Journal articles: 'Above ground net primary production'

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Pantel, A., J. T. Romo, and Y. Bai. "Above-ground net primary production of plains rough fescue [Festuca hallii (Vasey) Piper] after a single defoliation on five landform elements." Canadian Journal of Plant Science 91, no. 4 (July 2011): 689–96. http://dx.doi.org/10.4141/cjps2010-030.

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Pantel, A., Romo, J. T. and Bai, Y. 2011. Above-ground net primary production of plains rough fescue [ Festuca hallii (Vasey) Piper] after a single defoliation on five landform elements. Can. J. Plant Sci. 91: 689–696. Above-ground net primary production (ANPP) was determined for plains rough fescue [Festuca hallii (Vasey) Piper] following a single defoliation to 7.5 cm stubble height on five landform elements in the Northern Mixed Prairie. The landform elements included north aspect-concave slopes, north aspect-convex slopes, south aspect-concave slopes, south aspect-convex slopes, and level uplands. Above-ground net primary production was determined for 2 yr after defoliating plants in May through November. Above-ground net primary production after defoliation was not dependent on landform elements in the first (P=0.23) and second years (P=0.22) after defoliation. In the first year after June through September defoliation, ANPP was reduced 29 to 41% (P <0.01), whereas May, October, or November defoliation had no significant effect on ANPP. Above-ground net primary production did not vary significantly (P=0.61) among months of defoliation in the second year after defoliation. Less ANPP in the first year after June through September defoliation indicates the need for ≥1 yr of deferred use to allow plants to regain their production potential. Unaffected ANPP after May, October, or November defoliation suggests plains rough fescue can be grazed annually. Recuperation of ANPP after defoliation depends on the month of the year in which plains rough fescue is defoliated, but not on landform elements in the Northern Mixed Prairie.

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Chen, Yuxiang, Gilzae Lee, Pilzae Lee, and Takehisa Oikawa. "Model analysis of grazing effect on above-ground biomass and above-ground net primary production of a Mongolian grassland ecosystem." Journal of Hydrology 333, no. 1 (January 2007): 155–64. http://dx.doi.org/10.1016/j.jhydrol.2006.07.019.

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Aragão, L. E. O. C., Y. Malhi, D. B. Metcalfe, J. E. Silva-Espejo, E. Jiménez, D. Navarrete, S. Almeida, et al. "Above- and below-ground net primary productivity across ten Amazonian forests on contrasting soils." Biogeosciences 6, no. 12 (December 1, 2009): 2759–78. http://dx.doi.org/10.5194/bg-6-2759-2009.

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Abstract. The net primary productivity (NPP) of tropical forests is one of the most important and least quantified components of the global carbon cycle. Most relevant studies have focused particularly on the quantification of the above-ground coarse wood productivity, and little is known about the carbon fluxes involved in other elements of the NPP, the partitioning of total NPP between its above- and below-ground components and the main environmental drivers of these patterns. In this study we quantify the above- and below-ground NPP of ten Amazonian forests to address two questions: (1) How do Amazonian forests allocate productivity among its above- and below-ground components? (2) How do soil and leaf nutrient status and soil texture affect the productivity of Amazonian forests? Using a standardized methodology to measure the major elements of productivity, we show that NPP varies between 9.3±1.3 Mg C ha−1 yr−1 (mean±standard error), at a white sand plot, and 17.0±1.4 Mg C ha−1 yr−1 at a very fertile Terra Preta site, with an overall average of 12.8±0.9 Mg C ha−1 yr−1. The studied forests allocate on average 64±3% and 36±3% of the total NPP to the above- and below-ground components, respectively. The ratio of above-ground and below-ground NPP is almost invariant with total NPP. Litterfall and fine root production both increase with total NPP, while stem production shows no overall trend. Total NPP tends to increase with soil phosphorus and leaf nitrogen status. However, allocation of NPP to below-ground shows no relationship to soil fertility, but appears to decrease with the increase of soil clay content.

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Aragão, L. E. O. C., Y. Malhi, D. B. Metcalfe, J. E. Silva-Espejo, E. Jiménez, D. Navarrete, S. Almeida, et al. "Above- and below-ground net primary productivity across ten Amazonian forests on contrasting soils." Biogeosciences Discussions 6, no. 1 (February 25, 2009): 2441–88. http://dx.doi.org/10.5194/bgd-6-2441-2009.

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Abstract. The net primary productivity (NPP) of tropical forests is one of the most important and least quantified components of the global carbon cycle. Most relevant studies have focused particularly on the quantification of the above-ground coarse wood productivity, and little is known about the carbon fluxes involved in other elements of the NPP, the partitioning of total NPP between its above- and below-ground components and the main environmental drivers of these patterns. In this study we quantify the above- and below-ground NPP of ten Amazonian forests to address two questions: (1) How do Amazonian forests allocate productivity among its above- and below-ground components? (2) How do soil and leaf nutrient status and soil texture affect the productivity of Amazonian forests? Using a standardized methodology to measure the major elements of productivity, we show that NPP varies between 9.3±1.3 Mg C ha−1 yr−1 (mean±standard error), at a white sand plot, and 17.0±1.4 Mg C ha−1 yr−1 at a very fertile Terra Preta site, with an overall average of 12.8±0.9 Mg C ha−1 yr−1. The studied forests allocate on average 64±3% and 36±3% of the total NPP to the above- and below-ground components, respectively. The ratio of above-ground and below-ground NPP is almost invariant with total NPP. Litterfall and fine root production both increase with total NPP, while stem production shows no overall trend. Total NPP tends to increase with soil phosphorus and leaf nitrogen status. However, allocation of NPP to below-ground shows no relationship to soil fertility, but appears to decrease with the increase of soil clay content.

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Chambers, Jeffrey Q., Joaquim dos Santos, Ralfh J. Ribeiro, and Niro Higuchi. "Tree damage, allometric relationships, and above-ground net primary production in central Amazon forest." Forest Ecology and Management 152, no. 1-3 (October 2001): 73–84. http://dx.doi.org/10.1016/s0378-1127(00)00591-0.

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Siche, Raúl, and Enrique Ortega. "Emergy and value of the net primary production (NPP) above ground in natural areas." Ecological Questions 10 (July 21, 2008): 99. http://dx.doi.org/10.12775/v10090-009-0011-2.

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Qin, Xiao-jing, Jiang-tao Hong, Xing-xing Ma, and Xiao-dan Wang. "Global patterns in above-ground net primary production and precipitation-use efficiency in grasslands." Journal of Mountain Science 15, no. 8 (August 2018): 1682–92. http://dx.doi.org/10.1007/s11629-017-4772-6.

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Baeza, S., F. Lezama, G. PiÃ±eiro, A. Altesor, and J. M. Paruelo. "Spatial variability of above-ground net primary production in Uruguayan grasslands: a remote sensing approach." Applied Vegetation Science 13, no. 1 (February 2010): 72–85. http://dx.doi.org/10.1111/j.1654-109x.2009.01051.x.

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9

Szumigalski, Anthony R., and Suzanne E. Bayley. "Net above-ground primary production along a bog-rich fen gradient in Central Alberta, Canada." Wetlands 16, no. 4 (December 1996): 467–76. http://dx.doi.org/10.1007/bf03161336.

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10

Gibson, N. "The Environments and Primary Production of Cushion Species at Mt Field and Mt Wellington, Tasmania." Australian Journal of Botany 38, no. 3 (1990): 229. http://dx.doi.org/10.1071/bt9900229.

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Primary production of four species of alpine cushion plants were studied over a 2-year period. The climate of these areas was found to be severe but with a high degree of variability on a seasonal and yearly basis. The growing season at the higher altitude sites generally exceeded 6 months. Net above ground primary production of the four cushion species ranged from 282 to 709 g m-2 year-1. Reproductive effort fluctuated between species and years, ranging from 0 to 30% of net above ground production. Patterns in dry matter accumulation suggest no individual species would show consistently superior growth rates under present climatic conditions. Soil moisture and soil nutrient status was found to be similar between all sites. Altitude of the sites (830-1400 m) was found to be strongly correlated with the timing of flowering and/or seed set but appeared to have little effect on net primary production.

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Halinen, Päivi, and Mikko Raatikainen. "Seasonal dynamics and primary production of the flora in a winter rye field in Finland." Agricultural and Food Science 63, no. 2 (April 1, 1991): 115–30. http://dx.doi.org/10.23986/afsci.72399.

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The total weed seed storage in the plough layer of 20 cm was 93 965 seeds/m2, of which 36 taxa were defined. The proportion of seeds of annual and winter annual species in soil was 89.6 %. The number of rye seeds emerging in autumn was 614 per m2 and weeds 224 per m2. The total number of weeds was 381/ m2 when the calculation was based on the time of maximal appearance. 0.3 % of the total amount of weeds emerged. Rye and Elymus repens were the dominant species in the above-ground vegetation, whereas the biomass of the other weeds remained poorly developed because of marked shading from these two. The maximum biomass of the living above-ground vegetation, 614 g/m2, was achieved in the middle of August (12. VIII). Net above-ground primary production, measured by the harvesting method, was 664 g/m2 · year and underground production 190 g/m2 · year, giving a total production of vegetation and detritus of 854 g/ m2 · year. The net efficiency of the primary producers was 0.7 %.

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12

Comeau, Philip G., and James P. Kimmins. "Above- and below-ground biomass and production of lodgepole pine on sites with differing soil moisture regimes." Canadian Journal of Forest Research 19, no. 4 (April 1, 1989): 447–54. http://dx.doi.org/10.1139/x89-070.

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The distribution of tree biomass and the allocation of production was measured in four stands of lodgepole pine (Pinuscontorta var. latifolia Engelm.), two growing on sites with xeric soil moisture regimes and two on sites with mesic soil moisture regimes. At the time of sampling the stands were 70–78 years old. Aboveground biomass ranged from 116.5 Mg•ha−1 on one xeric site to 313.1 Mg•ha−1 on one mesic site. Stem biomass represented 68 and 73% of total tree biomass on the xeric and mesic sites, respectively. Total root biomass represented between 20 and 28% of total lodgepole pine biomass. Fine and small roots (<5 mm diameter) represented 4 and 1.5% of total tree biomass on the xeric and mesic sites, respectively. Total net primary production ranged from 7.9 Mg•ha−1•year−1 on the xeric sites to 11.9 Mg•ha−1•year−1 on the mesic sites. Stemwood production represented 20 and 27% of total net primary production on the xeric sites and 35% on both mesic sites. Belowground production represented 38 and 46% of total net primary production on the two mesic sites (4.5 and 5.5 Mg•ha−1•year−1, respectively) and 55 and 66% on the two xeric sites (4.3 and 6.3 Mg•ha−1•year−1, respectively). Fine and small roots represented 82–94% of belowground production. Production allocation was in the following order: fine and small roots > stems > foliage > coarse roots > branches, for all but the wettest site, where stem production exceeded fine and small root production.

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Pantel, A., J. T. Romo, and Y. Bai. "Above-Ground Net Primary Production for Elymus lanceolatus and Hesperostipa curtiseta After a Single Defoliation Event." Rangeland Ecology & Management 64, no. 3 (May 2011): 283–90. http://dx.doi.org/10.2111/rem-d-10-00027.1.

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Kosykh, Natalia P., Natalia G. Koronatova, Natalia B. Naumova, and Argenta A. Titlyanova. "Above- and below-ground phytomass and net primary production in boreal mire ecosystems of Western Siberia." Wetlands Ecology and Management 16, no. 2 (October 25, 2007): 139–53. http://dx.doi.org/10.1007/s11273-007-9061-7.

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15

Day, J. W., Carlos Coronado-Molina, F. R. Vera-Herrera, R. Twilley, V. H. Rivera-Monroy, H. Alvarez-Guillen, R. Day, and W. Conner. "A 7 year record of above-ground net primary production in a southeastern Mexican mangrove forest." Aquatic Botany 55, no. 1 (September 1996): 39–60. http://dx.doi.org/10.1016/0304-3770(96)01063-7.

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16

Adamek, Markus, Marife D. Corre, and Dirk Hölscher. "Early effect of elevated nitrogen input on above-ground net primary production of a lower montane rain forest, Panama." Journal of Tropical Ecology 25, no. 6 (October 8, 2009): 637–47. http://dx.doi.org/10.1017/s0266467409990253.

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Abstract:To evaluate N limitation on above-ground net primary production in a tropical lower montane rain forest, an N fertilization experiment was conducted for 2 y. The study site is located at 1200–1300 m asl in the Fortuna forest reserve in western Panama and has a mature, mixed-species stand growing on an Andisol soil. Control and N-fertilized (125 kg urea-N ha−1 y−1) treatments were represented by four replicate plots (each 40 × 40 m, separated by at least 40 m). Stem diameter growth was analysed by diameter at breast height classes and also for the three most abundant species. The three species did not respond to N addition. The response of stem growth and above-ground woody biomass production to N fertilization varied among dbh classes. Stem growth of trees of 10–30 cm dbh increased only in the first year of N addition while trees of 30–50 cm dbh responded in the second year of N addition, which may be due to differences in light conditions between years. Trees >50 cm dbh did not respond during 2 years of N addition. As a result, the overall stem growth and above-ground woody biomass production were not affected by N fertilization. Annual total fine litterfall increased in the first year of N fertilization, while annual leaf litterfall increased in both years of N addition. Above-ground net primary production, of which total fine litterfall constituted 68%, also increased only in the first year of N addition. The magnitude and timing of response of stem diameter growth and litterfall suggest that these aspects of above-ground productivity are not uniformly limited by N availability.

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Girardin, C. A. J., Y. Malhi, K. J. Feeley, J. M. Rapp, M. R. Silman, P. Meir, W. Huaraca Huasco, et al. "Seasonality of above-ground net primary productivity along an Andean altitudinal transect in Peru." Journal of Tropical Ecology 30, no. 6 (August 28, 2014): 503–19. http://dx.doi.org/10.1017/s0266467414000443.

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Abstract:Solar irradiance and precipitation are the most likely drivers of the seasonal variation of net primary productivity (NPP) in tropical forests. Since their roles remain poorly understood, we use litter traps, dendrometer bands and census data collected from one hectare permanent plots to quantify the seasonality of above-ground NPP components and weather parameters in 13 sites distributed along a 2800-m altitudinal gradient ranging from lowland Amazonia to the high Andes. We combine canopy leaf area index and litterfall data to describe the seasonality of canopy production. We hypothesize that solar irradiance is the primary driver of canopy phenology in wetter sites, whereas precipitation drives phenology in drier systems. The seasonal rhythm of canopy NPP components is in synchrony with solar irradiance at all altitudes. Leaf litterfall peaks in the late dry season, both in lowland (averaging 0.54 ± 0.08 Mg C ha y−1, n = 5) and montane forests (averaging 0.29 ± 0.04 Mg C ha y−1, n = 8). Peaks in above-ground coarse woody NPP appears to be triggered by the onset of rainfall in seasonal lowland rain forests (averaging 0.26 ± 0.04 Mg C ha y−1, n = 5, in November), but not in montane cloud forests.

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Giroux, Jean-François, and Jean Bédard. "Estimating above- and below-ground macrophyte production in Scirpus tidal marshes." Canadian Journal of Botany 66, no. 2 (February 1, 1988): 368–74. http://dx.doi.org/10.1139/b88-059.

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Different methods to estimate primary production of Scirpus marshes of the St. Lawrence estuary were compared. Quadrats 25 × 25 cm and cores 10 cm in diameter were found to be the optimal size to sample above- and below-ground standing crops, respectively. Ash content for different plant parts of various species was measured to obtain more accurate estimates of organic matter. A series of allometric equations relating stem height and mass were developed to estimate aerial standing crop from permanent nondestructively sampled plots. This method, however, overestimated standing crop compared with the destructive (harvest) method. The relationship between the above- and below-ground standing crop was also determined for the dominant species and used to predict belowground biomass without destructive sampling. Finally, the Smalley method provided the best estimates of net annual above- and below-ground production when losses attributed to decomposition were not considered. For less intensive studies, however, the methods based on peak standing crop and on the difference between maximum and minimum biomass would yield good approximations of above- and below-ground production.

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Dunham, Kevin M. "Litterfall, nutrient-fall and production in an Acacia albida woodland in Zimbabwe." Journal of Tropical Ecology 5, no. 2 (May 1989): 227–38. http://dx.doi.org/10.1017/s0266467400003515.

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ABSTRACTLitterfall was recorded for one year in Acacia albida woodland in Mana Pools National Park, Zimbabwe. Leaves fell throughout the year, but leaf-fall rate peaked in the wet season. Litterfall was 1.5 t ha−1 year−1, comprising 50% leaves, 20% fruits, 17% ‘fine’ material (mainly frass), 4% flowers and 9% wood and bark. Net above ground production by A. albida trees was 1.7 t ha−1 year−1, including leaf production of 1.0 t ha−1 year−1, twig production of 0.3 t ha-1 year−1 and fruit production of 0.3 t ha−1 year−1. Insects consumed about 26% of leaf production. Net above ground herbaceous production was estimated from rainfall data using regression equations: it was 6.8 t ha−1 year−1 for annual grasses and 2.8 t ha−1 year−1 for forbs. Net above ground primary production in A. albida woodland was 11.3 t ha−1 year−1. The seasonal variations in the nitrogen, phosphorus, potassium, magnesium and calcium concentrations of different A. albida litter components were recorded. The estimated falls of N, P, K, Ca and Mg were 31.1, 2.1, 9.8, 15.0 and 3.4 kg ha−1 year−1 respectively.

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Smart, Simon Mark, Helen Catherine Glanville, Maria del Carmen Blanes, Lina Maria Mercado, Bridget Anne Emmett, David Leonard Jones, Bernard Jackson Cosby, et al. "Leaf dry matter content is better at predicting above‐ground net primary production than specific leaf area." Functional Ecology 31, no. 6 (February 27, 2017): 1336–44. http://dx.doi.org/10.1111/1365-2435.12832.

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Irisarri, J. Gonzalo N., Martín Oesterheld, José M. Paruelo, and Marcos A. Texeira. "Patterns and controls of above-ground net primary production in meadows of Patagonia. A remote sensing approach." Journal of Vegetation Science 23, no. 1 (August 1, 2011): 114–26. http://dx.doi.org/10.1111/j.1654-1103.2011.01326.x.

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Xu, J. G., and N. G. Juma. "Above- and below-ground net primary production of four barley (Hordeum vulgare L.) cultivars in western Canada." Canadian Journal of Plant Science 72, no. 4 (October 1, 1992): 1131–40. http://dx.doi.org/10.4141/cjps92-138.

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Information on above- and below-ground primary production for a wide range of agro-ecosystems is needed. The objective of this study was to quantify the shoot and root mass, shoot mass/root mass ratios, and root lengths of four barley (Hordeum vulgare L.) cultivars (Abee, Bonanza, Harrington and Samson) grown in a Black Chernozem in north-central Alberta. The cultivars were grown using a randomized complete block design with three replicates and were sampled at the tillering, stem-extension, heading, and ripening stages. Root mass and root lengths from soil cores were measured. The results showed that (1) shoot mass and root mass of Harrington and Bonanza were not different from those of Abee and Samson, but those of Abee were significantly greater than those of Samson, indicating that the below-ground input of organic matter could be a function of specific cultivar; (2) root mass increased rapidly until the heading stage, and shoot mass increased at a higher rate than roots between the heading and ripening stages, producing a widening of shoot/root ratios with time; and (3) decomposition of very small roots may have contributed to a more rapid decrease in root length than in root mass after the heading stage.Key words: Barley (Hordeum vulgare L.) cultivars, Typic Cryoboroll, root mass, root lengths, shoot/root ratio, soil organic matter

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Chapin, Carmen T., Scott D. Bridgham, and John Pastor. "pH and nutrient effects on above-ground net primary production in a Minnesota, USA bog and fen." Wetlands 24, no. 1 (March 2004): 186–201. http://dx.doi.org/10.1672/0277-5212(2004)024[0186:paneoa]2.0.co;2.

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Portela, Rita Cássia Quitete, Dalva Maria Silva Matos, Ludmila Pugliese de Siqueira, Maria Isabel Guedes Braz, Leonardo Silva-Lima, and Robert Hunter Marrs. "Variation in aboveground biomass and necromass of two invasive species in the Atlantic rainforest, southeast Brazil." Acta Botanica Brasilica 23, no. 2 (June 2009): 571–77. http://dx.doi.org/10.1590/s0102-33062009000200029.

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This paper describes the variation of the above-ground biomass, necromass, and net above-ground primary production (NAGPP) of two weed species, Panicum maximum Jacquin (Poaceae) and Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae), at two sites in the Poço das Antas Biological Reserve, southeast Brazil. Both species form mono-dominant stands in the matrix surrounding forest fragments. The organic matter was sampled monthly from each site, separated into biomass and necromass, and net above-ground primary production (NAGPP) was calculated. There was marked intra-seasonal fluctuation for both species; Pa. maximum generally had the largest values for necromass, total mass and NAGPP (NAGPP, Pa. maximum = 3953 g.m-2.y-1, Pt. arachnoideum = 2667 g.m-2.y-1). NAGPP did not vary between the two growth periods for Pa. maximum, but marked differences were found for Pt. arachnoideum (2% compared to 44% variation around the mean). The second growth year was drier and Pa. maximum produced much greater necromass in that year; Pt. arachnoideum showed little variation in biomass but much greater productivity in the drier second season. Pteridium arachnoideum appears to be more sensitive to climate, and especially rainfall.

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Aerts, R., and F. Berendse. "Above-Ground Nutrient Turnover and Net Primary Production of an Evergreen and a Deciduous Species in a Heathland Ecosystem." Journal of Ecology 77, no. 2 (June 1989): 343. http://dx.doi.org/10.2307/2260754.

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Turner, Monica, Rebecca Reed, William Romme, Mary Finley, and Dennis Knight. "Above-Ground Net Primary Production, Leaf Area Index, and Nitrogen Dynamics in Early Post-Fire Vegetation, Yellowstone National Park." UW National Parks Service Research Station Annual Reports 21 (January 1, 1997): 130–34. http://dx.doi.org/10.13001/uwnpsrc.1997.3341.

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The 1988 fires in Yellowstone National Park (YNP), Wyoming, affected >250,000 ha, creating a striking mosaic of burn severities across the landscape which is likely to influence ecological processes for decades to come (Christensen et al. 1989, Knight and Wallace 1989, Turner et al.1994). Substantial spatial heterogeneity in early post-fire succession has been observed in the decade since the fires, resulting largely from spatial variation in fire severity and in the availability of lodgepole pine (Pinus contorta var. latifolia) seeds in or near the burned area (Anderson and Romme 1991, Tinker et al. 1994, Turner et al. 1997). PostÂfire vegetation now includes pine stands ranging from relatively low to extremely high pine sapling density (ca 10,000 to nearly 100,000 stems ha-1) as well as non-forest or marginally forested vegetation across the Yellowstone landscape may influence ecosystem processes related to energy flow and biogeochemisty. We also are interested in how quickly these processes may return to their preÂ disturbance characteristics. In this pilot study, we began to address these general questions by examining the variation in above-ground net primary production (ANPP), leaf area index (LAI) of tree (lodgepole pine) and herbaceous components, and rates of nitrogen mineralization and loss in successional stands 9 years after the fires. ANPP measures the cumulative new biomass generated over a given period of time, and is a fundamental ecosystem property often used to compare ecosystems (Carpenter 1998). Leaf area (typically expressed as leaf area index [LAI], i.e., leaf area per unit ground surface area) influences rates of two fundamental ecosystem processes -Â primary productivity and transpiration -- and is communities (

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Prasad, V. Krishna, and K. V. S. Badarinth. "Land use changes and trends in Human Appropriation of Above Ground Net Primary Production (HANPP) in India (1961-98)." Geographical Journal 170, no. 1 (March 2004): 51–63. http://dx.doi.org/10.1111/j.0016-7398.2004.05015.x.

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Andersen, Roxane, Rémy Pouliot, and Line Rochefort. "Above-Ground Net Primary Production from Vascular Plants Shifts the Balance Towards Organic Matter Accumulation in Restored Sphagnum Bogs." Wetlands 33, no. 5 (July 9, 2013): 811–21. http://dx.doi.org/10.1007/s13157-013-0438-5.

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Shoo, Luke P., and Jeremy VanDerWal. "No simple relationship between above-ground tree growth and fine-litter production in tropical forests." Journal of Tropical Ecology 24, no. 3 (May 2008): 347–50. http://dx.doi.org/10.1017/s0266467408004975.

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An important deficiency of the tropical forest data set on above-ground net primary productivity (ANPP) is the paucity of studies where requisite components of forest productivity have been measured at the same location. Missing data on above-ground biomass increment (ABI, which refers to the incremental growth of trees) and fine-litter production (leaves, fruit, flowers, small twigs, but excluding coarse woody debris) is particularly problematic as these are the two major components of ANPP. The fragmentary nature of the data is reflected by the fact that only 13 of 39 (33%) plots reviewed by Clark et al. (2001) and 8 of 104 (8%) plots reviewed by Malhi et al. (2004) had data on both major components of productivity. In an attempt to retain the geographic coverage and replication of data in analyses, researchers have proposed ways to infer missing data. Typically ratios or (more recently) fitted relationships between ABI and litter production have been used for this purpose (Bray & Gorham 1964, Clark et al. 2001, Murphy 1975).

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Hik, D. S., H. A. Sadul, and R. L. Jefferies. "Effects of the Timing of Multiple Grazings by Geese on Net Above-Ground Primary Production of Swards of Puccinellia Phryganodes." Journal of Ecology 79, no. 3 (September 1991): 715. http://dx.doi.org/10.2307/2260663.

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Burrows, S. N., S. T. Gower, J. M. Norman, G. Diak, D. S. Mackay, D. E. Ahl, and M. K. Clayton. "Spatial variability of aboveground net primary production for a forested landscape in northern Wisconsin." Canadian Journal of Forest Research 33, no. 10 (October 1, 2003): 2007–18. http://dx.doi.org/10.1139/x03-124.

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Quantifying forest net primary production (NPP) is critical to understanding the global carbon cycle because forests are responsible for a large portion of the total terrestrial NPP. The objectives of this study were to measure above ground NPP (NPPA) for a land surface in northern Wisconsin, examine the spatial patterns of NPPA and its components, and correlate NPPA with vegetation cover types and leaf area index. Mean NPPA for aspen, hardwoods, mixed forest, upland conifers, nonforested wetlands, and forested wetlands was 7.8, 7.2, 5.7, 4.9, 5.0, and 4.5 t dry mass·ha1·year1, respectively. There were significant (p = 0.01) spatial patterns in wood, foliage, and understory NPP components and NPPA (p = 0.03) when the vegetation cover type was included in the model. The spatial range estimates for the three NPP components and NPPA differed significantly from each other, suggesting that different factors are influencing the components of NPP. NPPA was significantly correlated with leaf area index (p = 0.01) for the major vegetation cover types. The mean NPPA for the 3 km × 2 km site was 5.8 t dry mass·ha1·year1.

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Sternberg, Marcelo, Carly Golodets, Mario Gutman, Avi Perevolotsky, Jaime Kigel, and Zalmen Henkin. "No precipitation legacy effects on above-ground net primary production and species diversity in grazed Mediterranean grassland: a 21-year experiment." Journal of Vegetation Science 28, no. 2 (November 26, 2016): 260–69. http://dx.doi.org/10.1111/jvs.12478.

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Hertel, D., G. Moser, H. Culmsee, S. Erasmi, V. Horna, B. Schuldt, and Ch Leuschner. "Below- and above-ground biomass and net primary production in a paleotropical natural forest (Sulawesi, Indonesia) as compared to neotropical forests." Forest Ecology and Management 258, no. 9 (October 2009): 1904–12. http://dx.doi.org/10.1016/j.foreco.2009.07.019.

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Pollard, PC, and K. Kogure. "The role of epiphytic and epibenthic algal productivity in a tropical seagrass, Syringodium isoetifolium (Aschers.) Dandy, community." Marine and Freshwater Research 44, no. 1 (1993): 141. http://dx.doi.org/10.1071/mf9930141.

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The overall aim of this study, which was part of a multidisciplinary investigation, was to evaluate the role of epiphytic and epibenthic algae in a tropical seagrass, Syringodium isoetifoliurn (Aschers.) Dandy, community. Algal biomass (chlorophyll a) and productivity were determined over 20 days. The rates of photosynthesis were measured with both gas (oxygen) release and H14CO3 incorporation techniques. The photosynthetic characteristics of the algal community are described by the relationship between the rates of photosynthesis and irradiance (PI curve). The saturating light intensity (Ik), determined in the laboratory, was 240 �E m-2 s-1 (1 �E= 1 �mol). However, the maximum rate of net epibenthic production (Pmax) in situ of 2 g C g chla-1.h-1 was reached only at light intensities above the leaf canopy of more than 480 �E m-2 s-1 because of shading. The photoperiod (the period when algae were at Pmax was determined from the daily light profiles and used to calculate the mean net productivity of the epibenthic (4.2 g C m-2 day-1) and epiphytic (11.5 g C m-2 day-1.) algae during the study. The net epiphytic and seagrass productivities were equal and positively correlated (slope = 1.0; r2 = 0.92). However, the net seagrass leaf production was only 25% of the total seagrass net production. Most of the seagrass production appeared to be directed elsewhere, possibly into the below-ground tissue. Epiphytic algae accounted for more than four times the above-ground primary production. Compared with the bare sediment surface, the dense seagrass stand afforded 27�4 (s.d.) times more surface area on which the epiphyton could colonize. Thus, seagrasses provided the surfaces essential for maintaining the substantial epiphytic primary productivity, a passive but nonetheless important role. We compare our findings with other results of the multidisciplinary study and construct a carbon budget from which we infer a model of carbon transfer through this ecosystem. The algae were quantitatively the most important of the primary producers, seeming to provide most of the organic carbon to the higher trophic groups, at least for the period of this study.

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Van Dam, Bryce R., Christian Lopes, Christopher L. Osburn, and James W. Fourqurean. "Net heterotrophy and carbonate dissolution in two subtropical seagrass meadows." Biogeosciences 16, no. 22 (November 20, 2019): 4411–28. http://dx.doi.org/10.5194/bg-16-4411-2019.

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Abstract. The net ecosystem productivity (NEP) of two seagrass meadows within one of the largest seagrass ecosystems in the world, Florida Bay, was assessed using direct measurements over consecutive diel cycles during a short study in the fall of 2018. We report significant differences between NEP determined by dissolved inorganic carbon (NEPDIC) and by dissolved oxygen (NEPDO), likely driven by differences in air–water gas exchange and contrasting responses to variations in light intensity. We also acknowledge the impact of advective exchange on metabolic calculations of NEP and net ecosystem calcification (NEC) using the “open-water” approach and attempt to quantify this effect. In this first direct determination of NEPDIC in seagrass, we found that both seagrass ecosystems were net heterotrophic, on average, despite large differences in seagrass net above-ground primary productivity. NEC was also negative, indicating that both sites were net dissolving carbonate minerals. We suggest that a combination of carbonate dissolution and respiration in sediments exceeded seagrass primary production and calcification, supporting our negative NEP and NEC measurements. However, given the limited spatial (two sites) and temporal (8 d) extent of this study, our results may not be representative of Florida Bay as a whole and may be season-specific. The results of this study highlight the need for better temporal resolution, accurate carbonate chemistry accounting, and an improved understanding of physical mixing processes in future seagrass metabolism studies.

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Ruark, G. A., and J. G. Bockheim. "Biomass, net primary production, and nutrient distribution for an age sequence of Populustremuloides ecosystems." Canadian Journal of Forest Research 18, no. 4 (April 1, 1988): 435–43. http://dx.doi.org/10.1139/x88-064.

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The amounts and proportions of dry matter and macronutrients were measured in overstory trembling aspen (by tissue), understory vegetation, woody detritus, the forest floor, and the mineral soil in duplicate stands of 8, 14, 18, and 32 years and in a single stand of 63 years on an Entic Haplorthod in northern Wisconsin. The following changes occurred during secondary succession: (i) above- and below-ground aspen biomass increased, (ii) aboveground aspen production peaked between the ages of 18 and 32 years, (iii) the root to shoot ratio (R/S) of overstory aspen declined, (iv) the amounts and ecosystem proportions of macronutrients (N, P, K, Ca, and Mg) in the aspen overstory increased, and (v) the ecosystem proportions of nutrients in the understory declined. As the relative abundance of nutrients in overstory aspen increased, the labile nutrient pool in the mineral soil, particularly Mg and Ca, declined. The study suggests that understory roots play an important role in nutrient retention of successionary aspen stands in the upper Great Lakes region. Understory vegetation had an average R/S of 4.5 (compared with 0.18 to 0.58 for overstory aspen), with their small-root (< 0.3 cm) biomass comprising about 76% of the total ecosystem small-root pool. The proportion of nutrients in the living vegetation accounted for by the understory declined with stand age. However, from 13 to 24% of the total plant-available ecosystem amounts of nutrients resided in the understory of the 63-year-old stand. Relative to the ecosystem development model of Bormann and Likens, the reorganization phase in successionary aspen stands of the upper Great Lakes region may last 5 years or less. The aggradation phase lasts until about 70 years, after which time aspen is replaced by northern hardwoods.

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Sousa, Geocleber G. de, Sinara B. Sousa, Ana C. da S. Pereira, Virna B. Marques, Maria L. G. da Silva, and Jayrla da S. Lopes. "Effect of saline water and shading on dragon fruit (‘pitaya’) seedling growth." Revista Brasileira de Engenharia Agrícola e Ambiental 25, no. 8 (August 2021): 547–52. http://dx.doi.org/10.1590/1807-1929/agriambi.v25n8p547-552.

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ABSTRACT ‘Pitaya’ (Hylocereus undatus) is a fruit-bearing, climbing cactus with great food potential for the semiarid region. This study aimed to evaluate the production of ‘pitaya’ seedlings irrigated with low and high salinity water and grown in different light intensities. The experiment was conducted in a completely randomized design, in a 2 × 2 factorial arrangement, with two electrical conductivities of irrigation water: S1 - 0.3 dS m-1 (low salinity) and S2 - 5.0 dS m-1 (moderate salinity) in two environments: A1 - black net with 50% shading, and A2 - full sun, with ten replicates. The variables evaluated were plant height, main cladode diameter, above-ground biomass, root biomass, total plant biomass, number of secondary cladodes, root length, and length of secondary cladodes. The 50% shading (black net) promoted higher plant height, number of secondary shoots, and root length of the ‘pitaya’ plants. The irrigation with moderate saline water (5.0 dS m-1) reduced the number of secondary cladodes, length of root, and length of secondary cladodes. The ‘pitaya’ seedlings grown under 50% shading (black net) showed greater root dry biomass when irrigated with low-salinity water. Greater values of diameter of the primary cladode, above-ground dry biomass, and total dry biomass were observed under full sunlight and elevated saline stress.

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Sala, Osvaldo E., Laureano A. Gherardi, Lara Reichmann, Esteban Jobbágy, and Debra Peters. "Legacies of precipitation fluctuations on primary production: theory and data synthesis." Philosophical Transactions of the Royal Society B: Biological Sciences 367, no. 1606 (November 19, 2012): 3135–44. http://dx.doi.org/10.1098/rstb.2011.0347.

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Variability of above-ground net primary production (ANPP) of arid to sub-humid ecosystems displays a closer association with precipitation when considered across space (based on multiyear averages for different locations) than through time (based on year-to-year change at single locations). Here, we propose a theory of controls of ANPP based on four hypotheses about legacies of wet and dry years that explains space versus time differences in ANPP–precipitation relationships. We tested the hypotheses using 16 long-term series of ANPP. We found that legacies revealed by the association of current- versus previous-year conditions through the temporal series occur across all ecosystem types from deserts to mesic grasslands. Therefore, previous-year precipitation and ANPP control a significant fraction of current-year production. We developed unified models for the controls of ANPP through space and time. The relative importance of current-versus previous-year precipitation changes along a gradient of mean annual precipitation with the importance of current-year PPT decreasing, whereas the importance of previous-year PPT remains constant as mean annual precipitation increases. Finally, our results suggest that ANPP will respond to climate-change-driven alterations in water availability and, more importantly, that the magnitude of the response will increase with time.

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Hik, D. S., and R. L. Jefferies. "Increases in the Net Above-Ground Primary Production of a Salt-Marsh Forage Grass: A Test of the Predictions of the Herbivore-Optimization Model." Journal of Ecology 78, no. 1 (March 1990): 180. http://dx.doi.org/10.2307/2261044.

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40

Li, H., F. Zhang, Y. Li, X. Zhao, and G. Cao. "Thirty-year variations of above-ground net primary production and precipitation-use efficiency of an alpine meadow in the north-eastern Qinghai-Tibetan Plateau." Grass and Forage Science 71, no. 2 (March 22, 2015): 208–18. http://dx.doi.org/10.1111/gfs.12165.

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41

Frolking, S., N. T. Roulet, E. Tuittila, J. L. Bubier, A. Quillet, J. Talbot, and P. J. H. Richard. "A new model of Holocene peatland net primary production, decomposition, water balance, and peat accumulation." Earth System Dynamics 1, no. 1 (October 4, 2010): 1–21. http://dx.doi.org/10.5194/esd-1-1-2010.

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Abstract. Peatland carbon and water cycling are tightly coupled, so dynamic modeling of peat accumulation over decades to millennia should account for carbon-water feedbacks. We present initial results from a new simulation model of long-term peat accumulation, evaluated at a well-studied temperate bog in Ontario, Canada. The Holocene Peat Model (HPM) determines vegetation community composition dynamics and annual net primary productivity based on peat depth (as a proxy for nutrients and acidity) and water table depth. Annual peat (carbon) accumulation is the net balance above- and below-ground productivity and litter/peat decomposition – a function of peat hydrology (controlling depth to and degree of anoxia). Peat bulk density is simulated as a function of degree of humification, and affects the water balance through its influence on both the growth rate of the peat column and on peat hydraulic conductivity and the capacity to shed water. HPM output includes both time series of annual carbon and water fluxes, peat height, and water table depth, as well as a final peat profile that can be "cored" and compared to field observations of peat age and macrofossil composition. A stochastic 8500-yr, annual precipitation time series was constrained by a published Holocene climate reconstruction for southern Québec. HPM simulated 5.4 m of peat accumulation (310 kg C m-2) over 8500 years, 6.5% of total NPP over the period. Vascular plant functional types accounted for 65% of total NPP over 8500 years but only 35% of the final (contemporary) peat mass. Simulated age-depth and carbon accumulation profiles were compared to a radiocarbon dated 5.8 m, c.9000-yr core. The simulated core was younger than observations at most depths, but had a similar overall trajectory; carbon accumulation rates were generally higher in the simulation and were somewhat more variable than observations. HPM results were sensitive to century-scale anomalies in precipitation, with extended drier periods (precipitation reduced ∼10%) causing the peat profile to lose carbon (and height), despite relatively small changes in NPP.

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42

Frolking, S., N. T. Roulet, E. Tuittila, J. L. Bubier, A. Quillet, J. Talbot, and P. J. H. Richard. "A new model of Holocene peatland net primary production, decomposition, water balance, and peat accumulation." Earth System Dynamics Discussions 1, no. 1 (July 1, 2010): 115–67. http://dx.doi.org/10.5194/esdd-1-115-2010.

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Abstract. Peatland carbon and water cycling are tightly coupled, so dynamic modeling of peat accumulation over decades to millennia should account for carbon-water feedbacks. We present initial results from a new simulation model of long-term peat accumulation, evaluated at a well-studied temperate bog in Ontario, Canada. The Holocene Peat Model (HPM) determines vegetation community composition dynamics and annual net primary productivity based on peat depth (as a proxy for nutrients and acidity) and water table depth. Annual peat (carbon) accumulation is the net balance above- and below-ground productivity and litter/peat decomposition – a function of peat hydrology (controlling depth to and degree of anoxia). Peat bulk density is simulated as a function of degree of humification, and affects the water balance through its influence on both the growth rate of the peat column and on peat hydraulic conductivity and the capacity to shed water. HPM output includes both time series of annual carbon and water fluxes, peat height, and water table depth, as well as a final peat profile that can be ``cored'' and compared to field observations of peat age and macrofossil composition. A stochastic 8500-yr, annual precipitation time series was constrained by a published Holocene climate reconstruction for southern Québec. HPM simulated 5.4 m of peat accumulation (310 kg C) over 8500 years, 6.5% of total NPP over the period. Vascular plant functional types accounted for 65% of total NPP over 8500 years but only 35% of the final (contemporary) peat mass. Simulated age-depth and carbon accumulation profiles were compared to a radiocarbon dated 5.8 m, c.9000-yr core. The simulated core was younger than observations at most depths, but had a similar overall trajectory; carbon accumulation rates were generally higher in the simulation and were somewhat more variable than observations. HPM results were sensitive to century-scale anomalies in precipitation, with extended drier periods (precipitation reduced ~10%) causing the peat profile to lose carbon (and height), despite relatively small changes in NPP.

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Xiao, C., I. A. Janssens, Y. Zhou, J. Su, Y. Liang, and B. Guenet. "Strong stoichiometric resilience after litter manipulation experiments; a case study in a Chinese grassland." Biogeosciences 12, no. 3 (February 9, 2015): 757–67. http://dx.doi.org/10.5194/bg-12-757-2015.

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Abstract. Global climate change has generally modified net primary production (NPP) which leads to increasing litter inputs in some ecosystems. Therefore, assessing the impacts of increasing litter inputs on soil nutrients, plant growth and ecological carbon (C) : nitrogen (N) : phosphorus (P) stoichiometry is critical for an understanding of C, N and P cycling and their feedback processes to climate change. In this study, we added plant above-ground litter, harvested near the experimental plots, to the 10–20 cm subsoil layer of a steppe community at rates equivalent to annual litter input of 0, 15, 30, 60 and 120%, respectively, covering the entire range of the expected NPP increases in this region due to climate change (10–60%). We measured the resulting C, N and P content of different pools (above- and below-ground plant biomass, litter, microbial biomass). Small litter additions, which are more plausible compared to the expected increase predicted by Earth system models, had no effect on the variables examined. Nevertheless, high litter addition (120% of the annual litter inputs) significantly increased soil inorganic N and available P, above-ground biomass, below-ground biomass and litter. Our results suggest that while very high litter addition can strongly affect C : N : P stoichiometry, the grassland studied here is resilient to more plausible inputs in terms of stoichiometric functioning.

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Simon, John Nyandansobi, Narissara Nuthammachot, Teerawet Titseesang, Kingsley Ezechukwu Okpara, and Kuaanan Techato. "Spatial Assessment of Para Rubber (Hevea brasiliensis) above Ground Biomass Potentials in Songkhla Province, Southern Thailand." Sustainability 13, no. 16 (August 20, 2021): 9344. http://dx.doi.org/10.3390/su13169344.

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Currently, Songkhla Province of Thailand has been recognized as a convenient hub of rubber industry development, accompanied by an attendant abundance of rubber tree plantations. A spatialized assessment of the rubber tree was carried out to estimate its aboveground biomass potentials using remote sensing techniques and ecosystem modeling procedures. Moderate Resolution Imaging Spectroradiometer satellite-based estimations of the net primary productivity were derived and complemented with a calculated generic model, to quantify the respective above ground biomass potentials para rubber. Above ground biomass assessment findings revealed a mean value of 82.1 tonnes C ha−1 and an aggregate of 31. 9 million tonnes C ha−1 which is the theoretical potential, this is segregated into energy usable, and other economic purpose biomass potentials, with corresponding value ranges of 1624.1 to 6,041,531.2 million tonnes C ha−1 and 85.5 to 317,975.6 thousand tonnes C ha−1 respectively. Besides the theoretical above ground biomass potential (entire biomass accumulation ratio) commonly evaluated, the other potentials, which include naturally obtainable biomass usable for energy generation and the remaining share of the feedstock for non-energy uses, have been brought to light. Songkhla province has the potential for good carbon sink and sustainable supply of different pools of feedstock from the rubber tree that reinforces each other in providing a comprehensive view of biomass in energy and non-energy opportunities. The socioeconomic production and value chain analysis of the identified biomass pools needs to be evaluated; this will consequently guide policy toward a comprehensive rubber sector sustainable development.

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Jiménez, E. M., F. H. Moreno, M. C. Peñuela, S. Patiño, and J. Lloyd. "Fine root dynamics for forests on contrasting soils in the Colombian Amazon." Biogeosciences 6, no. 12 (December 3, 2009): 2809–27. http://dx.doi.org/10.5194/bg-6-2809-2009.

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Abstract. It has been hypothesized that as soil fertility increases, the amount of carbon allocated to below-ground production (fine roots) should decrease. To evaluate this hypothesis, we measured the standing crop fine root mass and the production of fine roots (<2 mm) by two methods: (1) ingrowth cores and, (2) sequential soil coring, during 2.2 years in two lowland forests growing on different soils types in the Colombian Amazon. Differences of soil resources were defined by the type and physical and chemical properties of soil: a forest on clay loam soil (Endostagnic Plinthosol) at the Amacayacu National Natural Park and, the other on white sand (Ortseinc Podzol) at the Zafire Biological Station, located in the Forest Reservation of the Calderón River. We found that the standing crop fine root mass and the production was significantly different between soil depths (0–10 and 10–20 cm) and also between forests. The loamy sand forest allocated more carbon to fine roots than the clay loam forest with the production in loamy sand forest twice (mean±standard error=2.98±0.36 and 3.33±0.69 Mg C ha−1 yr−1, method 1 and 2, respectively) as much as for the more fertile loamy soil forest (1.51±0.14, method 1, and from 1.03±0.31 to 1.36±0.23 Mg C ha−1 yr−1, method 2). Similarly, the average of standing crop fine root mass was higher in the white-sands forest (10.94±0.33 Mg C ha−1) as compared to the forest on the more fertile soil (from 3.04±0.15 to 3.64±0.18 Mg C ha−1). The standing crop fine root mass also showed a temporal pattern related to rainfall, with the production of fine roots decreasing substantially in the dry period of the year 2005. These results suggest that soil resources may play an important role in patterns of carbon allocation to the production of fine roots in these forests as the proportion of carbon allocated to above- and below-ground organs is different between forest types. Thus, a trade-off between above- and below-ground growth seems to exist with our results also suggesting that there are no differences in total net primary productivity between these two forests, but with higher below-ground production and lower above-ground production for the forest on the nutrient poor soil.

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Chhabra, A., V. Madhava Rao, R. R. Hermon, A. Garg, T. Nag, N. Bhaskara Rao, A. Sharma, and J. S. Parihar. "Energy Balance of Rural Ecosystems In India." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XL-8 (November 28, 2014): 411–17. http://dx.doi.org/10.5194/isprsarchives-xl-8-411-2014.

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India is predominantly an agricultural and rural country. Across the country, the villages vary in geographical location, area, human and livestock population, availability of resources, agricultural practices, livelihood patterns etc. This study presents an estimation of net energy balance resulting from primary production vis-a-vis energy consumption through various components in a "Rural Ecosystem". Seven sites located in different agroclimatic regions of India were studied. An end use energy accounting "Rural Energy Balance Model" is developed for input-output analysis of various energy flows of production, consumption, import and export through various components of crop, trees outside forest plantations, livestock, rural households, industry or trade within the village system boundary. An integrated approach using field, ancillary, GIS and high resolution IRS-P6 Resourcesat-2 LISS IV data is adopted for generation of various model inputs. The primary and secondary field data collection of various energy uses at household and village level were carried out using structured schedules and questionnaires. High resolution multi-temporal Resourcesat-2 LISS IV data (2013–14) was used for generating landuse/landcover maps and estimation of above-ground Trees Outside Forests phytomass. The model inputs were converted to energy equivalents using country-specific energy conversion factors. A comprehensive geotagged database of sampled households and available resources at each study site was also developed in ArcGIS framework. Across the study sites, the estimated net energy balance ranged from −18.8 Terra Joules (TJ) in a high energy consuming Hodka village, Gujarat to 224.7 TJ in an agriculture, aquaculture and plantation intensive Kollaparru village, Andhra Pradesh. The results indicate that the net energy balance of a Rural Ecosystem is largely driven by primary production through crops and natural vegetation. This study provides a significant insight to policy relevant recommendations for Energy Sustainable Rural India.

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Cotrufo, M. F., G. Alberti, I. Inglima, H. Marjanović, D. LeCain, A. Zaldei, A. Peressotti, and F. Miglietta. "Decreased summer drought affects plant productivity and soil carbon dynamics in a Mediterranean woodland." Biogeosciences 8, no. 9 (September 27, 2011): 2729–39. http://dx.doi.org/10.5194/bg-8-2729-2011.

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Abstract. Precipitation patterns are expected to change in the Mediterranean region within the next decades, with projected decreases in total rainfall and increases in extreme events. We manipulated precipitation patterns in a Mediterranean woodland, dominated by Arbutus unedo L., to study the effects of changing precipitation regimes on above-ground net primary production (ANPP) and soil C dynamics, specifically plant-derived C input to soil and soil respiration (SR). Experimental plots were exposed to either a 20 % reduction of throughfall or to water addition targeted at maintaining soil water content above a minimum of 10 % v/v. Treatments were compared to control plots which received ambient precipitation. Enhanced soil moisture during summer months highly stimulated annual stem primary production, litter fall, SR and net annual plant-derived C input to soil which on average increased by 130 %, 26 %, 58 % and 220 %, respectively, as compared to the control. In contrast, the 20 % reduction in throughfall (equivalent to 10 % reduction in precipitation) did not significantly change soil moisture at the site, and therefore did not significantly affect ANPP or SR. We conclude that minor changes (around 10 % reduction) in precipitation amount are not likely to significantly affect ANPP or soil C dynamics in Mediterranean woodlands. However, if summer rain increases, C cycling will significantly accelerate but soil C stocks are not likely to be changed in the short-term. More studies involving modelling of long-term C dynamics are needed to predict if the estimated increases in soil C input under wet conditions is going to be sustained and if labile C is being substituted to stable C, with a negative effect on long-term soil C stocks.

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Niu, Ben, Chaoxu Zeng, Xianzhou Zhang, Yongtao He, Peili Shi, Yuan Tian, Yunfei Feng, et al. "High Below-Ground Productivity Allocation of Alpine Grasslands on the Northern Tibet." Plants 8, no. 12 (November 22, 2019): 535. http://dx.doi.org/10.3390/plants8120535.

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The allocation of net primary production (NPP) between above- and belowground components is a key step of ecosystem material cycling and energy flows, which determines many critical parameters, e.g., the fraction of below ground NPP (BNPP) to NPP (fBNPP) and root turnover rates (RTR), in vegetation models. However, direct NPP estimation and partition are scarcely based on field measurements of biomass dynamics in the alpine grasslands on the Northern Tibetan Plateau (NTP). Consequently, these parameters are unverifiable and controversial. Here, we measured above- and belowground biomass dynamics (monthly from May to September each year from 2013 to 2015) to estimate NPP dynamics and allocations in four typical alpine grassland ecosystems, i.e., an alpine meadow, alpine meadow steppe, alpine steppe and alpine desert steppe. We found that NPP and its components, above and below ground NPP (ANPP and BNPP), increased significantly from west to east on the NTP, and ANPP was mainly affected by temperature while BNPP and NPP were mainly affected by precipitation. The bulk of BNPP was generally concentrated in the top 10 cm soil layers in all four alpine grasslands (76.1% ± 9.1%, mean ± SD). Our results showed that fBNPP was significantly different among these four alpine grasslands, with its means in alpine meadow (0.93), alpine desert steppe (0.92) being larger than that in the alpine meadow steppe (0.76) and alpine steppe (0.77). Both temperature and precipitation had significant and positive effects on the fBNPP, while their interaction effects were significantly opposite. RTR decreased with increasing precipitation, but increased with increasing temperature across this ecoregion. Our study illustrated that alpine grasslands on the NTP, especially in the alpine meadow and alpine desert steppe, partitioned an unexpected and greater NPP to below ground than most historical reports across global grasslands, indicating a more critical role of the root carbon pool in carbon cycling in alpine grasslands on the NTP.

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Belyakov, Sergiy, Orysia Gofman, Iryna Vyshenska, and Sergey Zvegintsev. "Analysis of Grassland ANPP Dynamics Due to Changes in Climate Variables at Ukrainian Biosphere Reserve ‘Askania-Nova’." Ekológia (Bratislava) 36, no. 3 (September 1, 2017): 235–46. http://dx.doi.org/10.1515/eko-2017-0020.

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AbstractThe Ukrainian feather-grass steppe ecosystems are highly vulnerable to climate changes. To study the impact of climatic factors on steppe ecosystems’ productivity, the correlation and stepwise regression analysis between ANPP and other variables were provided. The correlation of bioclimatic variables (month precipitation, relative humidity and air and soil temperatures) and above-ground net primary production (ANPP) were investigated for three study plots that represent major steppe microrelief: plain, slope and lowland. The results of multiple regression analysis showed the major components that influenced the ANPP at each of the study plots ‘Plain’, ‘Slope’ and ‘Lowland’. The precipitation and relative humidity in the months before the vegetation peak were most important for ANPP accumulation.Results of this study are important for the prediction of ecosystem changes under the climate changes and also for the development of nature conservation programmes.

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He, Liming, Rong Wang, Georgy Mostovoy, Jane Liu, Jing M. Chen, Jiali Shang, Jiangui Liu, Heather McNairn, and Jarrett Powers. "Crop Biomass Mapping Based on Ecosystem Modeling at Regional Scale Using High Resolution Sentinel-2 Data." Remote Sensing 13, no. 4 (February 22, 2021): 806. http://dx.doi.org/10.3390/rs13040806.

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We evaluate the potential of using a process-based ecosystem model (BEPS) for crop biomass mapping at 20 m resolution over the research site in Manitoba, western Canada driven by spatially explicit leaf area index (LAI) retrieved from Sentinel-2 spectral reflectance throughout the entire growing season. We find that overall, the BEPS-simulated crop gross primary production (GPP), net primary production (NPP), and LAI time-series can explain 82%, 83%, and 85%, respectively, of the variation in the above-ground biomass (AGB) for six selected annual crops, while an application of individual crop LAI explains only 50% of the variation in AGB. The linear relationships between the AGB and these three indicators (GPP, NPP and LAI time-series) are rather high for the six crops, while the slopes of the regression models vary for individual crop type, indicating the need for calibration of key photosynthetic parameters and carbon allocation coefficients. This study demonstrates that accumulated GPP and NPP derived from an ecosystem model, driven by Sentinel-2 LAI data and abiotic data, can be effectively used for crop AGB mapping; the temporal information from LAI is also effective in AGB mapping for some crop types.

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Journal articles on the topic 'Above ground net primary production'

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