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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

(First update on Jul 18 2003. Last on Jan 21 2005)

Facilitation

Facilitation (定着促進効果)

(Successional) facilitation

In which the influence of early species in a community succession is to facilitate establishment of later ones by changing the conditions encountered.

(Begon et al. 1996)

Facilitation
Fig. 1 Temporal changes in facilitation, competition and tolerance along successional sere

Type

Direct

  1. Amelioration of harsh environmental conditions = Resource modification
    1. Adjust light and temperature by shading
    2. Increase soil moisture
    3. Increase soil nutrients
    4. Adjust soil aerobic conditions
    patch Fig. 2 Study site to evaluate the effects of two patch-forming shrub species, Salix reinii and Gaultheria miqueliana, on cohabitants on Mount Koma (Photo by S. Uesaka). (Uesaka & Tsuyuzaki 2005)
    A deciduous shrub, S. reinii is likely to be facilitative, and an evergreen shrub, G. miqueliana seems to be inhibitive.
    The patches increase moisture and nutrients in the volcanic deposits, and decrease solar radiation on the ground surface.
  2. Alter characteristics of soil substrates
    1. Bulk density, and macropores
    2. Nurse logs
    3. Seed trap effect by diverse microtopography
  3. Epiphytes (e.g., orchids, ferns, mosses, algae)
    1. Autotrophic: obligate, facultative
    2. Heterotrophic: parasitic (asymmetrical effect)
    3. Auto-heterotrophic continuum (hemiparasites)

Indirect

  1. Eliminate potential competitors
  2. Introduce beneficial organisms, e.g., mycorrhizae and pollinators
  3. Protect from herbivores by physical modification of environment

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References
  • tussock (谷地坊主)
  • Begon M, Harper JL & Townsend CR. 1996. Ecology. Individuals, populations and communities. (3rd edn.). Blackwell Science, London
  • Koyama, A. & Tsuyuzaki, S. 2010. Effects of sedge and cottongrass tussocks on plant establishment patterns in a post-mined peatland, northern Japan. Wetlands Ecology and Management 18: 135-148
  • Uesaka, S. & Tsuyuzaki, S. 2004. Differential establishment and survival of species in deciduous and evergreen shrub patches and on bare ground, Mt. Koma, Hokkaido, Japan. Plant Ecology 175: 165-177

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