abiotic – Page 24

Tunnels from top to bottom

When I sat down to enjoy the sunshine and do a bit of sketching in the Don Valley trails on Sunday, I chose a young sapling to sit in front of. Not for any particular characteristic of the tree, but just that I like to have something at my back. I didn’t pay much attention to the tree initially, and I hung my camera bag on a broken-off branch before sitting down. When I got up and reached for my bag, I happened to notice these lines on the bark.

They’re obviously made by some sort of insect. Curious to what it may have been, I started poking around the ‘net. The answer to this question was not nearly as easy to find as I had expected it to be. Between yesterday and then again today I’ve spent several hours typing in search terms into Google and checking out promising links. This is easily the longest I’ve spent on researching a post to this point, and I didn’t even come up with anything conclusive for all that effort.

Research for my posts usually starts with a single, rather vague, descriptive term. For instance, when I was researching the Black Knot information, my first term was “black crusty growth on twig”. You usually get a few misses at first before hitting on to what’s obviously the correct identification. In this case I started off with “bark miner”. I’m familiar with leaf miners, which create tunnels between the two surfaces of a leaf, and this looked very similar. It seemed like a pretty obvious connection, but the search produced no viable hits. I changed my approach. “mines under bark lines on surface insect branch”.

This turned up a lot of not very useful stuff, but did contain one page that had something. It was a fact sheet on the Allegheny Serviceberry. What does that have to do with insect mines? It had a section on pests. The first paragraph read, “Cambium miners cause concern when noticed but are not very damaging to the tree. The mines can extend from a twig all the way down to the roots. The mines form light-colored lines in the bark.” Aha! A lead!

So the next search term was “cambium miners”. The cambium is the layer of reproducing cells in a tree located between the outer bark and the inner hardwood which is the source of the tree’s outward growth. It’s just a narrow layer, and in a young thin-barked tree like ash, maple, birch, and other deciduous species, it’s pretty close to the surface. This seemed promising.

Most hits I found just simply called them cambium miners, without identifying the species or even the order of insects they belonged to. I didn’t find this especially useful. However, after poking through a number of hits I came across a page from an online resource called Tree Dictionary. The page seemed to be focused on pests of trees as well, and included a lot of information on various fungi. Also paragraphs on sapsuckers, squirrels, frost, beetles, and, the object of my search, cambium miners.

The page indicates that cambium miners are flies belonging to the genus Phytobia. The flies lay their eggs on branches near the top of the tree, and the young larvae mine their way through the cambium down toward the roots, where they stay till they pupate. There isn’t actually a lot of information on the life history of this genus on the web, at least that I turned up in my initial searches. I was able to determine that there are a number of different species that have different host preferences, and some are cambium miners while others are leaf miners.

Knowing the species of my tree would help. I’m not certain, as it’s a small sapling in the middle of winter with no leaves. I can rule out birch fairly safely, I would think, and cherry, because there aren’t any horizontal lines. Beech and maple would be grey. Hawthorn would have spines. But that still leaves me with an assortment of options, including common species like ash, and less common ones such as alder, hickory, etc. I’m leaning toward ash, given the location and its commonness.

On the website ForestPests.org I found an informative factsheet on the Ash Cambium Miner. The page indicates that the larvae of this fly mine in straight or serpentine tunnels near the top of the tree, but the further down they get (and presumably, the older they get), the more their tunnels take on a zig-zagging appearance until they’re distinctly so by the time they reach the roots, where they’ll spend about 10 months. They overwinter there, then exit the roots in late spring and pupate in the soil.

I continued to poke around, pressing on and changing the search terms to see if I could turn anything else up. I had a few other potential culprits, including flat-headed borers (metallic wood boring beetles, the group that includes Emerald Ash Borer), and small moths of the genus Cydia, but none of the online resources seemed to match as well. I’m still not positive on calling them Phytobia sp, either, given that I couldn’t find any resource showing their mines to be able to compare to the ones I photographed, but the information all seems to match pretty well.

Today I spent the day laying laminate floor in the family room at my parents’ house. I’m pretty sure that laminate wood flooring is a little like vinyl tile in that they make the wooden planks out of pressed particleboard (or something resembling it) and then print a design on top, rather than laying an actual wood veneer over it. However, I assume they use an actual image of woodgrain to create the print image, so the laminate planks represent actual woodgrain patterns.

What does this have to do with cambium miners? Well, on both of the sites mentioned above, they indicate that the mines left by the larvae get grown over as the tree continues to grow and result in small discolourations in the wood. These show up as small dark marks on stumps when the tree is cut or, as in the case here, in wooden planking, where they’re called “pith flecks”, among other names. They apparently don’t show up in ash wood very well, but are fairly noticeable in most other types of wood. I’m not sure what type of wood this laminate is supposed to be an imitation of, but it’s got a distinctly reddish tinge.

Here’s a close-up of the pith flecks in the woodgrain of the laminate print. You can see nearly all of them are associated with the tree-ring growth mark, where the larva would have been tunneling close to the surface of the bark (the dark growth line). A couple of the marks are further in; apparently there are some species that will occasionally feed in the xylem (the layer under the cambium) for short periods, and that could be what these are.

Despite that these marks are due to insect damage, they’re not generally considered defects of the wood by most lumber manufacturers, but they are recognized as such by the Fine Hardwood Veneer Association (who knew there was such a thing?). I suppose that, over the course of a tree’s life, there’s a good chance it will be infested at least once so it would be hard to completely eliminate the marks from wood products.

Insects. They’re everywhere.

Memes and memoirs

I completely forgot about daylight saving time being today. Fortunately, it’s Sunday, and there was nowhere we had to be this morning. In past years, daylight saving has taken place in April, which is after the start of the field season, so if you slept in accidentally, you’d have volunteers waiting for you to show up at the research station. This works out better.

I was tagged yesterday by Wrenaissance Reflections to participate in a meme that’s been circulating some of the blogs I read. I don’t participate in a lot of memes usually, but the ones that are novel or interesting can be fun to do.

The word “meme” (pronounced “meem”) was coined by Richard Dawkins in his book The Selfish Gene (which I’ve actually read, for a university course). In it he describes the idea that natural selection acts at the level of the gene (or the phenotypic manifestation of the gene, anyway), rather than the whole organism, and that a gene favoured by natural selection will be passed on whether or not it’s in the best interest of the organism (hence the idea of a “selfish” gene). He used the word meme to describe a cultural unit that propogates itself socially, in a manner like that of genes, in that it’s replicated from one individual to the next through speech or action, with interesting, practical or generally strong ideas or trends catching on, and weaker ones “dying out” and going extinct. Factors that influence the survival of genes, such as mutation, variation and competition, also affect the survival of memes.

Dawkins created the word from the Greek mimeme, meaning to imitate, and shortened it to sound like “gene”. He gave as examples things like tunes, clothing fashion, manufacturing techniques, new words and current buzzwords, cultural beliefs, etc. The idea of a meme as an online game or task passed between friends wasn’t within his original focus, but it does fit his definition, and these days the word “meme” has come to refer to these things. I suppose, as a kid, in the days before the internet got big, those chain letters or postcard projects you’d get in the mail with threats of bad luck should you break the chain were another form of memes.

Wikipedia has a lot of info on memes, and it’s an interesting read. Certainly there’s more information there than I can present in a short blog post.

Anyway, back to Wren’s meme tag. The current meme in question was started by BookBabie, after she read a book review of a memoir and her husband suggested she should write one (a memoir, not a book review). She commented that her memoir would be much too short, but later stumbled on a book called Not Quite What I Was Planning: Six-Word Memoirs by Writers Famous and Obscure. The book is based on a story that Hemingway once bet he could sum up (his life? a fictional life?) in six words, which he did with “For Sale: baby shoes, never worn.” The idea appealed to BookBabie and she started up the meme, which has really caught on, favoured by the natural selection of cultural pressures that Richard Dawkins has described. Proof of this is in the fact that I’ve never heard of BookBabie before following the link in the meme back to her blog, and yet here I am, doing her meme.

The rules, faithfully copied-and-pasted from blog to blog as the meme gets passed along, are as follows:

1. Write your own six word memoir

2. Post it on your blog and include a visual illustration if you’d like

3. Link to the person that tagged you in your post and to this original post if possible so we can track it as it travels across the blogosphere

4 .Tag five more blogs with links

5. And don’t forget to leave a comment on the tagged blogs with an invitation to play!

I had to give this a lot of thought, and I checked out a number of other people’s 6-word memoirs while doing so. Bookbabie’s was “This too shall pass, I hope.” Wren, who tagged me, wrote, “Cynicism and enchantment coexist within me.” Jennifer of A Passion for Nature wrote, “She never cared much for sun.” Beth from Beth’s Stories wrote, “Happy mom loves to climb mountains.” Ruth at Nature Knitter wrote, “Knitting and nature rock my world.” You can keep tracking them back to the taggers, or spend quite a lot of time reading the comments and trackbacks on BookBabie’s original post.

As far as my own tags, a lot of the blogs I follow have already posted their own 6-word memoir. However, I don’t think Nina of Nature Remains, Mary of Mary’s View, Susannah of Wanderin’ Weeta, or Carolyn at Roundtop Ruminations have played yet, so to these four, and anyone else who’d like to – tag, you’re it… but only if you want to!

I had come up with a half dozen and actually settled on a take-off from Hemingway’s classifieds-themed one at first: Lost: curious heart, answers to Nature. So much of my life and my interest is wrapped up in the outdoors and nature that you can sum a lot up in that. But, it’s not the whole me, and I wasn’t completely satisfied with that. There’s more to me that isn’t touched upon by that statement. My creative side, my artwork and need to work hands-on. My desire to share my knowledge with interested people and the enjoyment I take from that. Also, aspects of my personality. Those who know me in person know me to be a very quiet person, shy at times, independent and often a bit of a loner. But if you get me talking on a subject close to my heart, I can open right up. I’m good at hiding my shyness, usually, and am friendly and open with people, and I love to share things and teach interested people.

I was reading a completely unrelated website when something within it sparked a thought. And so I wrote this, which I think sums me and my life up nearly completely:

From deep within, a quiet song

Feeling deficient in sunlight

Yesterday and today were gorgeous. The sun was out, the sky was mostly blue with the occasional puffy cloud. The sunshine was much appreciated, and I took advantage of the warming rays to go for a short walk. Yesterday on the morning news they said that to that point we’d only had 20 hours of sunshine (not overcast) so far this February. In an average February the Toronto area would see about 110 hours over the full month. So we’re a little deficient this year.

If you’re like me, long stretches of overcast skies can start to wear at you. I find the winter rather long, and beginning usually in January I begin to itch for the spring to arrive (and it’s not just because, as an Ontario naturalist, that’s when all the activity starts, nor is it strictly that I find the minus temperatures difficult to enjoy being out in).

Many people will go through periods of the “winter blues”, characterized by low energy and depressed enthusiasm for things. A more severe form of this is SAD (Seasonal Affective Disorder) or SSAD (subsyndromal SAD, slightly milder), and sufferers show symptoms of mild or severe depression, occasionally (but rarely) even becoming suicidal. It’s generally associated with decreased sunlight during the winter months, both in the form of shorter day lengths and increased numbers of cloudy days. The exact mechanism affecting the brain is unclear.

In northern latitudes it can be very common. Here in Ontario, studies have shown that 2 to 3% of the population suffers from SAD in the winter (no mention of whether most of these live in the northern part of the province). In Alaska, nearly 9% of people may suffer from SAD, and a further quarter of the population may have the less severe SSAD. An even higher 20% of people in Ireland and Scandinavia may be affected by SAD. Some studies have suggested there may be a genetic basis to the disorder (Icelanders, including those of Icelandic descent in other regions of the world, are resistant to the disorder), and research has found that women are up to eight times more likely to be affected than men (think it has anything to do with our natural hormonal mood swings?).

The treatment? Usually exposure to specially designed lamps, which help compensate for the lower natural light levels. Sometimes antidepressant medication is also prescribed. The lightbox mimics light levels on a partly-cloudy day (about 10,000 lux, whereas cloudy days are around 3,000 lux, sunny days 50,000 lux, and indoor light only about 400 lux). About 30 minutes a day exposed to this lightsource helps most sufferers. Since we don’t know for sure why people suffer from SAD, we can’t say for sure why more light helps, but there’s substantial proof that it does.

People with milder symptoms (the “winter blues” or SSAD) may simply be helped by spending more time outdoors, particularly if combined with regular exercise, such as going for a walk during your noonhour. Taking vitamin supplements, particularly vitamin D which your body needs sunlight to produce and so many people are deficient in during the winter, may also help.

My personal belief is that the cats have got it right. Look at this guy, doesn’t he look like one happy cat? And it’s probably because he’s been able to stave off SAD by lying in sunny puddles all day. I enjoy a good curl-up in the sun, too, but unfortunately it’s much harder to find a human-sized puddle than it is a cat-sized one.

The days are getting longer now. December 21 was the winter solstice, the shortest day of the year. The spring equinox, the day when day and night are equal, will be March 20. Today in Toronto sunrise was at 7:16am and sunset at 5:48pm. In two weeks, at the end of the month, those times will be 6:56am and 6:04pm – 36 more minutes of daylight. By St. Patrick’s Day, just a month from now, sunrise will be 7:26am (don’t forget daylight saving) and sunset 7:26pm (there’s a neat coincidence) – nearly an hour and a half more daylight than we have now. So cheer up, fellow winter-weary, there’s light on the horizon!

The bad lands of South Dakota

Yesterday we got another dump of snow, a good six inches worth, which piled on top of the foot we got last week, which was on the foot from the week before, with very little melting in between. It’s a shame that I’m not more into winter sports, because it seems the conditions out there at the moment are perfect for just about any of them. However, given that my pastime is hiking, and hiking in knee-deep snow is not only a lot of work but also results in very wet feet, it doesn’t work as well for me. I should learn to snowshoe, but haven’t.

So for those of you who need a short break from all the snow, like I do, I offer some sweltering hot South Dakota grasslands in the summer. I was sorting out some of the pictures last night, and thinking fondly of the warm temperatures. These were taken last July, during a cross-country car trip (final destination was a fall employment contract in British Columbia). I tried to pace myself so that I could make some stops along the way and do some birding, and the formations of the badlands combined with the birdlife made it a target destination.

When I first got there it was overcast and lightly raining, and I was a little disappointed at the muted colours and potential for low bird activity. Little did I know how preferable this was to the clear sky! I had put on jeans and a long-sleeved shirt when I first arrived, but within half an hour of the sun coming out I’d stripped off as much clothing as was socially acceptable and lathered myself up with sunscreen.

The formations are caused by erosion of soft sediment and volcanic ash over the course of millions of years. The landscape has gone through many changes, starting out as a large sea some 75 million years ago, becoming lush, wet floodplains about 40 through 25 million years ago, and then undergoing regional uplifting some 5 million years ago that began the erosion resulting in the formations seen today. Because of the area’s wet history, many well-preserved fossils can be found in the layers, often exposed by erosion (I didn’t see any while I was there, but I was focussed more on the wildlife). I took so many photos of these cool formations, but they’re a little like mountains – when you look back at the photos, they all sort of look the same, even though each one seemed marvelous and new when you took the picture.

I loved the colours in these formations, called the Yellow Mounds. It was only in a very small area of rock where these rainbow walls could be found, so I have to assume there was some local event here when the sediment was laid down that created these unique hues (or, alternatively, where the unique hues were exposed by erosion). The Badlands National Park visitors guide indicates they were caused by the uplifting of the area exposing the ocean mud to the air where it became yellow (through oxidation? does that suggest high sulfur content?). Lots of great information about the geology of the park can be found in their guide (in pdf form at the above link).

Spotted Towhee, Badlands National Park, SD

This was one of the first birds I came across in the park, in a small sheltered area with a good stand of juniper trees. It’s a Spotted Towhee, previously considered the same species as the Eastern Towhee (no spots) that we have here at home. He was singing from the trees while I was there, but staying mostly hidden.

Western Meadowlark, Badlands National Park, SD

At my next stop this young Western Meadowlark had obviously gotten quite used to the bustling parking lot; he walked back and forth along the edge and under the cars looking for bugs, paying little attention to the people. He got so close at a couple points that I could no longer focus on him with my telephoto lens (which has a close-focus of 1.5m). Look at him strutting…

Lark Sparrow, Badlands National Park, SD

I tried starting down one of the trails to get away from the crowded lookout spots, but the beating sun (which came out just after I made my first stop at the towhee) turned me back quickly – I just didn’t have enough water to make it very far. However, in the short area I did traverse, I found this Lark Sparrow, evidently quite upset with me being in the area. I love the Prickly Pear cactus. :)

Lark Sparrows, Badlands National Park, SD

A short search of possible hiding places turned up this little fledgling huddled at the base of a small shrub. Although it had left the nest, it was only a day or two out of the nest, as it didn’t flush when I peeked in at it.

Just down the road a bit was this Lark Sparrow family. The youngster (on the right, taking off after its parent) was considerably older than the one I found in the bush. Considering that these were the first Lark Sparrows I’d ever seen, I felt fortunate to have come across multiple whole families of them.

Meadowlarks were the bird of the day. They were at virtually every stop. While I struggled to turn up a Rock Wren or a Lark Bunting, meadowlarks were a dime a dozen.

Upland Sandpiper, Badlands National Park, SD

I had really been hoping to see an Upland Sandpiper while there, but departed the park gates without having seen one. Then, not 100 metres outside the park, I spotted this guy perched on a fencepost at the side of the road.

Mammals weren’t very apparent, but there were a couple colonies of prairie dogs who all very obligingly posed for pictures near the side of the road (the road seemed to bisect the colony; I wasn’t sure what this did for roadkill statistics, but didn’t figure it could be good. However, there was no evidence that it was a problem, either).

Black-tailed Jackrabbit, Badlands National Park, SD

And finally, I startled this jackrabbit from underneath the boardwalk where he was trying to keep cool. He paused after going out about 50 metres into the grass to look back at me, before taking off and disappearing from view. Even though it was just a quick view, I was excited to see him. Check out those ears! Their giant ears are used for keeping cool in the scorching prairie heat, through heat loss over the broad, exposed surface area.

Well, that’s it for South Dakota. We’ll be back to the regularly scheduled Ontario winter tomorrow!

Snowstorm, the day after

I took a break this afternoon to wander outside and enjoy the snow of yesterday. It had stopped snowing last night, and the day dawned clear, with a gorgeous blue sky and brilliant sunshine. These are the sorts of days that I love about winter. That, sitting by the fire, and fat softly-falling snowflakes. I could do without the slushy, slippery roads, the freezing rain, the bitterly cold winds (although these are all easier to take while sitting by the fire). The bright white snow and blue sky wonderfully set off the green conifers and red dogwood.

The snow in the front yard was clean and pristine, stretching out beneath the big trees. I can’t bring myself to walk through it, it doesn’t seem right to spoil something so clean and fresh and full of promise. I’ll leave that to the squirrels and rabbits, and I skirt around.

The smooth white of the unbroken snow makes a great canvas, catching the shadows of the big maple above. It seems somewhat abstract, like something that should be hanging in a museum somewhere. Nature is a great artist.

One downside to all this snow is the necessity of clearing it from the driveway so people can come and go. Here a snowball has rolled down off the giant snowbanks created by the plow (they were at least up to my waist in front of the house, and can be larger along the drive). My parents have an old 1945 Ford tractor that my dad has managed to keep running all these years and has hooked a plow to, used primarily in the winter for clearing snow. It’s been a faithful machine, and, given the length of the driveway (see the second photo), let’s hope it continues to be!

All this deep snow can be a challenge to ground-foragers such as the juncos and tree sparrows. At these times feeders become an invaluable resource that allows more birds to survive the harsh weather than might be able to without a supplemental food source. My mom tries her best to keep the feeders stocked through the winter, though wading through knee-deep snow can be a challenge. Certainly appreciated by the birds!

I wasn’t the only one out enjoying the fresh snow. The two younger horses were having a grand old time frolicking in the white stuff, throwing up plumes of it as they raced through. After a few laps around the field they pulled up near the gate where I stood, their bellies caked with snow, their nostrils wide as they panted deeply. But their eyes sparkled with energy and enjoyment.

Mine too.