Acorns from small to large of the Willow Oak, Quercus phellos (very small, at center), the Southern Red Oak, Quercus falcata, the White Oak, Quercus alba, and the Scarlet Oak, Quercus coccinea, from southern Greenville County, SC, USA, scale bar at upper right is 1.00 cm Photo by David Hill, published under Creative Commons https://www.flickr.com/photos/dehill/7891890620/

My aging dog sits by my side in the evening and together we listen to the plunk of acorns on the roof. I can tell he is getting older; years ago every acorn was accompanied by shock and vigorous barking protestations. But while he is barking less, this year has involved a lot of acorns sounds. Acorns cover the ground. People come up to me and ask, “What’s with the acorns?”

The ninety species of oaks in North America all produce seeds called acorns, which were once an important part of the diet of Native Americans. They had to be soaked and dried and ground into flour. While we don’t eat them today, acorns are a big part of our world and a part of the diet of seed predators such as squirrels.

And here’s the scoop. Yes, there are more acorns this year than most years. It’s a plot by the oaks.

Periodically, the region’s oak trees have a year when they put out many more acorns than usual. Such a year is a called a mast year, and it is important to maintaining the trees. Most years, the oaks put out acorns but most of the acorns are eaten by squirrels and chipmunks, some end up in the bottom of pond, paved over in roadways, or like the parable- falling on some other type of barren ground. Very few even germinate, much less survive the other dangers they need to escape to reach adulthood.

Then along comes the mast year. The oaks put tremendous energy into making more acorns than usual; a large oak will produce 10,000 acorns in a mast year. This synchronous high production means that the animals that eat acorns are unlikely to eat them all, an effect called predator satiation. More oaks germinate, more grow, and a little cohort of the year grow up together.

This phenomena of seed production is intriguing because the natural selection that pushes oaks to produce more offspring in some years acts on all of the population at once. It would not work if they simply made more acorns all the time, or one tree had a single unexpected year of high production by itself. They all have to do it together and it has to be periodic.

Mast years occur in other plants as well. In some ecosystems a mast year combined with a fire that has cleared out habitat will produce a lot of seedlings, more than mast year by itself. White pine forests have been found to work this way.

The most famous mast events in the world are those associated with bamboo. Bamboo is a broad term for about a 1,000 species in the same subfamily of grasses. Some species native to Northern India have a reproductive cycle in which they bloom and put out masses of seeds every 48 years, and then die. This event, called Mautam, produces enormous amounts of food for rats and results in a “rat flood” and unfortunately, a local famine for humans.

Fortunately for us, a mast year in the mixed forests of New England is unlikely to dramatically increase stored product pests and cause us to be over run with rodents. Squirrels and chipmunks are likely to thrive this year, however, and most of us will enjoy them. My dog, immune to the acorns, may bark at the squirrels they attract. Then another year, the numbers of acorns and of squirrels and chipmunks will fall again.

Several people have asked me what triggers a mast year. Scientists do not know. We do know it is not simply the weather such as precipitation or temperature patterns. Neither does a mast year predict the winter conditions likely to come. So for now we will just enjoy the mystery.

These young’uns emerged from a flower bed in front of McDonald Hall today. There were about 10 of them, and they started walking in different directions. They are baby snapping turtles, laid there by a mother snapping turtle weeks ago, probably in June. In Massachusetts all but three species of turtles are protected and cannot be collected in the wild. Snapping turtles are not protected, but like all turtles, have a long life span and do better if simply left alone. Because of their slow movement and long life spans, turtles have not fared well in the rapidly changing world of the last couple of centuries.

Generally, when turtles are wandering, they have an instinct telling them where to go. It they are in the road, move them out of danger in the direction they are going. It is OK to move hatchlings toward water, but realize that for many young animals wandering or breaking their way out of shells, and other difficult tasks can be important in their development.  In any case, if they look like they are going down a storm drain, into traffic, or into some other dire strait, feel free to move them to the edge of a water body and leave them near some type of cover like leaves. Adult snapping turtles, in contrast,  bite (seriously). So if you ever need to move one, let it chomp on a sick and move it without getting your hands close, or put it in a box.

But anyway, what should you do if you find them? In general, leave wild animals alone to do their thing. But it’s a scary world out there, so Don’t step on them and PLEASE DON’T DRIVE ON THEM.

Interesting Biology Tidbit: Turtles are interesting because in many species, sex ratio is determined not by genes but by the temperature the baby experiences while developing in the egg. This is a very primitive trait, older than the determination of sex by sex chromosomes. As climate warms, turtles experience a shift in sex ratio, moving to more males.  Conservation biologists are trying to figure out ways to help turtles survive in changing circumstances.

Jewelweed is in the foreground, with Phragmites and a little purple loosestrife behind it

Fall is a time of interesting edges.  Native plants like yarrow and the goldenrods sway next to asters in the areas between forest and meadow, or meadow and parkinglot.  One common plant is jewelweed, Impatiens capensis, also called “touch me not”. Jewelweed is known for its bright orange flowers, bright orange sap, and its  seed capsules that spring open when touched.  The name “jewel weed” may come from the fact that its leaves look silvery under water although some attribute it to the large blossoms, which hang like pendants.

In my own experience, there are plants that are perfectly lovely, but are never noticed, because we consider them weeds. Jewelweed may seem like a weed to us, because it is found in areas such as ditches. However, it is a valuable source of food for pollinators, being adapted to pollination by hummingbirds. It is especially important to the Ruby Throated Hummingbird, but it is also pollinated by other animals such as bees and butterflies.  It is also quite pretty, forming dense stands up to five feet high with orange blossoms that emerge for weeks in late summer and early fall. You can even buy jewelweed seeds, although it is an annual and less likely to be used in landscaping than perennials would be.

Like many of the native plants in our area, jewelweed has been used for medicinal purposes. Its sap is rumored to help with poison ivy and nettle rashes, and it is possible it was used that way by native Americans, although the actual efficacy of jewelweed  for that particular purpose isn’t well known. Its effectiveness as a fungicide and usefulness at killing infections such as athlete’s foot has been verified in scientific studies.  There is some contradictory information in the literature about whether you can eat it. Some sources say – “cut up and fry those greens,” and others say- “nope, you’ll get sick.” Most seem to suggest that you should not eat the seed pods and that children will suffer the most from ingestion.

So break open that stem and spread goo on your skin and you’ll be fine, but stay away from eating it unless you know a lot more about it than any of sources of information I have.  Enjoy the fall, as you walk near the woods and hear the popping of jewelweed spreading seeds, and a bit of joy, in late September.

The end of August slides warmly past, hot sticky days end in nights cooler than those of a month ago. The dry ground of the garden waits for a storm. In the dark on the weathered steps in the back of the house I sit at night to listen to the loud insect chorus of the later summer.  Into this time, poised for those first leaves to change, waiting with baited breath for the start of school, sneak the goldens.  Their lacy blossoms shimmer in a haze of bee and beetle activity, nestled in the thick of plants most would call weeds.  Suddenly the sides of roadways and  the rare unmown meadows glint with the dappled flecks of goldenrods, patient natives offering nectar while their neighbor, Joe Pye weed fades from mauve to tan.

Goldenrods are members of a genus in the aster family.  The genus, Solidago, has more than a hundred species. Several are native to this area, most to North America, although some are in Central America and a few on other continents. Some like seaside goldenrod, Solidago sempervirens, live in more specialized niches  such as salt marches.  Goldenrods are rugged perennial plants with tough stems and    underground rhizomes (lateral stems new plants can grow from). The stems produce a latex when cut, once used to make rubber. The plants also contain compounds used in traditional medicines against sore throats, toothache and kidney problems.

In addition, goldenrods have an important place in the history of ecology. Dick Root, an eminent ecologist at Cornell University, spent much of his career studying the groups of small creatures (insects, mites etc.) that live on goldenrods. Within that tiny microcosm of the world, he looked for, and with his many students, found new ideas about how ecological niches are organized, how communities work, and what herbivores do to the plants they eat.

Goldenrods are insect pollinated. Their heavy sticky pollen does not cause the hayfever that ragweed, flowering at the same time, does.  Insects such as bees and  wasps, buzz about, sometimes collecting the nectar many goldenrod species produce.  In Europe, goldenrods are planted in gardens; their  abundant, tiny flowers form a halo of yellow on the tops of stalks .  In China and Germany, cultivated goldenrods have escaped and become invasive. However, in North America, where they are an important part of ecosystems, their natural beauty is often overlooked.  Rejoice in the pleasure of the goldenrod,  which can be found swaying in the light late August breeze, by many of the roads and walkways in this area!

Iris pseudacorus photo by Jean-Jaques Milan http://en.wikipedia.org/wiki/Iris_pseudacorus#mediaviewer/File:Iris_pseudacorus_001.jpg

Walking around  the campus, I am almost cheered by the bright bloom  of the yellow iris (Iris pseudacorus L. )  in  the streams and along the paths  toward the woods . Almost , but not cheered, it turns out, because I know two things. First, there is a lot more yellow iris on campus  than last year, and second, because the yellow iris doesn’t belong here.  It is an invasive species, albeit a lovely one.

Yellow iris spreads. While in some temperate regions it is still planted for horticulture, in others, like Massachusetts  it has been banned. Did you know there were banned plants?  Usually they are plants that are considered “noxious” even if they are attractive, because they are so hard to control.  In fact, the yellow iris is on the  Massachusetts list of prohibited  plants. This list is not a list of all the plants you ought to avoid as a gardener  but is a list of plants that are so difficult to control  that “the sale, trade, purchase and distribution” are prohibited in the state.  In case you think this is a case of governmental overreaching, consider that invasive species  have been estimated to cost  the US upwards of $120 billion a year¹. In 2011 the Department of the Interior spent 100 million on  invasive species  from prevention to control and restoration².  Every state, the federal government, and  other nations, have agencies set up to limit the spread of invasive species., which represent not only economic costs but one of the major causes of species extinctions.

I discovered that yellow iris was on this list last year when I was admiring some in a clump near the parkinglot  toward the back of campus. “Wow,” I thought. “I know blue flag iris is a common native  wetland plant. These yellow ones are really lovely  too, I wonder why I haven’t seen them before? I wonder   if they belong here?

And indeed, the reason I had not seen here is because they are not native and are only now establishing .To prevent their spread,  we will  need to have a plant removal day.

Look for invitation!

In the meantime, if you are looking for plants that won’t spread and cause ecological problems, I  would plant natives. One place to find out about native plants is the New England Wildflower Society, both online or at their Garden in the Woods site near Framingham.

1. Pimentel et al 2005. Ecological Economics.  52:273-288.

http://www.plantright.org/pdfs/Pimentel-et-al2005.pdf

2. http://www.fws.gov/home/feature/2012/pdfs/costofinvasivesfactsheet.pdf

The click beetles are members of the beetle family Elateria. They have a spine on one part of their exoskelton that fits into a groove in another part. The beetle can use it to make a suddenly click and dramatic popping movement. It uses this to evade predation and to right itself from laying on its back .There are about 965 species in North America, so don’t ask me which one it is specifically. On this on you can see alarming looking spots on the back which are likely to frighted bird predators.

Younger son and a friend found this one in a wood pile. They had no idea what it was and thought it was dead. I initially filmed it for about 6 minutes before I gave up . It just laid there. Then later, it popped around a lot. I eventually released it back to the wood pile. This one was about 3cm, which you can see in the photos. Here is a short video of it clicking. This is 5 seconds of what was a 5 minute clip.

click4

In the middle of the winter, my American Holly, probably 6 years old, started to look sick. At least that’s what I thought. Almost overnight, at least half of the bush was brown. The leaves were shiny and brown, though, not dull and dry like I might have expected if they were dead. I couldn’t figure out what the problem was. I wondered if perhaps, they were just in some type of rotation, were they going to drop off and be replaced like the white pine needles do periodically? ?  Why would only have the bush be rurning brown? Perhaps it was really a second Holly , rooted next to the first?

This mystery remained and I passed the bush each day, watching it turn browner and greener on one half and the other, as snow melted, grass grew, , and weeds becan to fill the hollow at its base. Overwhelmed by the spring grading, finals, and an early summer course, I let the mystery lie. One day however, i took a closer look. It is one tree. Half was indeed, looking dead.  The branches from the two halves are intertwined, but all the green come from one base branch, and the brown from the others.

Further investigation suggests that i have a case of  Botryosphaeria Canker, a type of fungus, although there is an off chance the problem actually started with a different fungus, invading through the roots.  All of the fungi are worsened by a combination of drought (which we experienced last summer) and flooding, which we had experienced in the spring.  So I guess just leaving the holly and figuring that it would all be fine as long as it didn’t die from the drought, probably wasn’t best. The holly was likely stressed and more susceptible to an infection.

So keep your plants healthy, and avoid all of this grief, I suspose is the take home lesson. I removed the dead parts, but cannot guarentee the fungus cannot spread to the living remaninder.

(I”m on the left. With  a student in a tidal creek in Essex, MA)

I am covered in mud at the end of the day after a field trip with a small class to a salt marsh in Essex.  My hands smell of the deep rich sulfur scent of marshes by the sea, of sea wrack and salt water. I sniff deeply and exhale and remember the joy of hundreds maybe thousands of hours spent in marshes both salt and fresh. Hours on days like this, counting minnows,  counting larvae invertebrates, mapping vegetation .

In a salt marsh, the mud sucks at your old sneakers, clings to your calves, creeps up your pants.  Soft, and thick, it is the life of the marsh. In a tidal creek, I sink to my knees as I move forward slowly, trying to seine minnows. The mud’s richness comes from the death of plants, the trapping of tiny particles, the soft decay of algae. Bacteria quietly grow, using up the oxygen and turning the layers below the very thin top layer, a rich dark color.

Mud is elemental here. It holds the history of the marsh, the tale of hurricanes and storms, the movement forward and back of the constantly changing coast.  Crabs sidle by on its surface, ribbed mussels stick out only a bit, filtering the changing tide, cleaning the water from one cycle to the next. Up at the surface, the tough marsh pants will trap mud particles, raising the marsh surface while the processes of sea level rise and decay lower it. Tens of thousands of years of marsh accretion and loss , growing and declining,  have brought this place to be. I get to be here, and would have no other place today.Some people are made to revel in mud.   I am one, and today is a day for a tidal marsh.