In plant ecology

Plant ecology

Plant ecology is a subdiscipline of ecology which studies the distribution and abundance of plants, the interactions among and between members of plant species, and their interactions with their environment...

, the C-S-R Triangle theory is a theory of plant strategies developed by J. Philip Grime

J. Philip Grime

John Philip Grime is a prominent British ecologist and emeritus professor at the University of Sheffield. He is best known for his CSR theory on plant strategies, for the unimodal relationship between species richness and site productivity , for the Intermediate Disturbance Hypothesis, for the DST...

. The three strategies are competitor (C), stress tolerator (S), and ruderal (R). These strategies each thrive best in a unique combination of either high or low intensities of stress

Stress (biology)

Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...

 and disturbance.

Competitor

Competitors are plant species that thrive in areas of low intensity stress and disturbance and excel in biological competition

Competition (biology)

Competition is an interaction between organisms or species, in which the fitness of one is lowered by the presence of another. Limited supply of at least one resource used by both is required. Competition both within and between species is an important topic in ecology, especially community ecology...

. These species are able to out compete other plants by most efficiently tapping into available resources. Competitors do this through a combination of favorable characteristics, including rapid growth rate, high productivity (growth in height, lateral spread, and root mass), and high capacity for phenotypic plasticity

Phenotypic plasticity

Phenotypic plasticity is the ability of an organism to change its phenotype in response to changes in the environment. Such plasticity in some cases expresses as several highly morphologically distinct results; in other cases, a continuous norm of reaction describes the functional interrelationship...

. This last feature allows competitors to be highly flexible in morphology and adjust the allocation of resources throughout the various parts of the plant as needed over the course of the growing season.

Stress tolerator

Stress tolerators are plant species that live in areas of high intensity stress and low intensity disturbance. Species that have adapted this strategy generally have slow growth rates, long lived leaves, high rates of nutrient retention, and low phenotypic plasticity. Stress tolerators respond to environmental stresses through physiological variability. These species are often found in stressful environments such as alpine or arid habitats, deep shade, nutrient deficient soils, and areas of extreme pH levels.

Ruderal

Ruderals

Ruderal species

A ruderal species is a plant species that is first to colonize disturbed lands. The disturbance may be natural , or due to human influence – constructional , or agricultural .Ruderal species typically dominate the disturbed area...

 are plant species that prosper in situations of high intensity disturbance and low intensity stress. These species are fast-growing and rapidly complete their life cycles, and generally produce large amounts of seeds. Plants that have adapted this strategy are often found colonizing recently disturbed land, and are often annuals

Annual plant

An annual plant is a plant that usually germinates, flowers, and dies in a year or season. True annuals will only live longer than a year if they are prevented from setting seed...

.

Further reading

• Grime JP. (1977). Evidence for the existence of three primary strategies in plants and its relevance to ecological and evolutionary theory. The American Naturalist 111:1169–1194.