Effects of unusually large seed crop on litterfall and nitrogen retranslocation in Himalayan oaks

Abstract

We analyzed the effect of an unusually large seed crop in the two Central Himalayan oak species ( Quercus leucotrichophora A. Camus and Q. floribunda Lindl.) on litterfall and nutrient retranslocation from senescent leaves. In the year of the large seed crop, the developing mast-crop reduced the formation of leaf primordia, so demand for carbohydrates and nutrients was reduced the following spring when buds opened. Because of this, less carbohydrates and nutrients were translocated from old leaves, delaying their senescence, lengthening their life-span and reducing leaf-fall. In the following year, litterfall was massive and highly concentrated; the amounts of summer litterfall were significantly greater than in the summer season of normal years. Retranslocation of nitrogen from the senescent leaves in the year following the large seed crop was approximately double that recorded in a normal year.