Growth and net production of Sphagnum at five fen sites, subarctic eastern Canada

1989 ◽  
Vol 67 (4) ◽  
pp. 1203-1207 ◽  
Author(s):  
T. R. Moore
Keyword(s):  
Primary Production ◽  
Air Temperature ◽  
Net Primary Production ◽  
Mean Annual Temperature ◽  
Eastern Canada ◽  
Net Production ◽  
Sphagnum Fuscum ◽  
Average Rainfall ◽  
Wire Method

Growth in length and net primary production (NPP) were measured by the cranked wire method at five sites near Schefferville, northern Quebec, representing lawns of Sphagnum angustifolium, Sphagnum warnstorfii, S. warnstorfii/S. angustifolium, and hummocks of Sphagnum fuscum and Sphagnum capillifolium. From June to September, growth and NPP ranged from 4 to 24 mm and 29 to 142 g m−2, respectively. In an average rainfall year (1984), growth at the three lawn sites was higher than in the hummocks. In a dry year (1985, with half the average rainfall), growth in two of the three lawn sites was lower than in the hummocks. Growth of Sphagnum was weakly correlated with macroclimatic variables, such as air temperature, precipitation, and sunshine. The literature for Sphagnum production from arctic to temperate regions showed that hummock NPP was less than that of adjacent lawn/hollow sites and that a significant (r2 = 0.307, P < 0.001) portion of the variation in NPP can be ascribed to mean annual temperature.

scholarly journals Association Between Estuary Characteristics and Activities of the Critically Endangered Indo-Pacific Humpback Dolphin (Sousa chinensis)

2021 ◽  
Vol 8 ◽  
Author(s):  
Chi-hung Lin ◽  
Hsing-Juh Lin ◽  
Jian-Ping Suen ◽  
Lien-Siang Chou
Keyword(s):  
Primary Production ◽  
Net Primary Production ◽  
River Estuary ◽  
Late Summer ◽  
Critically Endangered ◽  
Physical Factors ◽  
Factors Affecting ◽  
Net Production ◽  
Sousa Chinensis ◽  
Autumn And Winter

The Indo-Pacific humpback dolphin (Sousa chinensis) has been reported to prefer estuary habitats. This study explored the environmental factors affecting a critically endangered population off the coast of Yunlin, Taiwan. We measured dolphin sighting rates and estuary characteristics affected by the watershed, including seven physical factors (watershed rainfall, watershed runoff, estuarine turbidity, pH, salinity, temperature, and dissolved oxygen) and two biological factors (estuarine net primary production and chlorophyll a concentration), at the Hsinhuwei River estuary in Taiwan. Dolphin activity was measured by sighting rate and behavioral indices for feeding and traveling between 2017 and 2018. We observed that when the maximum net production increased alongside rising temperatures in spring, both the dolphin sighting rate and foraging activity increased. This trend was maintained until heavy rainfall or increased river runoff occurred during late summer, which resulted in high turbidity in autumn and winter. Turbidity was significantly negatively correlated with dolphin activity (sighting rate and foraging). Furthermore, we found that dolphin traveling positively correlated with the chlorophyll a concentration and maximum net production factors, which could attract dolphins expecting more abundant prey fish in the estuary supported by the high primary production. This study provides empirical evidence on how estuary characteristics affected by the watershed can affect the sighting rate and behavioral activities of Indo-Pacific humpback dolphins.

Variation in foliar nitrogen and aboveground net primary production in young postfire lodgepole pine

2009 ◽  
Vol 39 (5) ◽  
pp. 1024-1035 ◽  
Author(s):  
Monica G. Turner ◽  
Erica A.H. Smithwick ◽  
Daniel B. Tinker ◽  
William H. Romme
Keyword(s):  
Primary Production ◽  
Net Primary Production ◽  
Lodgepole Pine ◽  
Tree Density ◽  
Aboveground Net Primary Production ◽  
Foliar Nitrogen ◽  
Net Production ◽  
Foliar N ◽  
N Concentration ◽  
Foliar N Concentration

Understanding nutrient dynamics of young postfire forests may yield important insights about how stands develop following stand-replacing wildfires. We studied 15-year-old lodgepole pine stands that regenerated naturally following the 1988 Yellowstone fires to address two questions: (1) How do foliar nitrogen (N) concentration and total foliar N vary with lodgepole pine density and aboveground net primary production? (2) Is foliar N related to litter production and to rates of gross production, consumption, and net production of soil NH4+ and NO3–? Foliar N concentration of new lodgepole pine needles averaged 1.38%; only stands at very high density (>80 000 trees·ha–1) approached moderate N limitation. Foliar N concentration in composite (all-age) needles averaged 1.08%, varied among stands (0.87%–1.39%), and declined with increasing tree density. The foliar N pool averaged 48.3 kg N·ha–1, varied among stands (3.6–218.4 kg N·ha–1), and increased with aboveground net primary production. Total foliar N was not related to laboratory estimates of net production of NH4+ or NO3– in soils. Lodgepole pine foliage is a strong N sink, and N does not appear to be limiting at this early successional state. The initial spatial patterns of postfire tree density strongly influence landscape patterns of N storage.

Biomass distribution and above- and below-ground production in young and mature Abiesamabilis zone ecosystems of the Washington Cascades

1981 ◽  
Vol 11 (1) ◽  
pp. 155-167 ◽  
Author(s):  
Charles C. Grier ◽  
Kristiina A. Vogt ◽  
Michael R. Keyes ◽  
Robert L. Edmonds
Keyword(s):  
Primary Production ◽  
Fine Root ◽  
Net Primary Production ◽  
Root Production ◽  
Fine Root Production ◽  
Biomass Distribution ◽  
Net Production ◽  
Young Stand ◽  
Mature Stand ◽  
Below Ground

Biomass distribution and above- and below-ground net primary production were determined for 23- and 180-year-old Abiesamabilis (Dougl.) Forbes ecosystems growing at 1200-m elevation in the western Washington Cascade Range. Total organic matter accumulations were 427.0 t•ha−1 in the young stand, and 1247.1 t•ha−1 in the mature stand. Aboveground tree and detritus biomass were 49.0 t•ha−1 and 130.2 t•ha−1, respectively, in the young stand compared with 445.5 t•ha−1 and 389.4 t•ha−1 in the mature stand. Net primary production (NPP) was 18.3 t•ha−1 in the young stand and 16.8 t•ha−1 in the mature stand. Belowground dry matter production was 65% of total net production in the young stand and 73% of total net production in the mature stand. Conifer fine root production was 35.9% of NPP in the young and 66.4% of NPP in the mature stand. This apparent shift in fine root production as a proportion of NPP may be related to detritus accumulation.

scholarly journals Allocation of forest net primary production varies by forest age and air temperature

2018 ◽  
Vol 8 (23) ◽  
pp. 12163-12172
Author(s):  
Xiang Song ◽  
Xiaodong Zeng ◽  
Dongxiao Tian
Keyword(s):  
Primary Production ◽  
Air Temperature ◽  
Net Primary Production ◽  
Forest Age

scholarly journals PRODUCTIVIDAD PRIMARIA EN LAGUNA LARGA, CAYO COCO, CUBA

2011 ◽  
Vol 3 ◽  
pp. 31 ◽  
Author(s):  
Mayrene Guimarais Bermejo ◽  
Roberto González de Zayas
Keyword(s):  
Primary Production ◽  
Primary Productivity ◽  
Net Primary Production ◽  
Ruppia Maritima ◽  
Halodule Wrightii ◽  
Phytoplankton Productivity ◽  
North Central ◽  
Net Production ◽  
The North ◽  
Total Productivity

Se determinó la productividad primaria en Laguna Larga, ubicada en la costa norte y central de Cayo Coco. La producción primaria del fitoplancton y la biomasa del macrofitobentos fueron medidas durante el 2008-2009 en dos sectores de la laguna. La producción primaria neta acuática del sector este fue de 4.32 ± 3.59 g C m-2 día-1 y en el sector oeste fue de 0.71 ± 0.41 g C m-2 día-1. Ambos sectores, atendiendo a la relación producción/respiración anual, fueron autotróficos para el oxígeno e hipertróficos para el carbono. Entre las especies más productivas del macrofitobentos estuvieron: Cladophoropsis sp., Halodule wrightii, Cladophora sp. y Ruppia maritima. La alta producción neta acuática registrada en el sector este, con respecto al oeste, se debe a la contribución del macrofitobentos a la productividad total. El fitoplancton en el sector este exhibió baja productividad (0.12 ± 0.07 g C m-2 día-1) con respecto al oeste (0.71 ± 0.41 g C m-2 día-1), lo que puede deberse a la competencia del macrofitobentos por los nutrientes.ABSTRACT Phytoplankton primary productivity and macrophyte biomass were determined during 2008-2009 for Laguna Larga, located on the north-central coast of Cayo Coco, Cuba. Aquatic net primary production was measured in two different sectors of the lagoon resulting in 4.32 ± 3.59 g C m-2 d-1 and 0.71 ± 0.41 g C m-2 d-1 in the eastern and western part, respectively. In regard to the annual production to respiration ratio, both sections showed autotrophic and hypertrophic levels for the oxygen and carbon metabolisms. The most productive species were Cladophoropsis sp., Halodule wrightii, Cladophora sp. and Ruppia maritima. Aquatic net production recorded for the eastern lobe was higher than the western lobe because of the macrophytobenthos contribution to total productivity. On the contrary, phytoplankton productivity in the eastern part was lower (0.12 ± 0.07 g C m-2 d-1) than the western lobe (0.71 ± 0.41 g C m-2 d-1), probably due to the macrophyte competition for nutrients.

scholarly journals Do increasing respiratory costs explain the decline with age of forest growth rate?

2019 ◽  
Vol 31 (3) ◽  
pp. 693-712 ◽  
Author(s):  
P. W. West
Keyword(s):  
Growth Rate ◽  
Water Stress ◽  
Primary Production ◽  
Fine Roots ◽  
Net Primary Production ◽  
Gross Primary Production ◽  
Forest Growth ◽  
Mean Annual Temperature ◽  
Data Set ◽  
Wide Range

Abstract Once forests have achieved a full canopy, their growth rate declines progressively with age. This work used a global data set with estimates from a wide range of forest types, aged 20‒795 years, of their annual photosynthetic production (gross primary production, GPP) and subsequent above- plus below-ground biomass production (net primary production, NPP). Both GPP and NPP increased with increasing mean annual temperature and precipitation. GPP was then unrelated to forest age whilst NPP declined progressively with increasing age. These results implied that autotrophic respiration increases with age. It has been proposed that GPP should decline in response to increasing water stress in leaves as water is raised to greater heights as trees grow taller with age. However, trees may make substantial plastic adjustment in morphology and anatomy of newly developing leaves, xylem and fine roots to compensate for this stress and maintain GPP with age. This work reviews the possibilities that NPP declines with age as respiratory costs increase progressively in, any or all of, the construction and maintenance of more complex tissues, the maintenance of increasing amounts of live tissue within the sapwood of stems and coarse roots, the conversion of sapwood to heartwood, the increasing distance of phloem transport, increased turnover rates of fine roots, cost of supporting very tall trees that are unable to compensate fully for increased water stress in their canopies or maintaining alive competitively unsuccessful small trees.

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