Seasonal Photosynthesis and Carbon Assimilation of Dynamics in a Zelkova serrata (Thunb.) Makino Plantation

As anthropogenic greenhouse gas emissions intensify global climate change, plantations have become an important tool to mitigate atmospheric CO2. Our aim in this study was to estimate carbon assimilation and clarify the impact of environmental factors on the photosynthesis of Zelkova serrata (Thunb.) Makino, an important plantation species that is extensively planted in low altitude regions of East Asia. We measured monthly gas exchange parameters and leaf area index to estimate carbon assimilation. The results showed that gas exchange was significantly affected by vapor pressure deficit and temperature, especially in the dry season, and both photosynthetic rate and carbon assimilation decreased. Lower daytime assimilation and higher nighttime respiration during the dry season, which caused a 43% decrease in carbon assimilation in Z. serrata plantations. Z. serrata exhibited lower photosynthetic rate and lower carbon assimilation following planting in a tropical monsoon climate area. Therefore, the effects of extreme weather such as high temperature and vapor pressure deficit on Z. serrata forest carbon budget could be stronger in the future. Leaf area showed seasonal variation, and severe defoliation was caused by a typhoon in the summer. The annual carbon assimilation was estimated at 3.50 Mg C ha−1 year−1 in the study area.

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Drought Impact on Carbon Assimilation of A Zelkova Serrata Plantation

10.21203/rs.3.rs-140975/v1 ◽

2021 ◽

Author(s):

Chung-I Chen ◽

Ya-Nan Wang ◽

Heng-Hsun Lin ◽

Ching-Wen Wang ◽

Jui-Chu Yu ◽

...

Keyword(s):

Gas Exchange ◽

Leaf Area ◽

Global Climate ◽

Carbon Assimilation ◽

Site Quality ◽

Gas Exchange Parameters ◽

Night Time ◽

Poor Site ◽

The Impact ◽

Zelkova Serrata

Abstract Background: As anthropogenic greenhouse gas emissions intensify global climate change, plantations have become an important tool to mitigate atmospheric CO2. Our aim in this study was to estimate carbon assimilation and clarify the impact of environmental factors on the photosynthesis of Zelkova serrata, an important plantation species, which extensively planted in low altitude of East Asia.Results: We measured monthly gas exchange parameters and leaf area to estimate carbon assimilation. The results showed that gas exchange was significantly affected by vapor pressure deficit and temperature, especially in the dry season, and both photosynthetic rate and carbon assimilation decreased. However, drought led to lower daytime assimilation and higher night-time respiration, which caused a 43% decrease in carbon assimilation. Additionally, the poor site quality and environmental stress may impact the growth and carbon assimilation of this species.Conclusions: Z. serrata may not be suitable for planting in a tropical monsoon climate area. Therefore, the effects of extreme weather on the forest carbon budget may be stronger in the future. Leaf area showed seasonal variation and serious defoliation caused by a typhoon in the summer. The monthly leaf assimilation rate was 0.88–4.17 μmol CO2 m-2 s-1, which was estimated to assimilate 3.50 Mg C ha-1 yr-1 in the study area.

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Detecting the Drought-Response Difference in Semiarid Ecosystems on the Mongolian Plateau: 10-Year Observation Using GOSAT SIF and MODIS PRI

10.5194/egusphere-egu21-3583 ◽

2021 ◽

Author(s):

Tomoki Kiyono ◽

Hibiki Noda ◽

Tomo’omi Kumagai ◽

Haruki Oshio ◽

Yukio Yoshida ◽

...

Keyword(s):

Vapor Pressure ◽

Leaf Area ◽

Vapor Pressure Deficit ◽

Surface Soil ◽

Gross Primary Production ◽

Influential Factor ◽

Soil Drought ◽

Mongolian Plateau ◽

Area Index ◽

The Impact

Atmospheric aridity and soil drought control vegetation water use and affect the terrestrial water and carbon cycles. Separating these two types of drought is difficult but crucial because they relate to different ecosystem properties and their impacts depend on vegetation types. We examine how well satellite-observed solar-induced chlorophyll fluorescence (SIF) captures the drought responses of taiga and steppe in semiarid areas on the Mongolian plateau, which have experienced a historic drought since the late 1990s. Ten-year records of the GOSAT SIF and the MODIS-band-1 photochemical reflectance index (PRI, also known as chlorophyll/carotenoid index) from Aqua consistently suggest that the taiga is sensitive to vapor-pressure deficit but insensitive to surface-soil drought, and that the opposite is the case for the steppe. The MODIS PRI changes reasonably with temperature and drought stress, and also with canopy shades, which is attributable to the xanthophyll cycle. However the most influential factor on the PRI is leaf area in both vegetations, and temperature is the second in the taiga, indicating the dominant effect of its pigment-pool size. The leaf area index of the taiga has almost similar values and seasonal patterns in each year, while the SIF shows remarkable interannual changes. The SIF yield in the taiga decreases 36&#8211;48% on average with the increase of vapor-pressure deficit from 1 kPa to 3 kPa under high-PRI conditions. Almost all detectable information from the SIF yield in the steppe is correlated with PRI on a monthly basis. The SIF in the steppe decreases nonlinearly when the surface-soil-water content fell below &#8764;0.154 m3 m&#8722;3, which agrees well with an eddy-covariance result in this region and implies the capability of satellite-based wilting-point estimation. We will further clarify which biological factors affected the observed results of SIF and PRI using the process-based model 'Soil-Canopy-Observation of Photosynthesis and Energy fluxes' (SCOPE) and show the impact of drought on the gross primary production in the past decade.

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A new perspective for transpiration estimation using an extended framework of isohydricity linking to drought-driven changes in VPD and leaf area

10.5194/egusphere-egu2020-1993 ◽

2020 ◽

Author(s):

Changming Li ◽

Hanbo Yang

Keyword(s):

Vapor Pressure ◽

Leaf Area Index ◽

Water Potential ◽

Leaf Area ◽

Vapor Pressure Deficit ◽

Soil Water Potential ◽

Area Index ◽

Atmosphere Interaction ◽

New Perspective ◽

New Framework

The framework of isohydry or anisohydry, which is usually defined as the sensitivity of leaf water potential (&#936;L) to soil water potential (&#936;s), has been rapidly adopted to solve a range of eco-hydrologic problems. While its reliability to describe the impacts of land-atmosphere interaction and seasonal phenology on plants has been recently questioned. In this study, we propose an expansion of the modern isohydricity framework to coordinate the dynamics of &#936;L&#160;derived from vapor pressure deficit (VPD) and leaf area index (AL), respectively. The contributions of VPD and AL to the sensitivity of &#936;L to &#936;s are calculated and further evaluated using the FLUXNET dataset, as to validate the applicability of the extended concept. Then, we suggested a new method to calculate transpiration based on the new framework to establish relationship between &#936;L&#160;and &#936;s&#160;at ecosystem scale. Our results illustrate that the new framework is reasonable for describing the dynamics of &#936;L and provides a promising potential for transpiration estimation.

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Gas Exchange and Nitrogen Compartmentalization of Eggplant under Nitrogen and Silicon Doses

Journal of Experimental Agriculture International ◽

10.9734/jeai/2019/v38i230295 ◽

2019 ◽

pp. 1-8

Author(s):

Ewerton Gonçalves de Abrantes ◽

Josinaldo Lopes Araujo Rocha ◽

Kariolania Fortunato De Paiva ◽

Railene Hérica Carlos Rocha ◽

Alexandre Paiva da Silva ◽

...

Keyword(s):

Gas Exchange ◽

Leaf Area Index ◽

Leaf Area ◽

Photosynthetic Rate ◽

Intercellular Co2 Concentration ◽

Co2 Concentration ◽

Dry Mass ◽

Nitrogen Accumulation ◽

Area Index ◽

Associated Variables

To evaluate the effect of fertilization with N and Si on gaseous exchanges, dry mass, concentrations, accumulations and compartmentalization of nitrogen fractions in eggplant. The experimental design was a randomized entirely design, in a 5 x 4 factorial arrangement with four replications and one plant per plot, totaling 80 experimental units. The experiment was conducted in a protected environment at Center of Sciences and Agri-Food Technology of the Federal University of Campina Grande, Campus of Pombal, Paraiba, Brazil, between July and September 2016. The nitrogen doses applied was 25, 125, 250, 350 and 500 mg dm-3 and four silicon doses was 0, 75, 150 and 200 mg dm-3 both supplied by root. In pre-flowering stage were evaluated growth components; gas exchange, which are: photosynthesis, stomatal conductance, transpiration rate and intercellular CO2 concentration; levels and accumulation of fractions of nitrogen (NO3-, NH4+, and total), and the silicon concentration in the leaves. There was no significant interaction (p >0.05) between the factors nitrogen and silicon doses for any of the evaluated variables. Nitrogen and silicon doses influenced the variables evaluated only independently each other. The nitrogen doses promoted increases in the photosynthetic rate and associated variables, dry matter yield of stem leaves and roots and in the concentration and accumulations of nitric, ammoniacal and total nitrogen in leaf, stem e roots and decrease the concentration of silicon in leaves. The silicon doses increased the leaf area index, the nitrate levels and accumulation in the roots and the silicon content in the leaves. In conclusion, the nitrogen supply increased the photosynthetic rate, dry mass and nitrogen accumulation and decreased the concentrations of silicon in leaf. Silicon did not interfered with growth of eggplant, however increased leaf area index, decreased nitrate levels and accumulations in the roots at lower doses of this element.

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Effect of Mycorrhizal Fungi on Gas Exchange of Micropropagated Guava Plantlets (Psidium guajava L.) during Acclimatization and Plant Establishment

HortScience ◽

10.21273/hortsci.33.3.501c ◽

1998 ◽

Vol 33 (3) ◽

pp. 501c-501

Author(s):

Andrés A. Estrada-Luna ◽

Jonathan N. Egilla ◽

Fred T. Davies

Keyword(s):

Tissue Culture ◽

Stomatal Conductance ◽

Gas Exchange ◽

Vapor Pressure ◽

Mycorrhizal Fungi ◽

Vapor Pressure Deficit ◽

Psidium Guajava ◽

Glomus Etunicatum ◽

Plant Establishment ◽

Use Efficiency

The effect of mycorrhizal fungi on gas exchange of micropropagated guava plantlets (Psidium guajava L.) during acclimatization and plant establishment was determined. Guava plantlets (Psidium guajava L. cv. `Media China') were asexually propagated through tissue culture and acclimatized in a glasshouse for eighteen weeks. Half of the plantlets were inoculated with ZAC-19, which is a mixed isolate containing Glomus etunicatum and an unknown Glomus spp. Plantlets were fertilized with modified Long Ashton nutrient solution containing 11 (g P/ml. Gas exchange measurements included photosynthetic rate (A), stomatal conductance (gs), internal CO2 concentration (Ci), transpiration rate (E), water use efficiency (WUE), and vapor pressure deficit (VPD). Measurements were taken at 2, 4, 8 and 18 weeks after inoculation using a LI-6200 portable photosynthesis system (LI-COR Inc. Lincoln, Neb., USA). Two weeks after inoculation, noninoculated plantlets had greater A compared to mycorrhizal plantlets. However, 4 and 8 weeks after inoculation, mycorrhizal plantlets had greater A, gs, Ci and WUE. At the end of the experiment gas exchange was comparable between noninoculated and mycorrhizal plantlets.

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Remote Sensing to Study Mangrove Fragmentation and Its Impacts on Leaf Area Index and Gross Primary Productivity in the South of Peninsular Malaysia

Remote Sensing ◽

10.3390/rs13081427 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1427

Author(s):

Kasturi Devi Kanniah ◽

Chuen Siang Kang ◽

Sahadev Sharma ◽

A. Aldrie Amir

Keyword(s):

Remote Sensing ◽

Leaf Area Index ◽

Leaf Area ◽

Primary Productivity ◽

Peninsular Malaysia ◽

Area Index ◽

Mangrove Area ◽

The Mean ◽

Shape Complexity ◽

The Impact

Mangrove is classified as an important ecosystem along the shorelines of tropical and subtropical landmasses, which are being degraded at an alarming rate despite numerous international treaties having been agreed. Iskandar Malaysia (IM) is a fast-growing economic region in southern Peninsular Malaysia, where three Ramsar Sites are located. Since the beginning of the 21st century (2000–2019), a total loss of 2907.29 ha of mangrove area has been estimated based on medium-high resolution remote sensing data. This corresponds to an annual loss rate of 1.12%, which is higher than the world mangrove depletion rate. The causes of mangrove loss were identified as land conversion to urban, plantations, and aquaculture activities, where large mangrove areas were shattered into many smaller patches. Fragmentation analysis over the mangrove area shows a reduction in the mean patch size (from 105 ha to 27 ha) and an increase in the number of mangrove patches (130 to 402), edge, and shape complexity, where smaller and isolated mangrove patches were found to be related to the rapid development of IM region. The Moderate Resolution Imaging Spectro-radiometer (MODIS) Leaf Area Index (LAI) and Gross Primary Productivity (GPP) products were used to inspect the impact of fragmentation on the mangrove ecosystem process. The mean LAI and GPP of mangrove areas that had not undergone any land cover changes over the years showed an increase from 3.03 to 3.55 (LAI) and 5.81 g C m−2 to 6.73 g C m−2 (GPP), highlighting the ability of the mangrove forest to assimilate CO2 when it is not disturbed. Similarly, GPP also increased over the gained areas (from 1.88 g C m−2 to 2.78 g C m−2). Meanwhile, areas that lost mangroves, but replaced them with oil palm, had decreased mean LAI from 2.99 to 2.62. In fragmented mangrove patches an increase in GPP was recorded, and this could be due to the smaller patches (<9 ha) and their edge effects where abundance of solar radiation along the edges of the patches may increase productivity. The impact on GPP due to fragmentation is found to rely on the type of land transformation and patch characteristics (size, edge, and shape complexity). The preservation of mangrove forests in a rapidly developing region such as IM is vital to ensure ecosystem, ecology, environment, and biodiversity conservation, in addition to providing economical revenue and supporting human activities.

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Leaf traits and gas exchange in saplings of native tree species in the Central Amazon

Scientia Agricola ◽

10.1590/s0103-90162010000600002 ◽

2010 ◽

Vol 67 (6) ◽

pp. 624-632 ◽

Cited By ~ 14

Author(s):

Keila Rego Mendes ◽

Ricardo Antonio Marenco

Keyword(s):

Gas Exchange ◽

Nitrogen Content ◽

Leaf Area ◽

Tree Species ◽

Leaf Traits ◽

Leaf Nitrogen ◽

Dry Season ◽

Leaf Thickness ◽

Rainfall Regime ◽

Leaf Nitrogen Content

Global climate models predict changes on the length of the dry season in the Amazon which may affect tree physiology. The aims of this work were to determine the effect of the rainfall regime and fraction of sky visible (FSV) at the forest understory on leaf traits and gas exchange of ten rainforest tree species in the Central Amazon, Brazil. We also examined the relationship between specific leaf area (SLA), leaf thickness (LT), and leaf nitrogen content on photosynthetic parameters. Data were collected in January (rainy season) and August (dry season) of 2008. A diurnal pattern was observed for light saturated photosynthesis (Amax) and stomatal conductance (g s), and irrespective of species, Amax was lower in the dry season. However, no effect of the rainfall regime was observed on g s nor on the photosynthetic capacity (Apot, measured at saturating [CO2]). Apot and leaf thickness increased with FSV, the converse was true for the FSV-SLA relationship. Also, a positive relationship was observed between Apot per unit leaf area and leaf nitrogen content, and between Apot per unit mass and SLA. Although the rainfall regime only slightly affects soil moisture, photosynthetic traits seem to be responsive to rainfall-related environmental factors, which eventually lead to an effect on Amax. Finally, we report that little variation in FSV seems to affect leaf physiology (Apot) and leaf anatomy (leaf thickness).

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The Impact of Noah-MP Physical Parameterizations on Modeling Water Availability during Droughts in the Texas-Gulf Region

Journal of Hydrometeorology ◽

10.1175/jhm-d-20-0189.1 ◽

2021 ◽

Author(s):

Wen-Ying Wu ◽

Zong-Liang Yang ◽

Michael Barlage

Keyword(s):

Leaf Area Index ◽

Leaf Area ◽

Water Availability ◽

Water Storage ◽

Rooting Depth ◽

Surface Model ◽

Terrestrial Water Storage ◽

Area Index ◽

Terrestrial Water ◽

The Impact

AbstractTexas is subject to severe droughts, including the record-breaking one in 2011. To investigate the critical hydrometeorological processes during drought, we use a land surface model, Noah-MP, to simulate water availability and investigate the causes of the record drought. We conduct a series of experiments with runoff schemes, vegetation phenology, and plant rooting depth. Observation-based terrestrial water storage, evapotranspiration, runoff, and leaf area index are used to compare with results from the model. Overall, the results suggest that using different parameterizations can influence the modeled water availability, especially during drought. The drought-induced vegetation responses not only interact with water availability but also affect the ground temperature. Our evaluation shows that Noah-MP with a groundwater scheme produces a better temporal relationship in terrestrial water storage compared with observations. Leaf area index from dynamic vegetation is better simulated in wet years than dry years. Reduction of positive biases in runoff and reduction of negative biases in evapotranspiration are found in simulations with groundwater, dynamic vegetation, and deeper rooting zone depth. Multi-parameterization experiments show the uncertainties of drought monitoring and provide a mechanistic understanding of disparities in dry anomalies.

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Improved Irrigation Management of Sweet Orange with Huanglongbing

HortScience ◽

10.21273/hortsci12013-17 ◽

2017 ◽

Vol 52 (6) ◽

pp. 916-921 ◽

Cited By ~ 5

Author(s):

Said A. Hamido ◽

Kelly T. Morgan ◽

Robert C. Ebel ◽

Davie M. Kadyampakeni

Keyword(s):

Soil Water ◽

Leaf Area ◽

Sweet Orange ◽

Irrigation Management ◽

Irrigation Treatment ◽

Irrigation Scheduling ◽

Water Dynamics ◽

Stem Water Potential ◽

Area Index ◽

The Impact

Because of the decline in production and negative economic effects, there is an urgent need for strategies to reduce the impact of Huanglongbing (HLB) on citrus [Citrus ×sinensis (L.) Osbeck]. The objective of this study was to evaluate the impact of different irrigation schedules on total available soil water (TAW) and water uptake characteristics of citrus trees affected by HLB in central and southwest Florida. The study was initiated in Jan. 2014 for 2 years on 5-year-old sweet orange trees located in three commercial groves at Arcadia, Avon Park, and Immokalee, FL. Each grove had three irrigation scheduling treatments including the University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS) recommendations, Daily irrigation, and an Intermediate treatment. All groves received similar volumes of water per week based on evapotranspiration (ETo) reported by the Florida Automated Weather Network. Sap flow (SF) measurements were taken for two trees per treatment for at least 10 days per site (twice/year). During those periods, leaf area, leaf area index (LAI), and stem water potential (Ψ) were determined. Also, TAW was determined using drainage curve and capacitance soil moisture sensors installed at incremental soil depths of 0–15, 15–30, and 30–45 cm. Results showed significant differences in average SF, LAI, Ψ, and TAW measurements among treatments. Diurnal SF value under daily irrigation treatment increased by 91%, 51%, and 105% compared with UF/IFAS irrigation in Arcadia, Avon Park, and Immokalee, respectively. Soil water contents (WCs) under daily treatment increased by 59%, 59%, and 70% compared with UF/IFAS irrigation treatment in Arcadia, Avon Park, and Immokalee, respectively. Our results indicated that daily irrigation improved tree water dynamics compared with IFAS or Intermediate irrigation scheduling treatments and reduced tree stress with the same volume of water.

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Application of the Priestley–Taylor Approach in a Two-Source Surface Energy Balance Model

Journal of Hydrometeorology ◽

10.1175/2009jhm1124.1 ◽

2010 ◽

Vol 11 (1) ◽

pp. 185-198 ◽

Cited By ~ 69

Author(s):

Nurit Agam ◽

William P. Kustas ◽

Martha C. Anderson ◽

John M. Norman ◽

Paul D. Colaizzi ◽

...

Keyword(s):

Heat Flux ◽

Energy Balance ◽

Surface Energy ◽

Vapor Pressure ◽

Latent Heat ◽

Latent Heat Flux ◽

Vapor Pressure Deficit ◽

Surface Energy Balance ◽

Area Index ◽

Wide Range

Abstract The Priestley–Taylor (PT) approximation for computing evapotranspiration was initially developed for conditions of a horizontally uniform saturated surface sufficiently extended to obviate any significant advection of energy. Nevertheless, the PT approach has been effectively implemented within the framework of a thermal-based two-source model (TSM) of the surface energy balance, yielding reasonable latent heat flux estimates over a range in vegetative cover and climate conditions. In the TSM, however, the PT approach is applied only to the canopy component of the latent heat flux, which may behave more conservatively than the bulk (soil + canopy) system. The objective of this research is to investigate the response of the canopy and bulk PT parameters to varying leaf area index (LAI) and vapor pressure deficit (VPD) in both natural and agricultural vegetated systems, to better understand the utility and limitations of this approximation within the context of the TSM. Micrometeorological flux measurements collected at multiple sites under a wide range of atmospheric conditions were used to implement an optimization scheme, assessing the value of the PT parameter for best performance of the TSM. Overall, the findings suggest that within the context of the TSM, the optimal canopy PT coefficient for agricultural crops appears to have a fairly conservative value of ∼1.2 except when under very high vapor pressure deficit (VPD) conditions, when its value increases. For natural vegetation (primarily grasslands), the optimal canopy PT coefficient assumed lower values on average (∼0.9) and dropped even further at high values of VPD. This analysis provides some insight as to why the PT approach, initially developed for regional estimates of potential evapotranspiration, can be used successfully in the TSM scheme to yield reliable heat flux estimates over a variety of land cover types.

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