded me of a sora rail, which I assume is nonsense at this time of year. A woodcock started peenting from an opening in the woods to the north of the boardwalk. The acoustics were funny, and every peent seemed to come from a different spot in the woods. I don’t believe there was more than one: the calls were regular and never overlapped, and he might well have been moving in and around sparse tree cover, projecting his voice in all directions. I haven’t roamed around off trail in that section of the woods, and today was wet enough that I was disinclined to. That’s a project for another day.

As I walked west of bur reed marsh, the woodcock took off and started his whistling, kissing flight overhead. I wonder if he favors the burned vegetation. I once heard that the woodcock likes the burned prairies because they show off his legs so nicely. Vain woodcocks. Was that Aldo Leopold? or Ken Wood, another great Madison naturalist? Ken was master personifier and brilliant observer, and this sounds like his sense of humor. It’s a luxury to have a woodcock show all to yourself so early in the morning. There have been times in Madison that I’ve watched woodcocks in the prairie with 30 other people, all perched along the trails watching up as the birds fly and squinting out when they drop to the ground and start peenting.

The trail crossed the road to a wet marsh. The day was growing lighter. I had walked into a cloud of spring peeper calls. I hadn’t expected to hear them so early in the year, but they were unmistakable, a din of songs all piled up on each other. This is most likely what I had heard in the marsh as well, with some variation that I didn’t recognize.

I walked back along the north trail that runs the length of the east woods, studying the white oaks and the bur oaks. Catkins aren’t opened yet on the Ostrya, though they are on the alders lining the visitor center. The elms are in flower, and I looked for first leaves shoots of Hepatica and Anemone in the woods. Nothing yet that I notice, but at this rate they’ll be out soon.

On the walk back there were wood ducks, song sparrows, blue jays, robins and cardinals singing. Oddly, no chickadees that I recall.

February 22, 2017

I left the house a bit before five this morning. Drippy fog settled down on the region overnight. It was about 50 degrees, and a robin was singing. On a May morning two decades ago, I awoke at about 4:30 to the sound of an exotic thrush singing outside. I had just taken an ornithology class, and my head was brimming with bird songs. I dressed quickly and raced outside: that also was a robin. This morning’s robin caught me almost equally off guard. I know robins are early-morning singers, but it seems so early in the year for this sort of thing. We have winter-resident robins here and in fact well up into Wisconsin, and they are perhaps primed and ready to go when the temperatures rise early in the spring, as they have this year, even with the days still relatively short. The robin had sunrise beat by about an hour and a half. Can you measure backwards from sunrise to the first robin song of the morning? If so, does the length of the robin-ruler change with the temperature? Does stamina increase and singing start earlier as the spring wears on, or does it decrease?

Temperatures have been higher than average for most of January and February, and reading the high 50s and 60s for about a week now. In the past two weeks, bluebirds and mourning doves have been singing and moving around the neighborhoods. Chickadees have been singing their hearts out. Red-bellied woodpeckers have been especially noisy, even for red-bellied woodpeckers. Enormous flocks of cranes flew over on Sunday, impossibly high, as loud as if they were in a park on the other side of the street. Male redwing blackbirds showboated around the pond behind the visitor center yesterday. I think about our little prairie experiment on the west side and worry about about how early the weeds will emerge this spring.

We burned our rain garden over the weekend, and the Arboretum has been burning the East Woods. This morning I started at P10 and walked south and east through the blackened forest. The charred leaves and naked trees had a subduing effect in the fog. Aside from the sound of I-88 blaring away to the south, I was completely alone there. The burned woods stretched off as far as I could see. Heavy, isolated raindrops hit the charred leaves at intervals. The sound was shorter, less resonant, than it would have been on dead leaves. A fallen log was still burning steadily, flames darting out from beneath the edge of the burned-out base. The tree had fallen and the bark had decomposed. The burning base was no bigger than a campfire. How did it feel to come across spontaneous fire like this in the wild when it was still easier to carry fire from place to place than to start a fire from scratch​? Over and over, groups of people must have rediscovered this mystery and felt grateful, awed. Was it a living thing? Was it a gift? Even today, it’s hard to believe that such a thing as fire can exist here with us.

Further on, a spark rose from the darkness about 20 feet up and arced down toward the ground, going out before it had traveled more than 5 feet or so. I walked toward it and found a tree smoldering in a small section where the spark had emerged. The fire had apparently hit the tree on the downhill side and flamed all the way up, leaving one section burning. Fire is capricious: this looks to me to have been a particularly thorough, even fire, but even so there are strips and patches of unburned leaves in the middle of the woods, and some logs that might have burned well go untouched while others burn slowly for days.

Chorus frogs called from the lower parts of the woods toward the interstate. I crossed the road at P8 and walked the path separating the burned section to the west from unburned woods to the east. This is where I typically start sedge walks, but there was too much happening in the woods this morning for me to pay attention to sedges. Some bird had been calling in the woods since I started walking, and now that I’d gotten used to the burn I was puzzling over it. It was reminiscent of a spring peeper, though certainly not that, similarly incessant but less methodical, less insistent. I crossed the road and hit the edge of the spruce plot. A fire break had been raked along the length of it and I followed this to the road, walking through dry woods and spongy places with the burn off to the left and the spruces to the right.

I caught back up with the trail and crossed the road to the unburned section east of Big Rock. There was a sudden noise in the woods, like something hitting the ground abruptly. I sometimes think of myself as unflappable, but at times like this I’m not. I shined a light at the deer or coyote or potential assailant. A raptor—barred owl perhaps? I’m not sure what else it could have been—fumbled around on the ground and turned to fly up into a nearby tree. I followed with my light, but the fog was still too thick to see where the bird had gone. Barred owls don’t spend a lot of time on the ground, I don’t believe, and I suspect what I had heard was the moment of impact when the bird hit the mouse on the ground. If so, what a quiet descent! I hadn’t heard a thing before the impact. I’m not sure this is what happened. I’ve seen mice get taken, and they scrabble at least a little bit. I once heard what I believed to be a rabbit scream in the woods, taken by predator. So much happens in the dark that we see only a bit of, and we imagine the rest. I guess that’s why the dark is scary. We’d be fine out there at night without our overactive imaginations.

I walked back to my bike, retrieved my backpack, and rode toward the visitor center. To the west of the oak collection, I heard the unmistakable whistling of a woodcock flying low overhead. He landed and uttered a single peent in the field between the planted buckeyes and woods adjoining the Carex lacustris marsh. I waited a few minutes, but he had no more to say, not this time of day. I think evening is more a woodcock’s time. This is the second earliest in the year I have heard a woodcock call. The earliest was February 19, my mom’s birthday, up in Madison, Wisconsin, and I believe that was the record for our area at that time. Welcome back, woodcocks.

I was almost back to my office, trucking along, when suddenly a song sparrow began singing in the field to the east of the visitor center. Still foggy, sun still down, still February, and he was singing as though his life depended on it. Spring seems to have come.

February 8, 2017

 

Do not move
Let the wind speak.
that is paradise.

– Ezra Pound, Canto 120

 

This morning I locked up at Parking Lot 11, the northwestmost intersection of the main trail with the road. The temperature is hovering around freezing this morning. For a minute, the very faint sound of wind mixed with the the pattering of ice crystals in the branches above, and frozen mist drifted across my face and glasses. The air smelled smoky from a brush pile that had been burned earlier this month. The trail was gray in the glow from the clouds at two hours before sunrise.

I walked to the woodland trail that circles north and east from the Big Rock Visitor Station. I recall walking this with Larry Pinto, a neurobiologist from Northwestern University, when I first started working at the Arboretum. It was spring, and we walked the hilltop past a flock of Virginia bluebells. I don’t remember how I met Larry, and I am sure that’s the only time we went for a walk. Moreover, I think that was the only time I’d walked this particular trail before this morning. I am always seduced by the Big Rock, which leads me due north and then sometimes off to the west around the Heritage Trail. But the Woodland Trail was great, trailing out through the same forest I have been walking through but somehow altogether different. I think of Ezra Pound: “Make it new.” Any new trail changes your perspective and makes the familiar unfamiliar. The woodland trail turned to the northwest overlooking the prairie and wet meadows that run along the northeast edge of the Arboretum beneath the power lines, lined with red and white oaks upslope and bur oaks below. I looked down at the road I sometimes bike in on: I’d never seen it from above. I followed the shortcut trail to the Big Rock to keep walking along this overlook. There is a monstrous bur oak and many large ones. A cloud of scrubby little trees mushrooms up along the edge of the meadow – willows? If there are sugar maples in the woods, I’m not seeing them.

Looking at trees in the dark this past month has been a change in perspective. Tree silhouettes are largely unfamiliar to me. I’m a sedge systematist by training, and I spend much of my time with a hand lens, belly-down or pulling an inflorescence to my eye to study. I constantly tell students to bring the hand lens to their eye, bring the specimen up, maximize their field of view. You see more this way. I’ve approached oaks similarly: endbuds and acorn caps, trichomes, leaf characters. At night, these don’t serve quite as well. You get the tree against the cloudy sky, generally intermixed with others. You get the texture of the bark, the carpet of leaves beneath. You get the whole landscape: you get everything except the things you need a hand lens to see.

I spent yesterday plunging through a checklist of the world’s roughly 2000 sedges (Carex only, my friends… with the whole family it would have been closer to 6000), putting them into Tree of Life order. I have never had a great enthusiasm for sedge classification. I love sedges, the places they grow, the ways they divvy up the landscape and fill space, their shapes and textures and colors and shapes. But for whatever reason, I could not get enthused about infrageneric classification. That changed over the course of a one-week meeting late last month, when we had more than 20 sedge taxonomists in a room talking about the Tree of Life. The primary reason for our meeting was to take the work we’ve done on the phylogeny of sedges and try hammering it into a new classification. As the group talked, I took notes. My friend Eric has a brilliant way of keeping a conversation going, and with him leading, we walked through the Carex Tree of Life in a way none of us could alone. At each node we would stop and someone would say, in effect, “I know this place. This is where…” and the conversation would run off into why the sedges in that particular lineage might belong together despite the fact that they’ve been classified under disparate sections for so many years. We had the perspective of field work and herbarium study spanning numerous countries and all the continents where sedges grow. Like any walk in the woods with a group of excellent naturalists, I felt the place was completely new. I saw species I’ve known for 20 years in their correct context for the first time.

Yesterday I dove back in to reconstruct the structure of that conversation, align 2000 sedges according to their relations, hang them up under a mix of formal and casual names that seem to have been waiting in the wings for years. The Himalayan Clandestinae. The Bladder sedges. Everyone in the group is excited to start describing groupings. We’re seeing old friends by new paths and meeting new ones along the way. At every turn, there a surprise or something that is not expected, but satisfying in retrospect because of how it makes sense. It is a walk through evolutionary history, peppered with folks you know and folks you’d like to get to know.

I passed the Big Rock, and the geese were honking in the wetlands across the road to the north. We had a soaking rain the night before last, and water is still pooled at the base of the boulder. On the walk out, I heard a barred owl calling from the east end of the woods. I expect to hear great horned owls one of these mornings, then the screech owls will start up. I expect it will be two and a half months till the bluebells bloom. In the meantime, I have plenty of oaks and sedges to work on, and many to get to know.

February 6, 2017

Grant Avenue smelled of skunk this morning from Lee almost all the way to Finley. I wonder whether Aldo Leopold would have thought differently about skunks if he’d lived in Downers Grove in the 21^st century. He opens A Sand County Almanac with “January Thaw:”

Each year, after the midwinter blizzards, there comes a night of thaw when the tinkle of dripping water is heard in the land. It brings strange stirrings, not only to creatures abed for the night, but to some who have been asleep for the winter. The hibernating skunk, curled up in his deep den, uncurls himself and ventures forth to prowl the wet world, dragging his belly in the snow. His track marks one of the earliest datable events in that cycle of beginnings and ceasings which we call a year.

Downers Grove is an exceptionally skunky town, and while there has been an uptick of skunk activity as it warmed up the past few weeks, I am not sure the skunks ever did lie down to sleep for the winter this year. Hibernation for a skunk in the Chicago region in 2017 may not be the hibernation of a skunk in central Wisconsin in the 1940s. We know that the wildflowers Leopold tracked at his shack on the Wisconsin River bloom earlier now then they did when he was making notes. It’s probably reasonable to expect the skunks to behave differently as well, and all the more so 100 miles south of the shack and 60 miles closer to Lake Michigan.

It was about 25 degrees when I got to the gate, partly cloudy, ten minutes past five. I had thought I’d do a short walk today so I could get into work earlier, but I was struck by a desire to park my bike at the Big Rock Visitor Station and walk the long way around to work, come in by foot. I recalled Martin Luther, who is said to have made the statement that he had so much to do, he had to start his day with three hours of prayer. I have so much less to do than Luther did. He set about reforming the church: today I had meetings and some oak research to conduct. I could surely spare as much time for meditation as Luther could.

I walked what may be my favorite section of the east woods, the rolling moraine to the east of the Big Rock station, with the depressional woods off to the north and topography reminiscent of the driftless area. I stumbled off the trail and meandered down along the edge of the standing water. The soil is frozen solid, crunchy and ragged from heaving with every freeze and relaxing with each thaw. The leaves are frosted in place, and a massive dead log emerges from the water. There’s no sound: I think I hear a bird, but I realize it’s my nose whistling. Warblers will be back in a couple of months.

I followed the road back to the trail, crossed over to the hilltop at the eastmost turn in the trail and down through the bur oaks above Parking Lot 10. One oak struck me this morning: it’s a bur oak near the bottom of a slope, bristling with adventitious shoots clustered around the scars left by fallen lateral branches. There wasn’t another tree like it in sight, and I didn’t see another one on my walk today. I doubt this is a response to some mistreatment visited on this tree in particular. It is perhaps a heritable predilection to resprout in response to injury. Is it adaptive here? Perhaps not, but we should know in a few generations. Oaks carry a lot of variation in each population. They are so highly heterozygous that the progeny of even a first-generation cross between populations of a single species may carry a great proportion of the range of variation of the parent populations. This works if the variation you care about is governed by a lot of genes and the parent populations are heterozygous for a good number of them. This may not be the only way it works, but it’s sufficient, and oaks certainly are configured this way.

Further on in the oak collection, I found a marcescent oak I hadn’t noticed last month. It is a small Hill’s oak (Quercus ellipsoidalis E.J.Hill) planted from seed 25 years ago, accession 204-92. This tree, like one of our marcescent black oaks, is collected from northern climates, this one from Winneshiek County, Iowa. Like the bristly shoots of the bur oak that passed earlier in the morning, these marcescent leaves may reflect past adaption, or they may a juvenile attribute that is neither adaptive nor particularly maladaptive. I begin to doubt, however, that the variation within species has much if anything to do with climate of origin. We’ll see.

Much of the trail to the west of the oak collection was dominated by bur oaks, with some red oaks and ironwood (Ostrya virginiana). One oak confused me: it had the appearance above of being a bur oak, but the bark was much more shallowly ridged. I was guessing in fact that it was a black walnut, but I couldn’t find any leaves beneath to support that. I think the East Woods would be as good a place as any to study hybridization between bur and white oaks. The problem would be sampling: how to get to the canopy and sample those leaves? I’ve always made do with sampling shoots ca. 15 feet up at the most… this may be the year to get serious about canopy leaves.

I passed the Carex lacustris marsh, Marlin Bowles’s dry prairie, Meadow Lake, the Children’s Garden and the groundcover garden and got to my desk 20 minutes earlier than I had thought I would. It’s 8:15 now, just 3 hours into my morning, and, Martin Luther and the skunks, I’d better get back to work.

January 18, 2017

This morning was cold, damp, and murky. Biking in from the gate I could see about 30 feet by the headlight. The mist streamed steadily through the light, racing downward and toward me as I rode. I biked west to the eastmost shortcut road, which is gated off in the winter. The unused road past the gate pitches downward through the woods. Last week’s storm scattered branches over the pavement. I locked up at the walkway and headed east. I’ve walked or skied this trail many times, but picking it up at this point, in the middle, gives me a strange feeling. The woods directly to the east remind me of trails in the Finger Lakes region of New York where my wife grew up, dominated by red oaks and sugar maples, with American beech and ironwood and Carex platyphylla underfoot… the last of these species is missing here, but white bear sedge takes its place. Looking at the distribution map for the species in New York, I see the two counties flanking my wife’s birthplace have herbarium vouchers for the species, but her county does not. I ought to have collected it last time I saw it.

I hiked into the spruce plot, a foreboding place before dawn. This dark, monotonous monoculture of spruces planted in a rectangle with sharp margins doesn’t have a lot to recommend it in the day, at least during the growing season—mosquitoey from June onward, nothing to speak of growing in the understorey—but this foggy morning it was transporting. A little stream babbled on my right, nothing moved. The spruces towered above. I could have been on the Apostle Islands in November.

Coming out of the spruce plot was a bit jarring. It wasn’t yet six, but the glowing sky seemed awfully bright. I crossed the road and hiked up a slight rise on the other side where I found Carex woodii in my first year at the Arboretum. I looked around with the flashlight and found plenty of Pennsylvania sedge and something much greener, but no C. woodii that I could see. I’ll find it this week: it’s lurking along the edges of the road, distinctive with its bladeless, burgundy leaf sheaths and tall shoots. I’d like to see it in midwinter before the snow returns.

Hiking around the corner to the oak collection, I was struck by a few very small trees that were utterly marcescent. While many oaks, especially the black oaks and their relatives, have some marcescent shoots, basically all the trees in the collection have dropped the lion’s share of their leaves. But on these few trees, it appears that hardly a leaf fell in the autumn. Two are southern species—post oak and blackjack oak—and one is a widespread east Asian species, Quercus mongolica. Out of place, I could easily understand this degree of marcescence as a maladaptive consequence of evolving further south. But the fourth species is our common black oak, accession 185-92. When I returned to the building, I expected to find that the accession was a southern collection, something from downstate Illinois or the Ozarks. It turns out, however, to be from Merioneth Drive just east of Crete, Will County, Illinois. That is south of us, but less than a 1-hour drive. Can that be enough to explain the phenotypic difference? Victoria Sork wrote an arresting article in American Naturalist in 1993 showing local adaption to herbivores in red oak on the scale of 100s of meters. The article floored me at the time: knowing how far oak pollen moves, I had assumed that oaks would exhibit little if any local adaptation. It may be that a Will County population is just different enough to behave as we see in our oak collection. On the other hand, it may be that what I’m looking at is just young oak behavior (though I’ve listed all the young oaks I observed this morning to be marcescent). I need to keep my eyes peeled. I have another two months or so before the trees start going again. Once secondary growth starts up, the leaves are likely to drop.

I hiked the remaining distance to my bike. It was 6:20 by now, but still foggy enough that the sky wasn’t growing light very quickly.

January 16, 2017

It was just above freezing this morning; sidewalks and driveways were glazed with ice. The road through the Arboretum is not particularly nice on mornings like this. I walked my bike along the base of the woods where I had walked out last week. There are even more big old sugar maples than I had realized out here. When I interviewed for this job 13 years ago, I asked on a drive-through with the director of research whether there were a lot of maples at the Arboretum, and he told me I was driving through a sugar maple forest right at that moment. It was January, but all the same I could not have impressed him. We were, I believe, at the very turn where I was carefully walking my bike this morning: today, I felt all I could see was great big sugar maples. These trees are magnificent, messy-headed beasts as wide as a window frame, heading straight up and then bursting into a crown of branches at the top. Their bark is grey and platy, and their trunks are massive, heaving out of the soil. I leaned my bike against several trees to walk up and look at this maple or that one, seeing the bark as though for the first time. Tom Brown tells a story about being instructed to study the robins. He protested that he’d seen robins enough already. He was asked, “how many spots on the robin’s breast?” Of course he couldn’t say. There’s always more to see.

Naturalists tend to be both romantic and realistic in this way: there is always more to see in the tree that you’ve walked past a thousand times, or the patch of forest you’ve biked through so many times. I estimate that on my bike rides into the Arboretum since we moved to Downers Grove I’ve biked this particular turn at least 750 times. That’s a sobering statistic. As I walked through this morning, I saw as much as I might in a forest I’d never visited before. How many big old sugar maples at the northeast corner of the road through the East Woods? I hadn’t thought before today of the fact that I couldn’t even answer that. We tend not to see much when we don’t have questions. Forget your curiosity and you won’t see anything new. The naturalist’s romantic streak shows in the notion that we can look at the same individual over and over and always see something new. We can, but only as long as we stay curious and keep asking questions.

I parked my bike at the Big Rock Visitor Station and walked the heritage trail clockwise. The trail traverses a moraine that looks over a couple of kettle ponds to the south. The larger one pond I botanized once: it is surrounded by bur-reed and rice cutgrass and clearweed, and it is filled with bladderwort. I had not expected to find bladderwort in such a pond, but there it was, festooned with little traps. Why do we find bladderwort with its traps in these rich ponds, when it must be so costly to build the traps? Perhaps traps are easy to build. Perhaps they just confer so much benefit that it’s worth growing them wherever you are. Perhaps the bladderwort got there first. The smaller pond today was frozen solid, branches emerging from the surface of the ice. I walked out to the middle of it, turned slowly, then walked back to the trail and sat for a minute. The traffic on I-88 hummed. An Arboretum truck trundled by, snowplow raised. The mallards and the Canada geese started talking. It was 5:49.

I rarely walk this trail and had taken it just for a change of pace. I recalled it as a shrubby, overgrown secondary forest, and I half-expected to just walk briskly through on a roundabout way to the Big Rock. But when I came down the hill to the westmost turn in the trail, I realized I had underestimated the place. There were perhaps a dozen bona fide open-grown bur oaks, branches stretched out, wide-crowned, towering over the brush beneath. Against the glow of the cloudy sky, the oaks are unmistakable, hearkening back to before European settlement. Why did they persist here? Why weren’t they cut down? How old are they? What is coming up beneath them with brush-cutting and fire? About 10 years ago I was part of a project that assembled the land-use history of the East Woods, but I and my staff were focused exclusively on vouchering the flora. I obviously have some reading to do. I walked on and crossed a beautiful bridge, read a sign about the bur oaks. I’m essentially a first-time visitor. I’ll be in the habit now of watching this place more often.

I made the final turn around the end of the trail and headed back up the trail, parallel to the boundary road and northeast end of Eagle Lake, came to the Big Rock, where my sons and their friends built a little shelter two years ago, back out through the oak forest to the parking lot, and back to work. Geese were still cackling. Rain had started, and I was glad to get back to the building, slip out of my shoes and get a cup of coffee. As I finish writing this, I read that the roads on the east and west sides of the Arboretum are closed due to the ice. This means more walking, less biking and driving. That’s not so bad.

January 11, 2017

This morning I locked my bike up at parking lot 10, on the southeast edge of the road going around the East Woods. The woods there are dominated by large old trees, all silhouettes an hour before dawn. I was hoping to find a tree that I heard fall as I was biking out last night. I had left at about 4:30, and the wind was ferocious. Somewhere between P10 and P8, I believe, I had heard the unforgettable sound of a great tree cracking and then falling through the woods, crashing through other trees on its way down. I’ve only once seen a tree of this size go down, in a red oak woods in Madison about 20 years ago. It had been the same sound: a substantial crack that could only be from something very large breaking. The sound was riveting, and I looked around rapidly to see if I was in the way… I had no idea where the sound had come from, but it was close. Then I saw the tree about 30 feet away, falling downhill parallel to the trail I was on. It fell like a dancer falls, arched legs and back and arms, until she catches herself in a short run. But of course the oak kept falling, knocking through maple saplings and scraping the bark off nearby trees until it hit the ground and bounced, slowly, as a massive body must. The tree had broken off perhaps 15 feet above the base, and the wood was wet and ragged, twisted in the places where it was still attached. The bark sloughed off like soaked flannel, sagging and buckled at the edges. The ground around the tree was remarkably undisturbed: wildflowers and sedges and leaf litter was mostly intact, with only occasional broken spots where a branch had punctured the ground. The bark on the trees the falling oak had struck was scraped off cleanly, and the exposed wood was fresh and white. Since then, I have felt that every fallen tree in the woods is a near-miss at watching another tree go down. I hope to see such a thing once more before I go.

At the top of the hill just south of P10, the oaks all appeared to be forest-grown, not a lot of knobs of lower branches broken off after decades of growing in the sun. There were branches on the ground, some large enough to trip you if you weren’t paying attention, but no large trees across the path, and nothing newly fallen of any size that I could see in the woods around me. Walking down the hill, the white oaks increasingly pick up short, skinny lower branches, decorated with marcescent leaves. Tree after tree showed this pattern: a naked crown and young branches that had retained their leaves after the life was out of them. This is not uncommon in oaks, and it stands out better at night. Why do the trees do this? Is there some advantage to trees that exhibit marcescence? And why the younger branches, unless marcescence is just a developmental side-effect, a failure to get all the way to the abscission layer in the fall. There may be nothing deliberate about it: it may be a textural artifact on an otherwise functional tree, no more functional than thinking wrinkles.

At the bottom of the hill, just east of parking lot 8, the woods open to the south, grading from forest to savanna to wet meadow. I picked my way through to the edge of the Phragmites and reed-canary grass meadow, then walked to P10 and crossed the road. I grew restless and turned on my flashlight, exploring initially for sedges. Hunting for sedges is my go-to activity outside, and it’s reliable fun in almost any season. I found Carex blanda and C. albursina, and a whole mess of something I should know but couldn’t put my finger on. I know there should be flocks of C. hirtifolia out there, but I didn’t see any. It may be that this is one of the odd woodland sedges that is not semi-evergreen. There’s work to be done on this.

I prowled and scanned on the forest floor and was having a great time out there in the dark, when I suddenly realized the tree I was looking around was a cottonwood in the middle of the oak forest. I turned off my light and looked at the bark, turned it back on and searched for cottonwood leaves among the white oak and sugar maple litter at the base of the tree, looked for the great buds on the branch tips above. Why was I surprised by the cottonwood? Should I be? I’m always unduly influenced by my own typically too-narrow experience of plants. Jason Sturner collected a cottonwood specimen northwest of the Big Rock Visitor Station in 2007, and presumably there are scattered cottonwoods elsewhere in the forest. I’ve just not noticed them, or I’ve noticed them and not given them enough thought to remember having seen them. This tree was perhaps 2½ feet in diameter, which is not particularly large for the fast-growing cottonwood. I gather that it established in the shade under the oaks. I have something else to keep a watch for this year.

On my walk out, I my full attention to the standing trees, and I was now all the more happy to have the flashlight with me. I kicked around among the white oaks, the red oaks, the sugar maples, studying silhouettes in the dark and bark by flashlight. The old maples seem to have branches that diverge more near the crown than the oaks of the same height and diameter. I worked my way back to the easternmost edge of the woods, came up to the road from the forest side. There was a fallen hop-hornbeam, quite old, but no big trees. There was the stump of an oak that must have fallen over a decade ago, sawed off to get the trunk off of the road, but nothing newly fallen.

Wherever that big old tree was, I didn’t run across it. Dawn was coming on by the time I got back to my bike, and I left my light off as I biked through the clearing towards work.

—————-

Addendum, 4:30 p.m. On the bike-ride out later that day, I found what I suspect is the tree I had heard snap off in the wind. It was to the north of the road, not to the south, a white ash riddled with fungus, ca. 1.5 ft dbh, broken off about 6′ above the base.

January 9, 2017

I worked for two semesters during graduate school as a teaching assistant for Dr. Ray Evert, a brilliant and delightful human, a great plant anatomist. He was an inveterate and enthusiastic observer. Almost every lab I taught he was right there beside me, walking around and helping the students interpret what they were seeing. He peered through every scope, continually teaching and reteaching students to focus and perform Kohler illumination, helping them to interpret what they were seeing. Our field of view in the course tacked from less than half a millimeter to the whole plant. We waded into microscopic worlds with Dr. Evert by our side, jumping into a slide disoriented, blind to everything outside the sharp-edged circle of light that we navigated around the slide, uncertain as to where we were. Often it was frustrating, spending inordinate amounts of time simply not seeing what we were looking for. But then suddenly we would find it, or realize that we had been looking at it and could only now see it and understand what the drawing on the chalkboard earlier that day had meant. We traversed the length of a vessel cut lengthwise from a tree trunk 40 years earlier or digested out of a tree trunk in bubbling lye, then switched slides to stare end-on down another vessel cut, most likely, from the same tree. We drew, looked again, erased and redrew, thought back to the chalkboard drawings on the board, considered what Dr. Evert had put into those drawings and what he had left out, most likely deliberately. We went back to the scope, did more drawings, then occasionally glanced out the window to give our eyes a break, watched a tree branch shudder under the weight of a squirrel leaping, vessels creaking against each other.

A colleague is coming into town in a few weeks, and we’re going to spend the day hunting sedges for a winter-root study he is conducting. He wants the plants frozen, and it looks as though he’ll get his wish. On my bike ride in this morning, I had in mind to start relocating populations I know of that he might like to see. I turned off my light and walked to a trailhead where I know I can easily find five species. Within a minute, I could see well enough to get around and know where I was in the woods, but it was still nighttime, and I couldn’t see any sedges. Flipping on my light, I gained a 3-foot circle of visibility at my feet. Sliding my flashlight circle around on the forest floor, I found Carex hitchcockiana and a little colony of Carex jamesii. I found, moreover, that the Carex jamesii is more widespread than I thought, covering more of the ditch bank than I had noticed in summer. The leaves were green, despite the fact that temperatures have been well below freezing for at least a week, maybe more. I pulled off the edge of a few clumps to bring them back to the herbarium, looked at them closely under my light. Around me the great East Woods was all but invisible to me: coyotes and foxes, deer mice and meadow voles, white and bur and red oaks, puffed-up chickadees and nuthatches, cardinals ready to burst into song in the clear morning, torpid skunks and raccoons and chipmunks, woodland sunflower stalks, carpets of oak leaves and patches of snow and heaps of decomposing tree trunks. All I could see was the sedge in my hand.

I switched off my light, squeezed my eyes shut and reopened them. The East Woods was back. I pocketed the sedges and walked back to my bike, surrounded by oaks and sugar maples. I much prefer the woods at night without a flashlight. I biked for about 30 seconds before I remembered to switch my light back on: you can see well enough by night, but not that well. In my office I flipped on the computer to start writing, and I remembered something Dr. Evert had said to me in one of the interstices of the anatomy lab, when the students were all working quietly and we were waiting for a moment of need. There were a few such in every lab, and we were often quiet during them ourselves, but occasionally we’d swap short anecdotes or memories or jokes. During one of these Dr. Evert had told me about meeting Saul Bellow, asking him how he had come across Katherine Esau’s Plant Anatomy, referenced in one of Bellow’s books. During another, he had told me a good Groucho Marx line about a fly crawling up a wall, but I cannot remember it now. What I remembered this morning was an emphatic and puzzled observation Dr. Evert had made about computers. Dr. Evert, to my recollection, had a typewriter and a microscope and books and files in his office, but no computer. How, he asked in that lab, could people get any work done when they were pulled into the computer all the time? When he walked through the halls, he’d pass colleague after colleague staring into his or her monitor. There was something devouring about it, too captivating. Walking past office after office that week, I looked in and saw too that everyone was staring at his or her computer.

As I switched my computer on and started writing this morning, the day opened up outside. The sun came up, the birds started moving, and I had my coffee and wrote. At one point I pulled out the sedges I’d filed in my pocket and put them under the scope, to see if the bases looked as they ought to for C. jamesii. The whole business of seeing the world works like this, tacking back and forth between fields of view. You see what’s inside the field, and you make the most of every field and you tie the fields together. That’s the fun of it. It would be no fun at all with only a single field of view.

4 January 2017

I arrived in the East Woods today during astronomical twilight, still dark enough out to see the stars clearly, but I could see the day brightening as I walked in. From the furthest bend of the road going through the east woods, the lights of the suburbs and the business park to the north and northeast reminded me of coming into Las Vegas at night 25 years ago. I was 21, sitting in the back seat, a hitchhiker with a tall eastern European medical student who was also hitchhiking, living on white rice and raw bacon and ketchup and cream cheese (an unlikely but delicious combination), scouring used book stores for medical texts he couldn’t find back home; a 17- or 18-year-old kid from Texas, our driver, who was out to see the world before heading off to the military; and his German exchange student, who was sharp and a bit exasperated. I believe the boy’s parents had sent him and the exchange student off with the car and a gas card to see the west. He was nostalgic as all get out, compulsive, young. It was dark, and I had just caught a ride out of the Canyonlands and Zion and Arches. I was in the state you feel coming off the trail when you are suddenly back in the car, and your campsite of that morning is locked up instantaneously in the past, inaccessible to you, and you are a little stunned. What were we doing going through Las Vegas? I can’t tell you what I was feeling the second before we saw the city, but I remember the feeling of buoyancy as we came up over the hill to the east of Las Vegas on I-15, and I suddenly saw all those bright lights in the distance, orderly stars crammed into the gridwork of the streets and sidewalks. Peering over the shoulders of the guys in the front seat, I was flying through the west. I had once previously experienced this feeling, in the foothills of the alps in southern France, watching the lights of the houses on a far slope grade almost indistinguishably into the stars above. Both times, I felt I could jump and land among the lights with just a little push off.

I biked to the trail that leads west from the Big Rock Visitor station and walked the remaining way into the visitor center. I had in mind to start making observations of the woods today as a backdrop to a book on the American oaks – I think every year of my adult life has started with some vague plan of this sort – but I hadn’t reckoned on it being so dark. Trails stretch out when the sun goes down, and everything looks new and strange. I like walking in the woods, and I think a part of me will always have faith in a romantic fantasy that my senses will pick up where my eyes leave off, and I’ll be able to just sense the species I’m walking past. That of course is nonsense: the only way to make that move from one sense to the other is through work, taking the time to learn an individual during the day, get to know it well, then come back to that individual at night. At night, I find I am much more taken by the woods as a whole than I am by individual trees. A few individual trees grab my attention as I walk by, but I more impressed by the sound of the bike wheels rolling over the frozen chips, the structure and texture of the woods around me. I stopped at a bench overlooking one of the little ponds that appeared on the east side after the drainage tiles were smashed around 2005 or 2006. It was now what they call nautical twilight, and the early morning breeze was moving frozen things around a bit. Birds were still: I thought I heard something calling in the distance, but only once. It was only 12 degrees Fahrenheit, but I still expected to hear a bit more.

I walked on toward the visitor center, came up over the hill by Marlin Bowles’ lime prairie at the corner of the geographic collections, and off across Meadow Lake stood the illuminated trees that the Arboretum strings up each year. I was looking toward the west edge of the lake, to the very spot where three nights earlier my family and I had been standing, and my sons had gotten into a conversation about whether or not the lights constituted a work of art. One claim was that strings of lights should not, under any condition, be thought of as art; the counterclaim was that hung in the bedroom, those lights would just be lights, but out here, strung across the lake and up in the trees, they became art. I stayed out of the argument, but this morning as I walked the remaining quarter mile to my office, I watched the trees in front of the visitor center as I approached and then walked under them, and I was struck by what the lights accomplished. The lights so carefully track the architecture of the trees that they bring out some essential aspects of the structure that I would not have seen in the daytime. Like a fluorescent dye administered by a doctor, or a stain used by a cytogeneticist, the lights highlight the trees’ structural essentiality. From a distance, the artificial colors (blue, white, electric green) reveal one person’s understanding of the tree’s essence. Like the lights of the suburbs, or of Las Vegas, or of a village on hillside, the lights on the trees provide an insight into the architecture of the world that is harder to put our fingers on in the daytime. A walk at night, for me, highlights the structure and texture of the landscape much more than a walk during the day, when individual trees continually distract me.