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Shiro TSUYUZAKI
Plant community ecology / Environmental conservation

Mount Usu / Sarobetsu post-mined peatland
From left: Crater basin in 1986 and 2006. Cottongrass / Daylily

(Update on December 6, 2007)

Growth stage (Life history stage)

Life history

A system of interrelated adaptive traits forming a set of reproductive tactics

There are various definitions on each life history stage, depnding on research objectives. This page is for terrestrial seed-plant community ecology.


Stage

Table. Growth stages on terrestrial seed plants.

Stage Definition
Seed A structure that encapsulates the embryo. The seeds are often in dormant and makes a seedbank

↓ germination

Seedling A young plant reproduced by means of seeds (not by sprouts). On forestry, seedling often means young trees less than the defined height, 1.0-1.3 m. For monitoring tree growth on Mount Koma, we define trees less than 30 cm high for trees.
seedling seedling
[Left] A Picea mariana seedling emerged on a petri dish with three-layered filter paper in an incubator. The length is about 2 cm. [Right] A P. mariana seedling on burned ground surface after the 2004 wildfire at Poker Flat near Fairbanks, Alaska, on July 30 2007 (by Narita K).
Sapling
  1. young tree, that does not produce any flowers and fruits even if the environmental conditions are appropriate
  2. in the case of the researches on Mount Koma, the height of saplings ranges from 0.3 m to 1.3 m (= DBH). A sapling of Magnolica kobus
  3. plants having a DBH greater than 0 and less than the minimum adult DBH defined in the tree parameters
Juvenile An immature (non-flowering) individual resembling an adult except reproductive activity, i.e., seedlings and saplings

↓ growth / competition
Adult The mature stage. In the case of terrestrial plants, it is recognized by theproduction of reproductive organs, such as flowers and fruits. See an adult Robinia pseudoacacia

↓ seed dispersal
Time has passed ...

Dead A individual makes neither photosynthesis nor respiration

*: the definitions of seedling and junenile are totally fuzzy.

Examples

Annuals
  1. From seed dispersal to seedling emergence
  2. Seedling establishment
  3. Seedling development
  4. Sapling, or juvenile
  5. Pole development
  6. Maturation
Perennials (based on age)
  1. Viable seeds in soil
  2. Seedlings
  3. Juvenile plants
  4. Immature plants
  5. Mature virginile plants
  6. Plants in the initial phase of generative period
  7. Plants in the period of life culmination
  8. Senescing plants
  9. Senile plants
  10. Plants in the dormant state

References

  • Akasaka, M. & Tsuyuzaki, S. 2005. Tree seedling performance on microhabitats along an elevational gradient on Mount Koma, Japan. Journal of Vegetation Science 16: 647-654
  • fire ecology (火災生態学)

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