Light-growth response relationships in Pacific silver fir (Abies amabilis) and subalpine fir (Abies lasiocarpd)

1992 ◽  
Vol 70 (10) ◽  
pp. 1919-1930 ◽  
Author(s):  
K. Klinka ◽  
Q. Wang ◽  
G. J. Kayahara ◽  
R. E. Carter ◽  
B. A. Blackwell

Pacific silver fir and subalpine fir, both typically inhabiting high-elevation forests in northwestern North America, were considered shade-tolerant species, the former more tolerant than the latter. To determine their relative shade tolerance, established advance regeneration was sampled along a light gradient ranging from open areas to inside a forest stand, and analysis of irradiance, growth, and leaf measures was obtained. Relationships between the percentage of above-canopy light (in the photosynthetically active wavelengths) associated with each study tree and its 1991 height increment, 1991 lateral increment, caliper at the base of the 1991 leader, and specific leaf area were examined for individual sites, and sites were grouped according to soil moisture. There were strong, consistent, and similar relationships between irradiance, growth performance, and specific leaf area for both species. As irradiance decreased, growth performance decreased and specific leaf area increased. In spite of ecological differences between the study sites for each species, it was concluded that on fresh sites, Pacific silver fir and subalpine fir are very tolerant of shade. Both are equally well adapted to survive under high shade and snowpack by allocating more resources to caliper and lateral growth than to height growth and by increasing specific leaf area. Key words: shade tolerance, advance regeneration, irradiance, growth performance, specific leaf area, Pacific silver fir, subalpine fir.

1988 ◽  
Vol 18 (10) ◽  
pp. 1234-1242 ◽  
Author(s):  
N. J. Livingston ◽  
T. A. Black

Container-grown 1-0 seedlings of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), western hemlock (Tsugaheterophylla (Raf.) Sarg.), and Pacific silver fir (Abiesamabilis (Dougl.) Forbes) were spring planted on a south-facing high-elevation clearcut located on Mount Arrowsmith, Vancouver Island, British Columbia, and their growth and development was measured over three successive growing seasons. Treatments designed to modify seedling microclimate, including provision of shade cards, irrigation, and irrigation and shade cards combined, had a marked effect on the extent and type of growth in all species. Irrigated seedlings had the largest shoot dry masses and the highest shoot to root dry mass ratios. Shaded seedlings had larger shoots than untreated seedlings, which had the lowest shoot to root dry mass ratios. All seedlings showed a pronounced decline in seasonal growth 1 year after planting. Douglas-fir seedlings exhibited a high degree of drought tolerance; in the driest year there was only a 20% difference in total dry matter production between irrigated and nonirrigated seedlings. Western hemlock and Pacific silver fir seedlings, despite not being drought tolerant, expended water to achieve growth and thereby exposed themselves to desiccation. Measurements of growing-season seedling dry matter production were better related to estimates of growing-season transpiration, obtained by summing the products of seedling leaf area, hourly D/(RvT′), where D is vapour pressure deficit, Rv is the gas constant for water vapour, and T′ is the absolute air temperature, and stomatal conductance derived from a boundary-line analysis model, than to estimates of growing-season average total seedling canopy conductance, i.e., the average of the products of seedling leaf area and stomatal conductance.


1994 ◽  
Vol 72 (12) ◽  
pp. 1749-1757 ◽  
Author(s):  
G. G. Wang ◽  
H. Qian ◽  
K. Klinka

To improve understanding of light – growth response relationships in western red cedar, seedlings were grown on three environmentally comparable sites representing nearly optimum growth conditions for the species in coastal British Columbia. On each site, the seedlings were planted on transects extending from a clearcut to the interior of an adjacent old-growth stand. After three growing seasons, seedling mortality, vigour, growth characters, and foliar nutrients were compared across five light classes and between study sites using analysis of variance and related to the percentage of above-canopy light available to each seedling using regression analysis. Three-year mortality was ≤ 27%, and most mortality (≥ 85%) occurred at ≤ 20% of above-canopy light. Seedling growth improved consistently with increasing light; however, the actual growth response at > 40% of above-canopy light varied with study site. The pattern of variation in the growth characters suggested that planted seedlings were able to acclimate morphologically to varying light conditions in three structural traits typically associated with shade adaptation: specific leaf area, height to caliper ratio, and aboveground to root biomass ratio. Specific leaf area and height to caliper ratio decreased and aboveground to root biomass ratio increased with increasing light. This study does not support the contention that under optimal moisture and nutrient conditions carbohydrate deficiency increases the allocation of net biomass production to aboveground structures. We consider western red cedar in the study area to be a. very shade-and exposure-tolerant species but not one that is specifically adapted to an understory environment. Key words: Thuja plicata seedlings, light – growth response relationships, specific leaf area, height to caliper ratio, aboveground to root biomass ratio, shade tolerance.


1996 ◽  
Vol 26 (7) ◽  
pp. 1149-1157 ◽  
Author(s):  
Han Y.H. Chen ◽  
Karel Klinka ◽  
Gordon J. Kayahara

We studied growth, crown architecture, and specific leaf area acclimation of a shade-intolerant species, Pinuscontorta Dougl. ex Loud. var. latifolia Engelm., and a moderately shade-tolerant species, Pseudotsugamenziesii var. glauca (Beissn.) Franco, using naturally regenerated saplings along a wide range of light conditions. Study sites were located within a dry-summer, cool-temperate climate represented by the Dry Cool Interior Douglas-fir biogeoclimatic subzone near Williams Lake, British Columbia, Canada. In an open light environment, Pinuscontorta had a greater growth increment in both terminal and lateral shoots than did Pseudotsugamenziesii. With decreasing light availability (i) terminal increment, mean lateral increment, and total lateral increment decreased in both species (although Pinuscontorta reduced lateral growth significantly faster than Pseudotsugamenziesii); (ii) the ratio of mean lateral to terminal increment in Pinuscontorta did not change, but significantly increased in Pseudotsugamenziesii; (iii) the ratio of total lateral to terminal increment in Pinuscontorta decreased, but increased in Pseudotsugamenziesii; and (iv) specific leaf area in both species increased (in Pseudotsugamenziesii, it was always higher and increased marginally faster than in Pinuscontorta). We concluded that the less shade-tolerant Pinuscontorta was less plastic in crown architecture and specific leaf area than the more shade-tolerant Pseudotsugamenziesii.


2012 ◽  
Vol 5 (3) ◽  
pp. 363-374 ◽  
Author(s):  
David P. Matlaga ◽  
Lauren D. Quinn ◽  
Adam S. Davis ◽  
J. Ryan Stewart

The Asian grassMiscanthus sinensis(Poaceae) is being considered for use as a bioenergy crop in the U.S. Corn Belt. Originally introduced to the United States for ornamental plantings, it escaped, forming invasive populations. The concern is that naturalizedM. sinensispopulations have evolved shade tolerance. We tested the hypothesis that seedlings from within the invasive U.S. range ofM. sinensiswould display traits associated with shade tolerance, namely increased area for light capture and phenotypic plasticity, compared with seedlings from the native Japanese populations. In a common garden experiment, seedlings of 80 half-sib maternal lines were grown from the native range (Japan) and 60 half-sib maternal lines from the invasive range (U.S.) under four light levels. Seedling leaf area, leaf size, growth, and biomass allocation were measured on the resulting seedlings after 12 wk. Seedlings from both regions responded strongly to the light gradient. High light conditions resulted in seedlings with greater leaf area, larger leaves, and a shift to greater belowground biomass investment, compared with shaded seedlings. Japanese seedlings produced more biomass and total leaf area than U.S. seedlings across all light levels. Generally, U.S. and Japanese seedlings allocated a similar amount of biomass to foliage and equal leaf area per leaf mass. Subtle differences in light response by region were observed for total leaf area, mass, growth, and leaf size. U.S. seedlings had slightly higher plasticity for total mass and leaf area but lower plasticity for measures of biomass allocation and leaf traits compared with Japanese seedlings. Our results do not provide general support for the hypothesis of increasedM. sinensisshade tolerance within its introduced U.S. range compared with native Japanese populations.


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.


2021 ◽  
Vol 130 ◽  
pp. 108058
Author(s):  
Zhaogang Liu ◽  
Ning Dong ◽  
Hongxiang Zhang ◽  
Ming Zhao ◽  
Tingting Ren ◽  
...  

2003 ◽  
Vol 33 (5) ◽  
pp. 847-853 ◽  
Author(s):  
Sylvia E Welke ◽  
Graeme D Hope ◽  
Gary A Hunt

The effect of timber harvesting on the biomass, nutrient standing crop, and decomposition of fine roots (<2 mm) was studied in a high elevation, Engelmann spruce (Picea engelmannii Parry ex Engelm.) – subalpine fir (Abies lasiocarpa (Hook.) Nutt.) forest. Root dynamics were compared in openings of different sizes. The sequential core method was used to collect fine root samples over 4 years. Differences in fine root biomass between opening sizes were most significant for the active fine root portion and were most pronounced in the fall compared with the spring. Active fine root biomass was significantly lower in the 10-ha clearcuts (164 kg/ha) compared with control plots (275 kg/ha). Furthermore, active fine root biomass was often lower in the 1.0-ha opening than in the 0.1-ha and control plots. A similar trend was established for inactive fine root biomass, although this was not consistent over sampling years. Nutrient concentrations of K, but no other elements, were higher in control plots. Nutrient standing crops, however, followed trends observed in fine root biomass. In the 10-ha clearcuts, the largest changes in fine root biomass occurred at the edge of the opening. The findings suggest that small (<10 ha) cutblocks may maintain greater fine root longevity.


2020 ◽  
Vol 27 (15) ◽  
pp. 18793-18802
Author(s):  
Jinfeng Wang ◽  
Huanyu Bao ◽  
He Zhang ◽  
Jiao Li ◽  
Huachang Hong ◽  
...  

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