Tree crown conditions in Missouri, 2000-2003

The relationship between level of longitudinal growth strain and stress, modulus of elasticity, basic density, volumetric shrinkage, fiber classification, and stem form was investigated with 10 Eucalyptusregnans regrowth trees. Close relationships were observed. It is suggested that variations in these properties within trees are closely controlled, possibly to enable optimum positioning of the tree crown in relation to its immediate environment. The concept of fiber structure varying as a response to environment is supported by the observed variation in wood properties within and between trees of this species. The often-reported association between eccentric radial growth and reaction wood was not substantiated in this study.The data indicate that if economically justifiable, it would be possible to segregate trees that are likely to contain material that is hard to season.

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THE SEED PRODUCTION CAPACITY AND EFFICIENCY OF RED PINE CONES (PINUS RESINOSA AIT.)

Canadian Journal of Botany ◽

10.1139/b56-003 ◽

1956 ◽

Vol 34 (1) ◽

pp. 27-36 ◽

Cited By ~ 19

Author(s):

L. A. Lyons

Keyword(s):

Seed Production ◽

Production Efficiency ◽

Production Capacity ◽

Pinus Resinosa ◽

Proximal Part ◽

Red Pine ◽

First Year ◽

Tree Crown ◽

Second Year ◽

Pine Cones

The seed capacity of red pine cones varies from about 30 to over 110, depending on the size of the cone and its position in the tree crown, and is determined by the number of ovules that are structurally complete at the time of pollination. These ovules occur in a central "productive" region and constitute less than one-half of the total. The remaining ovules, most: of which are in the proximal part of the cone, never become structurally perfect, and do not contribute to seed production. Abortion of ovules in the productive region usually reduces seed production efficiency to 50–60%, and is accompanied mainly by withering of the nucellus in the first year and failure to produce archegonia early in the second year. The extent of ovule abortion during the first year varies indirectly with cone size, seed capacity, and height in tree.

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Mechanistic differences in utilization of absorbed excitation energy within photosynthetic apparatus of Norway spruce induced by the vertical distribution of photosynthetically active radiation through the tree crown

Plant Science ◽

10.1016/s0168-9452(98)00031-4 ◽

1998 ◽

Vol 133 (2) ◽

pp. 155-165 ◽

Cited By ~ 29

Author(s):

Vladimı́r Špunda ◽

Martin Čajánek ◽

Jiřı́ Kalina ◽

Irena Lachetová ◽

Miroslava Šprtová ◽

...

Keyword(s):

Vertical Distribution ◽

Excitation Energy ◽

Norway Spruce ◽

Photosynthetically Active Radiation ◽

Photosynthetic Apparatus ◽

Tree Crown ◽

Active Radiation ◽

The Vertical Distribution

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Resolving uncertainties in predictive equations for urban tree crown characteristics of the southeastern United States: Local and general equations for common and widespread species

Urban Forestry & Urban Greening ◽

10.1016/j.ufug.2016.09.009 ◽

2016 ◽

Vol 20 ◽

pp. 282-294 ◽

Cited By ~ 8

Author(s):

A. Blood ◽

G. Starr ◽

F.J. Escobedo ◽

A. Chappelka ◽

P.E. Wiseman ◽

...

Keyword(s):

United States ◽

Southeastern United States ◽

Tree Crown ◽

Predictive Equations ◽

Widespread Species ◽

Urban Tree ◽

Crown Characteristics

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Dispersal ofAcaciaseeds by ungulates and ostriches in an African savanna

Journal of Tropical Ecology ◽

10.1017/s0266467400009548 ◽

1996 ◽

Vol 12 (3) ◽

pp. 345-356 ◽

Cited By ~ 50

Author(s):

Maxine F. Miller

Keyword(s):

South Africa ◽

Seed Dispersal ◽

Seedling Recruitment ◽

Seedling Survival ◽

Tree Crown ◽

African Savanna ◽

Large Herbivores ◽

Mammalian Herbivores ◽

Open Environments ◽

Presence And Absence

ABSTRACTThe dispersal of AfricanAcaciaseeds in the presence and absence of large mammalian herbivores and ostriches was assessed in a savanna ecosystem in South Africa. In the absence of large herbivores,A. tortilisandA. niloticapods were mainly dispersed in the shade, directly beneath the tree crown and seeds remained in pods for over 18 months. In the presence of large herbivores,A. tortilis, A. niloticaandA. karrooseeds were freed from pods and were dispersed into open, non-shaded habitats. Impala dispersed mostA. tortilisseeds (18,900 ha−1), giraffe mostA. niloticaseeds (1060 ha−1) and giraffe and kudu mostA. karrooseeds (452 and 448 ha−1, respectively). Seedling survival in dung in open environments may exceed that of seedlings in soil shaded beneath the tree crown. It appears that seed dispersal by large herbivores may be advantageous to future seedling recruitment.

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