The Daily Bucket is a regular feature of the Backyard Science group. It is a place to note of any observations you have made of the world around you. Rain, sun, wind...insects, birds, flowers...meteorites, rocks...seasonal changes...all are worthy additions to the bucket. Please let us know what is going on around you in a comment. Include, as close as is comfortable for you, where you are located. Each note is a record that we can refer to in the future as we try to understand the patterns that are quietly unwinding around us.
November 4 and 6, 2013
Salish Sea, Pacific Northwest
Drifting across Barlow Bay earlier this week birdwatching - Kingfisher and Heron were in the trees along the shore - my kayak eased up against one of the big rocks by the steep hillside. Over the ages, several boulders have fallen from the headland forming little islands. Getting a close look at this rock I discovered that it was blooming with life, quite colorful and variously textured. As I circumnavigated the rock, I also discovered that this life varied depending on the aspect, steepness and proximity to the shore, forming different microhabitats. These photos will show you some of the multitude of living things on this one rock.
The tide was high just then on Monday at about 3 pm. The white line marks the level of the typical highest tide level. Notice the orange right above it.
That is the spray-zone lichen,
Caloplaca. It is one of the very few lichens that can survive salt water. A little higher up, several gray lichens also colonize the bare rock. There are several species here. The disc-shaped, lobed crust lichen is
Placopsis. Together, they make very pretty patterns.
This side of the rock is a vertical wall, and faces the afternoon sun. Exceedingly dry here, from sun and wind. Only lichens can manage this harsh environment. Lichens are a composite organism, a fungus and an alga living in a mutually beneficial symbiotic relationship. The
fungus portion chemically dissolves the rock as it adheres, forming a weatherproof housing. The
alga portion photosynthesizes, manufacturing food for all parts of the lichen. It appears to me that the orange lichen forms vertical bands down the face of the rock.
Like other fungi, lichens have fruiting bodies. Those of
Caloplaca look furry. It's hard to imagine photosynthetic pigments embedded inside these masses.
Paddling around the side of the rock you can see how sheer it is on that exposed side. Along the edge of the water there are limpets and barnacles. Limpets (a gastropod mollusk) can come and go as they please, but barnacles are glued in place and can not survive out of water. The top of the barnacle zone is a good marker of the very highest tide level. The wet rock below the surface shows how vividly colored this rock is. It looks like a chunk of metamorphic greenstone, one of the common bedrocks of the island. In places it shows reddish oxidation.
There were also spiders on this face. On Monday I thought the spider I saw there had lost its way and was marooned, but when I came back Wednesday, I found two of them, and lots of spider silk all over the rock. Evidently they live here full time. Anybody know who this is? or whether it's using the strand of spidey silk for support as it traverses this wall?
Another fruiting lichen species, lime green, plus Douglas Fir needles that have dropped from the headland above. There is some input of organic material onto this tiny island from beyond its moat.
Coming around the back of the rock, I found a meadow of mosses, lichens and stonecrop (
Sedum), a flowering succulent, with its spent flower stalks. Notice how the flatter surface allows plants to find root in the brand-new soil. The protection of the headland makes it less vulnerable to winter winds that might blast it away. (Note: This photo was taken on Wednesday, also about 3 pm. See how the tide is about a foot lower? it's still coming in)
A weathered crab leg up here suggests that a gull had a meal on this shelf. The local gulls are very fond of Decorator and Kelp Crabs in the bay.
I see a papery flake of Madrona bark nestled in the succulents. More organic input from the headland nearby, detritus helping to generate new soil. It goes without saying I couldn't get any closer to it up there to see if there were insects or worms in the mat of roots and rhizoids, but it's likely there are.
Having paddled and pulled my way all the way around the rock, I'm back to the side where I started. Several different colored moss species and lichens predominate here: it's not as benign a substrate as the meadow flat, but there are cracks, which are good purchase for moss rhizoids and collect water. The moss closer to the water is a different species than the one up in the meadow. Yet another microhabitat.
Then the leafy lichen zone brings us back to the corner of the vertical side.
Paddling off from the rock a little ways, I can see it as a tiny world, with many varied inhabitants, surviving and colonizing bare stone. The rock blooms with life.
Life in the bay on some quiet November days earlier this week. What's happening in your backyard? All observations welcome in the Bucket.
And -
"Green Diary Rescue" is Back!
"Green Diary Rescue" will be posted every
Saturday at 1:00 pm Pacific Time on the Daily Kos front page. Be sure to recommend and comment in the diary.