Prof. Dr. Asrar M. Khan/ Dr. M. Nadeem Hassan

1. Prof. Dr. Asrar M. Khan/ Dr. M. Nadeem Hassan Habitat & Niche

2. Habitat & Niche • Habitats are the places plants and animals normally live. • The habitat provides factors necessary for survival of individuals and populations. • A niche is the role and position of a species in nature. • In short, every aspect of a plant or animal's existence can determine its niche. • Another way of looking at it is that a niche is basically an organism's "job" in nature. • Obviously, the concepts of "niche" and "habitat" overlap, but with "niche" focusing more on the animal's "job," while "habitat" focuses more on what corner of nature the organism occupies.

3. Habitat • Types of environment in which a population or species regularly lives. • Environment includes biotic and abiotic factors e.g. forests, meadows, pasture, coniferous forest etc. • The habitat provides factors necessary for survival of individuals and populations. • Examples of important habitat features for animals include cover (i.e., protection from weather extremes and predators), nesting and birthing sites, feeding sites, and hibernation sites.

4. Habitat • Habitat can be divided into layers or zones/ Microhabitat • Forest canopy: leaves & branches • Shrub layer: leaves, branches, trucks • Herb layer: leaves, stems, mosses, ferns • Litter: dead fallen leaves, logs • Soil top soil, subsoil • Occupying Species: A species may occupy a specific part of a microhabitat with some limitations

5. Niche • Niche • The concept of ecological niche is useful in explaining how seemingly similar species can coexist in the same biotic community. Ecological niche is the particular combination of biotic and abiotic factors required by a species to live in any one location. Niche is sometimes thought of as the "role" an organism fills in the ecosystem. The term niche has been used by ecologists to refer to habitat, food, reproductive requirements, and physical and chemical factors related to a species survival. • Species’ or population’ role in its community • Characteristics of a niche: • Habitat & microhabitat (space occupied) • Food “spectrum” essential nutrients

6. Niche • Reproductive requirements; nutrition, nest/den sites • Seasonality: when are resources required or used • Climate requirement: Humidity, rainfall, sunlight • Two kinds of niche • Fundamental niche • All of the potential niche component components for a given species if there were no competition for those resources. • Realized niche • What the population actually gets while in competition with other species.

7. Niche • No two species can occupy the same niche at the same time without tough competition – one species have to give in. • Vacant niche; a niche that is not occupied by a species • Competition: • Organisms always compete for resource; space, food, mates/partner etc. • Intraspecies competition: competition between organism of a different species e.g. bats and bird compete for same insects.

8. Niche • Interspecies competition between the individuals of the same species • Competition drives natural selection • Co-evaluation: in a natural setting, species continuously compete and evolve with each other and the evolutionary change or one is based on the evolutionary change of another.Humans and our parasites • Invasive species are successful because have not co-evolved with the native species and can take their niche. New diseases, Invasive plants, invasive insects etc.

9. Niche • Reducing competition: • Different species often divide resources to reduce Intraspecies competition • Different species of birds will occupy different areas within the canopy of tree to reduce competition from other species.