Climax species

Climax species, also called late seral, late-successional, K-selected or equilibrium species, are plant species that will remain essentially unchanged in terms of species composition for as long as a site remains undisturbed. They are the most shade-tolerant species of tree to establish in the process of forest succession. The seedlings of climax species can grow in the shade of the parent trees, ensuring their dominance indefinitely. A disturbance such as fire may kill the climax species, allowing pioneer or earlier successional species to re-establish for a time. They are the opposite of pioneer species, also known as ruderal, fugitive, opportunistic or R-selected species, in the sense that climax species are good competitors but poor colonizers, whereas pioneer species are good colonizers but poor competitors. Climax species dominate the climax community, when the pace of succession slows down, the result of ecological homeostasis, which features maximum permitted biodiversity, given the prevailing ecological conditions. Their reproductive strategies and other adaptive characteristics can be considered more sophisticated than those of opportunistic species. Through negative feedback, they adapt themselves to specific environmental conditions. Climax species, closely controlled by carrying capacity, follow K strategies, wherein species produce fewer numbers of potential offspring, but invest more heavily in securing the reproductive success of each one to the micro-environmental conditions of its specific ecological niche. Climax species might be iteroparous, energy consumption efficient and nutrient cycling.^[1]

Disputed term

The idea of a climax species has been criticized in recent ecological literature.^[2] Any assessment of successional states depends on assumptions about the natural fire regime. But the idea of a dominant species is still widely used in silvicultural programs and California Department of Forestry literature.

Examples

White spruce (Picea glauca) is an example of a climax species in the northern forests of North America.

Other examples:

• Canadian Hemlock
• Pacific Silver Fir
• White Fir
• Yellow Carabeen
• Blue grama
• Douglas-fir
• Coast Redwood
• European Beech

See also

• Climax vegetation

Notes

References

• Selleck, G. W. "The climax concept". The Botanical Review. Volume 26, Number 4 / October, 1960. Springer.
• Drury, William H.; Nisbet, Ian C.T. 1973. "Succession". Journal of the Arnold Arboretum. 54: 331-368.
• Horn, H S. "The Ecology of Secondary Succession". Annual Review of Ecology and Systematics. November 1974. Annual Reviews.
• Swaine, M. D. and T. C. Whitmore. "On the definition of ecological species groups in tropical rain forests". Plant Ecology. Volume 75, Numbers 1-2 / May, 1988. Springer.
• Buchanan, J. Robert. "Turing instability in pioneer/climax species interactions". October 2004. Science Direct.