Characteristics of a Humid Cool Climate | Permaculture Thailand

Characteristics of a Humid Cool Climate

Permaculture Designers Manual



Section 12.2 –

Chapter 12 Characteristics of Humid Cool to Cold Climates in Permaculture Designers Manual

The cool humid climates are production areas for a great variety or berry crops; gooseberry; red, black and white currants; blueberry; cranberry; cherry, salad, and service berry; and a variety of bramble berries. The woods contain many species of wild-gathered edible fungi, some of them long since cultivated on logs or oak, poplar, birch, and sassafras (shiitake, Plturotus).

Evergreen and part-deciduous forests, fir forests (northern hemisphere), and species-rich meadows are found in the low areas still uncultivated, as are oaks and maples (for sugar), beech’s and alder.


In terms of “mast production” (the fallen food or acorns, beechnuts), truffles, and fungi, many natural forests are rich food resources.

It is to be expected that the recently glaciated areas of these climatic regions will also be well-provided with lakes. The waters of these lands can be rich in salmon fish, suckers, carp, pike, and sturgeon.

Pastures and remnant prairie and meadow are uniquely suited to these regions, and because or the often cool or cold and snowy winters, there is much emphasis on solid barns and houses, hay storage, field shelter, and root crop production for winter fodders and storage.

Houses must be carefully constructed for winter warmth, and in the colder areas are often built with cellars or pit storages.

In these cold temperate areas of earth, outlined in Holdrege Lore Zones (Figure 5.2), we are dealing with seasonal factors or frost, snow, ice, and (to the polar extremes), frozen ground We also lose a great deal or heat energy, hence growth on plants and animals to cold winds. Even on snow-free- coasts, nearby mountains, plateaus, and inland snowfields advert cold air to the fields and forests.


Climatic upsets include the foggy coastal climates of northern California to Vancouver, Western Europe, southern Chile and Tasmania, and the winter wet climates of the mid-latitudes.

Most of Europe, China, Japan, North America to the northwest and northeast, Canada, and the Andean slopes and southern half or South America, the southeast and a section of southwest Australia, and mountain climates of southwest Asia can all be typed as cool humid areas, as are the outer slopes or the Himalayas and other high foothill areas in more tropical areas. The cool highlands of the tropics lack frosts, and some growth occurs all year.

Original vegetation was, or can be, mixed broadleaf and pine forests (evergreen or deciduous), wet chlorophyll forest, meadows, cool swamps and marshes, fens and bogs Periglacial Lakes and moraine may occur over vast areas of the northern continents, and cool plains or steppes develop on treeless areas recently covered by ice.

In general, the areas considered here have their coldest month below  0°c,  and  warmest  above  20°c (mean or average temperatures). There is usually a Winter-dry period, although rain can occur in any month.

Since drought occurs mid-late summer. Most plant growth is in spring and summer, with a less marked period of autumn growth before the resting period of winter.

In Mediterranean areas, valley moors are favored agricultural sites, and on the slopes, deep-rooted and drought -resistant trees and vines are often grown. Towards  the older  coniferous  forests, soils are generally less fertile, but a band or brown/black day loams or high fer1illty lies within the area or broadleaf forests; the centers or contemporary agriculture.

The mesothermal climates lie in the westerly wind belt, with the roaring forties (Latitude 40-45) subarctic air in from polar low-pressure cells.

In general, there is a 7-10 day sequence or frontal rains. with occasional easterly gales produced by large stable high-pressure cells to the east winds are particularly damaging when they blow off coastal seas in summer, as salt-burn affects trees and gardens.

Thus, even inland and sheltered sites, windbreak is essential for animal health and crop protection, and forest edges must be developed both to retard fire and to prevent blow down or single age stands.

Oak, willow, black wood (Acacia mtla Ftoxylotl) , Coprosma rtptlls, poplar, hawthorn , alder, aspen, and birch are just  some of the ideal forest-edge trees for plantation protection.

On coasts, firs, cypress. Araucario  spp., Copmsma, waxberry Myro), and liyctum on snowfree areas provide frontline protection. With lower hedges of Wormwood, rosemary, Rosa mulhflor. Hawthorn, and gorse (Uftx) around fields and gardens. Some of the taller grasses (pampas grass) or “ledges” of succulents and hardy vines greatly assist garden protection.

Wind is a major determinant of yield over all coastal and upland regions of these climates.

In acidic peaty areas and turfs, fences of living peat or turf species can protect gardens. On cold exposed plateaus or coasts, dry stone walls, solid banks, or ditch and-bank are primary protection (many of these can later be planted to hardy shrubs or bamboo).

Low, flat valley sites, and especially those valleys at the foot of escarpments capped by high plateaus, may be subject to severe winter frosts in mountain foothills, frost can be all day in winter the shaded side of valley slopes.

Frosts affect pasture and herbaceous plants by stopping growth or causing frost death by plant cell rupture. A great many species of plants from bracken fern to tomatoes are frost-killed, and many foot area farmers choose crop plants on the basis of frost-free days in the growing season, or (where frosts can occur in any month) by excluding from field culture any plant which is frost-susceptible over its growing season.

Marginal or semi-hardy plants such as bamboo may survive frost if given an autumn dressing of fertilizers salts; high salt values in plant cells prevent cell rupture.

Cold humid air is viscous in now, and stabilizes in valleys as a dense air mass with a near-level upper surface. As most frosts form in calm clear weather, the upper cold air surface is rarely subject to strong winds, and this creates a marked frost line on hill slopes, often revealed by the contours joining frost-susceptible pines, jupiter, or evergreen

Down slope cold air now may 1evel a district pulsing beat of about one minute from highlands, and this pulsing can create a sense of surface waves in the cold air masses. Such waves are typical of large areas of the air above frosted ground.

Special frost-free sites, usually high on sun-facing valley slopes, in clearings on ridge forests, or in smaller clearings (less than 30 m across) in tall forest are therefore chosen growing sites in frosty areas.

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