[QUOTE=Colibri]
As a blanket statement, this is flatly incorrect. Temperate grasslands typically have a rainfall regime of between 10-35 inches of rain per year. Much of the Great Plains is within this range.
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It is obviously perfectly correct because many temperate woodlands also have a rainfall regime of between 10-35 inches of rain per year. As such rainfall clearly doesn’t explain why one area is woodland and one area is grassland.
Easily done. This is hardly uncommon knowledge and I am a little surprised that an ecologist of your standing is unaware of this.
"Acacia open forests and woodlands of southern Australia
In areas of the southeast and south of the central Australian Acacia shrublands most open forests and woodlands are dominated by Eucalyptus spp.. However North of the Great Australian Bight as far west as Spencer Gulf Eucalyptus open forests and woodlands are infrequent and there are large areas of woodlands and open woodlands characterised by trees such as western Myall (Acacia papyrocarpa), Casuarina cristata and Myoporum platycarpum. Apart from A. papyrocarpa, myall A. pendula is the only other species of Acacia which forms woodland communities over considerable areas in Southern Australia….
The most charcteristic species is mulga (Acacia aneura). Mulga communities together with mixed mulga/hummock grass communities and mulga mid-height grass communities occupy about 1, 500, 000 km^2 or about 20% of the total area of the continent. A. aneura is mostly found in areas receiving from 200 to 500mm mean annual rainfall, but is conspicuously absent from the semi-arid regions with a regular summer or winter drought….
The most extensive Acacia woodland formation excluding the A. aneura woodlands and those of northeastern Australia is that characterised by A. papyrocarpa. It forms woodlands to 10m in height in the 200-250mm rainfall belt to the Northwest of Port Ausgusta and Whyalla in South Australia and extends into Western Austalia as a fringe skirting the Nullabor plain.
Johnson, R.W. and Burrows, W.H. “Acacia open forests, woodlands and shrublands” in “Australian vegetation, R.H. Groves ed. Cambrdge Univeristy Press 1993.
I could go on quoting for this book for pages on the massive extent of woodlands in Southern Australia in regions below 400mm rainfall, and I haven’t even touched on the eucalypt woodlands and chenopod shrublands yet, but these few paragraphs clearly establish that there are indeed millions of square kilometres of temperate arid woodland on the continent.
Unfortunately I don’t have my copy of Bell on me, which would provide the best evidence of forest and woodland on central Asia. But this is so mundane that I’ll just use Synergy to pull out a couple of articles outlining the taiga woodlands and forests of Northern China and Tibet.
“Annual precipitations at the closest weather stations 42 or 87 km, respectively W Khonin Nuga Research Station varies between 250 and 260 mm. The Khentey Mountains were classified as a part of the temperate zone already by Meusel et al. (1965) and Hilbig and Knapp (1983). This view is supported by the present results, as more than the half of the vascular plant species investigated have their main occurrence in the temperate zone. The central Siberian forests form the interface between western Siberian dark taiga forests of Picea obovata, Abies sibirica, Pinus sibirica, and Larix sibirica and eastern Siberian taiga forests of Pinus sylvestris, L. gmelinii, Betula platyphylla, and species related to the two latter species (Walter and Breckle, 1986). This is why tree diversity in central Siberia is higher than in other parts of Siberia. In the Khentey Mountains, these diverse central Siberian forests border on the Mongolian–Daurian forest steppe. This situation yields a unique mixture of dark taiga, light taiga and forest steppe vegetation types (Dulamsuren et al., 2005). Plant diversity is especially high in the western Khentey Mountains, as many dark taiga species thin out in the drier eastern and southern parts of the Khentey.”
Choimaa Dulamsuren, Erik Welk, Eckehart J. Jäger, Markus Hauck and Michael Mühlenberg. Range-habitat relationships of vascular plant species at the taiga forest-steppe borderline in the western Khentey Mountains, northern Mongolia
Flora - Morphology, Distribution, Functional Ecology of Plants
Volume 200, Issue 4, 1 August 2005,
“Moreover, trees of Ulmus pumila are found over a wide precipitation range, and even grow in zonal desert steppes of southern Mongolia (Lindeman, 1981). Isolated trees, and sometimes even extended open forests, occur in semi-desert vegetation with Stipa glareosa and Anabasis brevifolia at sites with a mean annual precipitation of less than 130 mm (Wesche et al., 2005)…. The climate of the study site reflects the extremely continental situation of Mongolia… The average annual precipitation in Dalanzadgad is 131 mm (1937–1999, after data from the Meteorological Service of Mongolia), 70% of which falls in June, July and August. …Results of biogeographical, ecological and palaeoecological analyses support the view that today’s most isolated mountain forests in Central Asia persist due to self-supporting meso-climatic effects. These meso-climatic effects are related to the presence of permafrost-layers sheltered by the closed canopy of dwarf birch–willow forest. Larix charcoal and pollen analyses indicate that those birch–willow forests were once connected to a much more extensive taiga forest that was reduced by climatic shifts and human influence during the warm and dry middle Subboreal at around 4350 cal yr BP in the Gobi Altay and 3800 cal yr BP in the southern Mongolian Altay.
Georg Miehe, Frank Schlütz, Sabine Miehe, Lars Opgenoorth, Jan Cermak, Ravčigijn Samiya, Eckehart J. Jäger and Karsten Wesche. “Mountain forest islands and Holocene environmental changes in Central Asia: A case study from the southern Gobi Altay, Mongolia” Palaeogeography, Palaeoclimatology, Palaeoecology, Volume 250,
Honestly not being snide in any way Colibri, but you not knowing that vast areas of sub-humid Australia and Central Asia are or at least were naturally covered in woodland or even forest vegetation surprises me. None of this is even vaguely controversial. I’m assuming there’s been some misunderstanding here somewhere.
