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Vegetation, Ice and Deserts of the Paleo-Earth

posted Jul 26, 2011, 2:43 PM by Abel Mendez   [ updated Jul 29, 2011, 3:46 AM ]
In our previous post we discussed the distribution of landmasses of the Paleo-Earth. Here we used the Visible Paleo-Earth (VPE) datasets to estimate the global surface coverage of vegetation, ice, and deserts in the last 750 million years, during the Phanerozoic (Figure 1).  The vegetation regions were defined as any region with over 25% vegetation cover. Ice covered areas include permanent and mountain ice with over 75% ice cover. Deserts are those regions without ice and with less than 25% vegetation cover. We also included as vegetation cover the potential presence of simple photosynthetic eukaryote biota before the appearance of plants 450 Ma (Strother et al., 2011).

    According to this preliminary analysis, Earth landmasses today are covered by about 68% vegetation, 11% ice, and 21% desert (Table 1). However, during the Devonian and Cretaceous vegetation cover reached 95%; Earth was a truly "forest planet." Last global glaciation (Snowball Earth) occurred before the Phanerozoic 650 Ma with over 60% ice cover. Later, and smaller, ice caps included the Ordovician, the Carboniferous-Permian, and today. Interestingly, Earth's today is in a period with the lowest global vegetation cover since the appearance of land plants 450 Ma.

Figure 1. Percent of surface coverage of vegetation, ice, and deserts in the last 750 million years. Dotted line correspond to today values (data shown in Table 1).

Table 1. Percent of surface coverage of vegetation, ice, and deserts in the last 750 million years. 

 Age
(Mya)
Age Name
 Vegetation
(%)
Ice
(%)
Desert
(%)
 000 Present 68.310.7 21.0
 020 Early Miocene 81.51.7 16.8
 035 Late Eocene 84.80.9 14.3
 050 Early Eocene 88.20.8 11.0
 065 Late Cretaceous (K-Pg) 88.90.2 10.9
 090 Late Cretaceous95.40.04.6
 105 Early Cretaceous97.20.0 2.8 
 120 Early Cretaceous95.5 0.0 4.5 
 150 Late Jurassic96.0 0.04.0 
 170 Middle Jurassic89.2 0.0 10.8 
 200 Late Triassic82.5 0.0 17.5 
 220 Late Triassic83.6 0.0 16.4 
 240 Middle Triassic83.3 0.0 16.7 
 260 Late Permian78.8 13.1 8.2 
 280 Early Permian81.2 9.9 8.9 
 300 Late Pennsylvanian77.6 20.1 2.3 
 340 Middle Mississippian89.8 7.7 2.5 
 370 Late Devonian96.10.0 3.9 
 400 Early Devonian97.4 0.0 2.6 
 430 Middle Silurian94.7 0.0 5.3 
 440 Early Silurian78.8 0.0 21.2 
 450 Late Ordovician78.7 0.0 21.3 
 470 Middle Ordovician58.5 11.6 29.9 
 500 Late Cambrian47.0 0.0 53.0 
 540 Early Cambrian0.0 0.0 100.0 
 560 Late Proterozoic0.4 0.0 99.6 
 600 Late Proterozoic0.2 16.2 83.6 
 660 Precambrian0.0 63.3 36.7 
 690 Precambrian0.0 49.1 50.9 
 750 Precambrian 0.0 36.6 63.4 

References


Strother, P. K., Battison, L., Brasier, M. D., and Wellman, C. H. (2011). Earth's earliest non-marine eukaryotes. Nature, 473, 505-509.