Mature Eucalyptus Research Articles

Chemical composition and antimicrobial activity of Eucalyptus radiata leaf essential oil, sampled over a year

This study investigated the seasonal variation of the chemical composition and antimicrobial activity of Eucalyptus radiata leaf essential oil. Young and mature Eucalyptus radiata leaf material was collected monthly (January 2014 to December 2014), hydrodistilled and analyzed using GC-MS. Essential oil yields ranged from 0.14% to 4.31% (w/w). The major compounds were 1,8-cineole (65.7% ± 9.5), α-terpineol (12.8% ± 4.4) and limonene (6.5% ± 2.4). Chemometric tools were used to determine seasonal variations, which showed slight variance in E. radiata chemistry between seasons. The minimum inhibitory concentration (MIC) assay showed that the highest activity was noted against the Streptococci (0.19–2.00 mg/mL) and Lactobacillus acidophilus (0.19–1.75 mg/mL). The activity of the E. radiata leaf essential oil is dependent on the unique ratio of its compounds. The E. radiata leaf essential oil showed good oil yields, a relatively consistent chemical profile and noteworthy antimicrobial activity that rivals other commercial Eucalypt counterparts.

Analysing the drying behavior of juvenile and mature Eucalyptus saligna wood in drastic drying test for optimal drying schedule

The heterogeneity of characteristics observed in the pith-bark direction within a log causes sawn pieces of wood have different behaviors during water removal. Understanding these differences is important for the industry regarding the possibility of classification of the lumber into juvenile wood and mature wood, facilitating the drying in separate loads. Thus, this study aimed to evaluate the behavior of juvenile and mature wood samples of Eucalyptus saligna when subjected to drastic drying. In order to do this, test specimens were submitted to drastic drying at 100°C to obtain the drying times, drying rates and dimensions of end checks. These data were applied in equations to obtain the parameters initial temperature, final temperature and drying potential, used in the elaboration of drying schedules. In juvenile wood we observed that the basic density was lower and the initial moisture content was higher. Mature wood showed a lower drying rate. Drying schedules were developed separately for juvenile and mature wood, the drying schedule for the latter considered milder than the drying schedule developed for juvenile wood.

Variation of Wood Pulping and Bleached Pulp Properties Along the Stem in Mature Eucalyptus globulus Trees

The wood of a mature (40-year-old) Eucalyptus globulus Labill tree was characterized at different stem height levels (0%, 10%, 35%, and 50% of total height) regarding pulping, bleaching, and paper properties. Pulp yields increased upwards from 46% to 50%, and Kappa number decreased from 17.5 to 12.3 at 0 and 50% height, respectively. The estimated specific wood consumption ranged from 3.2 m3 odt-1 to 3.1 m3 odt-1 at 0% and 50% height levels, respectively. Pulp drainage varied along the stem, with less drainability (20.3 oSR) and higher water retention value (1.07 g.g-1) at the base. Pulp fiber length increased (827 µm vs. 877 µm) and width decreased (19 µm vs. 17 µm) from 0% to 50% height levels. Tensile, tear, and internal bond strength decreased upwards, with mean values of 34.9 N.m.g-1, 3.1 mN.m2.g-1, and 95.8 J.m-2, respectively. These findings support the use of mature E. globulus trees without loss of pulp production and quality.

Precipitation, not CO2 enrichment, drives insect herbivore frass deposition and subsequent nutrient dynamics in a mature Eucalyptus woodland

Herbivorous insects are important nutrient cyclers that produce nutrient-rich frass. The impact of elevated atmospheric [CO2] on insect-mediated nutrient cycling, and its potential interaction with precipitation and temperature, is poorly understood and rarely quantified. We tested these climatic effects on frass deposition in a nutrient-limited mature woodland. Frass deposition by leaf-chewing insects and its chemical composition was quantified monthly over the first 2 years at the Eucalyptus free-air CO2 enrichment experiment and contrasted with leaf nitrogen concentration, rainfall and temperature. Leaf-chewing insects produced yearly between 160 and 270 kg ha−1 of frass depositing 2 to 4 kg ha−1 of nitrogen. Frass quantity and quality were influenced by rainfall and average maximum temperatures. In contrast, elevated CO2 did not impact nitrogen concentrations in fully expanded leaves and frass deposition to the woodland floor. Two years of elevated CO2 did not alter nutrient transfer by leaf-chewing insects. This may be due to the low nutrient status of this ecosystem, duration of CO2 fumigation or climatic conditions. However, rainfall co-occurring with seasonally higher temperatures exerted strong effects on nutrient cycling, potentially through shifts in leaf phenology with consequences for insect population dynamics and insect-mediated nutrient transfer.

Model-data synthesis for the next generation of forest free-air CO2 enrichment (FACE) experiments.

The first generation of forest free-air CO2 enrichment (FACE) experiments has successfully provided deeper understanding about how forests respond to an increasing CO2 concentration in the atmosphere. Located in aggrading stands in the temperate zone, they have provided a strong foundation for testing critical assumptions in terrestrial biosphere models that are being used to project future interactions between forest productivity and the atmosphere, despite the limited inference space of these experiments with regards to the range of global ecosystems. Now, a new generation of FACE experiments in mature forests in different biomes and over a wide range of climate space and biodiversity will significantly expand the inference space. These new experiments are: EucFACE in a mature Eucalyptus stand on highly weathered soil in subtropical Australia; AmazonFACE in a highly diverse, primary rainforest in Brazil; BIFoR-FACE in a 150-yr-old deciduous woodland stand in central England; and SwedFACE proposed in a hemiboreal, Pinus sylvestris stand in Sweden. We now have a unique opportunity to initiate a model-data interaction as an integral part of experimental design and to address a set of cross-site science questions on topics including responses of mature forests; interactions with temperature, water stress, and phosphorus limitation; and the influence of biodiversity.

Uptake of Cadmium by Hydroponically Grown, Mature Eucalyptus Camaldulensis Saplings and the Effect of Organic Ligands

The potential suitability of Eucalyptus camaldulensis for Cd phytoextraction was tested in a hydroponic study. Saplings were exposed to 4.5 and 89 μM Cd for one month, with and without EDTA and s,s-EDDS at 0.1, 1, and 5 mM. The saplings’ growth was not affected at the 4.5 μM Cd concentration, yet it decreased 3-fold at 89 μM, and almost all the Cd taken up was immobilized in the roots, reaching 360 and 5300 mg Cd kg−1, respectively (approximately 75% of which was non-washable in acid). The respective Cd root-to-shoot translocation factors were 0.14 and ≈5*10−4. At 0.1 mM concentration, EDTA and EDDS had no effect or even a positive effect on the saplings growth. This was reversed at 1 mM, and the chelants became lethal at the 5 mM concentration. At 89 μM Cd in the growth medium, 0.1 mM EDTA increased Cd translocation into the shoots by almost 10-fold, however it strongly reduced Cd content inside the roots. This hydroponic study indicates the feasibility of E. camaldulensis use for cleanup Cd-contaminated soils at environmental concentrations, both for site stabilization (phytostabilization) and gradual remediation (phytoextraction). EDTA was shown to be much more efficient in enhancing Cd translocation than s,s-EDDS.

Biomass and carbon storage of Eucalyptus and Acacia plantations in the Pearl River Delta, South China

Forest plantations represent an important carbon sink. In the Pearl River Delta (PRD) in Southern China, fast-growing Eucalyptus and Acacia are favoured plantation species, but little is known regarding their efficiency with respect to biomass production, partitioning and dynamics with stand age, or the contribution made by the understory, litter and coarse woody debris (CWD) to the volume of biomass and fixed carbon. Here, a set of 21 plantations of various ages were monitored for the pattern of biomass accumulation and partitioning. A continuous biomass expansion factor (BEF) method was applied to a set of forest inventory data (FID) over the periods 1989–2003 to estimate biomass accumulation, carbon storage and its pattern of change over time. The accumulation of biomass increased with stand age, reaching, respectively, 207.45 and 189.35tha−1 in mature Eucalyptus and Acacia plantations. The contribution of secondary biomass from the understory, litter layer and CWD accounted for, respectively, up to 10.2% and 20.3% of the total biomass in the two types of plantation, highlighting the significance of secondary biomass. At a similar growth stage, the ranking of the contribution to secondary biomass in the Eucalyptus plantations was litter>herbaceous plants>shrubs>CWD, while in the Acacia plantations, it was litter>CWD>shrubs>herbaceous plants. The Eucalyptus and Acacia plantations in the PRD accumulated some 2.66–7.84Mt of biomass and sequestered 1.33–3.92Mt of carbon. For both species, the bulk of the plantations (Eucalyptus 82.1%, Acacia 89.3%) were at the young to middle-aged stage. The Acacia plantations generated a higher biomass density than the Eucalyptus plantations. Forest management intensification and reforestation programmes, especially targeting Acacia or mixed Eucalyptus/Acacia forests, offer good potential for future carbon sequestration.

Nutrient fluxes in rainfall, throughfall and stemflow in Eucalyptus stands on the Zululand coastal plain, South Africa

Atmospheric deposition was assessed at two sites over a four-year period in post-canopy-closure (mature) Eucalyptus stands in the northern Dukuduku and southern KwaMbonambi commercial plantation forestry areas of Zululand, South Africa. The aim of this study was to determine the magnitude and relevance of nutrient addition with rainfall, throughfall and stemflow to commercial forestry in this region. Canopy cation exchange was used with rainfall and canopy drainage to derive wet, dry and total atmospheric deposition. Nutrient concentrations measured in the rainfall, throughfall and stemflow varied widely throughout the study period, and between sources and sites. Rainfall was slightly acidic at both sides, but became less acidic upon passing through the tree canopies. Canopy exchange and collection of dry deposition resulted in increased cation concentrations under the tree canopy, while the canopy generally absorbed nitrogen (N), from the rainfall, reducing the below canopy concentrations. Atmospheric deposition was shown to be responsible for large quantities of nutrients added to the eucalypt stands at each site. Annualised deposition averaged across all years at each site amounted to N, calcium, magnesium, and potassium (K) fluxes of 11.0, 6.0, 2.7 and 10.2 kg ha−1 y−1 at Dukuduku and 10, 10.6, 7.5 and 18.8 kg ha−1 y−1 at KwaMbonambi, respectively. Organic N fluxes contributed a further 8.1 kg ha−1 y−1 at Dukuduku and 7.1 kg ha−1 y−1 at KwaMbonambi to the total N deposition. Although K deposition values were high, additions of all other nutrients, although also high, were within the ranges reported in local and international research. Over the course of a full rotation, the atmospheric deposition levels recorded at these sites may have potential to supply a large proportion of the nutrients that are lost during stem-wood harvesting. This study adds value to understanding of nutritional sustainability of fast-growing plantation forests, demonstrating the importance of atmospheric deposition as a nutrient addition source to plantation-grown eucalypts along the Zululand coastal plain.

Phase change-related variations of dome shape in Eucalyptus urophylla × Eucalyptus grandis shoot apical meristems

Shoot apical meristem (SAM) domes derived from five different outdoor and in vitro sources of juvenile and mature Eucalyptus urophylla × Eucalyptus grandis akin genotypes were compared. Overall measurements of SAM dome height H and diameter D ranged from 2 to 35 μm and 20 to 80 μm, with significant differences according to the various physiological origins of plant material investigated. SAM domes from the mature trees “Mat” were taller than those from the rejuvenated ministock plants “Rej”; from the in vitro microcuttings “IVM” of the same clone and also from the in vitro juvenile seedlings “IVJ”, whereas outdoor seedlings “Juv” exhibited intermediate SAM dome height. SAM domes from the rejuvenated material “Rej”, from the in vitro mature “IVM” and juvenile “IVJ” origins were also narrower than those from the outdoor seedlings “Juv” and to lesser extent than those from the mature trees “Mat”. Overall, the mature source “Mat” displayed bigger and somehow sharper hemispherical domes than those from “Rej” and “Juv”, physiologically more juvenile, or those from the in vitro origins “IVM” and “IVJ” which looked flatter and smaller. SAM dome height, diameter D and H/D values varied also significantly according to the plastochron. More specifically, H, D, and H/D SAM differences between the five origins were not significant during the early plastochron phase corresponding to leaf initiation, to become more salient as leaf structures started to elongate and to differentiate. This was particularly obvious for mature tree “Mat” SAM dome shapes which showed at this stage much higher H/D values than the other SAM sources. A shape index S used for characterizing more accurately dome shape confirmed these trends. These observations provide additional arguments to the view that juvenility in trees becomes more and more time- and shoot-tip restricted as ageing increases in the course of time during the ontogenetical process and could be ultimately confined to the most organogenic phase of SAM, from which shoot characteristics derive.

In vitro rooting of two Eucalyptus urophylla X Eucalyptus grandis mature clones

The rooting capacity of microshoots derived from two mature Eucalyptus urophylla X Eucalyptus grandis half-sib clones kept for 3 y under intensive micropropagation was assessed in different in vitro conditions. A first set of experiments established that clone 147 microshoots rooted earlier and in greater proportions, while producing more adventitious roots overall than their homologs from clone 149. Modifying the composition of the basal 1/2-MS-derived rooting medium by 1/4-MS or Knop macronutrients, or reducing sucrose concentration to 10 g l−1 did not enhance the rooting rates. However, together with the growth regulators added, they had a significant effect on the number of adventitious roots formed. With rooting rates reaching 81%, the higher rootability of clone 147 over clone 149 was further confirmed by the second set of experiments with significant effects of the various auxins tested and strong clone × auxin interactions on the proportions of rooted microshoots and on the number of adventitious roots. The best rooting scores were given by 5 μM indole-3-butyric acid (IBA) and 12.5 μM 1-naphthaleneacetic acid (NAA), whereas the microshoots exposed to 5 or 12.5 μM indole-3-acetic acid (IAA) were less responsive. Lower light intensities did not improve significantly root capacities, although differences might exist according to the genotype. Overall, root and shoot elongation was stimulated by light. At the end of the experiment, the rooted microshoots were markedly taller than the non-rooted ones, with significant influences of auxins and light intensity, and to a lesser extent, of the genotypes.

Competitive Uptake of Trichloroethene and 1,1,1-Trichloroethane byEucalyptus camaldulensisSeedlings and Wood

The efficient use of trees for taking up volatile organic compounds (VOCs) from the subsurface for remedial and screening purposes is hampered because many poorly quantified co-occurring processes affect VOC concentrations in the tree, the most basic of which are VOC sorption and uptake by roots. Toward understanding the dominant sorption mechanisms, uptake of trichloroethene (TCE) and 1,1,1-trichloroethane (TCA) by Eucalyptus camaldulensis seedlings was studied in both single-solute and bi-solute experiments. Single-solute and bi-solute sorption experiments on wood from a mature Eucalyptus camaldulensis specimen were also carried out. Competition between TCE and TCA for sorption sites was found in both seedling uptake and wood sorption experiments, indicating that partitioning is not the sole mechanism governing compound interactions in these systems. The nonlinear single-solute sorption isotherms on wood were fit by a dual-mode model including partitioning and Langmuir terms. The dual-mode model calculated parameters were consistent with the results of the bi-solute sorption experiments. As a consequence of competitive sorption processes, uptake of individual compounds may be lower than expected when multiple VOC contaminants are present in the subsurface.

Failure of late instar larvae of the leaf beetle Chrysophtharta bimaculata to establish on mature host Eucalyptus leaves

Paropsine leaf beetle larvae from the genera Paropsis and Chrysophtharta can cause extensive defoliation to eucalypt stands in Australia and New Zealand. The larvae prefer immature leaves but the late instars (beyond the 2nd) consume most leaf material. With the consumption of all immature foliage and softer shoots, feeding on mature leaves might be necessary to complete larval development. Few studies have examined whether late instar larvae are able to establish on mature leaves, so the ability of 3rd and 4th instar C. bimaculata (Olivier) larvae to establish on mature Eucalyptus regnans (F. Mueller) leaves was tested. Groups of five larvae were placed on individual mature leaves with toughness ranging from 92.1 and 93.5g as measured with a penetrometer. Additional larvae were reared from neonates to pre-pupation under similar laboratory conditions to compare survivorship on the preferred immature leaves. The 3rd and 4th instar larvae did not establish on mature leaves although 10% of the 4th instar larvae developed into pre-pupae. In contrast, 76.7% of the larvae developed from neonates to prepupae on the immature leaves. If these findings were reflected in the field then C. bimaculata larvae would be restricted to feeding on immature foliage. When C. bimaculata larval densities are high then trees with the fewest immature leaves will suffer the least defoliation.

Hydraulic Impacts of a Mature Eucalyptus Plantation on a Shallow, Low-Permeability Aquifer

Hydraulic Impacts of a Mature Eucalyptus Plantation on a Shallow, Low-Permeability Aquifer

Self-incompatibility in Eucalyptus globulus ssp. globulus (Myrtaceae)

Controlled pollinations with self- and cross-pollen were applied to individual flowers of five mature Eucalyptus globulus Labill. ssp. globulus trees to investigate the site of action of the self-incompatibility mechanism. Growth of pollen tubes in styles at 2 weeks after pollination and ovule penetration by pollen tubes at 2 and 4 weeks after pollination were investigated by fluorescence microscopy. Some pollinated flowers were left to develop to seed maturity, then harvested to quantify the level of self-incompatibility of each tree. Trees ranged from 76 to 100% self-incompatible. There was no significant difference in the number of pollen tubes in the style between treatments although variation was present between trees. The number of pollen tubes present was similar to the number of ovules present within flowers. Penetration of ovules by pollen tubes over all five trees combined revealed no difference between treatments at 2 weeks after pollination; however, there was slightly greater penetration by cross-pollen tubes at 4 weeks after pollination. This difference was not large enough to account for the near complete lack of selfed-seed production, suggesting late pre- or post-zygotic arrest of selfed ovules.

The effect of seed trees on regrowth development in a mixed-species eucalypt forest

Summary Previous studies have shown that the retention of overwood can have suppressive effects on the development of regrowth. In this study we compared the effect of retaining seed trees (mature Eucalyptus pilularis), and removing seed trees, on the regrowth of E. pilularis and the more tolerant eucalypt species such as E. microcorys, E. propinqua, E. acmenoides, and E. paniculata. The study utilised a mixed hardwood stand located within Pine Creek State Forest, near Coffs Harbour in north-eastern New South Wales. The stand had been regenerated in 1972 leaving 15 seed trees/ha. Half of the seed trees were removed in 1990. Measurements of height, diameter, and distance of regrowth trees to the seed trees indicated that the height of regrowth was significantly affected by distance from seed tree (removed or retained). This suppressive effect was significantly more pronounced for E. pilularis than for more tolerant species. Height development of the regrowth improved significantly where seed trees had been removed. For the intolerant species the height-to-diameter ratio decreased with distance from seed tree (removed or retained), whereas for tolerant species the height to diameter ratio remained constant over all distances. The results of this study confirm that intolerant eucalypt species are more sensitive to overstorey competition than more tolerant species, and that the relative loss of production from the retention of mature trees may be smaller in mixed stands consisting of tolerant and intolerant eucalypt species than in mono-specific stands of intolerant species.

The Big Ash forest, Wallaby Creek, Victoria— changes during one lifetime

In 1949 the area of mature Eucalyptus regnans F.Muell1 (the Big Ash) on the Hume Range, Victoria, was a largely even-aged 230-year-old forest with a component of the overstorey derived from a fire in 1851. Subsequent fires have resulted in patchy regeneration where suitable gaps in the overstorey were present. In 1949 three main types of the understorey were present: type A, mature Pomaderris aspera; type B, dense immature Pomaderris aspera; and type C, coppiced Olearia argophylla and Bedfordia arborescens. In type A, ground fern was patchy and statistically correlated with patches of lower density Pomaderris aspera. Over a period of 48 years the eucalypt overstorey has been depleted by death and windthrow while understorey trees and shrubs have been severely damaged by sporadic heavy snowfalls and insect and fungal attack. The type A understorey is now showing signs of changing to Olearia argophylla dominance and the cover of ground fern and tree fern strata has doubled to more than 80% over this period in spite of damage caused by infrequent, but severe, droughts. The type B understorey is now mature and resembles type A, while the type C understorey shows invasion by Pomaderris aspera and regeneration of Olearia argophylla. No successful establishment of E. regnans has occurred. The rainforest in the gullies consists of alternating patches of forest and tree fern groves, the latter, together with rotting logs and upthrown root balls, providing niches for rainforest tree establishment. In swampy flats of Leptospermum grandifolium on the plateau Atherosperma moschatum is becoming increasingly dominant. Atherosperma moschatum is also invading mature understorey adjacent to riparian communities. This species and Olearia argophylla may constitute the final stage of the long secondary succession after fire in the Big Ash area. However, the Hume Range is adjacent to drier foothills and plains to the north, west and south. Whether the Big Ash will be spared from fire in future centuries is very doubtful.

Problems of regeneration of the mature Eucalyptus regnans F. Muell, (The Big Ash) forest, in the absence of fire at Wallaby Creek, Victoria, Australia

Summary This paper is based on observations on the regeneration of a mature E. regnans forest begun in 1949 and extending over the next 50 years. Any regeneration of E. regnans in the unburnt, mature forest is confronted by a phalanx of obstacles. The formation of large gaps which synchronously involve the overstorey, shrub understorey and fern stratum are an essential prerequisite for establishment, although success may not be assured unless the seedbed has been favourably prepared by mechanical disturbance or fire. In this study, regeneration, which was initiated experimentally by a heavy sowing of seed, scarification of soil, addition of nitrogenous fertilizer, creation of moderately good light conditions and the removal of competition by seedlings of understorey species in the first season, failed completely after 10–11 years even though understorey species which germinated from the soil seed bank continued to thrive. Processes of seed germination and seedling development are explored in terms of seed harvesting by ants, insect attack, heating and desiccation of the soil surface, mammal browsing, light intensity and dimorphic leaf orientation, mycorrhizal associations, root competition, allelopathic factors, leaf spot fungi and chewing and gall-forming insects. In the tall forest lateral light is considered critical for continued vigour of advanced seedlings with pendulous foliage. Thus, gaps which permit satisfactory development of young seedlings are inadequate for saplings, especially if they are in competition with vigorous regeneration of understorey species. Under light-limiting conditions, survival is severely jeopardized by any factor affecting leaf area or leaf function. It is concluded that while E. regnans appears to be physiologically tolerant of moderate shade it lacks the wider ecological tolerance to it. Without fire, the regeneration of E. regnans will almost certainly fail in the mature forest unless accompanied by exceptional circumstances. Group tree falls are needed to create regeneration but only on sites incompletely covered by dense ground fern. Synchronous gaps may be needed to disperse herbivore activity in the critical early years. Crown fire eliminates most of the difficulties encountered by E. regnans regeneration by causing mass seedfall, creating a suitable seed bed and by temporarily changing the microclimate, soil moisture regime, soil nutrient status, microbial populations and ant foraging activity. Regeneration may occur in groups following surface fires if large canopy gaps have been produced. In the unlikely event of a very long period without fire, succession to a form of rainforest is likely to occur, although the species may not be eliminated entirely from the area due to the possibility of chance establishment.

Transpiration from a mature Eucalyptus globulus plantation in Portugal during a spring-summer period of progressively higher water deficit.

The rates of transpiration from a mature Eucalyptus globulus Labill. stand in Portugal were evaluated during a drying period of the spring-summer 1994. Transpiration was measured by the Granier sap flow method and estimated by the Penman-Monteith model. During the experimental period daily transpiration varied between 3.64 and 0.50 mm day-1. For high-transpiration days, a good agreement was observed between Penman-Monteith estimates and sap flow measurements, both on a daily and on an hourly basis. However, for low-transpiration days, the Penman-Monteith model overestimated transpiration in comparison with the sap flow method. The diurnal variation of sap flow was then smoother and lagged behind the estimates of the Penman-Monteith model. E. globulus showed an efficient control of transpiration losses during dry periods through a progressive stomatal closure. As soil moisture deficit increased, the daily maximum stomatal conductance decreased from 0.46 to 0.14 cm s-1. The results also show that, on a seasonal basis, stomatal conductance and daily transpiration were mainly related to predawn leaf water potential and, thus, to soil moisture content.

Effects of soil phosphorus availability, temperature and moisture on soil respiration in Eucalyptus pauciflora forest

Rates of soil respiration (CO2 efflux) were measured for a year in a mature Eucalyptus pauciflora forest in unfertilized and phosphorus-fertilized plots. Soil CO2 efflux showed a distinct seasonal trend, and average daily rates ranged from 124 to 574 mg CO2 m−2 hr−1. Temperature and moisture are the main variables that cause variation in soil CO2 efflux; hence their effects were investigated over a year so as to then differentiate the treatment effect of phosphorus (P) nutrition.

Allocation of carbon in a mature eucalypt forest and some effects of soil phosphorus availability

Pools and annual fluxes of carbon (C) were estimated for a mature Eucalyptus pauciflora (snowgum) forest with and without phosphorus (P) fertilizer addition to determine the effect of soil P availability on allocation of C in the stand. Aboveground biomass was estimated from allometric equations relating stem and branch diameters of individual trees to their biomass. Biomass production was calculated from annual increments in tree diameters and measurements of litterfall. Maintenance and construction respiration were calculated for each component using equations given by Ryan (1991a). Total belowground C flux was estimated from measurements of annual soil CO2 efflux less the C content of annual litterfall (assuming forest floor and soil C were at approximate steady state for the year that soil CO2 efflux was measured). The total C content of the standing biomass of the unfertilized stand was 138 t ha-1, with approximately 80% aboveground and 20% belowground. Forest floor C was 8.5 t ha-1. Soil C content (0–1 m) was 369 t ha-1 representing 70% of the total C pool in the ecosystem. Total gross annual C flux aboveground (biomass increment plus litterfall plus respiration) was 11.9 t ha-1 and gross flux belowground (coarse root increment plus fine root production plus root respiration) was 5.1 t ha-1. Total annual soil efflux was 7.1 t ha-1, of which 2.5 t ha-1 (35%) was contributed by litter decomposition.