Size and age: intrinsic confounding factors affecting the responses to a water deficit in black spruce seedlings

Walsh, Denis; Rossi, Sergio; Lord, Daniel

doi:10.3832/ifor1412-007

Cited by 7 publications

(8 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…As our measurements of both predawn and midday leaf water potential indicate values close to −2.2 MPa (see Table ), the drop observed in the rate of cell enlargement could thus reflect the direct effect of low turgor pressure. These values were consistent with the physiological reaction observed in black spruce seedlings (Stewart & Bernier, ; Walsh et al, ). The low water potential values are related with low osmotic potential caused by solute accumulation in the living cells (i.e.…”

Section: Discussionsupporting

confidence: 89%

Compensatory mechanisms mitigate the effect of warming and drought on wood formation

Balducci

Cuny

Rathgeber

et al. 2016

Plant Cell & Environment

102

View full text Add to dashboard Cite

Because of global warming, high‐latitude ecosystems are expected to experience increases in temperature and drought events. Wood formation will have to adjust to these new climatic constraints to maintain tree mechanical stability and long‐distance water transport. The aim of this study is to understand the dynamic processes involved in wood formation under warming and drought. Xylogenesis, gas exchange, water relations and wood anatomy of black spruce [Picea mariana (Mill.) B.S.P.] saplings were monitored during a greenhouse experiment where temperature was increased during daytime or night‐time (+6 °C) combined with a drought period. The kinetics of tracheid development expressed as rate and duration of the xylogenesis sub‐processes were quantified using generalized additive models. Drought and warming had a strong influence on cell production, but little effect on wood anatomy. The increase in cell production rate under warmer temperatures, and especially during the night‐time warming at the end of the growing season, resulted in wider tree‐rings. However, the strong compensation between rates and durations of cell differentiation processes mitigates warming and drought effects on tree‐ring structure. Our results allowed quantification of how wood formation kinetics is regulated when water and heat stress increase, allowing trees to adapt to future environmental conditions.

show abstract

Section: Discussionsupporting

confidence: 89%

Compensatory mechanisms mitigate the effect of warming and drought on wood formation

Balducci

Cuny

Rathgeber

et al. 2016

Plant Cell & Environment

102

View full text Add to dashboard Cite

show abstract

“…Finally, the common SPEI fix of three fixed time scales, namely, 1 month (SPEI 1 ), 6 months (SPEI 6 ), and 12 months (SPEI 12 ), was adopted in the research. All the statistical methods and statistical mapping were completed using Matlab (R2012b) (MathWorks, Natick, MA, USA).…”

Section: Response To Drought As Affected By Different Forest Stock Vomentioning

confidence: 99%

“…In the early stages of drought, stomata are kept open as far as possible, and regular growth is maintained through continuous assimilation of CO 2 [12,13]; as the stress intensifies, stomata are closed to reduce water loss. Meanwhile, root growth is accelerated to increase the uptake of soil moisture [13,14].…”

Section: Introductionmentioning

confidence: 99%

Stock Volume Dependency of Forest Drought Responses in Yunnan, China

Luo

Zhou

et al. 2018

Forests

View full text Add to dashboard Cite

Abstract:Revealing forest drought response characteristics and the potential impact factors is quite an important scientific issue against the background of global climate change, which is the foundation to reliably evaluate and predict the effects of future drought. Due to the high spatial heterogeneity of forest properties such as biomass, forest age, and height, and the distinct differences in drought stress in terms of frequency, intensity, and duration, current studies still contain many uncertainties. In this research, we used the forests in Yunnan Province in Southwest China as an example and aimed to reveal the potential impacts of forest properties (i.e., stock volume) on drought response characteristics. Specifically, we divided the forest into five groups of stock volume density values and then analyzed their drought response differences. To depict forest response to drought intensity, the standardized precipitation evapotranspiration index (SPEI) was chosen as the explanatory variable, and the change in remote sensing-based enhanced vegetation index (deficit of MODIS-EVI, dEVI) was chosen as the response variable of drought stress. Given that the SPEI has different time scales, we first analyzed the statistical dependency of SPEIs with different time scales (1 to 36 months) to the response variable (i.e., dEVI). The optimal time scale of SPEI (SPEI opt ) to interpret the maximum variation of dEVI (R-square) was then chosen to build the ultimate statistical models for the five groups of stock volume density. The main findings were as follows: (1) the impacts of drought showed hysteresis and cumulative effects, and the length of the hysteresis increased with stock volume densities; (2) forests with high stock volume densities required more soil water and were therefore more sensitive to the changes in water deficit; (3) compared with the optimal time scale of SPEI (SPEI opt ), the SPEI with the commonly used time scale (e.g., 1, 6, and 12 months) could not well reflect the impacts of drought on forests and the simulation error of dEVI increased with stock volume densities; and (4) forests with higher stock volume densities were likely to experience a greater risk of degradation following higher atmospheric concentrations of greenhouse gases (Representative Concentration Pathway (RCP) 8.5). As a result, both the time scale of the meteorological drought index and the spatial difference in forest stock volumes should be considered when evaluating forest drought responses at regional and global scales.

show abstract

“…Se o período de déficit hídrico a campo for relativamente curto, os efeitos benéicos da muda menor do que 18 cm poderiam ser suprimidos pela competição interespecíica característica em ambientes tropicais, tendo em vista que a competição com a vegetação adjacente por luz e por recursos do solo pode ser uma restrição importante para mudas de pequenas dimensões por possuírem uma reduzida taxa de crescimento inerente ao tamanho (WALSH et al, 2014). Se o período de deiciência hídrica for estendido, mudas com maiores dimensões poderão compensar as perdas por transpiração pela exploração de um maior volume de substrato pelas raízes (Tabela 6).…”

Section: Discussionunclassified

Manejo hídrico na rustificação em mudas de Maytenus ilicifolia [(Schrad.) Planch.]

2017

View full text Add to dashboard Cite

ResumoAvaliou-se o efeito do tamanho da muda e do manejo da irrigação ao inal do ciclo de produção sobre a qualidade de mudas de Maytenus iliciloia. O experimento seguiu o delineamento inteiramente ao acaso em arranjo fatorial 2x3, em que mudas de duas classes de altura (maior ou menor que 18,0 cm) foram submetidas a três regimes hídricos (rega diária, rega a cada dois dias e redução gradativa da irrigação). Após oito semanas, quantiicaram-se atributos morfoisiológicos e de desempenho. A redução gradativa da irrigação promoveu maior taxa de assimilação líquida de carbono. A rega a cada dois dias possibilitou maior taxa de crescimento secundário, velocidade de acúmulo de biomassa nos tecidos aéreos e radiculares, com menor taxa de extravasamento de eletrólitos. Após o plantio, esses tratamentos mantiveram o maior teor relativo de água nas folhas (TRA). O TRA em mudas de menor tamanho foi signiicativamente maior até a terceira semana do plantio. Portanto, mudas de maior tamanho, submetidas à rustiicação por redução gradativa do regime de regas, apresentam melhor qualidade.Palavras-chave: Déicit hídrico; Espinheira-santa; Produção de mudas; Qualidade de mudas AbstractWater management in hardening Maytenus ilicifolia (Schrad.) Planch. seedlings. This study evaluated the effects of seedling height and irrigation management on M. iliciloia seedlings. The experiment used a completely randomized design in a 2 x 3 factorial arrangement. Seedlings of two height classes (greater than or less than 18.0 cm) were subjected to three irrigation regimes (daily irrigation, irrigation every other day, and gradual reduction of irrigation). After eight weeks, the morphophysiological and performance attributes of the seedlings were quantiied. Gradual reduction of irrigation promoted the highest rate of net carbon assimilation.Irrigating every other day resulted in greater secondary growth rate, biomass accumulation in the shoot and root tissues, and lower electrolyte leakage rate. After planting, these treatments maintained higher leaf relative water content (RWC). RWC in seedlings smaller than 18 cm was signiicantly higher until the third week after planting.Therefore, larger seedlings submitted to hardening by gradually reducing irrigation improves seedling quality.

show abstract

Size and age: intrinsic confounding factors affecting the responses to a water deficit in black spruce seedlings

Cited by 7 publications

References 35 publications

Compensatory mechanisms mitigate the effect of warming and drought on wood formation

Compensatory mechanisms mitigate the effect of warming and drought on wood formation

Stock Volume Dependency of Forest Drought Responses in Yunnan, China

Manejo hídrico na rustificação em mudas de Maytenus ilicifolia [(Schrad.) Planch.]

Contact Info

Product

Resources

About