Altitudinal Trends in Leaf Nutrient Contents, Leaf Size and D13C of Alchemilla Alpina

Résumé du livre

1. At the peak of the growing season, nitrogen and phosphorus concentrations increased with altitude particularly above 500 m. Leaf dry mass and area decreased with altitude, this trend being more pronounced above 500 m. The total amount of nitrogen per leaf, specific leaf area (SLA) and potassium concentration did not change with altitude. DeltaC-13 increased linearly with altitude. 2. Nitrogen, phosphorus and chlorophyll concentrations decreased throughout the growing season from a maximum in May; the decline at the end of the growing season was most rapid at high altitude. DeltaC-13 also decreased with time but uniformly at all altitudes. Potassium concentrations peaked in June and leaf size in July. SLA was lowest in July and highest in October. 3. The high nitrogen and phosphorus concentrations are probably caused. by low biomass acquisition because of low temperatures and a short growing season; changes in nitrogen supply may also be involved. The altitudinal trend in deltaC-13 is the consequence of a number of interacting properties of the plant and its environment.