Ecology PDF - Factors Affecting Species Distribution

Ecology: is the study of factors that control distribution and abundance of species. S.No. Omani habitat Example of Large Trees 1 Jidda (gravel plain covers most Acacia ehrenbergiana (Salam). of Oman) mass of roots that trap soil...

Ecology: is the study of factors that control distribution and abundance of species. S.No. Omani habitat Example of Large Trees 1 Jidda (gravel plain covers most Acacia ehrenbergiana (Salam). of Oman) mass of roots that trap soil particles blowing in the wind to produce a mound. When it rains, it collects up the water, but afterwards is very resistant to drought. 2 Sand dune of Rub Al-khali and Prosopis cineraria (Ghaf) Wahiba extremely deep roots giving it continuous access to very deep water 3 Batinah coast (Wet and more Acacia tortilis (Samur) and A. nilotica (Qarat) humid) nearto the ocean 4 Wadis Ziziphus (Sidr) is as Estm Massive trunk and root network extending through the gravel. But it is less drought resistant than Acacia, as there is always water available in the gravel 5 Mountain Sideroxylon (Buut) found on steep mountain sides, where there is little soil and unstable rocks. Jane mountain Olive and juniper (found in high altitude, where nights are very cold) Factors that control or affect the distribution of species: S.No. Factor Example 1 Climate Red Kangaroo in Australia becauseoftheclimate thekangaroolivesonlyon theseclimate They live only in hot arid lowland deserts. They can not live in too cold, too wet and too dry habitats. 2 Dispersal -Adverse habitat e.g.aquatic animals cannot cross land or animals living in vegetation cannot cross dry desert. -the ability to disperse 1) slow moving animals such as snails or worms have poor dispersal ability 2) animals that fly have good dispersal ability. e.g. flying birds (e.g. Grackles and Cattle egrets; flew over Atlantic ocean to south and central USA but cannot disperse further because of cold winter) and flying insects (e.g. Gypsy moth, a dangerous pest) Gypsy moth was arried by humans from Europe to to USA in 1850 killing many tree species in USA. carried 3) Plants that depend on wind dispersal have good dispersal ability. 3 Behaviour European corn borer (caterpillar): In the lab: It can feed on a variety of food (wheat, EEiiim barley, rice) In the wilderness: It only wants one type of food (maize) i 4 iiii Mosquiote larvae:- In the lab: they can live successfully in brackish water. In the wilderness, the adult female will never lay her eggs in brackish water. Herbivory animalseatingplants Example of sea urchins and limpets (algae-eating animals) limiting the distribution of seeweed (a brown algae) 5 Predation animals Invasive species e.g. Brown tree snakes native to Australia or Indonesia were eatinganimals introduced accidentally by humans to the island of Guam. Within 20 years, 12 species of birds and 6 species of lizards became extinct (not adapted to avoiding this alien predator). 6 Parasites or Pathogens Example, the fungus chestnut blight (invasive pathogen) from China introduced accidentally to USA→attacked all the chestnut trees. Brackish surface water is typically found in areas where freshwater rivers meet saltwater in the ocean. Acacia ehrenbergiana (Salam) Ziziphus (Sidr)  community of Plants animalsadaptedto aspecific climate biome it is alarge insider a marine a 2 Desert120 ofearthssurface notmuch biodiversity 3 forest dominatedbytrees 4 Grassland dominated by grass s tundra notmuchbiodiversity