scholarly journals Mapping seasonal and interannual Non-Structural Carbohydrate variation to drought-resistance strategies in eastern Amazon tree species

2021 ◽  
Author(s):  
Mauro Brum ◽  
Scott Saleska ◽  
Luciana F Alves ◽  
Deliane Penha ◽  
Valeriy Ivanov ◽  
...  
Keyword(s):  
Drought Resistance ◽  
Tree Species ◽  
Carbon Allocation ◽  
Southern Oscillation ◽  
Soluble Sugar ◽  
Abundant Species ◽  
Extreme Drought ◽  
Resistance Strategies ◽  
Structural Carbohydrate ◽  
Root Starch

Carbon allocation to non-structural carbohydrates (NSC) is essential for plant metabolism playing an important role in tree responses to drought. It is still unclear if and how interspecific hydraulic trait variation modulates NSC concentration dynamics in different plant organs, particularly in tropical tree species. We investigated whether drought-resistance strategies (inferred from hydraulic traits) explain seasonal and interannual NSC dynamics in leaves, branches, trunks, and roots in seasonal eastern Amazon tree species in Brazil. We measured NSC concentration in eight abundant species during three years, including the end of the wet and dry seasons of the typical regular years (2013-2014) and the extreme drought induced by El Niño–Southern Oscillation in 2015 (ENSO). Organs have an important contribution to explain the starch (ST), soluble sugar (SS), and NSC variance among trees. We showed seasonal and year-to-year homeostasis in ST and SS concentrations in a majority of organs during 2013 and 2014, but SS increased in all organs during the extreme ENSO drought, while the ST concentration did not. The increase in SS concentration was more evident in woody organs from species with intermediate and tolerant drought strategies. The drought-tolerant species maintain higher root starch concentrations and mobilize more SS during extreme drought.

scholarly journals Xeric Tree Populations Exhibit Delayed Summer Depletion of Root Starch Relative to Mesic Counterparts

Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1026
Author(s):  
Scott W. Oswald ◽  
Doug P. Aubrey
Keyword(s):  
Soil Moisture ◽  
Water Stress ◽  
Carbon Allocation ◽  
Soluble Sugar ◽  
Pinus Palustris ◽  
Coarse Roots ◽  
Moisture Availability ◽  
Root Starch ◽  
Soil Moisture Availability

Research linking soil moisture availability to nonstructural carbohydrate (NSC) storage suggests greater NSC reserves promote survival under acute water stress, but little is known about how NSC allocation responds to long-term differences in water availabilty. We hypothesized populations experiencing chronic or frequent water stress shift carbon allocation to build greater NSC reserves for increased survival probability during drought relative to populations rarely experiencing water stress. Over a year, we measured soluble sugar and starch concentrations from branches, stems, and coarse roots of mature Pinus palustris trees at two sites differing in long-term soil moisture availability. Xeric and mesic populations exhibited a cycle of summer depletion-winter accumulation in root starch. Xeric populations reached a maximum root starch concentration approximately 1–2 months later than mesic populations, indicating delayed summer depletion. Xeric and mesic populations reached the same minimum root starch at similar times, suggesting extended winter accumulation for xeric populations. These results suggest seasonal mobilization from root starch is compressed into a shorter interval for xeric populations instead of consistently greater reserves as hypothesized. Seasonal trends differed little between xeric and mesic populations for starch and sugars, suggesting the importance of roots in seasonal carbon dynamics and the primacy of starch for storage. If roots are the primary organ for longterm storage, then our results suggest that whole-plant mobilization and allocation respond to chronic differences in water availability.

scholarly journals Root carbon and nutrient homeostasis determines downy oak sapling survival and recovery from drought

2021 ◽  
Author(s):  
Sheng-Nan Ouyang ◽  
Arthur Gessler ◽  
Matthias Saurer ◽  
Frank Hagedorn ◽  
De-Cai Gao ◽  
...  
Keyword(s):  
Soluble Sugar ◽  
Recovery Process ◽  
Extreme Drought ◽  
Tree Level ◽  
Starch Degradation ◽  
Minor Role ◽  
Climate Conditions ◽  
Physiological Processes ◽  
Drought Relief ◽  
A Minor

Abstract The role of carbon (C) and nutrient uptake, allocation, storage and especially their interactions in survival and recovery of trees under increased frequencies and intensities of drought events is not well understood. A full factorial experiment with four soil water content regimes ranging from extreme drought to well-watered conditions and two fertilization levels was carried out. We aimed to investigate whether nutrient addition mitigates drought effects on downy oak (Quercus pubescens Willd.) and whether storage pools of non-structural carbohydrates (NSC) are modified to enhance survival after 2.5 years of drought and recovery after drought relief. Physiological traits, such as photosynthesis, predawn leaf water potential as well as tissue biomass together with pools and dynamics of NSC and nutrients at the whole-tree level were investigated. Our results showed that fertilization played a minor role in saplings’ physiological processes to cope with drought and drought relief, but reduced sapling mortality during extreme drought. Irrespective of nutrient supply, Q. pubescens showed increased soluble sugar concentration in all tissues with increasing drought intensity, mostly because of starch degradation. After 28 days of drought relief, tissue sugar concentrations decreased, reaching comparable values to those of well-watered plants. Only during the recovery process from extreme drought, root NSC concentration strongly declined, leading to an almost complete NSC depletion after 28 days of rewetting, simultaneously with new leaves flushing. These findings suggest that extreme drought can lead to root C exhaustion. After drought relief, the repair and regrowth of organs can even exacerbate the root C depletion. We concluded that under future climate conditions with repeated drought events, the insufficient and lagged C replenishment in roots might eventually lead to C starvation and further mortality.

Xylem anatomical and hydraulic drought resistance characteristics of common tree species in hilly areas of North China

2021 ◽  
Vol 41 (1) ◽  
Author(s):  
李泽东，陈志成，曹振，车路平，刘舒文，张永涛 LI Zedong
Keyword(s):  
Drought Resistance ◽  
Tree Species ◽  
North China ◽  
Common Tree

scholarly journals Non-structural carbohydrate concentrations in woody organs, but not leaves, of temperate and tropical tree angiosperms are independent of the ‘fast-slow’ plant economic spectrum

2021 ◽  
Author(s):  
J.A. Ramirez ◽  
D. Craven ◽  
J.M. Posada ◽  
B. Reu ◽  
C.A. Sierra ◽  
...  
Keyword(s):  
Global Change ◽  
Functional Traits ◽  
Carbon Allocation ◽  
Plant Traits ◽  
Vital Role ◽  
Change Factors ◽  
Leaf Habit ◽  
As Species ◽  
Structural Carbohydrate ◽  
The Relationship

SummaryBackground and AimsCarbohydrate reserves play a vital role in plant survival during periods of negative carbon balance. Considering active storage of reserves, there is a trade-off between carbon allocation to growth and to reserves and defense. A resulting hypothesis is that allocation to reserves exhibits a coordinated variation with functional traits associated with the ‘fast-slow’ plant economics spectrum.MethodsWe tested the relationship between non-structural carbohydrates (NSC) of tree organs and functional traits using 61 angiosperm tree species from temperate and tropical forests with phylogenetic hierarchical Bayesian models.Key ResultsOur results provide evidence that NSC concentrations in woody organs and plant functional traits are largely decoupled, meaning that species’ resilience is unrelated to their position on the ‘fast-slow’ plant economics spectrum. In contrast, we found that variation between NSC concentrations in leaves and the fast-slow continuum was coordinated, as species with higher leaf NSC had traits values associated with resource conservative species such as lower SLA, lower Amax, and high wood density. We did not detect an influence of leaf habit on the variation of NSC concentrations in tree organs.ConclusionsEfforts to predict the response of ecosystems to global change will need to integrate a suite of plant traits, such as NSC concentrations in woody organs, that are independent of the ‘fast-slow’ spectrum and that capture how species respond to a broad range of global change factors.

scholarly journals Effect of Disturbance Regimes on Spatial Patterns of Tree Species in Three Sites in a Tropical Evergreen Forest in Vietnam

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Do Thi Ngoc Le ◽  
Nguyen Van Thinh ◽  
Nguyen The Dung ◽  
Ralph Mitlöhner
Keyword(s):  
Spatial Patterns ◽  
Tree Species ◽  
Interspecific Interactions ◽  
Abundant Species ◽  
Evergreen Forest ◽  
Small Scale ◽  
Forest Types ◽  
Disturbance Regimes ◽  
Tropical Evergreen Forest ◽  
Disturbed Forest

The effects of disturbance regimes on the spatial patterns of the five most abundant species were investigated in three sites in a tropical forest at Xuan Nha Nature Reserve, Vietnam. Three permanent one-ha plots were established in undisturbed forest (UDF), lightly disturbed forest (LDF), and highly disturbed forest (HDF). All trees ≥5 cm DBH were measured in twenty-five 20 m × 20 m subplots. A total of 57 tree species belonging to 26 families were identified in the three forest types. The UDF had the highest basal area (30 m2 ha−1), followed by the LDF (17 m2 ha−1) and the HDF (13.0 m2 ha−1). The UDF also had the highest tree density (751 individuals ha−1) while the HDF held the lowest (478 individuals ha−1). Across all species, there were 417 “juveniles,” 267 “subadults,” and 67 “adults” in the UDF, while 274 “juveniles,” 230 “subadults,” and 36 “adults” were recorded in the LDF. 238 “juveniles,” 227 “subadults,” and 13 “adults” were obtained in the HDF. The univariate and bivariate data with pair- and mark-correlation functions of intra- and interspecific interactions of the five most abundant species changed in the three forest types. Most species indicated clumping or regular distributions at small scale, but a high ratio of negative interspecific small-scale associations was recorded in both the LDF and HDF sites. These were, however, rare in the UDF.

Phedimus Aizoon L. Responds to Drought Stress: Growth, Physiological Changes and Mechanism of Drought Resistance

2020 ◽  
Author(s):  
Yuhang Liu ◽  
Zhongqun He ◽  
Yongdong Xie ◽  
Lihong Su ◽  
Ruijie Zhang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Resistance ◽  
Soluble Sugar ◽  
Severe Drought ◽  
Physiological Changes ◽  
Moderate Drought ◽  
Negative Effect ◽  
Mda Content ◽  
Maximum Water ◽  
Mild Drought

Abstract A pot experiment was conducted to investigate the growth, physiological changes and mechanism of drought resistance of Phedimus aizoon L. under different levels of water content .CK: 75% ~ 80% of the MWHC (maximum water holding capacity), Mild drought: 55% ~ 60%, Moderate drought: 40% ~ 45%, Severe drought: 20% ~ 25%.We observed that the plants grew normally in the first two treatments, even the mild drought promoted the growth of the roots. In the last two treatments, drought stress had a significant negative effect on plant growth, at the same time, Phedimus aizoon L. also made positive physiological response to cope with the drought: The aboveground part of the plant (leaf, plant height, stem diameter) was smaller, the waxy layer of the leaves was thickened, the stomata of the leaves were closed during the day, and only a few stomata were opened at night, which proved that the dark reaction cycle metabolism mode of the plant was transformed from C3 cycle to CAM pathway. The activity of antioxidant enzymes (SOD, POD and CAT) was continuously increased to alleviate the damage caused by drought. To ensure the relative stability of osmotic potential, the contents of osmoregulation substances such as proline, soluble sugar, soluble protein and trehalose increased correspondingly. But plants have limited regulatory power, with aggravation of drought stress degree and extension of stress time, the MDA content and electrolyte leakage of leaves increased continuously. Observed under electron microscope,the morphology of chloroplast and mitochondria changed and the membrane structure was destroyed. The plant's photosynthetic and respiratory mechanisms are destroyed and the plant gradually die.

scholarly journals Root Traits Determine Variation in Nonstructural Carbohydrates (NSCs) under Different Drought Intensities and Soil Substrates in Three Temperate Tree Species

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 415 ◽  
Author(s):  
Li Ji ◽  
Khan Attaullah ◽  
Jun Wang ◽  
Dapao Yu ◽  
Yuchun Yang ◽  
...  
Keyword(s):  
Drought Stress ◽  
Environmental Conditions ◽  
Tree Species ◽  
Soluble Sugar ◽  
Specific Root Length ◽  
Root Traits ◽  
Root Tip ◽  
Root Surface Area ◽  
Nonstructural Carbohydrates ◽  
Soil Substrates

Nonstructural carbohydrates (NSCs) are a key factor in the physiological regulation of plants and can reflect buffering capacity of plants under diverse environmental conditions. The effects of diverse environmental conditions on plant NSCs and tissue or organ scales have been thoroughly studied, but their effects on fine root (root diameter < 2 mm) NSC concentrations are still not completely understood. Our aims were to explore the synergistic fluctuations in root traits and NSC concentrations under diverse environmental conditions. This study was conducted on two-year-old temperate seedling tree species (Juglans mandshurica Maxim., Fraxinus mandshurica Rupr., and Phellodendron amurense Rupr.) with different drought intensities and soil substrates. The specific root length (SRL) and specific root surface area (SRA) were significantly affected by drought intensities and soil substrates, while the root tissue density (RTD) and average diameter (AD) were not significantly affected by water intensities and soil substrates in all three species. The root C, N, and P concentration did not change according to drought stress but were significantly affected by the soil substrates in all three species. Similarly, the soluble sugar (SS) and starch (ST) concentrations were significantly affected by both the drought stress and the soil substrates in all three species. The AD explained 6.8% of the total variations in soluble sugar, while the SRL explains 32.1% of the total variation in starch. The root tip C, N, and P concentrations were not significantly correlated with NSCs under different treatments. The total variations in root tip morphology, chemistry, and NSC concentrations are greater among species than compared to different drought intensities and soil substrates. However, the root NSC concentrations were closely related to root morphological traits (SRL and AD) rather than chemical traits. On the basis of different soil resources, the species with thinner diameters have higher SS concentrations, while those of a thicker diameter have higher ST concentrations.

scholarly journals Are drought resistance strategies associated with life history strategy? A commentary on: ‘Arabidopsis species deploy distinct strategies to cope with drought stress’

2019 ◽  
Vol 124 (1) ◽  
pp. vi-viii
Author(s):  
Nicholas Kooyers
Keyword(s):  
Life History ◽  
Drought Stress ◽  
Drought Resistance ◽  
Life History Strategy ◽  
Resistance Strategies ◽  
Arabidopsis Species

This article comments on: M. Bouzid, F. He, G. Schmitz, R. E. Häusler, A. P. M. Weber, T. Mettler-Altmann and J. de Meaux. 2019. Arabidopsis species deploy distinct strategies to cope with drought stress. Annals of Botany 124(1): 27–40.

Differential drought resistance strategies of co-existing woodland species enduring the long rainless Eastern Mediterranean summer

2019 ◽  
Vol 40 (3) ◽  
pp. 305-320 ◽  
Author(s):  
Päivi J Väänänen ◽  
Yagil Osem ◽  
Shabtai Cohen ◽  
José M Grünzweig
Keyword(s):  
Drought Resistance ◽  
Tree Mortality ◽  
Eastern Mediterranean ◽  
Stomatal Closure ◽  
Woody Species ◽  
The Other ◽  
Severe Drought ◽  
Resistance Strategies ◽  
Safety Margins ◽  
Species Specific

Abstract In anticipation of a drier climate and to project future changes in forest dynamics, it is imperative to understand species-specific differences in drought resistance. The objectives of this study were to form a comprehensive understanding of the drought resistance strategies adopted by Eastern Mediterranean woodland species, and to elaborate specific ecophysiological traits that can explain the observed variation in survival among these species. We examined leaf water potential (𝛹), gas exchange and stem hydraulics during 2–3 years in mature individuals of the key woody species Phillyrea latifolia L., Pistacia lentiscus L. and Quercus calliprinos Webb that co-exist in a dry woodland experiencing ~ 6 rainless summer months. As compared with the other two similarly functioning species, Phillyrea displayed considerably lower 𝛹 (minimum 𝛹 of −8.7 MPa in Phillyrea vs −4.2 MPa in Pistacia and Quercus), lower 𝛹 at stomatal closure and lower leaf turgor loss point (𝛹TLP ), but reduced hydraulic vulnerability and wider safety margins. Notably, Phillyrea allowed 𝛹 to drop below 𝛹TLP under severe drought, whereas the other two species maintained positive turgor. These results indicate that Phillyrea adopted a more anisohydric drought resistance strategy, while Pistacia and Quercus exhibited a more isohydric strategy and probably relied on deeper water reserves. Unlike the two relatively isohydric species, Phillyrea reached complete stomatal closure at the end of the dry summer. Despite assessing a large number of physiological traits, none of them could be directly related to tree mortality. Higher mortality was observed for Quercus than for the other two species, which may result from higher water consumption due to its 2.5–10 times larger crown volume. The observed patterns suggest that similar levels of drought resistance in terms of survival can be achieved via different drought resistance strategies. Conversely, similar resistance strategies in terms of isohydricity can lead to different levels of vulnerability to extreme drought.

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