Lakes are an especial feature of the Tasmanian highlands, and especially of the central plateau. Here, at an elevation of about 2,500 ft., the heavy rainfall is held up in impervious (diabase, etc.) rock-basins, and elsewhere (e.g., in the west) are lakes of glacial origin. Great Lake (alt. 3,80o ft.) is 15 miles long and its natural depth was only 20 ft. It has importance in connection with a great hydro-electric supply scheme.
The coast-line (90o miles) receives its special character from recent subsidence, though there has been a still later but smaller elevation. Where the coast runs parallel to the grain of the high lands it is mostly closed (e.g., on the west) and presents few good openings. On the northeast and southeast, on the other hand, are many curious features of submergence (e.g., Freycinet and Tas man's peninsulas) and also some fine "drowned valley" harbours (Tamar, Derwent, see LAUNCESTON, HOBART) (v. inf.).
Tasmania lies in the southern temperate zone in the track of the east-moving cyclonic systems ("lows"), while no part is far removed from the sea. Hence its climate is cool, equable and moist, somewhat resembling that of southwest Eng land and Ireland. Like these, too, its weather conditions are exceedingly variable—hardly four consecutive days showing the same conditions—but in its case there is added to this variability an extraordinary local diversity due to the irregular and sharp-cut topographical features. Thus there is strictly no general climate of Tasmania, but, within limits, temperatures, and particularly rainfall, show remarkable ranges (e.g., 130 in. at Lake Margaret on the west coast ; 18 in. at Antill Ponds in the east midlands). Broadly speaking temperatures range from 65° F in summer to
F in winter, the east coast having temperatures in general c. 4° above those of the west coast owing to the influence of warm (north) and cool (south) sea-currents respectively. Rain fall is greatest in the west, where the highlands force precipita tion from the moist westerly winds (4o in. ay. ann. along the coast, rising to 6o in., and to 14o in. in the central northwest, with a late-winter maximum (e.g., Queenstown : ioo in. ; Aug., io in.; Feb., 4 in.). The northeast highlands also receive 4o-8o in., but the eastern and central lowlands are in the "rain-shadow" of the western heights and receive some 20 in. more or less with a maximum in spring and summer when southeast winds blow in with rain. (See also LAUNCESTON, HOBART.) It is the cool and
moist climate of Tasmania which lends it that relatively verdant and garden-like character which is such an attraction to Austral ians from hotter and drier latitudes.
The natural vegetation was one of the finest and, potentially, the most valuable in the Commonwealth though its natural riches have been largely dissipated. The chief controlling factor appears to be rainfall—or rather, availability of moisture. Thus the beech forests—so-called "myrtle"—which are peculiar to Tasmania are found in various separate areas but always where the ay. ann. rainfall is over so in. Eucalypts form the bulk of the forests in areas of intermediate rainfall and range from swamp and blue "gums" in the lower river-flats to the "snow" or "mountain" gum on higher slopes. Some of the "pines" (Huon, "celery-top," etc.) are also denizens of the lower and wetter valleys, e.g., in the southwest. The "wetter" forests have also often a dense and almost impenetrable undergrowth (tree-ferns, laurels, etc.). In the drier "rain-shadow" lowlands of the east and centre the forests become thinner—though the trees tend to become individually finer—and a type of wooded "park" or grass-land prevails. The wind-swept plateau-tops carry little but stunted scrub, grasses, and bog and moorland vegetation merging in places into "alpine," and the lower hills which lie along and immediately behind the west coast, with their relatively light rainfall (2o-4o in.) are matted over with the strange and impas sible "horizontal" (bauera) scrub. The western mountains and valleys still contain fairly large forest patches (e.g., the fine eucalypt forest of the Huon Valley), and the northeast also is well clad. In the lowlands and on the more accessible slopes the forests have been largely destroyed or wastefully depleted for their valuable contents. Commercially useful timber is supplied by many of the gums—blue, yellow (cider), swamp and stringy gums, peppermint, etc.—by the soft-wood pines, the beech, the blackwood of the northern basaltic slopes and valleys and also by the acacias (e.g., the "black wattle" supplying tanning bark). Tasmania has a relatively large extent of forested land (1,5oo,000 acres, nearly 9% of total area). But, from the scientific forester's point of view, the forests are not as valuable as might appear. There were (1926) only 176,00o ac. of reserved forests, or, with timber and fuel reserves, 1,817,20o ac.