Crown (botany)
This article includes a list of general references, but it lacks sufficient corresponding inline citations. (January 2010) |
The crown of a plant is the total of an individual plant's aboveground parts, including
The crown of a
.Shapes of crowns are highly variable. The major types for trees are the excurrent branching habit resulting in conoid shapes and decurrent (deliquescent) branching habit, resulting in round shapes. Crowns are also characterized by their width, depth, surface area, volume, and density. Measurements of crowns are important in quantifying and qualifying plant health, growth stage, and efficiency.
Major functions of the crown include light energy assimilation, carbon dioxide absorption and release of oxygen via
Crown classes
Trees can be described as fitting different crown classes. Commonly used are Kraft's classes.[1] Kraft designated these social classes based on temperate and boreal forests in Central Europe, so they do not necessarily work with every forest type in the world.
Kraft wrote in German so here are his classes with translations:
- 1 v vorherrschend (predominant)
- 2 h herrschend (dominant)
- 3 m mitherrschend (co-dominant)
- 4 b beherrscht (dominated / suppressed)
- 5 u unterständig (inferior) this is then split into 2 subclasses 5a (shade tolerant trees) and 5b (dying crowns / dying trees)
Often it has been simplified to Dominant, Co-dominant and Suppressed.[2]
Also
Ecological criteria
Height component (Stand layer / Height class):
- 100 Overstorey / Overlayer
- 200 Middlestorey / Middlelayer
- 300 Understorey / Underlayer
Vitality component (Tree vigor / vitality):
- 10 Lush
- 20 Normal
- 30 Retarded
Future growth potential component (Developmental tendency / conversion tendency):
- 1 High
- 2 Average
- 3 Lagging
and then additionally
Silvicultural Criteria
Commercial worth
- 400 Valuable, outstanding tree
- 500 Usable, wood
- 600 Poor to Unusable Quality
Trunk class
- 40 Valuable wood (≥50% of the trunk is high-quality timber)
- 50 Normal wood (≥50% of the trunk is normal-quality timber)
- 60 Substandard wood (<50% of the trunk is normal-quality timber)
Crown class
- 4 Deep crown (>½ the tree length)
- 5 Medium crown
- 6 Shallow crown (<¼ the tree length)
While both Kraft and IUFRO classifications are aimed at describing individual tree crowns both can and are applied to describe whole layers or storeys.[4]
See also
- Apical dominance
- Canopy (biology)
- Canopy (grape)
- Crown shyness
- Diameter at breast height
- Fruit tree forms
- , etc.)
- Habit (biology)
- Pruning
- Shoot
- Stratification (vegetation)
- Tree crown measurement
- Tiller (botany)
- Understory
References
- ^ "Archived copy" (PDF). Archived from the original (PDF) on 2017-05-19. Retrieved 2016-06-01.
{{cite web}}
: CS1 maint: archived copy as title (link) - ISBN 9783642752131, 624pp -pg 180
- ISBN 9783642752131, 624pp
- ^ National Forest Inventories: Contributions to Forest Biodiversity Assessments Gherardo Chirici, Susanne Winter, Ronald E. McRoberts Springer Science & Business Media, 2011 - 206pp
Further reading
- Kozlowski, T.; Kramer, P.; Pallardy, S. (1991) The physiological ecology of woody plants. Academic Press
External links
- Tree crown Archived 2007-12-02 at the Wayback Machine