An allometry-based model of the survival strategies of hydraulic failure and carbon starvation

Ecohydrology ◽  
2015 ◽  
Vol 9 (3) ◽  
pp. 529-546 ◽  
Author(s):  
Pierre Gentine ◽  
Marceau Guérin ◽  
María Uriarte ◽  
Nate G. McDowell ◽  
Willam T. Pockman
Keyword(s):  
Carbon Starvation ◽  
Survival Strategies ◽  
Hydraulic Failure

scholarly journals How do trees die? A test of the hydraulic failure and carbon starvation hypotheses

2013 ◽  
Vol 37 (1) ◽  
pp. 153-161 ◽  
Author(s):  
SANNA SEVANTO ◽  
NATE G. MCDOWELL ◽  
L. TURIN DICKMAN ◽  
ROBERT PANGLE ◽  
WILLIAM T. POCKMAN
Keyword(s):  
Carbon Starvation ◽  
Hydraulic Failure

scholarly journals Carbon starvation during drought-induced tree mortality – are we chasing a myth?

2015 ◽  
Vol 2 ◽  
pp. e005 ◽  
Author(s):  
Henrik Hartmann
Keyword(s):  
Tree Mortality ◽  
Stomatal Closure ◽  
Carbon Starvation ◽  
Carbon Limitation ◽  
Functional Roles ◽  
C Storage ◽  
Hydraulic Failure ◽  
Lethal Level ◽  
Potential Link ◽  
C Assimilation

Drought-induced tree mortality has received much attention in the recent past. McDowell et al.’s (2008) hydraulic framework links tree hydraulics with carbon dynamics and proposes two non-exclusive mortality mechanisms: carbon starvation (CS) and hydraulic failure (HF). CS is often referred to as the (partial) depletion of non-structural carbohydrates (NSC) in response to stomatal closure, reduced C assimilation and sustained C storage dependency during longer droughts. HF describes a lethal level of xylem dysfunction from runaway embolism during severe droughts. While HF can be readily inferred from the percentage loss of conductivity in vascular tissues at the time of death, CS is much more difficult to assess.Starvation is usually defined as a lack of food leading to suffering or death. In plants photosynthetic sugars play many functional roles, not only as a source of catabolic energy. For example, sugars are important for osmotic regulation of cell pressure and recent studies suggest a potential link between xylem parenchyma sugars and embolism repair following drought. Hence, carbon limitation could have a direct impact on tree hydraulics and HF; however, empirical evidence for such a mechanism is still inconclusive.Although HF appears to be predominant during drought mortality, our limited understanding of the roles of NSC in hydraulic function precludes any premature refutation of CS as a mechanism in drought-induced tree mortality.

scholarly journals Differences in Near Isohydric and Anisohydric Behavior of Contrasting Poplar Hybrids (I-101 (Populus alba L.) × 84K (Populus alba L. × Populus glandulosa Uyeki)) under Drought-Rehydration Treatments

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 402 ◽  
Author(s):  
Li Zhang ◽  
Li Liu ◽  
Han Zhao ◽  
Zaimin Jiang ◽  
Jing Cai
Keyword(s):  
Tree Mortality ◽  
Slow Growth ◽  
Threshold Value ◽  
Carbon Starvation ◽  
Populus Alba ◽  
Growth Strategies ◽  
Fast Growing ◽  
Hydraulic Failure ◽  
Hydraulic Safety ◽  
Slow Growing

Carbon starvation and hydraulic failure are considered important factors in determining the mechanisms associated with tree mortality. In this study, iso/anisohydric classification was used to assess drought resistance and mortality mechanisms in two contrasting poplar species, as it is generally believed that isohydric species are more susceptible to carbon starvation, while anisohydric species are more susceptible to hydraulic failure. However, these assumptions are rarely tested in poplar genotypes with contrasting growth strategies. Thus, we subjected potted poplar genotypes (I-101 (Populus alba L.) × 84K (Populus alba L. × Populus glandulosa Uyeki)) with fast and slow growth rates to drought–rehydration treatments. The slow-growing genotype maintained higher stomatal conductance and lower predawn leaf water potential than the fast-growing genotype, thus exhibiting a near-anisohydric stomatal behavior throughout the treatment period. The nonstructural carbohydrate (NSC) content indicated that the two genotypes had the same trend of carbon change (e.g., the NSC content in the leaves increased with drought and then decreased). However, when NSC content data were combined with the growth and photosynthetic data, it was observed that the slow-growing genotype mobilized carbon to maintain hydraulic safety, while the NSC content of the fast-growing genotype among tissues was static. The percent loss of hydraulic conductivity in the branches during treatments indicated that the fast-growing genotype could recover more quickly from xylem embolism than the slow-growing genotype. The slow-growing genotype with a slow growth recovery after rehydration showed a significant increase in carbon consumption, combined with a significant increase in the hydraulic safety threshold value, indicating that there may be drought tolerance. In comparison, the fast-growing genotype showed a faster hydraulic recovery ability that had no effect on the NSC content in the leaves and roots. Our findings demonstrate intraspecific isohydric behavior in poplar; however, the trade-off between carbon distribution and stomatal regulation should be considered separately within genotypes of the same species. In addition, NSC plays an important role in water–carbon balance in the drought–rehydration cycle.

scholarly journals Initial hydraulic failure followed by late-stage carbon starvation leads to drought-induced death in the tree Trema orientalis

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Yuri Kono ◽  
Atsushi Ishida ◽  
Shin-Taro Saiki ◽  
Kenichi Yoshimura ◽  
Masako Dannoura ◽  
...  
Keyword(s):  
Late Stage ◽  
Carbon Starvation ◽  
Hydraulic Failure ◽  
Trema Orientalis

scholarly journals Balancing the risks of hydraulic failure and carbon starvation: a twig scale analysis in declining Scots pine

2015 ◽  
Vol 38 (12) ◽  
pp. 2575-2588 ◽  
Author(s):  
Yann Salmon ◽  
José M. Torres-Ruiz ◽  
Rafael Poyatos ◽  
Jordi Martinez-Vilalta ◽  
Patrick Meir ◽  
...  
Keyword(s):  
Scots Pine ◽  
Carbon Starvation ◽  
Scale Analysis ◽  
Hydraulic Failure

scholarly journals Tree Mortality Risks Under Climate Change in Europe: Assessment of Silviculture Practices and Genetic Conservation Networks

2021 ◽  
Vol 9 ◽  
Author(s):  
Cathleen Petit-Cailleux ◽  
Hendrik Davi ◽  
François Lefèvre ◽  
Pieter Johannes Verkerk ◽  
Bruno Fady ◽  
...  
Keyword(s):  
Climate Change ◽  
Forest Management ◽  
Mortality Risk ◽  
Tree Mortality ◽  
Frost Damage ◽  
Carbon Starvation ◽  
Genetic Conservation ◽  
Future Climate ◽  
Extreme Climatic Events ◽  
Hydraulic Failure

General Context: Climate change can positively or negatively affect abiotic and biotic drivers of tree mortality. Process-based models integrating these climatic effects are only seldom used at species distribution scale.Objective: The main objective of this study was to investigate the multi-causal mortality risk of five major European forest tree species across their distribution range from an ecophysiological perspective, to quantify the impact of forest management practices on this risk and to identify threats on the genetic conservation network.Methods: We used the process-based ecophysiological model CASTANEA to simulate the mortality risk of Fagus sylvatica, Quercus petraea, Pinus sylvestris, Pinus pinaster, and Picea abies under current and future climate conditions, while considering local silviculture practices. The mortality risk was assessed by a composite risk index (CRIM) integrating the risks of carbon starvation, hydraulic failure and frost damage. We took into account extreme climatic events with the CRIMmax, computed as the maximum annual value of the CRIM.Results: The physiological processes' contributions to CRIM differed among species: it was mainly driven by hydraulic failure for P. sylvestris and Q. petraea, by frost damage for P. abies, by carbon starvation for P. pinaster, and by a combination of hydraulic failure and frost damage for F. sylvatica. Under future climate, projections showed an increase of CRIM for P. pinaster but a decrease for P. abies, Q. petraea, and F. sylvatica, and little variation for P. sylvestris. Under the harshest future climatic scenario, forest management decreased the mean CRIM of P. sylvestris, increased it for P. abies and P. pinaster and had no major impact for the two broadleaved species. By the year 2100, 38–90% of the European network of gene conservation units are at extinction risk (CRIMmax=1), depending on the species.Conclusions: Using a process-based ecophysiological model allowed us to disentangle the multiple drivers of tree mortality under current and future climates. Taking into account the positive effect of increased CO2 on fertilization and water use efficiency, average mortality risk may increase or decrease in the future depending on species and sites. However, under extreme climatic events, our process-based projections are as pessimistic as those obtained using bioclimatic niche models.

scholarly journals Diversity in Starvation Survival Strategies and Outcomes among Heterotrophic Proteobacteria

2021 ◽  
pp. 1-17
Author(s):  
Megan Bergkessel ◽  
Laurent Delavaine
Keyword(s):  
Regulatory Networks ◽  
Cell Envelope ◽  
Carbon Starvation ◽  
Survival Strategies ◽  
Model Organisms ◽  
Electrochemical Gradient ◽  
Bacterial Strains ◽  
Free Living ◽  
Starvation Survival ◽  
Cellular Integrity

Heterotrophic Proteobacteria are versatile opportunists that have been extensively studied as model organisms in the laboratory, as both pathogens and beneficial symbionts of plants and animals, and as ubiquitous organisms found free-living in many environments. Succeeding in these niches requires an ability to persist for potentially long periods of time in growth-arrested states when essential nutrients become limiting. The tendency of these bacteria to grow in dense biofilm communities frequently leads to the development of steep nutrient gradients and deprivation of interior cells even when the environment is nutrient rich. Surviving within host environments also likely requires tolerating growth arrest due to the host limiting access to nutrients and transitioning between hosts may require a period of survival in a nutrient-poor environment. Interventions to maximise plant-beneficial activities and minimise infections by bacteria will require a better understanding of metabolic and regulatory networks that contribute to starvation survival, and how these networks function in diverse organisms. Here we focus on carbon starvation as a growth-arresting condition that limits availability not only of substrates for biosynthesis but also of energy for ongoing maintenance of the electrochemical gradient across the cell envelope and cellular integrity. We first review models for studying bacterial starvation and known strategies that contribute to starvation survival<i>.</i> We then present the results of a survey of carbon starvation survival strategies and outcomes in ten bacterial strains, including representatives from the orders Enterobacterales and Pseudomonadales (both Gammaproteobacteria) and Burkholderiales (Betaproteobacteria). Finally, we examine differences in gene content between the highest and lowest survivors to identify metabolic and regulatory adaptations that may contribute to differences in starvation survival.

Analytic Survival Strategies

1996 ◽  
Author(s):  
Maureen Murphy ◽  
Karen Rosica
Keyword(s):  
Survival Strategies

Sustainable Illegality: Gagauz Women in Istanbul

2014 ◽  
Vol 8 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Bayram Unal
Keyword(s):  
Police Officers ◽  
Ethnic Origin ◽  
Social Processes ◽  
Survival Strategies ◽  
Preferential Treatment ◽  
National Group ◽  
Turkish Migrants ◽  
Illegal Migrants ◽  
Sociological Inquiry ◽  
The Social

This study deals with survival strategies of illegal migrants in Turkey. It aims to provide an explanation for the efforts to keep illegality sustainable for one specific ethnic/national group—that is, the Gagauz of Moldova, who are of Turkish ethnic origin. In order to explicate the advantages of Turkish ethnic origin, I will focus on their preferential treatment at state-law level and in terms of the implementation of the law by police officers. In a remarkable way, the juridical framework has introduced legal ways of dealing with the illegality of ethnically Turkish migrants. From the viewpoint of migration, the presence of strategic tools of illegality forces us to ask not so much law-related questions, but to turn to a sociological inquiry of how and why they overstay their visas. Therefore, this study concludes that it is the social processes behind their illegality, rather than its form, that is more important for our understanding of the migrants’ survival strategies in destination countries.

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