Leaf Spot of Hemp Dogbane Caused by Stagonospora apocyni, and its Phytotoxins

Stagonospora apocyni causes a leaf spot disease on hemp dogbane (Apocynum cannabinum L.). The fungus produced phytotoxins citrinin, mellein, tyrosol and α–acetylorcinol in liquid culture. All toxins caused necrosis when placed on leaves of hemp dogbane, and eight other weed species. All four toxins were non–specific phytotoxins. Citrinin showed antimicrobial properties against some bacteria and fungi.     

Effects ofFusarium solani naphthazarin toxins on the cytology and ultrastructure of rough lemon seedlings

Two naphthazarin phytotoxins (dihydrofusarubin and isomarticin) produced byFusarium solani were used to determine their effects on the cytology of leaves of rough lemon (Citrus jambhiri Lush) seedlings maintained in a dilute solution of the toxins. Dihydrofusarubin alone or in combination with isomarticin (80:20, v/v) caused cell necrosis above the midveins and lateral veins, plasmolysis or collapse of spongy mesophyll cells, collapse of phloem, depletion of starch, swelling of chloroplasts and disruption of cellular organization. At the ultrastructural level, the toxins affected chloroplast membranes by causing swelling, breaks in outer membranes, granal stack disorganization and swelling of intergranal membranes. The interstromal lamellae appeared as vesicles and sometimes as peripheral reticulum, with an increase in plastoglobuli. The tonoplast was broken or vesiculated. The only membranes not affected by the toxins were those of the nucleus and the mitochondria. This study establishes that the initial toxin effects of these fungal phytotoxins are on organellar membranes, primarily those of the chloroplasts, plasmalemma and tonoplast.Florida Agricultural Experiment Station Journal Series No. R-00648. This paper reports the results of research only. Mention of a trademark, warranty, proprietary product, or vendor does not constitute a guarantee by the US Department of Agriculture and does not imply its approval to the exclusion of other products or vendors that may also be suitable.     

Effects of Inoculum Density and Wounding on Stem Infection of Three Eastern US Forest Species by Phytophthora ramorum

Seedlings of three Eastern US forest species Quercus rubra (northern red oak), Quercus prinus (chestnut oak) and Acer rubrum (red maple) were inoculated by applying Phytophthora ramorum sporangia to stems at different inoculum densities with and without wounding. Disease occurred in all treatments involving wounds, and no disease was observed in unwounded treatments. Younger seedlings (2–3 years old) did not differ significantly from older seedlings (5–6 years old) in disease incidence, but older seedlings sustained smaller lesions compared with younger seedlings. For both old and young seedlings, disease on wounded stems was observed down to the lowest sporangia concentration utilized (500 sporangia/ml for old seedlings and 100 sporangia/ml for young seedlings). The results show that in the presence of wounding, even very low sporangia concentrations can result in disease, and further suggest that wounding caused by insects and other factors may play an important role in P. ramorum epidemiology in forest environments.     

Effects of rodent gnawing on the survival of current-year seedlings of Quercus crispula

Emergence, survival and mortality patterns of current-year oak (Quercus crispula Blume) seedlings were investigated for 4 consecutive years in a secondary oak forest in Hokkaido, northern Japan. Despite the emergence of a considerable number of oak seedlings in the years following masting, few current-year seedlings survived until the end of the growing season. Almost all of the seedlings died from damage to their stems caused by the gnawing of rodents. Rodent gnawing on transplanted oak seedlings was also observed in the year following masting but not in the year following a bad crop year. Cuttings of dwarf bamboo, Sasa, did not reduce the seedling mortality caused by gnawing. However, transplanted oak seedlings were gnawed more quickly when they were placed on the forest floor with a thicker Sasa covering. All rodents trapped in the vicinity of the study area were Apodemus speciosus Temminck. These results suggest that rodents strongly influence the recruitment of oak trees not only through the predation and dispersal of acorns but also through gnawing seedlings.     

Branch growth and leaf numbers of red maple (Acer rubrum L.) and red oak (Quercus rubra L.): response to defoliation

Summary Branch growth and leaf formation from terminal and from lateral buds of red maple (Acer rubrum L.) and red oak (Quercus rubra L.) were measured in response to simulated insect defoliation. A single large branch representative of the crown of each tree was used for enumeration of growth and of bud numbers throughout three successive years of 0, 50, 75, and 100% leaf removal for the entire tree. Leaf number per tree for both species after the last year of defoliation was reduced in direct proportion to the severity of defoliation, in comparison to the predefoliation status of the trees. Bud number per tree for red maple, but not for red oak, was also reduced in proportion to severity of defoliation.Averaged over all defoliation treatments, defoliation reduced branch growth more than leaf production. Furthermore, the reduction in branch growth and leaf production was greater in red oak than in red maple. Three years of successive defoliation reduced the mean lateral plus terminal branch growth by 40% in red oak and by 23% in red maple, while leaf number was reduced 22% in red oak and remained unchanged in red maple. In red maple, 100% defoliation caused greater branch death than the 50 or 75% defoliation treatments, and the amount of death was greater after each successive year of defoliation. In contrast to red maple, undefoliated red oak incurred a substantial amount of branch death throughout the study which was little affected by defoliation treatment.     

Suitability of native and ornamental oak species in California for Agrilus auroguttatus

Goldspotted oak borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae), is a new invasive species in southern California, USA. The extent of the host range of this insect is not known, but this knowledge will have a major impact on assessment of the risks that this pest poses to oaks [Quercus spp. (Fagaceae)]. We conducted laboratory tests to determine the potential suitability of native and ornamental oak species for larvae and adults of A. auroguttatus. We infested 179 cut logs (from 163 different trees) with eggs or larvae, measured neonate survival and, after 5 months, counted feeding galleries, and noted the proportion of galleries with late instars. Initial larval survival was generally high when larvae penetrated the phloem (range: 62–98% among oak species), and low by the time larvae began to feed at the phloem/xylem interface (range: 0–25% among oak species). The majority of larvae that established a visible feeding gallery survived to the fourth instar (total of 73% for all oak species). Larval galleries were established with greater frequency in red oaks (Section Lobatae) compared with other oaks (19 vs. 7 or 4%). All red oaks tested (Q. agrifolia Née, Q. kelloggii Newberry, and Q. wislizeni A. DC.) were likely suitable hosts for larvae. Larvae were apparently able to feed on some of the other oaks (Q. chrysolepis Leibmann, Q. suber L., Q. lobata Née, and Q. douglasii Hook & Arn), although it remains unclear whether these species would be preferred hosts under natural conditions. Adult longevity and fecundity varied little by species of oak foliage fed to adults. The host range of A. auroguttatus is likely limited by suitability of oak species for the larval rather than the adult life stage. Results support published field observations that red oaks are more suitable hosts than white oaks.     

Removal of water turbidity by natural coagulants obtained from chestnut and acorn

The ability of seed extracts of several species of chestnut and acorn to act as natural coagulants was tested using a synthetic turbid water. Active components were extracted from ground seeds of Horse chestnut and acorns of some species of family Fagaceae: Common oak, Turkey oak, Northern red oak and European chestnut. All investigated extracts had coagulation capabilities and their amounts depended on pH values and initial turbidities. The seed extracts from European chestnut and Common oak acorn were the most efficient expressing the highest coagulation activities, about 80% and 70%, respectively, in both low and medium investigated water turbidities at the lowest coagulant dose 0.5 ml/L.     

Ectomycorrhiza communities of red oak (<Emphasis Type="BoldItalic">Quercus rubra</Emphasis> L.) of different age in the Lusatian lignite mining district,East Germany

Ectomycorrhizal (ECM) communities were assessed on a 720 m² plot along a chronosequence of red oak (Quercus rubra) stands on a forest reclamation site with disturbed soil in the lignite mining area of Lower Lusatia (Brandenburg, Germany). Adjacent to the mining area, a red oak reference stand with undisturbed soil was investigated reflecting mycorrhiza diversity of the intact landscape. Aboveground, sporocarp surveys were carried out during the fruiting season in a 2-week interval in the years 2002 and 2003. Belowground, ECM morphotypes were identified by comparing sequences of the internal transcribed spacer regions from nuclear rDNA with sequences from the GenBank database. Fifteen ECM fungal species were identified as sporocarps and 61 belowground as determined by morphological/anatomical and molecular analysis of their ectomycorrhizas. The number of ECM morphotypes increased with stand age along the chronosequence. However, the number of morphotypes was lower in stands with disturbed soil than with undisturbed soil. All stands showed site-specific ECM communities with low similarity between the chronosequence stands. The dominant ECM species in nearly all stands was Cenococcum geophilum, which reached an abundance approaching 80% in the 21-year-old chronosequence stand. Colonization rate of red oak was high (>95%) at all stands besides the youngest chronosequence stand where colonization rate was only 15%. This supports our idea that artificial inoculation with site-adapted mycorrhizal fungi would enhance colonization rate of red oak and thus plant growth and survival in the first years after outplanting.     

Nitrate reductase and glutamine synthetase activities in relation to growth and nitrogen assimilation in red oak and red ash seedlings: effects of N-forms,N concentration and light intensity

The effects of growing seedlings of red oak (Quercus rubra) and red ash (Fraxinus pennsylvanica) with Hoagland solutions containing five N-regimes, differing in the N-forms (NH₄, NO₃) and concentrations (High and Low), in relation to light intensity were investigated by the utilization of enzymatic markers of the N assimilation pathway, nitrate reductase (NR) and glutamine synthetase (GS). Red oak and red ash showed different patterns of N-assimilation. Red oak seedlings assimilated NO₃ in low amounts in their roots and leaves, whereas red ash seedlings assimilated high amounts of NO₃, mostly in the leaves. A significant amount of constitutive NR activity was found in red oak seedlings supplied with NH₄ N-regime. This could be characteristic of a species adapted to soils that are poor in nitrogen. Root GS activity was lower in red oak seedlings than in red ash seedlings, indicating that the rate of NH₄ assimilation differed in these two hardwood species. Low irradiance reduced growth of both hardwood species, but greatly affected the specific leaf area of red ash and reduced NO₃ assimilation (when data are expressed per leaf area). Both species reacted similarly to N-regimes in terms of relative growth rate.     

Effect of winter flooding on mass and gross energy of bottomland hardwood acorns

Decomposition of red oak acorns (Quercus spp.; Section Erythrobalanus) could decrease forage biomass and gross energy (GE) available to wintering ducks from acorns. We estimated changes in mass and GE for 3 species of red oak acorns in flooded and non-flooded bottomland hardwood forests in Mississippi during winter 2009–2010. Mass loss of acorns was ≤8.1% and reduction in GE ≤0.03 kcal/g after exposure for 90 days. These small changes in mass and GE of red oak acorns would have minimal effect on carrying capacity of bottomland hardwood forests for ducks. © 2012 The Wildlife Society.     

Population dynamics and growth patterns for a cohort of northern red oak (Quercus rubra) seedlings

Summary I studied the survival and development of a 1986 cohort of northern red oak (Quercus rubra L.) seedlings growing under a variety of overstory and microsite conditions in a northern hardwood forest dominated by northern red oak, red maple (Acer rubrum L.) paper birch (Betula papyrifera Marsh.), and scattered white pine (Pinus strobus L.). Fifty naturally regenerating seedlings of oak were randomly selected in each of three canopy classes: no overstory, partial overstory, and complete overstory. Growth and mortality were measured for six years. Seedling height growth decreased with overstory density, with less growth evident with even a partial overstory. Seedling survival also declined with overstory density and depended on microtopography to a lesser extent. After six years, 92% of the seedlings survived in the open, compared to 54% under the partial overstory, and 36% under the complete overstory. The open environment, in which woody and herbaceous regrowth formed a low canopy reducing light intensities to about 50% of full sunlight, provided a favorable site for the growth and survival of northern red oak.     

Environmentally-based maternal effects: a hidden force in insect population dynamics?

Summary The nutritional environment of the parental generation of the polyphagous gypsy moth, Lymantria dispar, can significantly influence the growth and reproductive potential of the next generation through environmentally-based maternal effects. In the first experiment, members of the parental generation were reared on red oak trees (Quercus rubra L.) with known defoliation and phenolic levels. Diet in the offspring generation was homogeneous (synthetic diet). With genetic effects accounted for 1) offspring attained greater pupal weights when their mothers fed on trees with higher leaf damage levels, 2) daughters had a shorter prefeeding stage, a trait associated with dispersal tendency, when their mothers experienced higher condensed tannin levels, and 3) sons had lower pupal weights when their mothers experienced greater condensed tannin levels. In the second experiment, members of the parental generation were reared on either red or black oak (Q. velutina) trees. Offspring of each mother were divided among four diets: red oak, chestnut oak (Q. prinus L.), a standard synthetic diet, and a low-protein synthetic diet. The parental host species accounted for 24% of the variation in daughters' development time; offspring diet accounted for 52%. When mothers were reared on black oak rather than red oak, their offspring developed significantly faster when the F1 diet was chestnut oak. Environmentally-based maternal effects can significantly influence the expression of offspring dispersal potential, growth rate, and offspring fecundity. These traits contribute to natality and survival in natural populations and, hence, to population growth potential. Theoretical models of insect population dynamics demonstrate that the presence of a time delay in a density dependent response can induce destabilization. Maternal effects act on a time delay and may participate in the destabilization characteristic of outbreak species.     

Effect of a strong cold storage induced desiccation on metabolic solutes,stock quality and regrowth,in seedlings of two oak species

Bare-root seedlings of pedunculate oak (Quercus robur L.) and northern red oak (Quercus rubra L.) were lifted in January and stored at 1.8°C, at 82% relative humidity, until their fresh weight declined by 33%. Root growth potential (RGP), fine root electrolyte leakage (REL), fine root water content (RWC), shoot tip water content (SWC), starch and metabolic solute contents in root and shoot, were measured just after lifting and after treatment. Survival of treated seedlings was also assessed in a field trial. RWC, SWC, REL, RGP were dramatically affected by desiccation during cold storage. In both species, root soluble carbohydrate level, inositol level and isocitrate level increased, whereas root starch level and shoot soluble carbohydrate level decreased. In northern red oak, treated seedlings had higher root contents of soluble carbohydrates, inositol and proline than in pedunculate oak. Moreover, treatment induced proline accumulation only in northern red oak roots. These differences could explain why field survival of treated seedlings was significantly better in northern red oak than in pedunculate oak.     

Inadequate Cold Tolerance as a Possible Limitation to American Chestnut Restoration in the Northeastern United States

The American chestnut (Castanea dentata (Marshall) Borkh.), once a major component of eastern forests from Maine to Georgia, was functionally removed from the forest ecosystem by chestnut blight (an exotic fungal disease caused by Cryphonectria parasitica (Murr.) Barr), first identified at the beginning of the twentieth century. Hybrid‐backcross breeding programs that incorporate the blight resistance of Chinese chestnut (Castenea mollissima Blume) and Japanese chestnut (Castenea crenata Sieb. & Zuc.) into American chestnut stock show promise for achieving the blight resistance needed for species restoration. However, it is uncertain if limitations in tissue cold tolerance within current breeding programs might restrict the restoration of the species at the northern limits of American chestnut's historic range. Shoots of American chestnut and hybrid‐backcross chestnut (i.e., backcross chestnut) saplings growing in two plantings in Vermont were tested during November 2006, February 2007, and April 2007 to assess their cold tolerance relative to ambient low temperatures. Shoots of two potential native competitors, northern red oak (Quercus rubra L.) and sugar maple (Acer saccharum L.), were also sampled for comparison. During the winter, American and backcross chestnuts were approximately 5°C less cold tolerant than red oak and sugar maple, with a tendency for American chestnut to be more cold tolerant than the backcross chestnut. Terminal shoots of American and backcross chestnut also showed significantly more freezing damage in the field than nearby red oak and sugar maple shoots, which showed no visible injury.     

Radial growth and climate responses of white oak (Quercus alba) and northern red oak (Quercus rubra) at the northern distribution limit of white oak in Quebec, Canada

Aim The objectives of this study were: (1) to compare radial growth patterns between white oak (Quercus alba L.) and northern red oak (Quercus rubra L.) growing at the northern distribution limit of white oak; and (2) to assess if the radial growth of white oak at its northern distribution limit is controlled by cold temperature. Location The study was conducted in three regions of the Ottawa valley in southern Québec. All stands selected were located at the northern limit of distribution of Q. alba. Methods Twelve mixed red and white oak stands were sampled and increment cores were extracted for radial growth analyses. For each oak species, 12 chronologies were derived from tree‐ring measurement (residual chronologies). Principal components analysis and redundancy analysis were used to highlight the difference between radial growth in both species and to determine their radial growth–climate association. Results There was little difference between the radial growth of each species; Q. alba, however, exhibits more year‐to‐year variation in growth than Q. rubra. More than 65% of the variance in radial growth was shared among sites and species. Both species showed a similar response to climate, which suggested that the limit of distribution of Q. alba might not be determined by effects on growth. Both species had a classic response to climate and drought in the early growing season. Main conclusions The northern distribution limit of Q. alba does not appear to be directly controlled by effects on growth processes as indicated by the similarities in radial growth and response to climate between the two species. The location of the stands on southern aspects suggested that cold temperature could have been a major factor controlling the distribution limit of Q. alba. However, it is speculated that stands growing on southern aspects may be more prone to forest fires or to drought, which would favour the maintenance and establishment of oaks, and of Q. alba in particular. Models relating the northern distribution limits of species to broad climate parameters like annual mean temperature will need to be reviewed to incorporate more biologically relevant information. Such assessments will in turn provide better estimates of the effect of climate changes on species distribution.     

Use of forested field edges by a blueberry insect pest,Rhagoletis mendax (Diptera: Tephritidae)

1. The blueberry maggot fly, Rhagoletis mendax Curran, is a pest of wild and highbush blueberries. In wild blueberries, most flies colonize fields from forest edges annually. Flies were associated with forest canopies adjacent to colonized fields.
2. Flies were captured up to 6 m high (limited by trap placement height) and may occur at greater tree heights. Fly abundance relative to tree species was highest in red oak.
3. Releases of marked flies from tree canopies showed that release height had no effect on distance into the field that flies dispersed. This is important because the main fly control tactic is the application of a 25- to 30-m-wide swath of insecticide along field perimeters.
4. In the laboratory, flies preferred leaves and leaf extracts of red oak compared to other leaf tree and shrub species, including blueberry. Electroantennographs demonstrated that the female antennae consistently responded to compounds extracted from red oak leaves. Mass spectra and gas chromatograph retention times of five antenna-active compounds matched those of (i) trans-β-ocimene, (ii) linalool, (iii) 4,8-dimethyl-1,3,7-nonatriene, (iv) indole, and (v) trans-nerolidol.
5. We speculate flies recruit to trees before movement into blueberry fields primarily for food, as supported by their arrestment response to leaf extracts.

     

A glimpse at future forests: predicting the effects of <Emphasis Type="Italic">Phytophthora ramorum</Emphasis> on oak forests of southern Appalachia

The highly pathogenic Phytophthora ramorum, causal organism of sudden oak death (SOD), is established in forests of the Pacific Northwest (USA) and is threatening invasion of other regions. Given the breadth of its host range, with dozens of asymptomatic ornamental hosts and with oaks, Quercus spp., in the red oak (Erythrobalanus) subgenus particularly susceptible, we investigated the consequences of its invasion and establishment in oak-dominated deciduous forests of the eastern USA. We evaluated the nature and extent of pathogen invasion using vegetation assessments coupled with growth simulations. The woody plant community was assessed in three strata (upper, mid- and lower) and was used to characterize forest composition and structure. Using the Forest Vegetation Simulator (FVS), we then projected woody vegetation growth 50 years into the future with and without the effects of SOD. In forest simulations lacking pathogen invasion, little change in composition or structure is forecasted. Both red oaks and white oaks (subgenus Leucobalanus) increase slightly but significantly over the length of the simulation. In contrast, in SOD-affected forests our projections predict a significant loss of red oaks within 10 years of pathogen invasion. Basal area of white oaks and non-oaks is expected to increase more so in the absence of red oaks. The loss of red oaks to pathogen infection will result in greater increases in red maple, Acer rubrum, and yellow poplar, Liriodendron tulipifera, than in forests free of SOD. Loss of red oak represents a significant loss of hard mast, with potentially devastating consequences for wildlife. Red oak loss will also affect decomposition rates, nutrient cycling, forest structure, and timber values, with consequences for forest health and sustainability.     

TEMPORAL AND SPATIAL PATTERNS OF SPECIFIC LEAF WEIGHT IN SUCCESSIONAL NORTHERN HARDWOOD TREE SPECIES

Temporal and spatial patterns of specific leaf weight (SLW, g/m²) were determined for deciduous hardwood tree species in natural habitats in northern lower Michigan to evaluate the utility of SLW as an index of leaf photosynthetic capacity. No significant diurnal changes in SLW were found. Specific leaf weight decreased and then increased during leaf expansion in the spring. Most species, especially those located in the understory, then had relatively constant SLW for most of the growing season, followed by a decline in SLW during autumn. Specific leaf weight decreased exponentially down through the canopy with increasing cumulative leaf area index. Red oak (Quercus rubra), paper birch (Betula papyrifera), bigtooth aspen (Populus grandidentata), red maple (Acer rubrum), sugar maple (A. saccharum), and beech (Fagus grandifolia) generally had successively lower SLW, for leaves at any one level in the canopy. On a given site, comparisons between years and comparisons of leaves growing within 35 cm of each other showed that differences in SLW among species were not due solely to microenvironmental effects on SLW. Bigtooth aspen, red oak, and red maple on lower-fertility sites had lower SLW than the same species on higher-fertility sites. Maximum CO₂ exchange rate, measured at light-saturation in ambient CO₂ and leaf temperatures of 20 to 25 C, increased with SLW. Photosynthetic capacities of species ranked by SLW in a shaded habitat suggest that red oak, red maple, sugar maple, and beech are successively better adapted to shady conditions.     

Colonization, survival, and causes of mortality of Camerariu hamadryadella (Lepidoptera: Gracillariidae) on four species of host plants

Abstract.

• 1 The abundance, survival, and causes of mortality of Cameraria hamadryadella (Clemens) (Lepidoptera: Gracillariidae) were examined on four host plant species in Virginia, U.S.A. Quercus alba L. and Q.rubra L. are native within the geographic range of C.hamadryadella, and Q.robur L. and Q.benderi Baenitz are exotic. Q.robur is native to Europe, North Africa, and Asia and was probably introduced prior to 1850, and Q.benderi is of hybrid origin and introduced to cultivation before 1900. Q.alba and Q.robur are in the subgenus Lepidobalanus (white oaks), and Q.rubra and Q.benderi are in the subgenus Erythrobalanus (red oaks).
• 2 Larval mines of C. hamadryadella were abundant on both white oak species, including the exotic Q.robur, but were rare on host plants in the red oak subgenus. Un-hatched eggs of C.hamadryadella were not observed on red oaks. Other observations on host distribution indicate that C.hamadryadella is rarely found on red oaks. These observations are interpreted as circumstantial evidence that C. hamadryadella generally avoids ovipositing on red oaks.
• 3 Survival of C.hamadryadella to the adult stage was similar among all host species, but larvae tended to survive longer on hosts in the red oak subgenus. The observation of higher survival rates of early instar larvae on red oaks suggests that no nutritional or secondary chemical barrier reinforces the observed pattern of oviposition.
• 4 Significant differences in the distribution of the causes of mortality were detected between native and exotic host plant species. Larvae and pupae on native hosts were more likely to die because of predation, while those on exotic host plants were more likely to die because of parasitism and host feeding by adult female parasitoids. This pattern could arise because parasitoids prefer to forage on exotic host plants or because predators avoid foraging on exotic plants.
• 5 This study shows for C. hamadryadella that the only barriers to colonization and use of exotic hosts, in the white and red oak subgenera, are the presence of cues sufficient to stimulate oviposition and/or the absence of cues to deter oviposition. It also suggests that the presence of closely related native host plants in the region of introduction will increase the probability that exotic plants will be colonized by phytophagous insects.

     

Aboveground nitrogen and phosphorus use by five plantation-grown trees with different leaf longevities

Aboveground nitrogen (N) and phosphorus (P) requirement, retranslocation and use efficiency were determined for 28-year-old red oak (Quercus rubra L.), European larch (Larix decidua Miller), white pine (Pinus strobes L.), red pine (Pinus resinosa Ait.) and Norway spruce (Picea abies (L) Karst.) plantations on a similar soil in southwestern Wisconsin. Annual aboveground N and P requirements (kg/ha/yr) totaled 126 and 13 for red oak, 86 and 9 for European larch, 80 and 9 for white pine, 38 and 6 for red pine, and 81 and 13 for Norway spruce, respectively. Nitrogen and P retranslocation from current foliage ranged from 81 and 72%, respectively, for European larch, whereas red pine retranslocated the smallest amount of N (13%) and Norway spruce retranslocated the smallest amount of P (18%). In three evergreen species, uptake accounted for 72 to 74% of annual N requirement whereas for two deciduous species retranslocation accounted for 76 to 77% of the annual N requirement. Nitrogen and P use (ANPP/uptake) was more efficient in deciduous species than evergreen species. The results from this common garden experiment demonstrate that differences in N and P cycling among species may result from intrinsic characteristics (e.g. leaf longevity) rather than environmental conditions.