Acclimation and Adaptation in Plants

Adapted from: Anderson, P. and D. Chmura. Silvicultural Approaches for Adapting Forests to Climate Change. Task Force on Adapting Forests to Climate Change (TAFCC).

Plant populations may naturally adjust to climate change in three ways:

1. Altered physiology and development

Altered physiology and development in response to environmental change can occur in some plants. One example of this is environmental preconditioning. In such cases, prior exposure to water stress can induce physiological changes (osmotic adjustment) that ameliorate the effects of further exposure (Dr. Tom Kolb, pers. comm.).

2. Evolution-in-place

Evolution generally means the slow change in species over a long period of time. Through natural selection, the offspring of a species has a greater survival rate and thus has a greater chance of having surviving offspring. This process selects those variants within a population that are best adapted to their existing ecosystem. Adaptation also plays a role in which individuals will be selected for survival. For example, the slight toughening of the seed coat may allow more seeds to pass undigested through a herbivore and thus have a greater chance of germinating and sprouting into a new plant.
Some species have made more rapid changes through mutation. Mutations within the genetic DNA of an offspring can happen from one generation to the next and bring about dramatic change to a species. If the mutation improves fitness (the ability to be more competitive) and if the mutation is heritable, then the offspring will be able to continue to exploit the mutation to its benefit.

3. Migration to new habitats

Because terrestrial plants grow in the earth, they are limited, unlike most animals, in their ability to move into zones with more desirable climate. Their only means of movement is through propagules. Propagules are moved in a variety of ways, such as by:

  • Wind – Seed from many plants are carried on the wind; at times these distances can be relatively far.
  • Animals – Seeds and vegetative propagules can be moved by animals from one location to another in the gut and deposited with the feces. They can also become embedded in hair, hoofs, and paws and later deposited. Humans also transport seeds and propagules both purposefully and by accident.
  • Rhizomes and stolons – Above and below ground, laterally growing stems can move the location of a plant many meters per growing season.
  • Water – The movement of water either in streams or via sheet flow movement across the land can carry seeds and other propagules long distances from the originating plant.
  • Land slides – The physical movement of soil and rock down slopes can carry propagules from higher to lower elevations.

Adapted for by Tom DeGomez, University of Arizona

External Links
Task Force on Adapting Forests to Climate Change

Related to Acclimation and Adaptation in Plants:

  • Ecosystem-Based Effects
  • Climate Variation and Ecosystem Responses
  • Vulnerability of Forest Ecosystems to Climate Variation
  • Climate Variation and Stressors on Forest Stands
  • Vulnerabilities Vary with Forest Stand Development