Foliage height influences specific leaf area of three conifer species

2003 ◽  
Vol 33 (1) ◽  
pp. 164-170 ◽  
Author(s):  
John D Marshall ◽  
Robert A Monserud

Specific leaf area (SLA), the ratio of projected leaf area to leaf dry mass, is a critical parameter in many forest process models. SLA describes the efficiency with which the leaf captures light relative to the biomass invested in the leaf. It increases from top to bottom of a canopy, but it is unclear why. We sampled stands with low and elevated canopies (young and old stands) to determine whether SLA is related to water potential, as inferred from branch height and length, or shade, as inferred from branch position relative to the rest of the canopy, or both. We studied western white pine (Pinus monticola Dougl. ex D. Don), ponderosa pine (Pinus ponderosa Dougl. ex P. & C. Laws.), and interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca) in northern Idaho. SLA decreased with branch height (P < 0.0001) at rates that varied among species (P < 0.0001). Branch length had no influence on SLA (P = 0.85). We detected no differences with canopy elevation (P = 0.90), but the slopes of lines relating SLA to branch height may have differed between the canopy elevation classes (P = 0.039). The results are consistent with predictions based on the hypothesis that SLA decreases as the gravitational component of water potential falls. The lack of a strong shading effect simplifies the estimation of canopy SLA for process models, requiring only species and branch heights.

1999 ◽  
Vol 29 (5) ◽  
pp. 521-535 ◽  
Author(s):  
Robert A Monserud ◽  
John D Marshall

Allometric equations predicting individual branch and total crown leaf area, leaf mass, and branch wood mass were developed for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca), ponderosa pine (Pinus ponderosa Dougl. ex Laws.), and western white pine (Pinus monticola Dougl. ex D. Don) on the Priest River Experimental Forest in northern Idaho. Whole crowns were weighed fresh in the field by crown quarter. Two antithetic random branches were sampled from each crown quarter, weighed fresh in the field, and returned to the laboratory for detailed analysis. Nonlinear weighted regression with the general allometric equation was used to estimate all parameters. For the branches, branch diameter and length, foliated length, and position in the crown explain 82-97% of the variation. Specific leaf area (leaf area/mass) differs significantly among species and increases with distance from the tree top. For whole trees, sapwood area at breast height, crown ratio and length, and crown competition factor (CCF) explain 94-99% of the variation. The assumption of linearity and constant ratio between leaf area and sapwood area held rather generally. Differences between two alternative estimators (branch summation vs. crown weighing) of total crown biomass and leaf area were not statistically significant. For stands, stand totals were estimated from the whole-tree equations and stand-inventory data. Generally, these stand estimates were intermediate between coastal forests west of the Cascades and drier forests in the rain shadow of the Rocky Mountain crest.


2020 ◽  
Author(s):  
Carolyn G. Anderson ◽  
Ben Bond-Lamberty ◽  
James C. Stegen

AbstractSpecific leaf area (SLA, leaf area per unit dry mass) is a key canopy structural characteristic, a measure of photosynthetic capacity, and an important input into many terrestrial process models. Although many studies have examined SLA variation, relatively few data exist from high latitude, climate-sensitive permafrost regions. We measured SLA and soil and topographic properties across a boreal forest permafrost transition, in which forest composition changed as permafrost deepened from 54 to >150 cm over 75 m hillslope transects in Caribou-Poker Creeks Research Watershed, Alaska. We characterized both linear and threshold relationships between topographic and edaphic variables and SLA and developed a conceptual model of these relationships. We found that the depth of the soil active layer above permafrost was significantly and positively correlated with SLA for both coniferous and deciduous boreal tree species. Intraspecific SLA variation was associated with a fivefold increase in net primary production, suggesting that changes in active layer depth due to permafrost thaw could strongly influence ecosystem productivity. While this is an exploratory study to begin understanding SLA variation in a non-contiguous permafrost system, our results indicate the need for more extensive evaluation across larger spatial domains. These empirical relationships and associated uncertainty can be incorporated into ecosystem models that use dynamic traits, improving our ability to predict ecosystem-level carbon cycling responses to ongoing climate change.


2006 ◽  
Vol 21 (3) ◽  
pp. 142-148 ◽  
Author(s):  
Karl Froese ◽  
Han-Sup Han

Abstract We collected residual stand-damage data from a mixed conifer stand in northern Idaho that had been commercially thinned with a cut-to-length harvesting system. The stand composition after harvesting was 76% grand fir (Abies grandis); 14% Douglas-fir (Pseudotsuga menziesii var. glauca); 5% western redcedar (Thuja plicata); and 5% lodgepole pine (Pinus contorta), western white pine (Pinus monticola), and ponderosa pine (Pinus ponderosa). For all crop trees, damage to the bole, roots, and crown was assessed using systematic sampling with a random start and fixed area plots. Wounding occurred on 37.4% of the remaining trees, but the severity of wounding varied significantly by species (P < 0.05). Eighty-four percent of wounding for all species combined was considered as small size (<194 cm2). The greatest average amount of damage to a bole occurred along the first 2 m up from the ground (67.2%) and also within 4 m of the forwarder centerline (67.7%). Gouges were present on 41% of all scars. Tree location to forwarder trail appears to have a significant effect on the number and height of scars on a tree (P < 0.05). We estimated that throughout a 20-year period, volume losses for grand fir because of decay would be 2.57% compared to 1.31% in an undamaged stand of similar composition. West. J. Appl. For. 21(3): 142–148.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jorge Palomo-Kumul ◽  
Mirna Valdez-Hernández ◽  
Gerald A. Islebe ◽  
Manuel J. Cach-Pérez ◽  
José Luis Andrade

AbstractWe evaluated the effect of ENSO 2015/16 on the water relations of eight tree species in seasonally dry tropical forests of the Yucatan Peninsula, Mexico. The functional traits: wood density, relative water content in wood, xylem water potential and specific leaf area were recorded during the rainy season and compared in three consecutive years: 2015 (pre-ENSO conditions), 2016 (ENSO conditions) and 2017 (post-ENSO conditions). We analyzed tree size on the capacity to respond to water deficit, considering young and mature trees, and if this response is distinctive in species with different leaf patterns in seasonally dry tropical forests distributed along a precipitation gradient (700–1200 mm year−1). These traits showed a strong decrease in all species in response to water stress in 2016, mainly in the driest site. Deciduous species had lower wood density, higher predawn water potential and higher specific leaf area than evergreen species. In all cases, mature trees were more tolerant to drought. In the driest site, there was a significant reduction in water status, regardless of their leaf phenology, indicating that seasonally dry tropical forests are highly vulnerable to ENSO. Vulnerability of deciduous species is intensified in the driest areas and in the youngest trees.


1993 ◽  
Vol 23 (4) ◽  
pp. 749-755 ◽  
Author(s):  
Bert M. Cregg

Xylem pressure potential (ψx), net photosynthesis (A), needle conductance (gn), and transpiration (E) were measured periodically throughout the 1991 growing season on 16 ponderosa pine (Pinusponderosa Dougl. ex Laws.) trees growing in a 23-year-old provenance planting in eastern Nebraska. The trees studied were from four diverse sources: western Montana, northwest South Dakota, southern New Mexico, and central Arizona. In addition to water relations and gas exchange, specific leaf area, stomatal density, and surface to volume ratios were determined on 1-year-old foliage of each tree. Compared with the other seed sources, gas exchange of the South Dakota source was lowest early in the summer, when ψx was generally high, and highest in the late summer, when ψx declined. However, the relation of gn to ψx did not appear to differ among the seed sources. The South Dakota source had lower stomatal density and needle length than the other sources tested. No differences in specific leaf area or surface to volume ratio were observed. Overall, variation in physiology and needle morphology among seed sources of mature ponderosa pine appears to be more subtle than intraspecific variation of seedlings of other species reported in the literature.


1989 ◽  
Vol 4 (1) ◽  
pp. 15-17 ◽  
Author(s):  
David L. Wenny ◽  
Richard L. Woollen

Abstract Douglas-fir (Pseudotsuga menziesii var. glauca) ponderosa pine (Pinus ponderosa var. ponderosa), and western white pine (Pinus monticola) where chemically root pruned with cupric carbonate (CuCO3) during greenhouse production. The interior walls of Styroblock 4A® and Ray Leach® pine cell containers (each 66 cm³) were coated with latex paint containing CuCO3 at concentrations of 0, 30, 100, or 300 g/l. Seedlings were potted after one growing season, initiating a standard root growth potential test (Duryea 1984). The number and length of new roots more than 1 cm in length were measured. Seedling root systems increased in total root number and length, especially in the upper segments of the root plug, as a result of chemical root pruning. Seedling height and caliper were unaffected by the cupric carbonate treatments during the production phase, and a latex paint carrier did not decrease seedling growth. West. J. Appl. For. 4(1):15-17, January 1989.


2017 ◽  
Vol 44 (11) ◽  
pp. 1134 ◽  
Author(s):  
Rachael H. Nolan ◽  
Kendal A. Fairweather ◽  
Tonantzin Tarin ◽  
Nadia S. Santini ◽  
James Cleverly ◽  
...  

Partitioning of water resources amongst plant species within a single climate envelope is possible if the species differ in key hydraulic traits. We examined 11 bivariate trait relationships across nine woody species found in the Ti-Tree basin of central Australia. We found that species with limited access to soil moisture, evidenced by low pre-dawn leaf water potential, displayed anisohydric behaviour (e.g. large seasonal fluctuations in minimum leaf water potential), had greater sapwood density and lower osmotic potential at full turgor. Osmotic potential at full turgor was positively correlated with the leaf water potential at turgor loss, which was, in turn, positively correlated with the water potential at incipient stomatal closure. We also observed divergent behaviour in two species of Mulga, a complex of closely related Acacia species which range from tall shrubs to low trees and dominate large areas of arid and semiarid Australia. These Mulga species had much lower minimum leaf water potentials and lower specific leaf area compared with the other seven species. Finally, one species, Hakea macrocarpa A.Cunn ex.R.Br., had traits that may allow it to tolerate seasonal dryness (through possession of small specific leaf area and cavitation resistant xylem) despite exhibiting cellular water relations that were similar to groundwater-dependent species. We conclude that traits related to water transport and leaf water status differ across species that experience differences in soil water availability and that this enables a diversity of species to exist in this low rainfall environment.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0232506
Author(s):  
Carolyn G. Anderson ◽  
Ben Bond-Lamberty ◽  
James C. Stegen

Specific leaf area (SLA, leaf area per unit dry mass) is a key canopy structural characteristic, a measure of photosynthetic capacity, and an important input into many terrestrial process models. Although many studies have examined SLA variation, relatively few data exist from high latitude, climate-sensitive permafrost regions. We measured SLA and soil and topographic properties across a boreal forest permafrost transition, in which dominant tree species changed as permafrost deepened from 54 to >150 cm over 75 m hillslope transects in Caribou-Poker Creeks Research Watershed, Alaska. We characterized both linear and threshold relationships between topographic and edaphic variables and SLA and developed a conceptual model of these relationships. We found that the depth of the soil active layer above permafrost was significantly and positively correlated with SLA for both coniferous and deciduous boreal tree species. Intraspecific SLA variation was associated with a fivefold increase in net primary production, suggesting that changes in active layer depth due to permafrost thaw could strongly influence ecosystem productivity. While this is an exploratory study to begin understanding SLA variation in a non-contiguous permafrost system, our results indicate the need for more extensive evaluation across larger spatial domains. These empirical relationships and associated uncertainty can be incorporated into ecosystem models that use dynamic traits, improving our ability to predict ecosystem-level carbon cycling responses to ongoing climate change.


HortScience ◽  
1998 ◽  
Vol 33 (6) ◽  
pp. 988-991 ◽  
Author(s):  
Yoshiaki Kitaya ◽  
Genhua Niu ◽  
Toyoki Kozai ◽  
Maki Ohashi

Lettuce (Lactuca sativa L. cv. Summer-green) plug transplants were grown for 3 weeks under 16 combinations of four levels (100, 150, 200, and 300 μmol·m-2·s-1) of photosynthetic photon flux (PPF), two photoperiods (16 and 24 h), and two levels of CO2 (400 and 800 μmol·mol-1) in growth chambers maintained at an air temperature of 20 ±2 °C. As PPF increased, dry mass (DM), percent DM, and leaf number increased, while ratio of shoot to root dry mass (S/R), ratio of leaf length to leaf width (LL/LW), specific leaf area, and hypocotyl length decreased. At the same PPF, DM was increased by 25% to 100% and 10% to 100% with extended photoperiod and elevated CO2 concentration, respectively. Dry mass, percent DM, and leaf number increased linearly with daily light integral (DLI, the product of PPF and photoperiod), while S/R, specific leaf area, LL/LW and hypocotyl length decreased as DLI increased under each CO2 concentration. Hypocotyl length was influenced by PPF and photoperiod, but not by CO2 concentration. Leaf morphology, which can be reflected by LL/LW, was substantially influenced by PPF at 100 to 200 μmol·m-2·s-1, but not at 200 to 300 μmol·m-2·s-1. At the same DLI, the longer photoperiod promoted growth under the low CO2 concentration, but not under the high CO2 concentration. Longer photoperiod and/or higher CO2 concentration compensated for a low PPF.


2007 ◽  
Vol 37 (11) ◽  
pp. 2096-2105 ◽  
Author(s):  
Kelsey Sherich ◽  
Amy Pocewicz ◽  
Penelope Morgan

Trees respond to edge-to-interior microclimate differences in fragmented forests. To better understand tree physiological responses to fragmentation, we measured ponderosa pine ( Pinus ponderosa Dougl. ex P. & C. Laws) and Douglas-fir ( Pseudotsuga menziesii (Mirbel) Franco) leaf area, crown ratios, sapwood area, basal area (BA) growth rates, and BA growth efficiency at 23 long-established (>50 year) forest edges in northern Idaho. Trees located at forest edges had more leaf area, deeper crowns, higher BA growth rates, and more sapwood area at breast height than interior trees. Ponderosa pine had significantly higher BA growth efficiency at forest edges than interiors, but Douglas-fir BA growth efficiency did not differ, which may relate to differences in photosynthetic capacity and drought and shade tolerance. Edge orientation affected BA growth efficiency, with higher values at northeast-facing edges for both species. Edge effects were significant even after accounting for variation in stand density, which did not differ between the forest edge and interior. Although edge trees had significantly greater canopy depth on their edge-facing than forest-facing side, sapwood area was evenly distributed. We found no evidence that growing conditions at the forest edge were currently subjecting trees to stress, but higher leaf area and deeper crowns could result in lower tolerance to future drought conditions.


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