GULLIES AND WOODED SLOPES

General Overview

Since they are partially shaded, gullies receive less sun energy (solar radiation), and are generally cooler. Also, as noted in the text box on Climate Shapers in Section 1, cool air from higher elevations spills down along gullies. Depending on orientation, they can also be more sheltered from prevailing winds. As in the photo at right, the steeper gullies do not support farming or grazing. Thus they usually have denser and more mature forest, with a greater overall leaf surface. Through their leaves, plants give off moisture, in a process called evapo-transpiration. This, in addition to the fact that gullies form natural drainage channels, is one reason why gullies tend to be more humid.

A Few Key Species Often Found in Gullies

Huilco or wilco (Mimosaceae family, Anadenanthera colubrina)
Prior to colonization, the huilco was a major species in the valleys of Loja province. It was a sacred tree to the Incas; and the Quechua name Huilcopamba, from which Vilcabamba is derived, means sacred valley. The huilco population has been greatly reduced through most of its original range. In the Vilcabamba valley, remnant stands have been preserved at the Rumi-Wilco Reserve, and the tree is being actively replanted there. Small stands also remain above San Pedro, and there is a cluster near the cemetery.

Though a fairly small tree, the huilco catches the eye with its fine, feathery compound leaves and broad, variable canopy. The white flowers grow in dense clusters in November and December. The large flat seed pod is tinged with yellow-green when mature, and is dark brown when dry. The strong wood is used for beams and lintels in house construction. An extract of the bark was also used in the past to tan leather.

Ceibo (Bombaceae family, Ceiba insignis)
Different species of ceibo are found in a variety of very dissimilar ecosystems throughout Ecuador. The ceibo pictured on the right, which grows up to 40 m (130 ft), was part of the original valley forest. Scattered individuals rather than large stands were, and still are, typical. The tree is generally found on rocky soils. The base of the trunk is bulbous, and often covered with thick, irregularly-shaped spines. The crown is broad but thin. During the dry season, the ceibo loses its palm-shaped, compound leaves. The cottony fibres (kapok) from the large seed capsules were at one time used to stuff mattresses and pillows. Kapok was also used for life jackets, because of its natural resistance to water saturation. The wood is used for canoes, toy-making, and boxes.

Custard apple, chirimoya (Annonaceae family, Annona cherimola)
This native shrub of the Andes is most common at mid elevations. It is also cultivated for its fruit (seen in almost the exact center of the photo at left), sometimes sold locally, and as a shade tree for coffee. Its leaves make a rich humus. The delicately sweet flavour and custard-like texture of the fruit make it an exotic food experience; though getting a good mouthful of the flesh, given the many seeds, is challenging.

Espiritu santo (Crassulaceae family, Kalauchoe species)
This herbaceous plant stands out along shaded paths, even when not in flower. The leaf is scalloped at the edge, and often tinged with purple or bronze. According to a local guide with traditional plant medicine knowledge, an infusion of the leaves can be used for intestinal problems.

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