Chapter 5 CLIMATIC FACTORS
5.2 The classification of broad climatic zones
5.3 Patterning in global weather systems; the engines of the atmosphere
5.7 Landscape effects
5.8 Latitude effects
5.10 Designers' checklist
Finally, some news I can use! I admit I skimmed the bits on the humid climates and paid more attention to the arid examples, since wind, cold and desiccation are our limiting factors on our site. The details on the effectiveness of windbreaks for seasonal soil moisture storage are going to be hard on the household budget, as it convinced me there is no good rationale to delay the major windbreak planting that we need to do, in addition to everything else this spring.
The phrase "lumpy texture" kept coming to mind as well. Where the soil/ground cover is lumpy, the snow here melts. Where it is windblown, or settled on last year's cut pasture, it just evaporates. We can use this observation to wring out every drop of moisture. How is not so obvious, because voles congregate in the unmown areas in winter (we leave areas unmown at the end of the season to shift them away from the new apple trees!). Rockpiles, spent flower stems, those sorts of things might be useful lumpers.
I spent a lot of time just staring at Figure 5.13. I wonder if we can use strategic gaps in our plantings to steer the frost to the least damaging areas. Maybe dig a seasonal pond that becomes a frost trap. Late spring frosts are a serious problem for our main crop; anything I can do to gain an advantage is probably worth it.
The section on wind harmonics (p 123) drives home the need for local observation and lore, and for longer than just one year. Our prevailing wind is down valley from the west. 20 mph prevailing winds are regular. It whips to the east for a few hours before a weather system comes through. But our biggest energy winds, the kind that make saplings bend to where you think they will break, have come in the spring from the south. Our heaviest winter snows have come from the south too. It took more than one year on site to notice this pattern.
My DH is a color vision scientist. I showed him Figure 5.9, the curve of photosynthesis vs solar spectrum. He rephrased it: the green we see in plants is the energy they don't use. The color of anything is the energy it doesn't absorb. There followed a brief discussion on how UV light damages DNA in cells, which in animals the response is inflammation (sunburn) and cancer. He also recalled that plants make different pigments that encode different wavelengths of light, which have to do with triggering changes that relate to the physiological functions. Far more complex than Table 5.3 indicates, and we should probably sit down and do a Youtube video on it. Quantum mechanics for farmers. There is a narrow window of photon energies (wavelengths) between that which breaks molecular bonds and that which breaks proteins. Only this is what cells can harness as solar energy. What we happen to call the visible spectrum is simply the limited range of light in which cells can safely capture and transport light, convert to energy and information.
I really need to get him in front of a video camera. And I really ought to convert an old digital camera to a UV/IR sensor. I say that, then I go buy trees instead.
Visible light is definitely the kind we have the most of. The rainbow centers on the most plentiful daylight (filtered down a bit from the sun's actual radiation courtesy of our gracious atmosphere). A good argument that we evolved to see things in daytime, or at most twilight (our low-light sensors are most receptive to blues, not reds or infrared).
Night-time averages are a lot longer-wave, lower-energy, based on what's being released by the earth, the atmosphere, and of course any warm-bodied critters. Hence the effectiveness of IR (infra-red) cameras and goggles for night vision enhancement. Some snakes have IR heat-sensitive pits in their snouts, an adaptation for hunting at night or underground? Or maybe to avoid pissing off your venomous mate with a bumbling approach while entering the dark burrow.
Aaand back on topic:
I'm also biased toward the cold, dry, climate details. Frost shortens our season; we don't have as much wind as some places, but we have intense sun and drying conditions.
I'll be following along avidly for the drought-management or wind-management details, and then here comes the planting suggestions and its all bananas and casuarina. Any time someone with experience in both temperate and tropical climates wants to offer a plant-functions translation, or suggest a resource, I'd be most appreciative.
Since reading this chapter, I am excited about the frost-prevention potential of our new building site. I was grumpy about the passive-solar angles being shaded by our sparse evergreen trees to the south, but we had other reasons to build there (not least of which was, the in-laws offered us that corner, not the middle of the lot).
Now I'm thinking about the small, tree-sheltered clearing south of the new building as a possibly ideal frost shelter. If the trees aren't tall enough or close enough, I might boost it with a few shrubs or shade trees. Maybe use reflection off the building, too, which could whip up in August to serve as shade instead of heat. Looking for productive, partial-shade trees for that side of the building, tolerant of 1000 meters near the Canadian border (probably realistically zone 3, though our valley is 5).
I noticed something interesting during our weird winter without any end-of-year snow:
The evergreen trees (and everything else outdoors) collect impressive hoarfrost, then drops it like tinkling snow in the slightest breeze. Those trees are not waiting for Father Sky to hand out the snow or rain; they are making their own as fast as they can, with every cold snap. Not only are evergreens great heat soaks and radiators, they are also lovely dendritic condensers.
It's still likely to be a drought year, and I'm trying not to make it worse with our current attempts to deal with frozen pipes. (Maintaining a trickle of water to prevent the pipes freezing is a common and effective tactic, but it seems highly irresponsible the winter before a drought.) So I just blew over a hundred bucks on more insulation, and pipe warmers, to rig up a temporary second line that we can turn off instead of draining each night, or guiltily leaving the tap trickling.
Maybe it will all flow down to the pond come spring. (it's a greywater sink). But still.
Aaand back to the chapter:
Does anyone have more current biogeological references than the 1971 and 1943 references Mollison cites near the beginning of this chapter?
In particular, I'm looking for a good reference for plants of the inland Pacific Northwest, and perhaps animals and fungi as well. I'd love insights into similar geological regions too.
Toward the end of that first section, he makes a little plug for respecting native traditional practices, as they often were quite sophisticated and didn't depend on outside aid.
This should be repeated until it goes without saying.
It doesn't necessarily make sense to eschew outside aid in this era of cheap energy and information. Also, worth noting native peoples were not masochistically independent; there is tons of evidence as well as living proof that most native peoples had well-established trade relationships for key limiting resources (high-energy oils and other nutrient-dense foods like dried fish, nuts, and berries; medicines and spices; minerals like salt, metals, tool stones(chert/flint/obsidian/pyrite), and pigments; luxuries like incense, dishwares, furs, and silk (the high-tech fibers of the all-natural era)).
But I don't want to become fatally dependent on trade for the necessities of life, and leave my posterity without the skills to live where we are. Can we use it wisely rather than letting it make us dependent, desolate, or depleted?
What can we do now, using "outside aid," to put ourselves and future generations in a better position once aid is less available?
Diagram 5.7 is pretty confusing. I finally got a few of the numbers to add up, but I'm still baffled by the 70% absorbtion, 6% reflection by the ocean. What happens to the other 24%? Or is that what's absorbed by the land?
Then he marks the land as absorbing 27%, and the mountain as reflecting 8%. Also doesn't add up. I was able to re-draw it following the text, and most of the other numbers did add up and make sense if you did the math. but still.
Does anyone have a newer version of this diagram 5.7, or a different (accurate) reference that you like? This site (http://www.nrel.gov/gis/wind.html) has a lot of specific maps for the US, but I'd love to see world distribution on some of this stuff.
It could be particularly useful to have a map like the one National Geographic put out a few years ago, of total sunlight hitting various parts of the world. (It was part of an issue on skin color - they colored the map showing what melanin levels would be predicted just based on sunlight hours, vitamin D production, and vitamin B breakdown due to sun on skin, and made an utterly beautiful map of the land masses that's also useful if you're wondering about solar energy or photosynthetic potential.)
The potential for more weird weather should definitely worry folks, especially folks like us that have barely got a handle on our location's "normal" weather to begin with. Wind observations.... anyone got a good garden-variety tool for that? I bought a mini weather station but haven't set it up yet; and I'd love to know how other people watch the weather. NOAA, weatherunderground.com, and other weather resources are great, but I want to know what people actually care about, and how you track it. Is a $70 weather station a bad bargain when I could get the same info from a thermometer and a wind sock? Or a "weather rock" (if you don't know this joke, look it up).
Excited to get some questions in at the beginning of the new thread. The catch-up week was lovely, thanks.
And I'll be chiming back in when I've finished the whole chapter, I'm sure.
Erica Wisner wrote:Interesting about the light wavelengths' effects on proteins ... but is there really a "gap" where proteins don't break down under visible light? Or do we just not see the proteins that break down under visible light very often because of selective pressures? (Animals made of lipids or proteins that break down in ordinary daylight wouldn't last long on the surface of our planet. Maybe in deep-sea or underground environments? We have definitely evolved better protection - coatings, pigments, and behaviors - as we've spread around the globe, from waxy plants to mud-bathing elephants to well-brought-up Midwesterners and their sensible sweaters.)
From the DH, patient answerer of all my biology questions:
DH wrote:There is a safe zone for proteins. The gap between UV and IR absorption damage is log units deep. UV promotes electronic transitions in aromatic organic molecules that facilitate undesired intermolecular bonding or photodissociation. Far IR promotes vibrational transitions that encourage atomic nuclei in atoms to line up in low energy configurations (cooking).
But you can't photodamage or cook proteins with a visible light. Those little halogen ovens are using the IR, not the visible.
And as for pit vipers, score another wifely opportunity to nag!
Erica Wisner wrote:Some snakes have IR heat-sensitive pits in their snouts, an adaptation for hunting at night or underground? Or maybe to avoid pissing off your venomous mate with a bumbling approach while entering the dark burrow.
Someday I will prevail and the DH will write his book about sensory biology. There is a whole chapter in infrared sensation in the outline. He is busy working on retinal blinding diseases and mapping the brain's network of neurons when he's not irrigating our trees, so it might be a while, but I keep hounding.
http://hint.fm/wind/ - a cool conceptual map of wind at large scale
http://www.ncdc.noaa.gov/ - for USA folks - National Climate Data Center has been aggregating local data - most solid data sets are associated with airports
http://www.wcc.nrcs.usda.gov/climate/windrose.html - a wind rose is a great way to view local prevailing wind, but local effects can be so strong.
@ERICA, You might want to check out Klinka & Krajina's Indicator Plants of Coastal British Columbia. As far as I know there is really nothing else like it, and it does consider higher elevation species and some over the mountain crossovers... it just might not hit you nail quite on the head. Alas... biogeographic plant ecology work had its prime in the 70s-80s and now a days botany departments are all about genetics research, and very little about field observation.
Also consider hunting around the Pacific Northwest Research Station USDA, as they have a remarkably robust archive of old forestry stuff, probably including some cool plant community classification work (likely from the 80s
To my understanding the current global ecoregional standard are the zones developed by WWF and partners. EPA has some US standards.
Pojar & Mckinnon has an inland twin Parish et al. which is a good guide with extra info, but not necessarily as rich as we hope, and nothing compared to the Flora of the British Isles
The Beaufort Number chart kind of made me giggle... Where I'm at now, pretty much all winds are in the 'severe' classification.
Some interesting ideas to consider, and lots of definitions. His notion of every 100m in elevation = 1 degree further away from the equator was particularly interesting.
I always noticed at my old house that areas of the veggie garden at the edges of old mature trees were much more protected from frosts than totally open areas.
It's also refreshing to read someone who acknowledges climate is more complex than just greenhouse gas emissions.
While Mollison went on at great length about windbreaks and shelterbelts, there is one aspect of them that I have not seen mentioned in any permaculture literature that I have come across. Mollison does make brief comments about drifting snow, but does not discuss it in depth. However, this relates to the use of shelterbelts in snowy prairie like, windy areas such as the Midwestern area of the United States.
In the wind, blowing snow will as easily go up hill as it will down hill. Shelterbelts have a capacity to catch a tremendous amount of snow out on the prairie. Following the principle of slowing the flow of moisture across the land, a good permacultural practice would be to position the shelterbelts high on the land such that the collected snow when melting in the spring would soak into the soil as it moves down hill. Catchment dams and ponds could also be positioned higher up on the topography as a result of the shelterbelts being higher.
It would be great to see some permaculture folks in the Midwest experiment with this concept. This would be of most advantage in the rolling hill type geographies on the prairie. If anyone has heard of example of this please share. I suspect this has likely not been put into practice because neither Mollison nor many other permaculture practitioners to date have been working in snowy prairie like locations.
There is about 5' of very dense thicket style trees. Any tree that gets above this thicket shows severe damage from the wind conditions. Branches literally only grow on sheltered side.
One of the 'edge' trees and the subsequent wind deformation/damage.
During winter there is no snow on top of the dam, and plenty of bare rocks. On the leeward side of the dam, the snow deposited gets to be 35-45 feet deep by spring.
The climate context can be associated with land form. Floodplains, beaches, embayments, lowland watersheds and headwaters each have generalized climate patterns that result in generalized natural patterns of vegetation and easy management strategies.
At the end of the chapter, Mollison focussed on shelterbelts (which is a critical tool). It is left to us to identify which climate phenomena drive our local situation or our landscapes.