Biomass and nutrients in an Engelmann spruce–subalpine fir forest in north central Colorado: pools, annual production, and internal cycling

1992 ◽  
Vol 22 (3) ◽  
pp. 315-325 ◽  
Author(s):  
Mary A. Arthur ◽  
Timothy J. Fahey

Biomass and nutrient dynamics were examined in a subalpine Piceaengelmannii Parry–Abieslasiocarpa (Hook.) Nutt. forest within Loch Vale watershed in north central Colorado by quantifying annual above- and below-ground production, biomass, nutrient pools, and internal nutrient transfers. Subalpine forest covers only 6% of the watershed, and the values reported here refer only to the forested area. Total ecosystem biomass was 42 kg•m−2, of which 30% was soil organic matter, 33% was detrital biomass (including deadwood and forest floor), and 36% was living biomass. Total forest biomass (not including soil organic matter) was 28.9 kg•m−2, of which root biomass was 11%. Net primary production was 520 g•m−2•year−1, of which fine root production was about 27% and foliar production was 30%. Much more N was recycled via fine root turnover than via aboveground litter fall (1.6 versus 0.9 g•m−2•year−1), whereas four times more Ca was returned via litter fall than via fine roots. Compared with other temperate coniferous forests, this subalpine forest had low production. Nutrient resorption contributed between 35 and 38% of the annual requirements of N, P, and K, but only 9% of Ca and 12% of Mg. Although a higher percentage of annual N requirement was met by resorption, this forest used N less efficiently than a similar forest in southwestern Alberta.

1996 ◽  
Vol 26 (8) ◽  
pp. 1326-1336 ◽  
Author(s):  
R.W. Ruess ◽  
K. Van Cleve ◽  
J. Yarie ◽  
L.A. Viereck

Fine root production and turnover were studied in hardwood and coniferous taiga forests using three methods. (1) Using soil cores, fine root production ranged from 1574 ± 76 kg•ha−1•year−1 in the upland white spruce (Piceaglauca (Moench) Voss) stand to 4386 ± 322 kg•ha−1•year−1 in the floodplain balsam poplar (Populusbalsamifera L.) stand, accounting for 49% of total production for coniferous stands and 32% of total production for deciduous stands. Fine root turnover rates were higher in floodplain (0.90 ± 0.06 year−1) stands than in upland (0.42 ± 0.10 year−1) stands. Across all sites, the ratio of fine root turnover to litter fall averaged 2.2 for biomass and 2.8 for N. Both values were higher in floodplain stands than in upland stands, and in coniferous stands than in deciduous stands. (2) The C budget method showed that C allocation to fine roots varied from 150 to 425 g C•m−2•year−1 and suggested that soil respiration was more dependent on C derived from roots than from aboveground inputs. The C allocation ratio (C to roots: C to litter fall) was inversely correlated with litter-fall C and varied from 0.3 to 69.5; there was a tendency for higher proportional belowground allocation in coniferous stands than in deciduous stands and the highest levels were at the earliest successional sites. (3) Estimates of apparent N uptake (Nu), N allocation to fine roots, and fine root production based on N budget calculations showed that annual aboveground N increments exceeded Nu estimates at half the sites, indicating that the method failed to account for large amounts of N acquired by plants. This suggests that plant and (or) mycorrhizal uptake of soil organic N may be more significant to ecosystem N cycling than mineral N turnover by the soil microbial biomass.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 823
Author(s):  
Anna Zielonka ◽  
Marek Drewnik ◽  
Łukasz Musielok ◽  
Marcin K. Dyderski ◽  
Dariusz Struzik ◽  
...  

Forest ecosystems significantly contribute to the global organic carbon (OC) pool, exhibiting high spatial heterogeneity in this respect. Some of the components of the OC pool in a forest (woody aboveground biomass (wAGB), coarse root biomass (CRB)) can be relatively easily estimated using readily available data from land observation and forest inventories, while some of the components of the OC pool are very difficult to determine (fine root biomass (FRB) and soil organic matter (SOM) stock). The main objectives of our study were to: (1) estimate the SOM stock; (2) estimate FRB; and (3) assess the relationship between both biotic (wAGB, forest age, foliage, stand density) and abiotic factors (climatic conditions, relief, soil properties) and SOM stocks and FRB in temperate forests in the Western Carpathians consisting of European beech, Norway spruce, and silver fir (32 forest inventory plots in total). We uncovered the highest wAGB in beech forests and highest SOM stocks under beech forest. FRB was the highest under fir forest. We noted a considerable impact of stand density on SOM stocks, particularly in beech and spruce forests. FRB content was mostly impacted by stand density only in beech forests without any discernible effects on other forest characteristics. We discovered significant impacts of relief-dependent factors and SOM stocks at all the studied sites. Our biomass and carbon models informed by more detailed environmental data led to reduce the uncertainty in over- and underestimation in Cambisols under beech, spruce, and fir forests for mountain temperate forest carbon pools.


Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 940
Author(s):  
Bohdan Konôpka ◽  
Milan Barna ◽  
Michal Bosela ◽  
Martin Lukac

This study reports on an investigation of fine root and foliage productivity in forest stands dominated by European beech (Fagus sylvatica L.) and exposed to contrasting intensities of mature forest harvesting. The main aim of this study was to consider the long-term effects of canopy manipulation on resource acquisition biomass compartments in beech. We made use of an experiment established in 1989, when five different light availability treatments were started in plots within a uniform forest stand, ranging from no reduction in tree density to full mature forest removal. We measured fine root standing stock in the 0–30 cm soil layer by coring in 2013 and then followed annual fine root production (in-growth cores) and foliage production (litter baskets) in 2013–2015. We found that the plot where the tree density was reduced by 30% had the lowest foliage and the highest fine root production. In 2013, this plot had the highest fine root turnover rate (0.8 year−1), while this indicator of fine root dynamics was much lower in the other four treatments (around 0.3 year−1). We also found that the annual fine root production represented around two thirds of annual foliage growth on the mass basis in all treatments. While our findings support the maintenance of source and sink balance in woody plants, we also found a long-lasting effect of tree density manipulation on investment into resource acquisition compartments in beech forests.


Radiocarbon ◽  
2001 ◽  
Vol 43 (2B) ◽  
pp. 595-601 ◽  
Author(s):  
L C R Pessenda ◽  
S E M Gouveia ◽  
R Aravena

During the last decade radiocarbon dating has been used extensively in distinct regions of Brazil to provide information about soil chronology in paleoenvironmental studies. This paper presents 14C data of soil organic matter (SOM), humin fraction, and charcoal in several soil profiles under natural vegetation from different Brazil locations (north, central, and southeast regions). The main objective is to compare the obtained 14C dating of total SOM with humin, the oldest fraction of SOM. In order to validate the humin ages these data are compared with the age of charcoal collected at similar depths. The 14C ages obtained on charcoal were, in most of the cases, in agreement with the humin fraction considering the experimental errors, or 20% older in average. The dates obtained from total SOM showed significantly younger ages than the humin fraction indicating contamination by younger carbon. These results show the humin fraction is considered a reliable material for 14C dating in soils. However, the humin fraction ages could be assumed as the minimum ages for carbon in soils.


2019 ◽  
Vol 4 (1) ◽  
pp. 187-202
Author(s):  
Walter A. Goldstein ◽  
Herbert H. Koepf ◽  
Chris J. Koopmans

AbstractThe effects of biodynamic preparations were tested in the context of comparisons of conventional, organic, and biodynamic systems and diverse crop rotations in Washington and Wisconsin, USA. Wisconsin research also entailed testing a new nettle-and-manure-based field spray preparation (NCP). Focus was on winter wheat and maize and on soil quality. In Washington, preparations increased root growth of winter wheat, microbial biomass, and soil organic matter. In Wisconsin, applying a combination of preparations that included NCP increased root growth of maize, root health, and particulate organic matter in the soil. Relative to the organic treatments, root dry matter increases associated with the use of preparations varied from 12% to 39% and root length differences varied from 10% to 37% depending on the experiment, crop, year, and preparation application. The biodynamic + NCP treatment also induced substantial, positive yield compensatory effects for maize and wheat under stress condition years. The response slopes were practically identical for wheat and maize, indicating that the effect is of the same magnitude for both crops. Results were higher average grain yields and gross financial returns than for organic grain. The greater root production and root health stimulated by preparations is probably linked to greater vegetative growth, enhanced yield under stress conditions, and increased soil quality and carbon in soils.


2020 ◽  
Vol 25 (1) ◽  
pp. 24-29
Author(s):  
Krishna Prasad Bhattarai ◽  
Tej Narayan Mandal ◽  
Tilak Prasad Gautam

The present study was conducted to understand the effect of altitude on the nutrient concentration, nutrient stock, and uptake in the fine root of the Terai Sal forest (TSF) and Hill Sal forest (HSF) in eastern Nepal. Annual mean fine root biomass in 0-30 cm soil depth was found higher in HSF (6.27 Mg ha-1) than TSF (5.05 Mg ha-1). Conversely, fine root production was higher in TSF (4.8 Mg ha-1 y-1) than HSF (4.12 Mg ha-1 y-1). Nitrogen, phosphorus, and potassium content in fine roots were slightly higher in TSF than HSF. Nutrient concentration in fine roots of smaller size (<2 mm diameter) was nearly 1.2 times greater than that of larger size (2–5 mm diameter) in both forests. In HSF total stock of different nutrients (kg ha-1) in fine root was 55.62 N, 4.99 P, and 20.15 K whereas, these values were 49.49 N, 4.14 P, and 19.27 K only in TSF. However, total nutrient uptake (kg ha-1y-1) by fine root (both size classes) was greater in TSF (48.5 N, 4.3 P, and 18.6 K) than HSF (36.9 N, 3.3 P, and 13.5 K). The variability in fine root nutrient dynamics between these two forests was explained by the differences in fine root biomass and production which were influenced by the combined effect of varied altitude and season. The fine root, as being a greater source of organic matter, the information on its nutrient dynamics is inevitable for the management of soil nutrients in the forest ecosystem.


1986 ◽  
Vol 16 (3) ◽  
pp. 529-538 ◽  
Author(s):  
Henry L. Gholz ◽  
Laurel C. Hendry ◽  
Wendell P. Cropper Jr.

Seasonal patterns of live, dead, and unknown viability fine (diameter, ≤10 mm) roots of pine and other vegetation in a young and old slash pine stand were sampled using monthly soil coring over a 24-month period. A distinct unimodal pattern for roots <1 mm in diameter in the surface soil was observed. Live roots increased in the spring to a peak in midsummer and then declined. Larger roots and roots deeper in the soil showed less distinct seasonal patterns, although maximum and minimum annual biomass values were sometimes significantly different. Decomposition of fine roots in buried mesh bags averaged 15–20% per year for roots <5 mm in diameter. An analysis of seasonal dynamics and decompositon rates were combined to construct organic matter budgets for the forest floor and soil. Estimated net root production for roots ≤10 mm in diameter was 590 and 626 g m−2 year−1 in the young and old stand, respectively. Root turnover contributed 214 and 452 g m−2 year−1 to detrital pools on the two sites, with the balance of production accumulating as standing root biomass or lost in decomposition. Root production and turnover rates decreased with increasing root diameter; most production was from roots <1 mm. Pine root production was greater and nonpine production was less in the older stand than in the younger stand. Compared with other temperate and boreal forests, root biomass was high and net root production relatively low. The low production:biomass ratio may be characteristic of low latitude (warm) and (or) low nutrient forest types.


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