- Species like the moss beneath this fern require a constant source of water.Thinkstock/Comstock/Getty Images
A habitat can be spatially characterized by its abiotic components: soil, temperature, salinity, sunlight and the water flowing through it. These factors affect the distribution of organisms to particular habitats. Extreme temperatures affect the thermoregulation for animals and proteins and the freezing of water within plants and animal cells. Water affects the distribution of organisms susceptible to desiccation. The salt concentration, or salinity, affects the water balance through osmosis for many organisms. For example, some terrestrial organisms can secrete excess salts through specialized glands and can live in salt flats. The variation in sunlight can affect the distribution of organisms. For example, the organisms at varying heights in dense forest space vary. Soil pH and mineral components can affect the nutrient and toxin uptake of the primary producers in a habitat. - The edge of this forest gets more sunlight and has less vegetation.Hemera Technologies/Photos.com/Getty Images
Within a patch is a gradient of resource availability and environmental factors, and thus organisms. This creates a variation across space within a habitat. Some organisms have the ability to adapt to edges, where human influence is higher. This phenomenon is called the edge effect. These edges can be diffuse and thus, there are heterogeneous densities of organisms within a patch. - The usual distribution of habitat patches is this clumped distribution.Photos.com/Photos.com/Getty Images
Habitat patches are often distributed into three spatial patterns: uniform, random and clumped. The degree to which a habitat patch is distributed across a landscape can affect whether an organism is adapted to survive there. Habitats can be distributed in rare cases uniformly in even intervals or more randomly. Usually, however, habitat patches are clumped into patches heterogeneously. In Charnov's 1976 classic study of habitat patches, an organism was found to be more likely to use patchy habitats where the payoff for suitable habitat is higher in more widely distributed habitats in random and uniform distributions. - Within a forest, a refuge limits the predators who seek out this prey.Jupiterimages/Photos.com/Getty Images
Spatial refuges or predator-free habitats can provide areas where prey can escape predators. If given a refuge, this limits the level of predation and provides a balance in species abundance between the two species types. This promotes the coexistence of predator/prey interactions. In a 1996 study, Holyoak and Lawler found that a series of connected patches, or corridors, gave the ability for prey to find a refuge away from predators. - This forest is perforated by a small section of nonhabitat, a parking lot.Ryan McVay/Digital Vision/Getty Images
Habitat patches can be formed by three types of fragmentation: perforation, typical fragmentation and internal fragmentation. In perforation, humans have altered smaller spaces within the larger habitat. In typical fragmentation, small sections of habitat are left within the larger areas of human-altered spaces, also known as matrices. In internal fragmentation, larger habitats have ribbons of continuous nonhabitat. For example, a road through a habitat can affect the organism's ability to reach its entire potential habitat.
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