Seasonal Variations In Biomass Research Articles

A model for the estimation of annual production rates of macrophyte algae

Data on seasonal biomass variation and productivity data based on short-term incubation experiments are presented for three species of macrophyte algae. The difficulties inherent in estimating annual productivity of benthic macroalgae are discussed, and a methodology is presented which combines field data obtained for biomass and production rates, data on the tidal regime of the study area and data on the variation of photosynthetically active radiation in a computer simulation of macrophyte primary productivity. The estimated annual productivity obtained for the three species is compared, and the differences between estimates using this approach and simple harvesting methods are examined. The application of studies of this nature in assessing the role of the macrophytobenthos in the mass balance of pollutants in estuaries is discussed, with reference to nutrient uptake.

Phytoplankton Production and Seasonal Biomass Variation of Seagrass, Ruppia maritima L., in a Tropical Mexican Lagoon with an Ephemeral Inlet

Plankton metabolism andRuppia maritima biomass were measured seasonally during 1982–83 in El Verde Lagoon, a small coastal lagoon with an ephemeral inlet on the Pacific Coast of Mexico. Total net aquatic primary production was 521 g C m−2 y−1. The water column was slightly heterotrophic, with an annual P/R ratio of 0.89. Our analysis indicates that tropical and subtropical coastal lagoons with restricted or seasonal inlets have generally higher net aquatic primary productivity levels than lagoons with permanently open inlets. We hypothesize that this is due to retention of nutrients and plankton stocks during the dry season. The seasonal pattern of water column metabolism was related to rainfall and riverflow, with higher values generally occurring during the wet season. Net production and respiration were about three times lower during the 1982 dry season as compared to the 1983 dry season which received considerable rains due to abnormal climatic conditions. The biomass ofR. maritima ranged from zero to 620 g dry wt m−2. Growth occurred only during the dry season and there were two distinct biomass peaks representing two separate crops. The second crop was heavily epiphytized with nitrogen-fixing algae. There was an apparent succession in dominance of water column productivity over the year, withRuppia dominating during the dry season and phytoplankton more important during the wet season.

Population dynamics of a tropical intertidal and deep-water population of Sargassum polyceratium (Phaeophyceae)

Plant numbers, plant size, number and length of primary laterals, reproduction, growth rates and turnover rates were recorded for an intertidal and a deep-water (30 m depth) population of Sargassum polyceratium Montagne at Curaçao, Netherlands Antilles, for 1.5 years. Both populations showed distinct seasonal variations in biomass and growth rates, with maxima in late summer-early autumn and minima in winter. The observed fluctuations were probably amplified by a severe autumn storm that significantly reduced biomass in both populations at the end of the first year. The main differences between the populations were a more compact growth form and higher growth rates and turnover rates of primary laterals in the intertidal population.

Annual and Seasonal Variations in Biomass of a Floating-leaved Plant, Trapa natans L., in Takahamairi Bay of Lake Kasumigaura, Japan

Annual and Seasonal Variations in Biomass of a Floating-leaved Plant, Trapa natans L., in Takahamairi Bay of Lake Kasumigaura, Japan

Diurnal and seasonal variation in biomass of arthropods in Tsavo East National Park, Kenya

African Journal of EcologyVolume 24, Issue 1 p. 47-51 Diurnal and seasonal variation in biomass of arthropods in Tsavo East National Park, Kenya P. C. Lack E. G. I./A. E. R. G., P. C. Lack E. G. I./A. E. R. G. Department of Zoology, South Parks Road, Oxford, U. K. British Trust for Ornithology, Beech Grove, Tring, Herts, U. K.Search for more papers by this author P. C. Lack E. G. I./A. E. R. G., P. C. Lack E. G. I./A. E. R. G. Department of Zoology, South Parks Road, Oxford, U. K. British Trust for Ornithology, Beech Grove, Tring, Herts, U. K.Search for more papers by this author First published: March 1986 https://doi.org/10.1111/j.1365-2028.1986.tb00341.xCitations: 24 AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume24, Issue1March 1986Pages 47-51 RelatedInformation

DYNAMICS OF SOIL MICROBIAL BIOMASS AND WATER-SOLUBLE ORGANIC C IN BRETON L AFTER 50 YEARS OF CROPPING TO TWO ROTATIONS

Amounts and turnover rates of biomass and water-soluble organic C (WSOC) were measured at the Breton plots where records of long-term management of a Gray Luvisolic soil are available. Plots (control, manure, and NPKS) which had been cropped to either a wheat-fallow or a wheat-oats-barley-forage-forage rotation for 50 yr were sampled 13 times during 1981 and 1982. Biomass C and flush of microbial N were measured using the chloroform fumigation technique. Long-term crop yields were used to derive C supply to the plots. Regression analyses were used to relate seasonal fluctuations in environmental conditions to biomass and WSOC dynamics. Reinoculation with soil was unnecessary but Lysobacter sp. formed a greater proportion of isolates following incubation of fumigated soil than of unfumigated samples. Reinoculation with Lysobacter sp. is suggested to provide a more standardized biological assay. The 5-yr rotation contained 38% more N but 117% more microbial N than did the 2-yr rotation, and manured treatments contained twice as much microbial N as did NPKS or control plots. A management effect on soil organic matter quality is indicated. Averge turnover rates of biomass were 0.2–3.9 yr−1; being 1.5–2 times faster in the 2-yr rotation than in the 5-yr rotation. Replenishment of the WSOC component would have to occur 26–39 times yr−1 to supply microbial turnover. Most of the biomass must be dormant because annual C inputs are two orders of magnitude less than maintenance energy requirements. Seasonal variations in biomass were most consistently related to losses during desiccation and regrowth upon moistening. Regrowth appears to be at the expense of native soil organic matter. Management practices and environmental conditions therefore affect amount of organic matter by controlling both input of C and biomass turnover. Key words: Crop rotations, Luvisol, organic matter, biomass, soluble C, Breton plots

Composition, abundance, and phenology fF foliose red algae associated with two central California kelp forests

Seasonal variations in biomass and reproductive phenology of red algae were studied in two central California kelp forests with different physical environments. At each site, random 0.25-m 2 samples of foliose red algae were collected monthly and biomass (g dry weight) and reproductive condition recorded for each species. At the more protected, rocky site, the perennials Botryocladia pseudodichotoma (Farl.) Kyl., Gigartina corymbifera (Kutz.) J. Ag., and Rhodymenia californica var. califomica Kyl. were most abundant. At the more exposed site with moving sand, both perennials ( Gigartina corymbifera and Rhodymenia pacifica Kyl.) and annuals such as Polyneura latissima (Harv.) Kyl., Phycodrys setchellii Skottsb., and Nienburgia andersoniana (J. Ag.) Kyl. were abundant. At both sites, the biomass of female and tetrasporic plants was generally very low relative to the total biomass. Reproductive plants at the protected site occurred from March to October whereas various species were reproductive at different times during the year at the exposed site. Several interacting factors appear to regulate red algal composition and abundance in these kelp forests. Overstory development, lack of disturbance, and invertebrate overgrowth seems most important at the protected site whereas physical disturbance in the form of sand and water movement appear to be more important at the exposed site.

Seasonal Variation in Biomass and Zonation of Nine Intertidal Algae in Relation to Changes in Radiation, Sea Temperature and Tidal Regime

Article Seasonal Variation in Biomass and Zonation of Nine Intertidal Algae in Relation to Changes in Radiation, Sea Temperature and Tidal Regime was published on January 1, 1985 in the journal Botanica Marina (volume 28, issue 12).

Variation in distribution and biomass of marine benthic algae off Kulien, S Sweden

Samples of the macrobenthic flora were collected at 2, 4, 6, 8 and 10 m below mean water level at Kullen, S Sweden. The frequency, length, reproductive pattern and biomass of the commonest species, and the variations of these with depth and season are discussed. The species composition and the size of the plants indicate that the flora is strongly affected by the brackish environment. Only few species contributed substantially to the total mean biomass (100.1 g dry wt 0.25 m–2): Fucus Serratus (56%), Laminaria digitata (7%), L. saccharina (4%), Furcellaria lumbricalis (14%), the Phyllophora species (5%) and Chondrus crispus (3%). Species with thin filamentous or sheet–like thalli made up the remaining ca. 11%. The contribution made by this group increased with depth from 1% at 2 m to 48% at 10 m. The mean biomass at each depth was strongly correlated to the irradiance. The seasonal variation in biomass followed that of the irradiance but with a lag. In winter and late summer the growth was also influenced by temperature and nutrient concentrations. The total biomass is delimited by the low and fluctuating salinity in Öresund.

Biomass potential of eelgrass(Zostera marinaL.)

Several phenomena related with the biomass potential of eelgrass (Zostera marina L.) are reviewed. Data on the spatial and temporal distribution of the species are presented and treated in detail in relation to the effects of several factors (e.g., height in the (sub)littoral, temperature, light), which in turn influence the vegetative morphology and biomass. The temporary presence of reproductive shoots and the phenological differences between annual and perennial populations related with differences in habitat selection strongly affect the seasonal variation in biomass. Methods applied for biomass determination in terms of fresh, dry, and ash‐free dry weights are presented and discussed and the results critically compared. In addition, methods and results related with indirect estimates of standing stock are discussed.

Soil and plant concentrations of cadmium and zinc in the vicinity of a smelter

Cadmium, zinc and lead concentrations in soils and plants near a smelter at Avonmouth are reported for samples collected in May 1979 and in May 1980. The total metal soil concentrations fall as distance from the smelter increases and decrease rapidly with depth for cadmium and zinc. The concentrations of these two metals are highly correlated at all depths. Near the smelter, where the carbon content and pH values of the soils are lowest, almost all the cadmium, as measured by EDTA extraction, is available. Concentration of metals in plants also decrease with distance from the smelter, with concentrations being lower in samples collected in 1980. This is possibly due to a seasonal variation in biomass, producing a dilution effect. We conclude that uptake of cadmium and that of zinc by grass species have different relationships to the carbon content of the soil.

Maturity and growth of the Spring Spawning herring in the Kattegat-Skagerrak

Abstract The two mainindigenous herring (Clupea harengus L.) stocks in the Skagerrak and the Kattegat, the Skagerrak Spring Spawners (SSS) and the Kattegat Spring Spawners (KSS) have been studied regarding percentage number spawning at age, biomass and length increment, and gonad maturity cycle for the years 1969, 1971 and 1973–1976. The SSS were significantly (p < 0.01) longer and had a larger biomass at a fixed age than the KSS. Both stocks showed a strong seasonal variation in biomass with minimum in the first quarter and maximum normally in the third quarter of the year. The maturation cycle was different between the sexes: the recruited males of both stocks passed the winter in pre-maturity Stage IV, whereas the gonads of the females successively developed from Stage III to Stage IV during that time. The proportion of females and males were similar in both stocks. Normally, a small percentage of both stocks spawned at 2 years of age, but in 1971 it was 20 %. Almost all of the SSS spawned at 3 years o...

Determination of the number of instars and size variation in the larvae and pupae of Simulium chutteri Lewis 1965 (Diptera: Simuliidae) and some possible bionomical implications

Morphometric studies show that there are seven larval instars in Simulium chutteri. A guide for separating instars of S. chutteri is included. Seasonal and sexual size variation and seasonal variation in biomass in larvae and pupae of S. chutteri are statistically analysed and discussed. Water temperature is a major factor in determining larval and pupal size variation and duration of the pupal stage. Growth in S. chutteri follows a geometric pattern and is in agreement with previous works on other species. An overlap of larger and smaller larvae at the same developmental stage resulted from the coexistence of early winter and late summer generations, respectively. Larger larvae and pupae can result in autogenous and more fecund adult females. This is important in the population dynamics of this pest species and can lead to sudden unexpected population explosions. It is suggested that population explosions could be controlled by sharply reducing the population of large individuals of S. chutteri in the spring.

Ecological Studies and Mathematical Modeling of Cladophora in Lake Huron: 1. Program Description and Field Monitoring of Growth Dynamics

A 3-year program was conducted to examine the ecology of Cladophora glomerata and to develop a mathematical model useful in evaluating various management strategies for the control of this nuisance alga. This manuscript provides a detailed description of the field program and study site in support of subsequent papers dealing with the results of field monitoring, autecological studies, calibration and verification of the model, and the impact of a demonstration phosphorus removal program on Cladophora growth. A municipal wastewater treatment plant discharge at Harbor Beach, Michigan, on Lake Huron has resulted in severe nuisance conditions associated with the presence of Cladophora. An intensive field monitoring program was established at the site to record weather conditions daily, and levels of dissolved and stored phosphorus and standing crop of Cladophora on a weekly basis. The distribution of Cladophora was shown to be essentially symmetrical about the nutrient source. Seasonal variation in biomass followed a pattern of early spring growth, stabilization, and midsummer senescence. The high degree of spatial and temporal heterogeneity in the nearshore environment was clearly evident from the results of the monitoring program. Wind direction and velocity importantly affect dissolved phosphorus distribution. Internal phosphorus levels reflect long term trends in wind and current regimes. The growth of Cladophora is importantly influenced by internal phosphorus levels while the loss of algal material through sloughing is closely correlated with wind-storm events. The observations of nearshore dynamics point to the need for high sampling frequency in such systems.

Seasonal Variation in Biomass and Energy of Small Roots in Tropical Dry Deciduous Forest, Varanasi, India

Seasonal variation in small root (<25 mm diameter) biomass and energy in two stands of tropical dry deciduous forest showed that roots <6 mm diam. constituted 43 to 71 % of the peak biomass during the rainy season. The calorific value was found to increase with root diameter. Seasonal fluctuations in the calorific values occurred, with the lowest obtained during the rainy season. The mean biomass across the year was 6467-7627 kg ha-' d.w. (2730-3144 x 104 kcal ha-'). The net production was 2412-2785 kg ha- yr-' (759-838 x 104 kcal ha-' yr-'), representing a flow of about 0.13% of annual usable solar radiation (ca. 0.5% during the rainy season). The annual root biomass replacement was estimated to be 37%. The small root weight in these forests was compared with that of other tropical forests.

Seasonal variation in two species of unionid clams from Manitoba, Canada: biomass

The relationship between dry weight and shell length for Anodonta grandis and Lampsilis radiata is log dry weight = a + 3.0317 log shell length, where a varies seasonally. Average water content of clams varies seasonally from 83.18% for both species in February and May to 85.02% for L. radiata in July and 87.56% for A. grandis in July and October. Mean ash content of L. radiata (19.21%) is higher than that of A. grandis (12.68%) except in October (20.94%) when marsupia are filled with glochidia. Differences in reproductive timing and length of glochidial retention contribute to some of the seasonal variations in biomass in A. grandis and L. radiata.

Life‐history and production of the amphipod Gammarus pulex in a Dorset chalk stream

SUMMARY. The seasonal variation in population density of Gammarus pulex was studied in a Dorset chalk stream. The numbers increased markedly in June and July and reached a maximum of c. 10000m−2 in September whilst the most rapid decline in density occurred in October‐November and reached a minimum of 820 m−2 in February. The animals occurred in greater densities in habitats containing Ranunculus or Callitriche than in those devoid of vegetation. The population structure was determined monthly and was split into juveniles (length &lt;4mm), immature males, immature females, mature males and ovigerous females. The percentage of juveniles (39–76) was always the highest of any of the categories. Ovigerous females were found at all times of the year. The sex ratio varied with the time of year both for immatures and matures, although there was approximately a 1:1 ratio for the mature individuals. Seasonal variation in biomass showed a maximum of 7.l g dry wt m−2 in September and a minimum of 1.4 g dry wt m−2 in March. Production was calculated by two methods giving values of 12.9 g dry wt m−2 year−1 and 12.8 g dry wt m−2 year−1.

A summary of productivity measurements in the North Pacific Ocean : Koblentz-Mishke, O. J., 1963. Proc. Conf., Prim. Prod. Measure., Mar. and Freshwat., Univ. Hawaii, 21 August–6 September, 1961, U. S. Atom. Ener. Comm., Div. Tech. Inform., TID-7633: 10–17

Throughout the deep oceans, diversity in the benthos peaks at intermediate slope depths. In the western Mediterranean lower slope an accumulation of biomass, but not diversity, at depths of 1200–1350 m has been observed. However, the precise causes of this biomass peak are unknown. We examined the patterns of megafauna benthic biomass in the Catalan sea open slope, from 900 to 1750 m depth, expanding the results in the context of the whole continental margin. Sampling was carried out by combining an Otter-Trawl Maireta System (OTMS) and an Agassiz trawl, during four different seasons in 2008/2009. At the same time, current speed, temperature and salinity were obtained year-round by means of near-bottom deployed sensors (current meters and temperature-conductivity sensors). Total biomass followed an inverted U-shaped pattern, peaking at depths of 1050–1350 m. Range-related ecological forcings between shallower and deeper species may have caused this biomass accumulation at intermediate slope depths. We also report on the seasonal variations of biomass in the studied depth range, identifying a dynamic zone above 1000 m depth where populations of highly mobile species perform year-round migrations throughout the slope, and a more static region below 1000 m (i.e. the twilight zone end) with substantially less inter-annual variations. The arrival of new Western Mediterranean Deep Water from the deep basin to the lower slope in March–May may have driven the accumulation of biomass at 900 and 1050 m depth over the same period. In addition, an adjacent submarine canyon was sampled with the same procedures to characterize its benthic megafauna community. Analyses revealed higher diversity, but not biomass, inside the canyon than in the adjacent open slope, and a significantly different assemblage composition between the two habitats. These results strengthen the concept of submarine canyons as hotspots of biodiversity and underline the importance of their conservation as diversity repositories.

Coastal development in Volusia and Brevard Counties, Florida : Kofoed, J. W., 1963. Bull. Mar. Sci., Gulf and Caribbean, 13 (1): 1–10

Throughout the deep oceans, diversity in the benthos peaks at intermediate slope depths. In the western Mediterranean lower slope an accumulation of biomass, but not diversity, at depths of 1200–1350 m has been observed. However, the precise causes of this biomass peak are unknown. We examined the patterns of megafauna benthic biomass in the Catalan sea open slope, from 900 to 1750 m depth, expanding the results in the context of the whole continental margin. Sampling was carried out by combining an Otter-Trawl Maireta System (OTMS) and an Agassiz trawl, during four different seasons in 2008/2009. At the same time, current speed, temperature and salinity were obtained year-round by means of near-bottom deployed sensors (current meters and temperature-conductivity sensors). Total biomass followed an inverted U-shaped pattern, peaking at depths of 1050–1350 m. Range-related ecological forcings between shallower and deeper species may have caused this biomass accumulation at intermediate slope depths. We also report on the seasonal variations of biomass in the studied depth range, identifying a dynamic zone above 1000 m depth where populations of highly mobile species perform year-round migrations throughout the slope, and a more static region below 1000 m (i.e. the twilight zone end) with substantially less inter-annual variations. The arrival of new Western Mediterranean Deep Water from the deep basin to the lower slope in March–May may have driven the accumulation of biomass at 900 and 1050 m depth over the same period. In addition, an adjacent submarine canyon was sampled with the same procedures to characterize its benthic megafauna community. Analyses revealed higher diversity, but not biomass, inside the canyon than in the adjacent open slope, and a significantly different assemblage composition between the two habitats. These results strengthen the concept of submarine canyons as hotspots of biodiversity and underline the importance of their conservation as diversity repositories.