Seasonal dynamics of mobile carbon supply in Quercus aquifolioides at the upper elevational limit.

Many studies have tried to explain the physiological mechanisms of the alpine treeline phenomenon, but the debate on the alpine treeline formation remains controversial due to opposite results from different studies. The present study explored the carbon-physiology of an alpine shrub species (Quercus aquifolioides) grown at its upper elevational limit compared to lower elevations, to test whether the elevational limit of alpine shrubs (<3 m in height) are determined by carbon limitation or growth limitation. We studied the seasonal variations in non-structural carbohydrate (NSC) and its pool size in Q.

Mobile carbohydrates in Himalayan treeline trees I. Evidence for carbon gain limitation but not for growth limitation.

To test whether the altitudinal distribution of trees is determined by a carbon shortage or an insufficient sugar fraction (sugar:starch ratio) in treeline trees, we studied the status of nonstructural carbohydrates (NSC) and their components (total soluble sugars and starch) in Abies fabri (Mast.) Craib and Picea balfouriana var. hirtella Rehd.

[Altitudinal changes in leaf mass per unit area and tissue non-structural carbohydrates content of Abies fabri on Gongga Mountain of southwest China].

Taking the northeast slope of Moxi vally and southwest slope of Kangding vally in Gongga Mountain of Southwest China as sampling sites, this paper investigated the leaf mass per unit area (LMA) and tissue non-structural carbohydrates content (NSC) of Abies fabri distributed at the positions from lower elevations to alpine treeline during the periods of dormancy and vigorous growth. The results indicated that A. fabri had higher LMA and NSC in warm-moist Moxi valley than in hot-dry Kangding valley.