title: Concentrations and resorption patterns of 13 nutrients in different plant functional types in the karst region of south-western China.
abstract: OBJECTIVE
  Elucidating the stoichiometry and resorption patterns of multiple nutrients is an essential requirement for a holistic understanding of plant nutrition and biogeochemical cycling. However, most studies have focused on nitrogen (N) and phosphorus (P), and largely ignored other nutrients. The current study aimed to determine relationships between resorption patterns and leaf nutrient status for 13 nutrient elements in a karst vegetation region.
  
  
  METHODS
  Plant and soil samples were collected from four vegetation types in the karst region of south-western China and divided into eight plant functional types. Samples of newly expanded and recently senesced leaves were analysed to determine concentrations of boron (B), calcium (Ca), copper (Cu), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), molybdenum (Mo), N, sodium (Na), P, sulphur (S) and zinc (Zn).
  
  
  RESULTS
  Nutrient concentrations of the karst plants were lower than those normally found in other regions of China and the rest of the world, and plant growth was mainly limited by P. Overall, four nutrients revealed resorption [N (resorption efficiency 34·6 %), P (48·4 %), K (63·2 %) and Mg (13·2 %)], seven nutrients [B (-16·1 %), Ca (-44·0 %), Cu (-14·5 %), Fe (-205·5 %), Mn (-72·5 %), Mo (-35·6 %) and Zn (-184·3 %)] showed accumulation in senesced leaves and two nutrients (Na and S) showed no resorption or accumulation. Resorption efficiencies of K and Mg and accumulation of B, Ca, Fe and Mn differed among plant functional types, and this strongly affected litter quality. Resorption efficiencies of N, P and K and accumulation of Ca and Zn increased with decreasing concentrations of these nutrients in green leaves. The N:P, N:K and N:Mg ratios in green leaves predicted resorption proficiency for N, K and Mg, respectively.
  
  
  CONCLUSIONS
  The results emphasize the fact that nutrient resorption patterns strongly depend on element and plant functional type, which provides new insights into plant nutrient use strategies and nutrient cycling in karst ecosystems.
authors.affiliation: State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
authors.forename: Changcheng
authors.initials: C
authors.lastname: Liu
authors.forename: Yuguo
authors.initials: Y
authors.lastname: Liu
authors.forename: Ke
authors.initials: K
authors.lastname: Guo
authors.forename: Shijie
authors.initials: S
authors.lastname: Wang
authors.forename: Yao
authors.initials: Y
authors.lastname: Yang
mesh_terms: D000042:Absorption; D002681:China; D017753:Ecosystem; D029624:Ferns / Q000378:metabolism*; D019684:Magnoliopsida / Q000378:metabolism*; D008903:Minerals / Q000378:metabolism*; D012987:Soil / Q000737:chemistry; D013054:Spectrophotometry, Atomic
chemical_list: D008903:Minerals; D012987:Soil
keywords: karst ecosystem; multiple nutrients; nutrient concentration; nutrient limitation; plant functional type; plant nutrient use strategy; resorption efficiency; resorption proficiency; stoichiometry