Effects of drought on leaf carbon source and growth of European beech are modulated by soil type

Wen-Juan Yang,Jian-Feng Liu,Ze-Ping Jiang,Mai-He Li,Andreas Rigling,Arthur Gessler,Matthias Arend,Marcus Schaub,Yan-Yan Ni

doi:10.1038/srep42462

Abstract

Drought potentially affects carbon balance and growth of trees, but little is known to what extent soil plays a role in the trade-off between carbon gain and growth investment. In the present study, we analyzed leaf non-structural carbohydrates (NSC) as an indicator of the balance of photosynthetic carbon gain and carbon use, as well as growth of European beech (Fagus sylvatica L.) saplings, which were grown on two different soil types (calcareous and acidic) in model ecosystems and subjected to a severe summer drought. Our results showed that drought led in general to increased total NSC concentrations and to decreased growth rate, and drought reduced shoot and stem growth of plants in acidic soil rather than in calcareous soil. This result indicated that soil type modulated the carbon trade-off between net leaf carbon gain and carbon investment to growth. In drought-stressed trees, leaf starch concentration and growth correlated negatively whereas soluble sugar:starch ratio and growth correlated positively, which may contribute to a better understanding of growth regulation under drought conditions. Our results emphasize the role of soil in determining the trade-off between the balance of carbon gain and carbon use on the leaf level and growth under stress (e.g. drought).

Highlights

Source of variation Within-subject Period Period ×Treatment Period ×Soil Period ×Treatment ×Soil Between-subject Treatment Soil Treatment ×Soil
By analyzing levels of Non-structural carbohydrates (NSCs), nitrogen, and phosphorus in relation to growth, we aimed at testing: (1) how severe drought influences the relationship between leaf carbon assimilation and NSC export associated with tree growth, and (2) whether soil types affect this relationship
Drought resulted in increased leaf total NSC concentrations, but the magnitude differed between the two soil types (Table 1 and Fig. 1C)

Summary

Introduction

Source of variation Within-subject Period Period ×Treatment Period ×Soil Period ×Treatment ×Soil Between-subject Treatment Soil Treatment ×Soil. Differences in the physiology of the nutrient uptake system may contribute to species-specific variations in drought tolerance[38], and soil properties which determine nutrient availability and soil water relations may play a role in plants’ drought tolerance. European beech (Fagus sylvatica L.) is an ecologically dominant tree species in Central Europe occupying a wide range of mesic soils with contrasting pH and carbonate content[43] It is commonly considered as a drought-sensitive species[44,45], especially during early stages of establishment[46], but it has been reported that seedlings recover quickly from severe drought episodes and provenances may differ in their drought and post-drought response[47,48,49,50,51]. By analyzing levels of NSCs, nitrogen, and phosphorus in relation to growth, we aimed at testing: (1) how severe drought influences the relationship between leaf carbon assimilation and NSC export associated with tree growth (i.e. leaf NSC balance), and (2) whether soil types affect this relationship

Methods

Results

Discussion

Conclusion