Weight In October Research Articles

Seasonal fluctuation in the length-weight relationship of groupers in the Goto Islands, Japan

The length-weight relationships (LWRs) of 13 commercially important grouper species inhabiting the Goto Islands in southwestern Japan were established. The samples were collected between June 2007 and December 2013. We determined the monthly LWRs for the seven abundant species to determine whether these LWRs changed seasonally. Generalized additive models demonstrated significant differences in body weight compared to total length for all seven species during the year. Smoothing splines indicated that four species of groupers (Epinephelus awoara, E. fasciatus, E. areolatus, and Plectropomus leopardus) gained weight relative to the total length in a few months of spring to summer (April–September), corresponding to the spawning period of each species. Therefore, this increase was presumably due to the energy stored in the body for upcoming spawning events, followed by gonadal development for spawning. E. akaara decreased its weight relative to its length in September, indicating that it may exhaust energy during the spawning season and then reduce its weight. The remaining two species (E. bruneus and Hyporthodus septemfasciatus) gained weight from December to March and in October, respectively, which did not coincide with their spawning period. The increment of body weight in October for H. septemfasciatus may indicate that they stored energy in preparation for the upcoming winter because lower temperatures in winter decrease the food consumption rate. E. bruneus might be able to acquire sufficient energy during December–March despite a lower food consumption rate, possibly because of the abundance of prey inhabiting the Goto Islands.

Effects of photoperiod on nutrient digestibility, hair follicle activity and cashmere quality in Inner Mongolia white cashmere goats.

ObjectiveThis study investigated the effects of photoperiod on nutrient digestibility, hair follicle (HF) activity and cashmere quality in Inner Mongolia white cashmere goats.MethodsTwenty-four female (non-pregnant) Inner Mongolia white cashmere goats aged 1 to 1.5 years old with similar live weights (mean, 20.36±2.63 kg) were randomly allocated into two groups: a natural daily photoperiod group (NDPP group:10 to 16 h light, n = 12) and a short daily photoperiod group (SDPP group: 7 h light:17 h dark, n = 12). All the goats were housed in individual pens and fed the same diets from May 15 to October 15, 2015. The digestibility of crude protein (CP), dry matter (DM), and neutral detergent fiber (NDF) were measured in different months, along with secondary hair follicle (SHF) activity, concentration of melatonin (MEL), and cashmere quality.ResultsAlthough there was no significant difference in the live weights of goats between the SDPP and NDPP groups (p>0.05), the CP digestibility of goats in the SDPP group was significantly increased compared to the NDPP group in July, September, and October (p<0.05). For the DM and NDF digestibility of goats, a significant increase (p<0.05) was found during in September in the SDPP group. Furthermore, compared to the NDPP group, the SHF activity in July, the MEL concentration in July, and the cashmere fiber length and fiber weight in October were significantly increased in the SDPP group (p<0.05).ConclusionThe cashmere production of Inner Mongolia white cashmere goats was increased without obvious deleterious effects on the cashmere fibers in the SDPP group (metabolizable energy, 8.34 MJ/kg; CP, 11.16%; short daily photoperiod, 7 h light:17 h dark).

Short‐Term Effects of Diverse Compost Products on Soil Quality in Potato Production

Core Ideas Compost application increased soil organic matter content and improved soil quality. Compost products with greater C concentrations resulted in greater soil improvements. Particulate organic matter C was the index most responsive to compost addition. Mature composts with greater C concentrations and dry matter were most suitable. Soil quality has declined with intensive potato production practices in New Brunswick, Canada. Compost application may rapidly increase soil organic matter (SOM) and reverse declining productivity. This study assessed five diverse compost products for their short‐term effects on soil quality, and in particular SOM. Selected compost products derived from a range of forestry, marine, and municipal waste materials were compared with a non‐amended control. Treatments were applied to field plots at 45 Mg ha–1 dry weight in October of 2014 and 2015. Biological, chemical and physical soil properties under potato production in 2015 and 2016 (after one and after two consecutive applications) were used to evaluate soil quality. Compost application increased soil pH and concentrations of Mehlich‐3 extractable nutrients (K, Ca, Mg, and S). Compost reduced bulk density in the potato hill by 8% in both years. Particulate organic matter (POM) was the most sensitive indicator to compost‐application with twofold increases in POM‐C. Compost application increased soil organic carbon by 24% in 2016 and also increased permanganate oxidizable carbon, and soil respiration. Several soil properties were strongly correlated with compost composition, with better quality composts (i.e., more mature; greater in C, N, and other plant‐available nutrient concentrations) producing the greatest soil quality response. Overall, mature composts with greater C concentrations (i.e., low ash) and greater dry matter were most suitable for enhancing soil quality in New Brunswick potato production systems.

The Human Health Assessment to Phthalate Acid Esters (PAEs) and Potential Probability Prediction by Chromophoric Dissolved Organic Matter EEM-FRI Fluorescence in Erlong Lake.

Phthalate acid esters (PAEs) are suspected to cause wide environmental pollution and have adverse effects on human health. Three priority control phthalates, namely dimethyl phthalate (DMP), diethyl phthalate (DEP), and dibutyl phthalate (DBP), were determined in 45 water samples from the largest drinking water source in Jilin Province. Chromophoric-dissolved organic matter (CDOM), which are composed of complex compounds and are a proxy for water quality, can be monitored using a fluorometer. This study attempted to understand the correlations of the CDOM fluorescence regional integration (FRI) components with PAEs and CDOM characteristics under seasonal and spatial variations in the Erlong Lake. The characteristics of the CDOM absorption parameters in different water samples showed a higher aromatic content and molecular weight in October because of increased terrestrial inputs. The Σ3PAEs concentrations ranged from 0.231 mg L−1 to 0.435 mg L−1 in water, and DEP contributed to more than 90% of the Σ3PAEs. The FRI method identified five fluorescence components: one tyrosine-like (R1), one tryptophan-like (R2), one fulvic-like (R3), one microbial protein-like (R4), and one humic-like (R5) component. However, significant relationships exist between DEP and R3 (R2 = 0.78, p < 0.001), R4 (R2 = 0.77, p < 0.001), and R5 (R2 = 0.58, p < 0.001). Quantifying the relationship between CDOM and PAEs was highly significant, because the results will simplify the componential analysis of pollutants from a spatiotemporal perspective as compared to traditional chemical measurements. The human health risk assessment results revealed no human health risk (HQ < 1) in the Erlong Lake basin.

Growth of the halophyteAtriplex halimuson a green roof at the semi-arid Mediterranean region as affected by substrate type and irrigation regime

Aiming to exploit native, drought tolerant plants for use on green roofs at the semi-arid Mediterranean region, the effect of substrate type and irrigation frequency on growth of the halophyte Atriplex halimus was investigated on an extensive green roof in Athens, Greece. Rooted cuttings were planted in December 2012 in experimental modules with a green roof infrastructure on a fully exposed second-floor flat roof and were kept in culture until September 2014. Two types of substrate, 10 cm deep, were used, one with soil, i.e. grape marc compost:perlite:soil:pumice (3:3:2:2, v/v) and a lighter one, without soil, i.e. grape marc compost:perlite:pumice (3:3:4, v/v). Two irrigation frequencies were applied during the two dry periods, i.e. every 5 days (normal) and 9 days (sparse) in summer 2013 and every 4 days (normal) and 7 days (sparse) in summer 2014, when substrate moisture was 17-20% and 5-9% for normal and sparse, respectively. At the first growth period (2013) plant height was promoted by normal irrigation, while the above ground fresh and dry weight in October 2013 was promoted both by normal irrigation and soil amended substrate. At the end of the second growth period (2014), dry weight of the above ground part of the plant was higher under normal irrigation, while plant height was not affected by any of the main factors. No evidence of damage to the plant photosynthetic apparatus was recorded in any of the treatments, while stomatal resistance (Rleaf) was increased in plants under sparse irrigation indicating water limitation. Plants grew well and looked similar in all treatments. Thus A. halimus is suitable for use on extensive green roofs in areas with semi-arid Mediterranean climate, with soilless (light weight) substrate and sparse irrigation.

Family × Environment interactions in the growth and survival of Arctic charr (Salvelinus alpinus) grown in brackish and fresh water

We investigated whether Fraser strain Arctic charr Salvelinus alpinus L. reared in fresh water (FW) differed in survival and growth from full siblings transferred to brackish water (BW) and whether family performance was consistent throughout 1 year of commercial growth. Fish were grown communally (n = 3600) in either FW or BW from May 2008 to May 2009. Mean family survival in BW was moderately correlated with mean family survival in FW (r = 0.342; P = 0.032). Fish which survived until the conclusion of the experiment were significantly heavier in body weight at the baseline assessment than their full-sibs which died. Family by treatment interactions were detected for body weight, condition factor and specific growth across all measurement dates (May 2008, October 2008 and May 2009) and growth intervals. Despite the varied response of families to treatment, mean family body weight in FW was correlated phenotypically with BW body weight in October 2008 (r = 0.633, P < 0.0001) and marginally correlated in May 2009 (r = 0.289, P = 0.061). These data suggest that body weight in FW and body weight in BW should be analysed as separate, but correlated traits in Arctic charr breeding programs.

Body weight and blood parameters of Old Norse Sheep grazing coastal heathland

This study describes development in body weight and blood parameters of Old Norse Sheep grazing coastal heathland throughout the year without supplementary feeding. A group of approximately 80 ewes were observed for five years. The average body weight in October was 23.0 kg for lambs and 31.9 kg for ewes two years and older. The growth rate of lambs was 150–200 g/day during the first four months from birth but decreased to 51 g/day from August to October. The autumn weight increased the first five years of life. Ewes displayed weight loss and low levels of serum protein during winter, indicating moderate undernutrition. The weight loss was positively related to age and initial weight. The levels of vitamin B12 were higher than normally found in sheep on cultivated pasture. The serum levels of Ca, Mg and Cu were within the reference values, whereas the levels of inorganic P was slightly below the reference values.

INDICATORS OF PERFORMANCE IN THE FISHERY FOR SHRIMP PALAEMON SERRATUS (PENNANT) IN IRISH COASTAL WATERS

A commercial fishery for shrimp Palaemon serratus occurs on the south and west coasts of Ireland. Two temporal phases were identified: expansion from the mid 1970s to the late 1980s when maximum national landings were less than 150 t annually; and a second phase since 1990 when most years yielded more than 200 t. Maximum landings of 548 tons were reached in 1999. Three indicators of fishery performance are examined: total annual landings, weight landed per vessel per day and the average weights of individual shrimp in October and December, reconstructed from processors' records of graded shrimp. Total landings and daily landings weights correlated positively, whereas both correlated negatively with average individual shrimp weight in October and December over a 13-year period. Periodic and possibly cyclical recruitment events are identified as a contributor to improved yield.

Phenology of Chondrus ocellatus in Cheongsapo Near Busan, Korea

The reproductive phenology of Chondrus ocellatus and the effects of temperature and light on its growth were examined in Cheongsapo near Busan, Korea, from September 1994 to August 1995. The vegetative plants dominated over the year, with a peak occurrence in January. Gameto- and tetrasporophytes were most abundant in November and August. All vegetative and reproductive plants had a peak both in length and weight in October, when seawater temperature was highest (24°C). In laboratory culture, the maximum relative growth rate (RGR) of 2.94% day−1 was obtained at 20°C and 100 μmol photons m−2 s−1, whereas the lowest value was recorded at 25°C and 100 μmol photons m−2 s−1 in a 12: 12 h LD photoperiod regime. Among the three photoperiod regimes (8:16 h, 12:12 h, 16:8 h LD) tested, there was evidence of a higher RGR in the 12:12 h LD cycle. This result suggests that the growth and reproduction of C. ocellatus are correlated with the seawater temperature based on laboratory culture and field observations.

(39) Determination of the Optimum Species for Ohio Tree Liner Production in Retractable Roof Greenhouses

Many Ohio growers import liners from the West Coast due to the increased growing season on the West Coast. Lengthening the season in Ohio may provide a way for Ohio growers to produce liners of their own. Retractable roof greenhouses (RRG) are one possible way to extend the growing season in Ohio. Research done previously at The Ohio State University suggests that retractable roof greenhouses do in fact lengthen the growing season, and tree liners can be produced using RRG. The objectives of this study were: 1) to determine the optimal growing environment from three different environments; and 2) to determine the optimal species for tree liner production in Ohio. In Oct. 2004, 180 liners each of Cladrastis kentuckea, Quercus rubra, Stewartia pseudocamellia, Syringa reticulata, and Tilia cordata were upshifted to 3-gallon pots. In Mar. 2005, 90 of each species were transferred to either a flat roof retractable house (FRRG), peak roof retractable house (PRRG), or polyhouse. Growth was measured in Mar. (initial), June, Aug., and Oct. 2005 by taking leaf area, shoot and root dry weights, height, and caliper. There were no differences across species and dates between the environments for any of the parameters measured. Tilia showed the greatest increase in growth from June to October in all the parameters measured except leaf area. Cladrastis showed the greatest increase in leaf area from June to October. There were species by date interactions. Quercus had the greatest root weight in October. Syringa and Quercus were not significantly different from each other and had the highest shoot weights and leaf areas in October. Tilia, Quercus, and Syringa had the highest calipers in October.

Effect of Tree Canopy on the Growth of &lt;i&gt;Zoysia japonica&lt;/i&gt; Steud. under a Deciduous Forest with Different Tree Densities

The growth of grazed Zoysia japonica plants under a deciduous forest at 3 tree densities was investigated. Z. japonica sods were transplanted in March 1996. The rooting ratios of Z. japonica sods were 75, 86 and 98% under the 3 treatments consisting of low (300 trees/ha), medium (440 trees/ha) and high (630 trees/ha) tree densities (hereafter referred to as “thin, medium and dense treatments”),respectively. The highest rooting ratio recorded under the dense treatment was ascribed to the higher soil water content that was maintained under the dense canopy. Ground coverage of Z. japonica increased in all the treatments in the second and third years after transplanting. The most rapid increase in growth and highest dry weight of Z. japonica were recorded in the thin treatment with 60% coverage and 573 g/m2 dry weight in October of the third year. Estimated leaf area index (ELAI) of the trees increased gradually from the first year to the third year in all the treatments. The highest ELAI value was recorded in the dense treatment throughout the experiment. The amount of tree litter decreased from year to year in all the treatments, and no appreciable differences were recognized among the treatments. Therefore, the rooting of transplanted Z. japonica under the tree canopy did not seem to be inhibited by shading within the range of the thinning intensities examined, although the growth of Z. japonica was more rapid under the low density of 300 trees/ha with an average of 9 m height.

Diel feeding of the chaetognath Sagitta enflata in the Zanzibar Channel, western Indian Ocean

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 193:117-123 (2000) - doi:10.3354/meps193117 Diel feeding of the chaetognath Sagitta enflata in the Zanzibar Channel, western Indian Ocean Vidar Øresland* Institute of Marine Research, National Board of Fisheries, PO Box 4, 453 21 Lysekil, Sweden *E-mail: v.oresland@imr.se ABSTRACT: The diel feeding cycle of Sagitta enflata, the dominant chaetognath in the Indian Ocean, was investigated, using gut content analyses, between the monsoon periods on 2 occasions, October 1995 and May 1996. Zooplankton samples were collected every second hour during a 24 h period close to a drifting buoy in the middle of the Zanzibar Channel. S. enflata made up 64% (October) and 77% (May) of all chaetognaths in this study. S. enflata and all chaetognaths contributed as much as 30 and 33%, respectively, of the total 90 µm net zooplankton wet weight in October (May samples could not be weighed due to occurrence of phytoplankton). S. enflata fed most actively at night. Small copepods with a mandible width <0.07 mm (prosome length <1 mm) were its predominant prey. Feeding rate and mean number of small copepods found in S. enflata were 3 times higher in October than in May. In contrast, the estimated daily predation impact on the standing stock of small copepods (by number) was around 1% for both periods. This may be a negligible predation effect considering the short life-span of tropical copepods. It is suggested that predation effects are related to temperature, since a similar predation impact may be important in cold polar waters where copepod life-spans are much longer. Daily cannibalistic predation impact (by number) was estimated to be between 1 and 4% (October) and between 2 and 9% (May) using assumed maximum and minimum digestion times of 8 and 2 h. Cannibalism, therefore, may be an important source of mortality in S. enflata populations. KEY WORDS: Zooplankton · Chaetognatha · Sagitta enflata · Flacisagitta enflata · Copepods · Feeding · Predation · Cannibalism · Indian Ocean Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 193. Publication date: February 28, 2000 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 2000 Inter-Research.

飼育下におけるアワビ稚貝の摂餌量

Daily amounts of food intake and feces excreted by juvenile abalone Haliotis discus and H. d. hannai, were measured on a bimonthly basis with Wakame (Undaria pinnatifida, Phaeo-phyceae) for food, and then the annual amounts of food consumption and the bimonthly assimilation efficiencies were derived by species. The daily food intake by H. discus showed a downward tendency from 45mg dry weight in October to 26mg in April, but in the subsequent period from May to October it increased to the higher level of 53-67mg. That by H. d. hannai was 28mg in October and descreased to 21mg in February, but it also increased to the 51-56mg level in the period from May to October. The annual amounts of food consumption by H. discus and H. d. hannai were about 16g and 13g in dry weight, respectively. The caloric values of Wakame for food and feces were measured with a bomb calorimeter. The daily amounts of food intake and feces excreted in the unit of weight were thus con-verted into their equivalent caloric values. The bimonthly assimilation efficiencies calculated by using such estimates in terms of caloric value, showed a fairly stable level of some 70-80% in both species.

Measurement of Cordgrass, Spartina alterniflora, Production in a Macrotidal Estuary, Bay of Fundy

A one-year field study was conducted of the growth, mortality, and loss dynamics of aSpartina alterniflora low marsh in the Minas Basin, a macrotidal estuary at the head of the Bay of Fundy. Data were used to examine the suitability of four methods for estimating annual net aerial primary production (NAPP) of a marsh subject to energetic tidal flooding. Shoots start to grow in April and reach maximum height (about 0.5 m) and weight in October. Maximum shoot density (900–1,600 m−2) occurs around June and drops thereafter due to the export of entire shoots. The average shoot produces about seven leaves and at least 2–3 are lost during the growing season. All remaining vegetation dies before the end of November. Methods based on harvesting vegetation underestimated NAPP, especially at lower elevations where export is greater due to more frequent and prolonged tidal flooding. The highest NAPP values, on the order of 500–600 g m−2 y−1, were obtained using methods based on the population dynamics of individual shoots. These methods are recommended for energetic tidal environments because they include the production of vegetation exported during the growing season.

Stimulation of Isopentenyl Pyrophosphate Incorporation into Polyisoprene in Extracts from Guayule Plants (Parthenium argentatum Gray) by Low Temperature and 2-(3,4-Dichlorophenoxy) Triethylamine

Rubber particles isolated from guayule (Parthenium argentatum Gray) stem homogenates contain a polyprenyl transferase which catalyzes the polymerization of isopentenyl pyrophosphate into polyisoprene. The polymerization reaction is stimulated with the addition of an allylic pyrophosphate initiator and forms a polymer of polyisoprene with a molecular weight distribution from 10(3) to 10(7). The polymerization reaction in crude stem homogenates is not affected by the addition of an initiator probably due to the high activity of isopentenyl pyrophosphate isomerase furnishing saturating levels of dimethylallyl pyrophosphate. Polyisoprene formation in stems of guayule plants exposed to cold winter temperatures increased from 15.4 milligrams per gram dry weight in October to 24.5 milligrams per gram dry weight in January and increased from 16.2 to 38.1 milligrams per gram dry weight in the same period by additionally treating the plants with 5000 ppm of 2-(3,4-dichlorophenoxy)triethylamine. The rate of polymerization of isopentenyl pyrophosphate into polyisoprene in stem homogenates of the cold treated plants increased from 12.1 nanomoles per hour per gram fresh weight in October to 144.3 nanomoles per hour per gram fresh weight in January and increased from 17.7 to 446.8 nanomoles per hour per gram fresh weight in the same period by additionally treating the plants with 5000 ppm of 2-(3,4-dichlorophenoxy)triethylamine. These results show that the increase in polyprenyl transferase activity partially accounts for the increase in polyisoprene synthesis in guayule plants exposed to low temperature and treated with 2-(3,4-dichlorophenoxy)triethylamine.

Diurnal and seasonal variations in activity of crassulacean acid metabolism and plant water status in a northern latitude population of Opuntia erinacea.

A northern latitude population of Opuntia erinacea in eastern Washington State, U.S.A. was investigated with regard to daily and seasonal activity of Crassulacean acid metabolism and water relations. Fresh samples were collected throughout the light and dark periods on 21 dates between October 1979 and December 1980. Daily activity of CAM varied seasonally with daily maximum titratable acidity values ranging from 190 μEq·g(-1) fresh weight in October 1979 to 84 μEq·g(-1) in January 1980, to 230 μEq· g(-1) fresh weight in June 1980. Daily patterns of acid fluctuation were generally typical of CAM plants. Afternoon increases in acid concentration were noticed occasionally, and morning peaks in acidity were frequently observed. Plant water potentials were generally more closely correlated with median cladophyll temperature than with precipitation patterns, exhibiting sharply increased negativity around 6C. The data suggest the importance of available moisture and temperature in regulation of CAM, the existence of a cryoprotection mechanism involving reduction of plant water content, and the necessity of spring recovery for post-winter resumption of CAM activity.

Belowground growth of Spartina alterniflora Loisel.: habit, functional biomass and non-structural carbohydrates

Observations on the growth habit of a thatch island Spartina alterniflora colony in Nova Scotia indicated that an individual shoot clump lives for 2 years and then dies. There were three distinct phases of growth during the year: rapid leaf and root growth in June and July, vigorous rhizome growth and production of overwintering tillers concurrent with reproductive development in August and September, and finally, a period of no obvious change from October until the following May. There was a distinct autumn accumulation of non-structural carbohydrates in underground parts, with sugars accounting for 31% of the dry weight in October and starch 4%. Ratios of functional belonground biomass to end of season aboveground biomass were roughly constant for stands more than 1 year old; the ratio of annual net production of belowground parts to end of season aboveground biomass was estimated as 1·75.

The effect of seed treatment with benzimidazole‐based fungicides on infection of the foliage of overwintered salad onions by Botrytis cinerea

SUMMARYSeed treatments of carbendazim (Bavistin 50% W.p.) and thiophanate‐methyl (Mildothane 50% W.p.) applied to overwintered salad onions at 250 g a.i./kg seed protected the foliage of plants from infection by Botrytis cinerea during the seasons 1973–1976. Crop establishment and yield were also improved. Seed treatment with calomel was not effective. Chemical analysis of treated non‐viable seeds, retrieved from the soil, indicated that 73% carbendazim and 46% thiophanate‐methyl remained attached to the seeds after 9 months in the soil. Analyses of onion leaves revealed that each fungicide was represented by similar quantities of carbendazim, 5 μg/g fresh weight in October 1975 reducing to 1 μg/g fresh weight in May 1976. Bioassay tests showed that the fungicide was acropetally distributed and was present in all leaves early in the season (October) but was absent from some new leaves formed in the following spring.Carbendazim‐insensitive isolates of B. cinerea occurred after three seasons' use of this chemical. Sensitive isolates failed to grow on agar containing 1 μg/ml benomyl but all insensitive isolates (31 total) grew normally at this concentration and some were capable of growth on agar containing 1000 μg/ml benomyl. The emergence of foliar isolates of the fungus insensitive to the benzimidazole‐based compounds used in the treatment of seeds indicated that these fungicides did not provide a permanent solution to the disease problem.

Daily Ration of Yellow Perch (Perca flavescens) from Lake Memphremagog, Quebec–Vermont, with a Comparison of Methods for In Situ Determinations

In situ estimates of daily ration for yellow perch (Perca flavescens) range from a high of 5.5–6.7% body weight in July to a low of 2.2–2.4% body weight in October. The seasonal pattern corresponds well to known patterns of growth. Comparison of three methods for in situ determination of daily ration levels indicated the method outlined here and the more complex method of Thorpe yield similar results. The method of Keast and Welsh and derivatives of this method which correct for digestion between sampling periods give unreliable values that are 50% below the other two and, in general, are below maintenance ration levels. Diet composition and feeding activity varied seasonally and with body size. Key words: body size relationships, diet composition, seasonality

Physiological aspects of the ecology of Dicranum fuscescens in the subarctic. II. Seasonal patterns of organic nutrient content

Individual plants of Dicranum fuscescens were collected from two field sites (a highland semitundra and a lowland lichen woodland) near Schefferville, Quebec (latitude 55° N), for 4½ months during 1974. Collections were made at 2-week intervals from June until the 2nd week in October. Samples were separated into green and brown shoot components and oven-dried. Subsequently analyses were carried out to determine concentrations of total carbohydrates (sugar and starch) and lipids in the respective tissues. Total carbohydrates were found to increase in the green tissues towards the end of the season reaching a maximum of between 10 and 10.5% ash-free tissue dry weight in October. Lipid concentrations showed a maximum of between 3.6 and 4.0% ash-free dry weight during July and subsequently declined, in the same tissues. Seasonal trends of nutrient concentration in the brown portions of the shoot were not marked.An investigation of biomass distribution in complete plants of D. fuscescens revealed that brown shoots accounted for more than half of the total. Mean lengths of these parts of the shoot were about twice those of the upper stem.