I finally finished cleaning and packaging the last of the wildflower seeds. Although there will be a few late-bloomers and maybe some seeds from a few trees or shrubs. It doesn’t look like so much, but over the years as I plant them out and harvest again, the bulking-up process should yield more and more plants for restoration and enjoyment.
Just two weeks ago, it was hard to believe we were going to get more rain in parts of the NW in four days than the total average for September. Here’s what the dry ground looked like before the moisture came (not sure about now, as I have been gone for the rains):
These are REALLY deep cracks in the clay soil, caused by a prolonged dry spell. You can’t see the bottom when you peer into them. Not unusual for our climate, but it has been very hot as well, evaporating even more water from the soil.
Clay in soil is of two types: the kind that swells when wet and shrink as it dries, and the kind that doesn’t. This is the first type, of course. The shrinking and swelling mixes soil particles over time, allows water and air to penetrate, and – when these cracks open, stuff can fall in, which facilitates the delivery of organic matter to deeper layers.
It also produces characteristic soil structure, which is a good thing: undisturbed soil organizes into shapes and aggregations called peds. These shapes are stuck together by the things that soil-dwelling microorganisms and roots exude. The space between the peds allows water to infiltrate slowly and the organic matter soaks up rain like a sponge instead of letting it run off the surface
Microorganisms especially soil fungi, are instrumental in holding carbon in the soil and sequestering atmospheric carbon. If you till the soil all the time, it destroys this structure, the extra oxygen accelerates decomposition, and microorganisms suffer. If you leave your soil alone, mulch it to protect it from rain pounding on it, and keep adding organic matter for the organisms, you have done your part to reduce atmospheric carbon and reduce pesticide and fertilizer use!
Late August observations: Some of the oaks are getting toasted. Some have dried up leaves, others show thinning and a yellow tinge to the canopy. This may be a sign of genetic responses to climate change. Some are going to be better at it than others.
At a conference I attended a few years ago, a researcher presented his calculations on weather patterns. At the seasonal/yearly scale, patterns are hard to see, but he examined longer term records of temp and rainfall statistically and found that in general, overall, the temperature is rising. Another conclusion presented at this same conference was that Oregon is getting hit harder by extremes of temperature and rainfall, with Washington still cushioned a little from these extremes. The heavy rainfall in the Puget Sound region of Washington is getting to be the norm rather than the exception. In Gopher Valley, my neighbor reported rain but not a deluge, at least not this time.
Another factor in the leaf stress in our oaks could be the incredibly wet and long spring/early summer rains that lasted till the end of June. This probably made it easy for fungal and bacterial leaf pathogens to infect the young leaves, and this is showing up now as the drought stress kicks in.
OTHER SIGNS OF LATE SUMMER
Even I get nervous when the yellow jackets starts to mass late in the season. But this tiny drama was cool. If you recollect the vulture post earlier this year, this is kind of a tiny version of that – meat eaters stripping a carcass really clean. I wouldn’t have noticed, except I was taking a picture of the giant cracks in the ground. This might have been a mole shrew or a baby mouse. Hard to tell because it was just fur and the head was some inches away. Yellow jackets are the coyotes of the insect world it would seem.
My son Patrick picked up this Giant Root Borer (deceased). Which it turns out is one of the biggest (by weight) long horned beetles in N America, (there are longer ones apparently).
Thanks to the Audubon Field Guide to N American Insects and Spiders and Bug Guide online http://bugguide.net/node/view/15740 for the i.d. Here is their post:
What you have there is a female Prionus californicus. Since she seems intact (that is, not chewed on by a predator), I would say that she probably fulfilled her biological duty and laid her eggs. She lays them in the ground at the bases of the host plants (just about any plant in this case), and the eggs hatch into larvae, which burrow in the soil, finding the roots of the hosts and feed until they reach maturity. This takes about 2-3 years.
The female uses a pheromone to attract males, then mating quickly occurs. The males are smaller, and have larger antennae which are elaborately articulated into serrations and plates which increase their surface area, thus enhancing their ability to detect the female pheromone.
The female of this species is quite large, and may well be the largest longhorn beetle in mass, but the palo verde root borer (Derobrachus spp.) is the largest in terms of length. Prionus is very common and there are probably hundreds per acre in natural habitat, but less common in developed areas. Hope that helps!
It’s easy to get nervous about how many of these things might be out there in the woods, note that the larvae take up to 3 years to mature – which means they’re eating the whole time and getting bigger and bigger (they are really huge, and you can see photos on the Bugguide website if you click on the beetle icon, and then go to Prionus). BUT natural landscapes and even ornamental ones can support a surprising number of critters. Like craneflies in your lawn: there can be a lot present, unseen, and you still will not notice much if any damage. And … recall that they are very nutritious food for something – perhaps birds or small rodents.
Since wood borers are probably scooting around and mating this time of year and invisible the rest of the time, it’s actually a fun and rewarding find and a sign of the season.
Working our way up from ground level, here’s a beautiful banded garden spider (Argiope trifasciata) that hangs out in grassy, dry areas: id. by our friends at http://www.spideridentification.org/ (the requests for i.d. of this spider range from “what’s this beautiful spider?” to “this spider is giving my child nightmares”…)
Here are a couple of more seasonal pics:
I was getting ready to dump out the partially finished compost when this Pacific tree frog (Pseudacris regilla) caught my eye – I think it was enjoying the cool moist habitat and decided the flies were easier to catch than if it had gone into some rodent hole for the dry season. After the tadpoles mature, the adults disperse to upland protected areas, and this one thought the compost was the best location.
If you are lucky enough to have amphibians in your yard, it’s good to know that they need a mosaic of habitat to survive all the life stages. Even some logs on the ground can keep the soil moist and cool and provide a nice holding area for reptiles, amphibians and – yes – slugs, but the slugs are food for reptiles and other creatures so it works out!
In late winter and into summer, the air is filled with the RIBBITS (see and hear one) of the tree frogs, but I have only been able to see them a few times. Very elusive. This one is getting to be a pet, I have pulled the lid off to show it off so many times.
The birds are done with mating and announcing territories, the frogs are aestivating, and things are very quiet. The crickets sounds have been either louder or more noticeable since the other racket has died down.
In the next post, I’ll have some moist fall photos of newts, lichens, and whatever surprises I find on the next walk.