Nutrient return by litterfall in evergreen podocarp-hardwood forest in new zealand

Abstract

Annual Iitterfall collected monthly for one year from 69 litter traps on 2.25 ha in the Orongorongo Valley near Wellington totalled 6180 kg/ha. Micro-litter was 4558 kg/ha (70% leaves, 26% twigs, and 4% seeds)macro-litter (large woody material) 1615 kg/ha, and insect litter 7 kg/ha, Accumulated forest floor litter was 143 t/ha. The relative abundance of 10 nutrient elements in the micro-litter was Ca >N >K > Mg >Al >P >Mn >Fe >Zn >Cu. Nutrient concentrations for the three categories of micro-litter varied seasonally as a result of specific litterfall contributions by different species in different months. Summer, autumn, and spring each provided about 30% of micro-litterfall and nutrients with about 8% falling in winter. Phosphorus in annual micro-litterfall, 2.8 kg/ha or 0.61 g/kg of litter, is low by world standards, but higher than in New Zealand hard beech or Australian eucalypt forests. Podocarp-hardwood forests may be adapted to sites of slightly higher P and N status than hard beech forests in the study area. © 1984 Taylor & Francis Group, LLC.