Nutrient movement into soils beneath eucalypt and exotic conifer forests in southern central Victoria

Abstract

Above-ground nutrient return to the soil was estimated by studying forest floor leachates for up to 2 years in two eucalypt forests (Eucalyptus obliqua and E. regnans) and two nearby conifer plantations (Pinus radiata and Pseudotsuga menziesii) near Narbethong in southern central Victoria. Forest floor leachate volumes were recorded approximately once a month and samples were analysed for pH and potassium, sodium, magnesium, and calcium concentrations.The volume of forest floor leachate was greater in the eucalypts than in the conifers. This was attributed to greater interception losses of water by the conifers.Forest floor leachate chemistry underwent regular seasonal fluctuations which were similar for each of the four forest types. Acidity was highest in spring and autumn and lowest in summer. Cation concentrations were highest in autumn and lowest in spring. This behaviour was attributed to changes in climate and in rates of litter decomposition.In contrast to cation concentrations, cation quantities entering the soil in forest floor leachate showed no pronounced seasonal variations although they tended to be high in winter. The quantities of cations added to the soil in forest floor leachate varied with forest type, and were significantly higher in E. obliqua than in the comparable P. radiata stand. Greater quantities of acid were added to the soil under P. radiata.The P. radiata soil contained lower quantities of exchangeable cations than the E. obliqua soil. This was consistent with the 0307-692X/78/1200-0357 $02.00 © 1978 Blackwell observed differences in forest floor leachate chemistry. Unlike the P. radiata soil, the P. menziesii soil did not appear to be depleted in exchangeable cations.It was concluded that P. radiata had depleted the exchangeable cation reserves in the soil studied but that the full significance of this is still unknown.

Biomass and nutrient distribution in two eucalypt forest ecosystems

“…Australian eucalypt forest (compared with data in Table 2 of Bevege (1978), and O' Connell et al (1978). It is similar to that found in a E. regnans forest near Narbethong (Feller 1978) but approximately twice as great as that found by Ashton (1975a) in other £. regnans forests.…”

“…The quantities of nutrients (kg/ha) present in litter generally decrease in the order N>Ca>Mg>K>P>Na (Tables 4 and 5) whereas the proportion of ecosystem nutrients present in litter generally decreases in the order Ca>N>Mg>K>Na>P, The differences in the two orders are mainly due to the relatively large quantities of N and P (total) present in the soil. The quantities of nutrients held in the litter of the two eucalypt plots generally lie within the range found for other eucalypt forests in Australia except that the quantity of N in the htter of plot ER is almost twice as great as that recorded in any other Australian eucalypt forest (by comparison with Table 2 in Bevege (1978) and O'Connell et al (1978) although it is less than that recorded for another E. regnans forest nearby (Feller 1978) and it is less than that found in the litter of several Acacia scrublands (by comparison with Table 3 in Bevege (1978)), This htter N quantity is also high in comparison with forests elsewhere in the world although there are many forests, either coniferous or of species which fix N, which have litter containing greater quantities of N (e,g, Gessel et al 1973, Grier et al 191 A, Kimmins 1977, Ovington 1962, Turner & Singer 1976,…”

“…Ovington 1962). The litter biomass in plot EO is less than that for similar forests near Narbethong (Feller 1978) and Mt. Disappointment (Attiwill 1964) but is within the range of values found for Australian dry sclerophyll forests (Bevege 1978).…”

The effect of spruce (Picea abies Karst.) on soil development: an analytical and experimental approach

“…The first is man's activities in forest ecosystems related to the intensification of silviculture. Much work has been carried out on biogeochemical cycles under different species (Switzer et al, 1968;Cole & Rapp, 1981), on the comparison of various species on the same site (NilghHrd, 1971;Feller, 1978; 1 The bioclimatic changes that the soils undergo below evergreen, and frequently dense, plantations; the energy reaching the soil is reduced, the precipitation interception is relatively constant throughout the year, and the soil climatic variations are well buffered, relative to those observed under comparable deciduous stands (Nilghhrd, 1969;Nys, 1987). 2 The great change in the nature of the soil organic matter due to the biophysical and biochemical composition of the coniferous litterfall (Bauzon et al, 1969).…”

Nutrient concentrations in foliage, litter and soil in relation to wood production of 7- to 15-year-oldPinus radiatain Victoria, Australia

“…9 and 10) are of interest since they are similar to the N and P concentrations of a stand well supplied in N and P. The change in concentration of N and P in the foliage between the ages 7 and 15 years will be 0.168 %Nand 0.04 %P which represents a reduction from the intercept values of9% and 20% respectively. Thus the rate of decrease in foliar concentrations over time was greater for P than for N. , and for other unthinned stands of P. radiata in southeastern Australia (Feller 1978, Florence and Lamb 197 4, Forrest andOvington 1970, Williams 19761n(y)=6.771 +0.51(1n(x}, r=0.954, n=15).…”