Tropical Biogeography Lecture Notes PDF

BST308/Notes/AHI/Feb2020 1 BST308/Notes/AHI/Feb2020 2 2 Any country that lies between the tropic of Cancer and the tropic of Capricorn is considered tropical BST308/Notes/AHI/Feb2020 3...

BST308/Notes/AHI/Feb2020 1 BST308/Notes/AHI/Feb2020 2 2 Any country that lies between the tropic of Cancer and the tropic of Capricorn is considered tropical BST308/Notes/AHI/Feb2020 3 3  Nearly every country in Africa is tropical. Palm trees are commonly featured in the tropics. The Burj al Arab, an iconic hotel in the United Arab Emirates, a tropical country. BST308/Notes/AHI/Feb2020 4 4 BST308/Notes/AHI/Feb2020 5 5 BST308/Notes/AHI/Feb2020 6 6  Tropical Rain Forest Precipitation – 250 cm/year Little temp. variation/abundant moisture Contains more species than other biomes. BST308/Notes/AHI/Feb2020 7 7  Savanna Precipitation 90 - 150 cm/year Open, widely spaced trees, seasonal rainfall Parts of Africa, South America & Australia BST308/Notes/AHI/Feb2020 8 8  Desert Precipitation 20 cm/year Dry, sparse vegetation; scattered grasses Parts of Africa, Asia, Australia, North America BST308/Notes/AHI/Feb2020 9 9 What is biogeography? The study of how species are scattered across the planet, and how they got that way. -Alfred Russel Wallace BST308/Notes/AHI/Feb2020 10 10  Biogeography  encompasses a large number of fields  includes a broad range of spatial and temporal scales  addresses some combination of organism (“bio”) and space (“geography”)  includes both basic and applied research BST308/Notes/AHI/Feb2020 11 11  Biogeography of tropical regions  ~250 millions of years ago, almost all land was in the form of one large continent, Pangaea.  Plants and animals both were widely distributed across this continent, with few geographical barriers to impede their dispersal. BST308/Notes/AHI/Feb2020 12 12  Plate tectonics The biogeographic regions of the world roughly coincide with the continents themselves Plate tectonics → theory that Earth's outer shell is divided into several plates that glide over the mantle, the rocky inner layer above the core. BST308/Notes/AHI/Feb2020 13 13  The Earth's crust has been found to be composed of several distinct plates. BST308/Notes/AHI/Feb2020 14 14  Biogeography of tropical regions More than 200 million years ago (shortly after dinosaurs evolved), this land mass began to break up into two parts: - Laurasia (which would eventually disintegrate into North America, Europe, Asia, Greenland and Iceland) and - Gondwanaland (later to break up to become South America, Africa, Australia, Antarctica and India). BST308/Notes/AHI/Feb2020 15 15 BST308/Notes/AHI/Feb2020 16 16  Evidence of the plate movement - clear folding in the Himalayan rocks. - The rocks start folding from near the valley floor and tilt towards the higher snow covered peaks. - These rocks are also sedimentary rocks, which suggests that they were on the sea bed long ago. BST308/Notes/AHI/Feb2020 17 17  also known as Gondwana the name given to the more southerly of supercontinents that were part of the Pangaea supercontinent incorporated present-day South America, Africa, Arabia, Madagascar, India, Australia, and Antarctica. BST308/Notes/AHI/Feb2020 18 18  Much evolution has occurred since Gondwanaland South American and Australian midges are more closely related to one another than they are to New Zealand species the midges of all three land masses are more closely related to one another than they are to African species. Southeast Asia has many conifers, while there are only two species in the New World tropics and one in Africa Dipterocarps are found mainly in Southeast Asia. Overall, tropics marks the highest diversity of plant & animal live on earth. BST308/Notes/AHI/Feb2020 19 19  the name given to the northernmost that were part of the Pangaea supercontinent incorporated present-day included North America, Europe, and Asia BST308/Notes/AHI/Feb2020 20 20  a great naturalist Used evolutionary theory to interpret the natural world. Helped found the modern science of biogeography. As he traveled through Indonesia, he was struck by the sharp distinction between the northwestern part of the archipelago and the southeastern, despite their similar climate and terrain. Sumatra and Java were ecologically more like the Asian mainland, while New Guinea was more like Australia. He traced a remarkably clear boundary which later became known as “Wallace’s Line.” He later recognized six great biogeographical regions on Earth, and Wallace’s Line divided the BST308/Notes/AHI/Feb2020 21 Oriental and the Australian regions. 21  a faunal boundary line drawn in 1859 by the British naturalist Alfred Russel Wallace separates the ecozones of Asia and Wallacea, a transitional zone between Asia and Australia. West of the line are found organisms related to Asiatic species; to the east, a mixture of species of Asian and Australian origin is present. The line is named after Alfred Russel Wallace, who noticed this clear division during his travels through the East Indies in the 19th century. The line runs through Indonesia, between Borneo and Sulawesi (Celebes), and through the Lombok Strait between Bali and Lombok. BST308/Notes/AHI/Feb2020 22 22 BST308/Notes/AHI/Feb2020 23 23 BST308/Notes/AHI/Feb2020 24 24 BST308/Notes/AHI/Feb2020 25 25 BST308/Notes/AHI/Feb2020 26