The role of stored carbohydrates and nitrogen in the growth and stress tolerance of planted forest trees

Abstract

Plants store compounds that supplement external resources to maintain primary functions. We reviewed the role of stored non-structural carbohydrates (NSC) and nitrogen (N) in juvenile woody species for spring growth and cold and drought stress tolerance, which are crucial processes for early performance of forest plantations. Plant functional types differed in NSC and N partitioning and allocation to new growth. In general, however, new leaves/shoots were more enriched in remobilized resources than new fine roots. Conifers used less remobilized resources than broadleaf species for fine root growth. New shoots/leaves were mostly comprised of remobilized N ([60 %) in conifers and broadleaf deciduous species, while broadleaf evergreens relied more on soil N (\50 % remobilized N). In contrast, few differences among functional groups existed in the contribution of remobilized carbon (C) to new leaves/shoots, which comprised 28-45 % of stored C reflecting the importance of current photosynthesis and distinctions in C and N remobilization physiology. The amount of N remobilized by an organ was positively related to its contribution to seedling N content. However, leaves are priority N sources in evergreens, which remobilized more N than predicted by their contribution to seedling N content. In contrast, roots in broadleaf evergreens and conifers were poor contributors of remobilized N. Under low stress, spring growth has little effect on NSC reserves. However, prolonged and intense photosynthesis depression strongly reduces NSC. In contrast, N reserves usually decline after planting and their replenishment takes longer than for NSC reserves. Strong storage reduction can hinder seedling stress acclimation and survival capacity. Resource storage can be promoted in the nursery by arresting plant growth and Electronic supplementary material The online version of this article (supplying resources at a higher rate than seedling growth and maintenance rate. We conclude that the way in which woody plants manage stored resources drives their growth and stress tolerance. However, plant functional types differ in storage physiology, which should be considered in silvicultural management.

Effect of controlled release fertilizer type and rate on mineral nutrients, non-structural carbohydrates, and field performance of Chinese pine container-grown seedlings

“…Studies with Picea abies L. and Pinus pinea L. seedlings, using low and high fertilization rates, indicated that NSC contents were positively and negatively correlated with fertilization rates, respectively (Kaakinen et al 2004;Villar-Salvador et al 2013). Stored N and NSC are functional attributes, indicative of seedling quality and a substantive body of evidence in the literature concludes that over-fertilization retards N storage (Millard and Grelet 2010;Villar-Salvador et al 2015). These inconclusive NSC responses to nursery fertilization imply effects beyond N uptake and storage on carbon assimilation and sequestration.…”

“…Timmer's conceptual model for optimizing fertilization based on investigating the impact of fertilization rates on plant dry mass and mineral nutrient status has not been assessed yet for CRF. Measurements of non-structural carbohydrate (NSC) levels in seedlings also appear to be useful for evaluating nursery practices (Millar and Grelet 2010;Villar-Salvador et al 2015). The lack of research using a sufficiently broad range of CRF rates to cover nutrient deficiency to toxicity (Oliet et al 2004(Oliet et al , 2009Luis et al 2009;Dumorese et al 2011), hinders seedling nutrient optimization.…”

Restoring forests: What constitutes success in the twenty-first century?

“…They discuss disturbance regimes in which restoration may benefit from artificial inoculation of nursery stock or introduction of ectomycorrhizae onto field sites, yet they also highlight the complexity of fully understanding this below-ground community and the challenges of artificially reintroducing a diverse ectomycorrhizal community across heavily disturbed landscapes. In another paper from an invited keynote presentation, Villar-Salvador et al (2015) traced the importance of stored non-structural carbohydrates and N in determining stress resistance of newly planted forest trees. Using a meta-analysis approach, they found distinctions among plant functional types in storage patterns of carbohydrates and N within plant tissues as well as their reallocation to support growth following transplant.…”

Influence of nitrogen fertilisation on biometric features of two-year-old seedlings of pedunculate oak subjected for root pruning

“…At the same time, increase in the amount of nitrogen in roots was about 5% (Coker 1984). In case of oak seedlings, the amount of nitrogen loss may be much greater than that in the pine, as in deciduous seedlings which loose leaves, the amount of nitrogen stored in the roots is considerably greater in comparison to coniferous seedlings (Villar-Salvador et al 2015).…”