Abiotic stress
Abiotic stress is defined as the negative impact of non-living factors on the living organisms in a specific environment.[1] The non-living variable must influence the environment beyond its normal range of variation to adversely affect the population performance or individual physiology of the organism in a significant way.[2] Whereas a biotic stress would include such living disturbances as fungi or harmful insects, abiotic stress factors, or stressors, are naturally occurring, often intangible, factors such as intense sunlight or wind that may cause harm to the plants and animals in the area affected. Abiotic stress is essentially unavoidable. Abiotic stress affects animals, but plants are especially dependent on environmental factors, so it is particularly constraining. Abiotic stress is the most harmful factor concerning the growth and productivity of crops worldwide.[3] Research has also shown that abiotic stressors are at their most harmful when they occur together, in combinations of abiotic stress factors.[4]
Effects of abiotic stress
Abiotic stress, as a natural part of every ecosystem, will affect organisms in a variety of ways. Although these effects may be either beneficial or detrimental, the location of the area is crucial in determining the extent of the impact that abiotic stress will have. The higher the latitude of the area affected, the greater the impact of abiotic stress will be on that area. So, a taiga or boreal forest is at the mercy of whatever abiotic stress factors may come along, while tropical zones are much less susceptible to such stressors.[5]
In plants
A plant’s first line of defense against abiotic stress is in its roots. If the soil holding the plant is healthy and biologically diverse, the plant will have a higher chance of surviving stressful conditions.[6]
In animals
For animals, the most stressful of all the abiotic stressors is heat. This is because many species are unable to regulate their internal body temperature. Even in the species that are able to regulate their own temperature, it is not always a completely accurate system. Temperature determines metabolic rates, heart rates, and other very important factors within the bodies of animals, so an extreme temperature change can easily distress the animal’s body. Animals can respond to extreme heat, for example, through natural heat acclimation or by burrowing into the ground to find a cooler space.[7] It is also possible to see in animals that a high genetic diversity is beneficial in providing resiliency against harsh abiotic stressors. This acts as a sort of stock room when a species is plagued by the perils of natural selection. A variety of galling insects are among the most specialized and diverse herbivores on the planet, and their extensive protections against abiotic stress factors have helped the insect in gaining that position of honor.[8]
See also
References
- ^ "Abiotic Stress". Biology Online. Retrieved 2008-05-04.
- ^ Vinebrooke, Rolf D. et al. “Impacts of multiple stressors on biodiversity and ecosystem functioning: the role of species co-tolerance.” OIKOS 104: 451– 457, 2004.
- ^ Gao, Ji-Ping, et al. “Understanding Abiotic Stress Tolerance Mechanisms: Recent Studies on Stress Response in Rice.” Journal of Integrative Plant Biology 49 (6): 742−750, 2007.
- ^ Mittler, Ron. “Abiotic stress, the field environment and stress combination.” Trends in Plant Science 11(1): 15–19, 2006.
- ^ Wolfe, A. “Patterns of biodiversity.” Ohio State University, 2007.
- ^ Cite error: The named reference
brusswas invoked but never defined (see the help page). - ^ Cite error: The named reference
roelwas invoked but never defined (see the help page). - ^ Goncalves-Alvim, Silmary J. and G. Wilson Fernandez. “Biodiversity of galling insects: historical, community and habitat effects in four neotropical savannas.” Biodiversity and Conservation 10: 79–98, 2001.