5 SOUTHERN BEECH TREES (Nothofagus)a With what environmental factors is the distribution of southern beech trees associated?b Fossil beech trees are found in Antarctica. What can you surmise about the climate of Antarcticaat the time beech trees lived there?c What was the distribution of beech trees at that time?d Why are there no living beech trees in Antarctica?e Did beech trees evolve on Laurasia or on Gondwana?f Explain the present-day discontinuous distribution of these ancient trees. How did populationscome to exist on different continents?6 BLACKPOLL WARBLER (Dendroica striata). Hint: Use North American biomes.a What are the two distinct habitats in which this bird occurs?b How do you explain its occurrence in such different habitats? (Hint: What do many birds do whenwinter comes?)C Can you determine whether these birds evolved on Laurasia or on Gondwana?d Why or why not?7 NORTH AMERICAN BIOMES. Examine the map of North American biomes.a Why isn't this map an accurate description of the modern distribution of these biomes?b Why doesn't the desert extend all the way to the Pacific coast in Southern California?c Why has the Miami, Florida, area been a successful area for the introduction of exotic tropicalspecies, such as parrots from South America?d Why were these tropical species originally absent from Florida?

Beeches are monoecious, having both female and male flowers on the same tree. These trees are deciduous and can grow in full sunlight or some shade.A. As a naturally growing forest tree, beech marks the important border between the European deciduous forest zone and the northern pine forest zone. These trees like rich, acidic soil that isn't compacted that is it grows well in loose soil. It likes moist, well-drained soil.It has adapted to an average annual precipitation of 30 to 50 inches annually in its natural growing range in the northeastern United States. While it can withstand temperatures between -42 and 100 F, it does not do well in hot summer weather. B. The presence of fossil southern beech trees in Antarctica suggests that the area had a warm climate without extended periods of winter temperatures below freezing, along with adequate moisture in the air for growth. Also the forest floor in the Antarctica would have been acidic which was perfect for the growth of beech trees. C. As mentioned above the millions of years ago Antarctica was under the grip of greenhouse effect and there was no no ice in Antarctica. So it was quite probable that the beech tree would have grown here. The growth of beech trees in Antarctica was probably either in patches or the trees were full fledgedly growing as forests. D. Now there is no living tree in Antarctica because of the extreme climate shift in Antarctica as it is completely ice covered now. E. Gondwana contained the southern continents—South America, Africa, India, Madagascar, Australia, and Antarctica. Hence beechtree involved in Gondwana land.