Physiological responses of <i>Atherosperma moschatum</i> to day length, night length and photosynthetic photon fluence rate

Olesen, Trevor

doi:10.1111/j.1469-8137.1995.tb04334.x

“…The maximum transmission to the forest floor was 3.8% of full daylight, while the median value was 0.3%. Such transmission values are far below what is needed to saturate the growth of A. moschatum (Olesen 1995).…”

Section: Introductionmentioning

confidence: 87%

Architecture of a Cool-Temperate Rain Forest Canopy

Olesen

¹

2001

Ecology

Self Cite

View full text Add to dashboard Cite

There have been few descriptions of tree crown asymmetry and its development. Here I present the most comprehensive geometric description to date of crown asymmetry within a forest canopy and use allometric, trigonometric, and growth analyses to tentatively identify the dominant cause.A 25.6 ϫ 25.6 m quadrat within a pure stand of Atherosperma moschatum Labillardière (Monimiaceae) in Tasmania was mapped with respect to the locations of tree trunks and crowns. Trunk girths and tree heights were also measured. Trunk girths were again measured ten years later. Standing biomass, growth rates, and structural properties of the trees were estimated from models.Crowns were more evenly spaced than trunks and showed a significant alignment by angle, both characteristics consistent with a tendency toward the optimal packing of the canopy. The displacement of crown locations from trunk locations was correlated both with the nearness of neighbors and with the east-facing aspect. For the quadrat as a whole, there was a projected tilt to the trees of 0.73 m 76.3Њ east of north. The displacement of crown locations from trunk locations was largely achieved early in tree development, consistent with a phototropic response to acute photosynthetically active radiation (PAR) limitation to growth in the understory, evident in the lower relative (projected canopy-area-specific) growth rates of the smaller trees, and with the propensity of A. moschatum to reproduce by vegetative sprouting.There was little evidence of size-dependent variation in the mechanical stresses within the trunks, but more detailed analysis of wood structure is needed. The overall height safety factor (a measure of buckling resistance) for the trees in the quadrat was 4.2, the highest reported factor to date for any tree species. Tasmania is an island in the ''roaring forties,'' and the high value of the safety factor is a likely response to strong and persistent winds.The estimates of the maximum growth rates of individual trees were 14.9 and 8.7 kg/ yr for each of two models. The estimates of the growth rate for the whole stand were 12.1 and 7 m 3 ·ha Ϫ1 ·yr Ϫ1 (8.5 and 4.9 metric tons per hectare per year, respectively).

show abstract

“…There are two lines of evidence that this was the case for the A. moschatum quadrat. Such transmission values are far below what is needed to saturate the growth of A. moschatum (Olesen 1995). Twelve of the most shaded saplings grew within the quadrat.…”

Section: Introductionmentioning

confidence: 89%

Architecture of a Cool-Temperate Rain Forest Canopy

Olesen

¹

2001

Ecology

Self Cite

View full text Add to dashboard Cite

There have been few descriptions of tree crown asymmetry and its development. Here I present the most comprehensive geometric description to date of crown asymmetry within a forest canopy and use allometric, trigonometric, and growth analyses to tentatively identify the dominant cause.A 25.6 ϫ 25.6 m quadrat within a pure stand of Atherosperma moschatum Labillardière (Monimiaceae) in Tasmania was mapped with respect to the locations of tree trunks and crowns. Trunk girths and tree heights were also measured. Trunk girths were again measured ten years later. Standing biomass, growth rates, and structural properties of the trees were estimated from models.Crowns were more evenly spaced than trunks and showed a significant alignment by angle, both characteristics consistent with a tendency toward the optimal packing of the canopy. The displacement of crown locations from trunk locations was correlated both with the nearness of neighbors and with the east-facing aspect. For the quadrat as a whole, there was a projected tilt to the trees of 0.73 m 76.3Њ east of north. The displacement of crown locations from trunk locations was largely achieved early in tree development, consistent with a phototropic response to acute photosynthetically active radiation (PAR) limitation to growth in the understory, evident in the lower relative (projected canopy-area-specific) growth rates of the smaller trees, and with the propensity of A. moschatum to reproduce by vegetative sprouting.There was little evidence of size-dependent variation in the mechanical stresses within the trunks, but more detailed analysis of wood structure is needed. The overall height safety factor (a measure of buckling resistance) for the trees in the quadrat was 4.2, the highest reported factor to date for any tree species. Tasmania is an island in the ''roaring forties,'' and the high value of the safety factor is a likely response to strong and persistent winds.The estimates of the maximum growth rates of individual trees were 14.9 and 8.7 kg/ yr for each of two models. The estimates of the growth rate for the whole stand were 12.1 and 7 m 3 ·ha Ϫ1 ·yr Ϫ1 (8.5 and 4.9 metric tons per hectare per year, respectively).

show abstract

“…This may mean that the end of competition between fruit and new vegetative growth within the canopy was not sufficient to compensate for the gap in photosynthetic capacity. Olesen (1995) showed that dawn TNSC concentrations were a good guide to carbon limitation to growth in the tree Atherosperma moschatum Labill. under constant temperatures.…”

Section: Flowering and Sympodial Branchingmentioning

confidence: 98%

Branch development in custard apple (cherimoya Annona cherimola Miller × sugar apple A. squamosa L.) in relation to tip-pruning and flowering, including effects on production

Olesen¹,

Muldoon²

2009

Trees

View full text Add to dashboard Cite

Custard apple has cryptic axillary buds, hidden from view by the base of the petiole. This has led to confusion about custard apple's flowering habit. Flowering only occurs during early branch development, and can be forced at any time of the growing season simply by removing leaves. Here, we show that flowering is terminal, not extra-axillary, and that the apparent continuation of the main stem beyond the flower is, instead, a sympodial branch. Secondary (including sympodial) branching only occurs during early branch development. Thereafter, axillary bud release is inhibited by the subtending leaf. Here, we show that summer tip-pruning of all branches arrests canopy development until the following spring owing to this inhibition. Although summer tip-pruning prevented new vegetative growth in the canopy, fruit size decreased relative to the control trees by ca. 23%. The reason for this decrease was probably related to increased carbon limitation to growth given that dawn water soluble and total nonstructural carbohydrate concentrations were lower in the tip-pruned trees. Thus, it appears that the reduced competition between fruit development and new vegetative growth in the tip-pruned trees was more than matched by lower photosynthetic capacity in the arrested canopy. Trees grown inside a shade-house were more vigorous than those grown outside. The difference in vigour had little effect on fruit size.

show abstract

Physiological responses of Atherosperma moschatum to day length, night length and photosynthetic photon fluence rate

Cited by 4 publications

References 46 publications

Architecture of a Cool-Temperate Rain Forest Canopy

Architecture of a Cool-Temperate Rain Forest Canopy

Architecture of a Cool-Temperate Rain Forest Canopy

Branch development in custard apple (cherimoya Annona cherimola Miller × sugar apple A. squamosa L.) in relation to tip-pruning and flowering, including effects on production

Contact Info

Product

Resources

About