scholarly journals Above- and below-ground net primary productivity across ten Amazonian forests on contrasting soils

2009 ◽  
Vol 6 (12) ◽  
pp. 2759-2778 ◽  
Author(s):  
L. E. O. C. Aragão ◽  
Y. Malhi ◽  
D. B. Metcalfe ◽  
J. E. Silva-Espejo ◽  
E. Jiménez ◽  
...  

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.

2009 ◽  
Vol 6 (1) ◽  
pp. 2441-2488 ◽  
Author(s):  
L. E. O. C. Aragão ◽  
Y. Malhi ◽  
D. B. Metcalfe ◽  
J. E. Silva-Espejo ◽  
E. Jiménez ◽  
...  

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.


2015 ◽  
Vol 95 (2) ◽  
pp. 87-93 ◽  
Author(s):  
Martin A. Bolinder ◽  
Thomas Kätterer ◽  
Christopher Poeplau ◽  
Gunnar Börjesson ◽  
Leon E. Parent

Bolinder, M. A., Kätterer, T., Poeplau, C., Börjesson, G. and Parent, L. E. 2015. Net primary productivity and below-ground crop residue inputs for root crops: Potato (Solanum tuberosum L.) and sugar beet (Beta vulgaris L.). Can. J. Soil Sci. 95: 87–93. Root crops are significant in agro-ecosystems of temperate climates. However, the amounts of crop residues for these crop types are not well documented and they need to be accounted for in the modeling of soil organic carbon dynamics. Our objective was to review field measurements of root biomass left in the soil as crop residues at harvest for potato and sugar beet. We considered estimates for crop residue inputs as root biomass presented in the literature and some unpublished results. Our analysis showed that compared to, for example, cereals, the contribution of below-ground net primary productivity (NPP) to crop residues is at least two to three times lower for root crops. Indeed, the field measurements indicated that root biomass for topsoils only represents on average 25 to 30 g dry matter (DM) m−2 yr−1. Other estimates, albeit variable and region-specific, tended to be higher. We suggest relative plant DM allocation coefficients for agronomic yield (RP), above-ground biomass (RS) and root biomass (RR) components, expressed as a proportion of total NPP. These coefficients, representative for temperate climates (0.739:0.236:0.025 for potato and 0.626:0.357:0.017 for sugar beet), should be useful in the modeling of agro-ecosystems that include root crops.


Beskydy ◽  
2013 ◽  
Vol 6 (1) ◽  
pp. 33-42
Author(s):  
Petr Holub ◽  
Ivan Tůma ◽  
Karel Fiala

We assessed below-ground net primary productivity (BNPP) in the wet submontane Cirsium meadow occurred in the highland region of the Czech Republic. Effect of four different fertilization levels on BNPP was estimated in 1992. At the beginning of the growing season (April 29), total dry mass of rhizomes, roots and total below-ground plant parts of unfertilized stand reached 177, 1478 and 1657 g.m-2, respectively. Their living parts formed 42 % of their total dry mass. In comparison with unfertilized stands, however, the greatest accumulation of dry mass of rhizomes (504 g.m-2), roots (1503 g.m-2) and total below-ground dry mass (2008 g.m-2) was reached after application of 90 kgN.ha-1. Similarly, the highest BNPP values for living (435 g.m-2.yr-1) and total below-ground dry mass (351 g.m-2.yr-1) were calculated for the stand affected by the same amount of fertilization. These data show how variable role grasslands can play in accumulation and turn over of root biomass due to different levels of fertilization.


1991 ◽  
Vol 69 (3) ◽  
pp. 539-546 ◽  
Author(s):  
D. F. Grigal

Dynamics of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were determined for three perched bogs, formed by lake filling, and three raised bogs, formed by landscape swamping. N and K concentrations were higher in the undergrowth of perched bogs, and Ca and Mg concentrations were higher in subsurface anaerobic peat of raised bogs. Elemental pools in vegetation were in the order N > Ca > K > Mg > P; in surface peat, N > Ca > Mg > P = K. Differences in elemental mass between the bog types were closely related to biomass differences. The atmosphere potentially supplied from 3% of annual plant uptake of K to 20% of Mg; this fraction was inversely related to uptake as a proportion of the surface peat. Vegetation on raised bogs had a greater proportion of uptake from the atmosphere (15 vs. 12%), a faster rate of elemental turnover (3.8 vs. 4.8 years), and lower net primary productivity (NPP) than on perched bogs, all indicative of a lower nutrient status. The annual mineralization rate of the surface peat for both bog types was estimated at 1.5% year−1; NPP predicted from N mineralized at this rate agrees well with observations. The better nutritional status of perched bogs may be related to landscape position, with potential inputs via runoff from adjacent uplands. The nutrient capital in both bog vegetation and substrate was similar to that in upland northern conifer forests. Key words: acrotelm, ombrotrophic, raised bogs, nutrients, peatlands, nutrient cycling.


2017 ◽  
Vol 115 (6) ◽  
pp. 1232-1237 ◽  
Author(s):  
Miikka Tallavaara ◽  
Jussi T. Eronen ◽  
Miska Luoto

The environmental drivers of species distributions and abundances are at the core of ecological research. However, the effects of these drivers on human abundance are not well-known. Here, we report how net primary productivity, biodiversity, and pathogen stress affect human population density using global ethnographic hunter-gatherer data. Our results show that productivity has significant effects on population density globally. The most important direct drivers, however, depend on environmental conditions: biodiversity influences population density exclusively in low-productivity regions, whereas pathogen stress does so in high-productivity regions. Our results also indicate that subtropical and temperate forest biomes provide the highest carrying capacity for hunter-gatherer populations. These findings document that environmental factors play a key role in shaping global population density patterns of preagricultural humans.


Forests ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 764 ◽  
Author(s):  
Mislav Anić ◽  
Maša Ostrogović Sever ◽  
Giorgio Alberti ◽  
Ivan Balenović ◽  
Elvis Paladinić ◽  
...  

We analysed 10 years (2008–2017) of continuous eddy covariance (EC) CO2 flux measurements of net ecosystem exchange (NEE) in a young pedunculate oak forest in Croatia. Measured NEE was gap-filled and partitioned into gross primary productivity (GPP) and ecosystem reparation (RECO) using the online tool by Max Planck Institute for Biogeochemistry in Jena, Germany. Annual NEE, GPP, and RECO were correlated with main environmental drivers. Net primary productivity was estimated from EC (NPPEC), as a sum of −NEE and Rh obtained using a constant Rh:RECO ratio, and from independent periodic biometric measurements (NPPBM). For comparing the NPP at the seasonal level, we propose a simple model that aimed at accounting for late-summer and autumn carbon storage in the non-structural carbohydrate pool. Over the study period, Jastrebarsko forest acted as a carbon sink, with an average (±std. dev.) annual NEE of −319 (±94) gC m−2 year−1, GPP of 1594 (±109) gC m−2 year−1, and RECO of 1275 (±94) gC m−2 year−1. Annual NEE showed high inter-annual variability and poor correlation with annual average global radiation, air temperature, and total precipitation, but significant (R2 = 0.501, p = 0.02) correlation with the change in soil water content between May and September. Comparison of annual NPPEC and NPPBM showed a good overall agreement (R2 = 0.463, p = 0.03), although in all years NPPBM was lower than NPPEC, with averages of 680 (±88) gC m−2 year−1 and 819 (±89) gC m−2 year−1, respectively. Lower values of NPPBM indicate that fine roots and grasses contributions to NPP, which were not measured in the study period, could have an important contribution to the overall ecosystem NPP. At a seasonal level, two NPP estimates showed differences in their dynamic, but the application of the proposed model greatly improved the agreement in the second part of the growing season. Further research is needed on the respiration partitioning and mechanisms of carbon allocation.


2004 ◽  
Vol 20 (2) ◽  
pp. 221-224 ◽  
Author(s):  
Xiaoyong Chen ◽  
Derek Eamus ◽  
Lindsay B. Hutley

Fine roots and their turnover represent a dynamic aspect of below-ground biomass (BGB) and nutrient capital in forest ecosystems, and account for a significant fraction of net primary productivity (NPP) (Cuevas 1995, Vogt et al. 1990). On a weight basis, coarse roots contribute more to total ecosystem biomass than fine roots, but they account for only a small portion of annual root production (Eamus et al. 2002). Despite the fact that fine roots may compose less than 2% of total ecosystem biomass, they may contribute up to 40% of total ecosystem production (Vogt et al. 1990). Therefore, estimates of root production, like estimates of root biomass, should differentiate between coarse- and fine-root production.


2010 ◽  
Vol 7 (3) ◽  
pp. 3735-3763 ◽  
Author(s):  
K. Fenn ◽  
Y. Malhi ◽  
M. Morecroft ◽  
C. Lloyd ◽  
M. Thomas

Abstract. There exist very few comprehensive descriptions of the productivity and carbon cycling of forest ecosystems. Here we present a description of the components of annual Net Primary Productivity (NPP), Gross Primary Productivity (GPP), autotrophic and heterotrophic respiration, and ecosystem respiration (RECO) for a temperate mixed deciduous woodland at Wytham Woods in southern Britain, calculated using "bottom-up" biometric and chamber measurements (leaf and wood production and soil and stem respiration). These are compared with estimates of these parameters from eddy-covariance measurements made at the same site. NPP was estimated as 7.0±0.8 Mg C ha−1 yr−1, and GPP as 20.3+1.0 Mg C ha−1 yr−1, a value which closely matched to eddy covariance-derived GPP value of 21.1 Mg C ha−1 yr−1. Annual RECO was calculated as 18.9±1.7 Mg C ha−1 yr−1, close to the eddy covariance value of 19.8 Mg C ha−1 yr−1; the seasonal cycle of biometric and eddy covariance RECO estimates also closely matched. The consistency between eddy covariance and biometric measurements substantially strengthens the confidence we attach to each as alternative indicators of site carbon dynamics, and permits an integrated perspective of the ecosystem carbon cycle. 37% of NPP was allocated below ground, and the ecosystem carbon use efficiency (CUE, = NPP/GPP) calculated to be 0.35±0.05, lower than reported for many temperate broadleaved sites.


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