Active layer depth and soil properties impact specific leaf area variation and ecosystem productivity in a boreal forest

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.

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Controls on and consequences of specific leaf area variation with permafrost depth in a boreal forest

10.1101/2020.04.17.046474 ◽

2020 ◽

Author(s):

Carolyn G. Anderson ◽

Ben Bond-Lamberty ◽

James C. Stegen

Keyword(s):

Boreal Forest ◽

Leaf Area ◽

Active Layer ◽

Specific Leaf Area ◽

Net Primary Production ◽

Dry Mass ◽

Process Models ◽

Forest Composition ◽

Extensive Evaluation ◽

Few Data

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.

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El Niño-Southern Oscillation affects the water relations of tree species in the Yucatan Peninsula, Mexico

Scientific Reports ◽

10.1038/s41598-021-89835-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Jorge Palomo-Kumul ◽

Mirna Valdez-Hernández ◽

Gerald A. Islebe ◽

Manuel J. Cach-Pérez ◽

José Luis Andrade

Keyword(s):

Water Potential ◽

Leaf Area ◽

Tropical Forests ◽

Specific Leaf Area ◽

Tree Species ◽

Deciduous Species ◽

Mature Trees ◽

Seasonally Dry ◽

Seasonally Dry Tropical Forests ◽

Dry Tropical Forests

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.

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Foliage height influences specific leaf area of three conifer species

Canadian Journal of Forest Research ◽

10.1139/x02-158 ◽

2003 ◽

Vol 33 (1) ◽

pp. 164-170 ◽

Cited By ~ 74

Author(s):

John D Marshall ◽

Robert A Monserud

Keyword(s):

Water Potential ◽

Leaf Area ◽

Pinus Ponderosa ◽

Specific Leaf Area ◽

Ponderosa Pine ◽

Branch Length ◽

Dry Mass ◽

Process Models ◽

Pinus Monticola ◽

Northern Idaho

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.

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Evaluation of O3 Effects on Cumulative Photosynthetic CO2 Uptake in Seedlings of Four Japanese Deciduous Broad-Leaved Forest Tree Species Based on Stomatal O3 Uptake

Forests ◽

10.3390/f10070556 ◽

2019 ◽

Vol 10 (7) ◽

pp. 556 ◽

Cited By ~ 2

Author(s):

Masahiro Yamaguchi ◽

Yoshiyuki Kinose ◽

Hideyuki Matsumura ◽

Takeshi Izuta

Keyword(s):

Leaf Area ◽

Tree Species ◽

Net Primary Production ◽

Forest Tree ◽

Co2 Uptake ◽

Growing Seasons ◽

Whole Plant ◽

Broad Leaved Forest ◽

Leaf Level ◽

Species Specific

The current level of tropospheric ozone (O3) is expected to reduce the net primary production of forest trees. Here, we evaluated the negative effects of O3 on the photosynthetic CO2 uptake of Japanese forest trees species based on their cumulative stomatal O3 uptake, defined as the phytotoxic O3 dose (POD). Seedlings of four representative Japanese deciduous broad-leaved forest tree species (Fagus crenata, Quercus serrata, Quercus mongolica var. crispula and Betula platyphylla var. japonica) were exposed to different O3 concentrations in open-top chambers for two growing seasons. The photosynthesis–light response curves (A-light curves) and stomatal conductance were measured to estimate the leaf-level cumulative photosynthetic CO2 uptake (ΣPn_est) and POD, respectively. The whole-plant-level ΣPn_est were highly correlated with the whole-plant dry mass increments over the two growing seasons. Because whole-plant growth is largely determined by the amount of leaf area per plant and net photosynthetic rate per leaf area, this result suggests that leaf-level ΣPn_est, which was estimated from the monthly A-light curves and hourly PPFD, could reflect the cumulative photosynthetic CO2 uptake of the seedlings per unit leaf area. Although the O3-induced reductions in the leaf-level ΣPn_est were well explained by POD in all four tree species, species-specific responses of leaf-level ΣPn_est to POD were observed. In addition, the flux threshold appropriate for the linear regression of the responses of relative leaf-level ΣPn_est to POD was also species-specific. Therefore, species-specific responses of cumulative photosynthetic CO2 uptake to POD could be used to accurately evaluate O3 impact on the net primary production of deciduous broad-leaved trees.

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Observations of the Photosynthetic Physiology of Tree Species within the C3 Monocotyledon Genus Pandanus, and Comparison with Dicotyledon C3 Tree Species

Australian Journal of Botany ◽

10.1071/bt96106 ◽

1998 ◽

Vol 46 (1) ◽

pp. 103 ◽

Cited By ~ 1

Author(s):

Catherine E. Lovelock

Keyword(s):

Leaf Area ◽

Specific Leaf Area ◽

Tree Species ◽

Dark Respiration ◽

Dry Weight ◽

Weight Basis ◽

Growth And Survival ◽

Respiration Rates ◽

Leaf Dark Respiration ◽

Resource Levels

Photosynthetic characteristics of tree species from the tropical C3 monocotyledon genus Pandanus were compared with C3 dicotyledon species growing in similar environments. The Pandanus species had similar maximum photosynthetic rates (Amax) to dicotyledon tree species in leaves from both sun and shaded environments when Amax was expressed on an area basis. Because of the low specific leaf area of the schlerophyllous leaves of the Pandanus compared to the dicotyledon species, the similarity in Amax was no longer evident when Amax was expressed on a dry-weight basis. Leaf dark respiration rates of the Pandanus on a leaf area and weight basis were generally lower than the shade-intolerant dicotyledons and similar to the shade-tolerant dicotyledon species. Low dark respiration rates and low specific leaf area of the Pandanus may be important characteristics for growth and survival in environments where resource levels are low and the likelihood of tissue damage is high.

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Relationship between specific leaf area, leaf thickness, leaf water content and SPAD-502 readings in six Amazonian tree species

Photosynthetica ◽

10.1007/s11099-009-0031-6 ◽

2009 ◽

Vol 47 (2) ◽

pp. 184-190 ◽

Cited By ~ 88

Author(s):

R.A. Marenco ◽

S.A. Antezana-Vera ◽

H.C.S. Nascimento

Keyword(s):

Water Content ◽

Leaf Area ◽

Specific Leaf Area ◽

Tree Species ◽

Leaf Water ◽

Leaf Thickness ◽

Leaf Water Content

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Examination of Current and Future Permafrost Dynamics Across the North American Taiga-Tundra Ecotone

10.5194/egusphere-egu21-3066 ◽

2021 ◽

Author(s):

Bradley Gay ◽

Amanda Armstrong ◽

Batuhan Osmanoglu ◽

Paul Montesano ◽

Kenneth Ranson ◽

...

Keyword(s):

Boreal Forest ◽

Active Layer ◽

Rate Of Change ◽

The Arctic ◽

Integrated Analysis ◽

Layer Depth ◽

Vegetation Heterogeneity ◽

Tte Model ◽

Below Ground

<p>In the Arctic, the spatial distribution of boreal forest cover and soil profile transition characterizing the taiga-tundra ecological transition zone (TTE) is experiencing an alarming transformation. The SIBBORK-TTE model provides a unique opportunity to predict the spatiotemporal distribution patterns of vegetation heterogeneity, forest structure change, arctic-boreal forest interactions, and ecosystem transitions with high resolution scaling across broad domains. Within the TTE, evolving climatological and biogeochemical dynamics facilitate moisture signaling and nutrient cycle disruption, i.e. permafrost thaw and nutrient decomposition, thereby catalyzing land cover change and ecosystem instability. To demonstrate these trends, in situ ground measurements for active layer depth were collected to cross-validate below-ground-enhanced modeled simulations from 1980-2017. Shifting trends in permafrost variability (i.e. active layer depth) and seasonality were derived from model results and compared statistically to the in situ data. The SIBBORK-TTE model was then run to project future below-ground conditions utilizing CMIP6 scenarios. Upon visualization and curve-integrated analysis of the simulated freeze-thaw dynamics, the calculated performance metric associated with annual active layer depth rate of change yielded 76.19%. Future climatic conditions indicate an increase in active layer depth and shifting seasonality across the TTE. With this novel approach, spatiotemporal variation of active layer depth provides an opportunity for identifying climate and topographic drivers and forecasting permafrost variability and earth system feedback mechanisms.</p>

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