Anticipating global warming effects: A comprehensive study of drought impact of both flax plants and fibres

Currently, the effects of global warming are one of the most important topics on the agendas of a l l governments and international economic and scientific organisations on the planet. Temperatures and rainfal l wi l l be espe-cially subjected to increasing deregulation, and thus crop yields wil l be affected accordin g to geographic loca-tion. Cellulosic materials, such as bast fibres, are considered one solution to decrease human environmental impact: they are a renewable resource, biodegradable and have a lower carbon emission than synthetic materials. However, their quality, yield and mechanical properties depend on environmental conditions during plant growth. In this paper, we explored the possible impact of seasonal drought linked to future climate change on flax plants and fibre quality. Two batches of the same textile fla x plant cultivar were grown under two different field environmental conditions in the same year, one taken as a control under regular climatic conditions and the second one grown under drought stress. Carbon isotopic discrimination reveal an increase in water stress plant of the fibre delta C-13, reflecting that plants are indeed suffering from drought stress from a physiological point of view. We characterized the mechanical properties, biochemistr y and morpholog y parameters at both the stem and technical fibre scales. Our results showed that the plants of the two batches were morphologically different and that the drought-stressed plants were smaller, mainly in terms of the height of the stem (-28%) and diameter (- 16%). Biochemical analyses highlighted a contrasting lignin content between the two batches. A difference in protein content was also measured, with an increased amount in stressed fla x plants, with contrasting distri-butions revealed by tyrosine and tryptophan monitored by synchrotron UV fluorescence. In addition, poly-saccharide composition was also quantified with an increase in mannose and an important decrease in glucose in the drought-stressed technical fibres. Surprisingly, despite the difference in biochemistr y composition and morphological parameters, the mechanical properties of elementar y fla x fibres extracted from the two batches were not significantly different. This suggests that drought can affect the yield and biochemistr y of the extracted technical flax fibres but does not necessarily impact the longitudinal mechanical performance of single fibres.

Automated summary

The effects of global warming on crop yields and fiber quality are important. Cellulosic materials are considered a solution to reduce environmental impact, but their properties depend on environmental conditions. This study examines the impact of seasonal drought on flax plants and fiber quality.