scholarly journals Nutrient dynamics in decomposing litter from four selected tree species in Makurdi, Benue State, Nigeria

2019 ◽  
Vol 43 (1) ◽  
Author(s):  
Thomas Okoh ◽  
Esther Edu

Abstract Background Nutrient release during litter decomposition was investigated in Vitex doniana, Terminalia avecinioides, Sarcocephallus latifolius, and Parinari curatellifolius in Makurdi, Benue State Nigeria (January 10 to March 10 and from June 10 to August 10, 2016). Leaf decomposition was measured as loss in mass of litter over time using the decay model Wt/W0 = e−kd t, while $$ \mathrm{Kd}=-\frac{1}{t} In\left(\frac{Wt}{W0}\right) $$Kd=−1tInWtW0 was used to evaluate decomposition rate. Time taken for half of litter to decompose was measured using T50 = ln 2/k; while nutrient accumulation index was evaluated as NAI =$$ \left(\frac{\omega t\ Xt}{\omega \mathrm{o}X\mathrm{o}}\right). $$ωtXtωoXo. Results Average mass of litter remaining after exposure ranged from 96.15 g, (V. doniana) to 78.11 g, (S. lafolius) in dry (November to March) and wet (April to October) seasons. Decomposition rate was averagely faster in the wet season (0.0030) than in the dry season (0.0022) with P. curatellifolius (0.0028) and T. avecinioides (0.0039) having the fastest decomposition rates in dry and wet seasons. Mean residence time (days) ranged from 929 to 356, while the time (days) for half the original mass to decompose ranged from 622 to 201 (dry and wet seasons). ANOVA revealed highly significant differences (p < 0.01) in decomposition rates and exposure time (days) and a significant interaction (p < 0.05) between species and exposure time in both seasons. Conclusion Slow decomposition in the plant leaves implied carbon retention in the ecosystem and slow release of CO2 back to the atmosphere, while nitrogen was mineralized in both seasons. The plants therefore showed effectiveness in nutrient cycling and support productivity in the ecosystem.

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Mohamed Cissé ◽  
Salifou Traoré ◽  
Babou André Bationo

AbstractThis study was carried out to determine the rates of decomposition and nutrient release from pure and mixed leaf litter samples of three agroforestry species (Azolla africana Desv., Detarium microcarpum Guill. and Perr. and Vitellaria paradoxa C.F.Gaertn.) that have potential use as green manure. Litterbags containing a total of 5 g of pure and mixed leaf litter of different quality levels were incubated under field conditions from July to November in 2017. Litter decomposition and nutrient release (N, P, and K) rates were assessed in each litterbag. The decomposition rate (k) indicated that pure A. africana litter decomposed faster (k = 0.406 week−1) than its mixture with V. paradoxa (k = 0.114 week−1) and D. microcarpum (k = 0.103 week−1). The slowest decomposition rates were found for the pure D. microcarpum (k = 0.075 week−1) and V. paradoxa (k = 0.071 week−1) leaf litters. Mixing with A. africana litter increased the decomposition rate of both D. microcarpum and V. paradoxa leaf litter. We conclude that mixing litter of different quality can accelerate the decomposition of pure litter with poor quality and represents a practical biomass management option for farmers to improve nutrient cycling in agroforestry systems.


1992 ◽  
Vol 22 (2) ◽  
pp. 161-166 ◽  
Author(s):  
T.D. Schowalter

Decomposition of oak (Quercus spp.) logs (25–35 cm diameter, 3 m long) was compared among log substrates in Oregon, Minnesota, Kansas, and North Carolina during the first 2 years on the ground. Decomposition rates (k) for integrated logs averaged 0.28 ± 0.04 year−1 (mean ± 1 SD)) during this initial period. Decomposition reflected qualitative differences among log substrates (outer and inner bark, sapwood and heartwood). Inner bark had the highest nutritional quality and was the focus of insect and microbial activity during this early stage of decomposition; only 20% of initial mass remained after 2 years (k = 0.59 ± 0.15 year−1). Sapwood decayed more slowly than heartwood, with an overall decay rate of 0.20 ± 0.15 year−1). Heartwood lost 50% of its mass during the 1st year, but showed no further loss during the 2nd year, for an overall decay rate of 0.31 ± 0.05 year−1. Nutrient content generally declined during decomposition, but P accumulated in heartwood and Na accumulated in sapwood and heartwood during the 2nd year. Results indicate that decomposition of whole logs integrates different decomposition rates and lag times (i.e., time prior to initiation of decomposition) among log substrates varying in qualitative factors. Multiple-exponential models may be necessary to predict rates and sources of carbon and nutrient release to the atmosphere and soil.


2013 ◽  
Vol 16 (1) ◽  
pp. 1-6
Author(s):  
Ali Munawar ◽  
. Indarmawan ◽  
Hery Suhartoyo

Vegetation establishment is considered as a critical step of mined land rehabilitation. The growing plants do not only prevent soil erosion, but also play important roles in soil ecosystem development. Their litterfall is the main process of transferring organic matter and nutrients from aboveground tree biomass to soil. Thus, its quantification would aid in understanding biomass and nutrient dynamics of the ecosystem. This study was aimed to investigate the litter production and its decomposition rate in a reclaimed mined land using albizia and sesbania, and theireffects on some soil properties. The litter under each stand was biweekly collected for four months. At the same time litter samples were decomposed in mesh nylon bags in soils and the remaining litters were biweekly measured. Soil samples were taken from 0-15 cm depths from each stand for analyses of soil organic C, total N, and cation exchange capacity (CEC). The results demonstrated that total litter production under albizia (10.58 t ha-1 yr-1) was almost twice as much as that under sesbania stands (5.43 t ha-1 yr-1). Albizia litter was dominated by leaf litter (49.26%) and least as understory vegetation (23.31%), whereas sesbania litter was more evenly distributed among litter types. Decomposition rates of all litters were fastest in the initial stage and then gradually decreased. Sesbania leaf litters decomposed fastest, while albizia twigs slowest. Differences in the litter production and decomposition rates of the two species had not sufficiently caused significant effects on organic-C, total N, and CEC of the soilsafter one year of revegetation.Keywords: Albizia (Paraserianthes falcataria), decomposition rates, litter, mined land, Sesbania grandiflora


2021 ◽  
Author(s):  
D.-G. J. M. Hougni ◽  
A. G. T. Schut ◽  
L. S. Woittiez ◽  
B. Vanlauwe ◽  
K. E. Giller

Abstract Aim Recycling of cocoa pod husks has potential to contribute to mineral nutrition of cocoa. Yet little is known of the nutrient content and nutrient release patterns from the husks. The potassium (K) rich husks are usually left in heaps in cocoa plantations in Africa. We aimed to understand and quantify release patterns of K and other nutrients from husks under varying rainfall regimes and assessed the effects of partial decomposition and inundation on nutrient leaching rates. Methods We incubated chunks of cocoa pod husks to assess decomposition rates and we measured nutrient leaching rates from two sets of husk chunks: one set was placed in tubes that were submitted to simulated scheduled rainfall events while the second set was continuously inundated in beakers. Results Decomposition of husks followed a second-order exponential curve (k: 0.09 day−1; ageing constant: 0.43). Nutrient losses recorded within 25 days were larger and more variable for K (33%) than for other macronutrients released in this order: Mg > Ca ≈ P > N (less than 15%). Potassium leaching was mainly driven by rainfall frequency (P < 0.05) and reinforced by intense rainfall, especially at lower frequency. Under water-saturated conditions, 11% of K was leached out within 48 h from fresh husks compared with 92% from partially decayed husks. Conclusion Some initial decomposition of cocoa pod husks is required to expose K to intense leaching. As decomposition progresses, abundant K losses are to be expected under frequent and/or intense rainfall events.


1998 ◽  
Vol 6 (1) ◽  
pp. 1-12 ◽  
Author(s):  
M Francesca Cotrufo ◽  
Björn Berg ◽  
Werner Kratz

There is evidence that N concentration in hardwood leaf litter is reduced when plants are raised in an elevated CO2 atmosphere. Reductions in the N concentration of leaf litter have been found for tree species raised under elevated CO2, with reduction in N concentration ranging from ca. 50% for sweet chestnut (Castanea sativa) to 19% for sycamore (Acer platanoides). However, the effects of elevated CO2 on the chemical composition of litter has been investigated only for a limited number of species. There is also little information on the effects of increased CO2 on the quality of root tissues. If we consider, for example, two important European forest ecosystem types, the dominant species investigated for chemical changes are just a few. Thus, there are whole terrestrial ecosystems in which not a single species has been investigated, meaning that the observed effects of a raised CO2 level on plant litter actually has a large error source. Few reports present data on the effects of elevated CO2 on litter nutrients other than N, which limits our ability to predict the effects of elevated CO2 on litter quality and thus on its decomposability. In litter decomposition three separate steps are seen: (i) the initial stages, (ii) the later stages, and (iii) the final stages. The concept of "substrate quality," translated into chemical composition, will thus change between early stages of decomposition and later ones, with a balanced proportion of nutrients (e.g., N, P, S) being required in the early decomposition phase. In the later stages decomposition rates are ruled by lignin degradation and that process is regulated by the availability of certain nutrients (e.g., N, Mn), which act as signals to the lignin-degrading soil microflora. In the final stages the decomposition comes to a stop or may reach an extremely low decomposition rate, so low that asymptotic decomposition values may be estimated and negatively related to N concentrations. Studies on the effects of changes in chemical composition on the decomposability of litter have mainly been made during the early decomposition stages and they generally report decreased litter quality (e.g., increased C/N ratio), resulting in lower decomposition rates for litter raised under elevated CO2 as compared with control litter. No reports are found relating chemical changes induced by elevated CO2 to litter mass-loss rates in late stages. By most definitions, at these stages litter has turned into humus, and many studies demonstrated that a raising of the N level may suppress humus decomposition rate. It is thus reasonable to speculate that a decrease in N levels in humus would accelerate decomposition and allow it to proceed further. There are no experimental data on the long-term effect of elevated CO2 levels, and a decrease in the storage of humus and nutrients could be predicted, at least in temperate and boreal forest systems. Future works on the effects of elevated CO2 on litter quality need to include studies of a larger number of nutrients and chemical components, and to cover different stages of decomposition. Additionally, the response of plant litter quality to elevated CO2 needs to be investigated under field conditions and at the community level, where possible shifts in community composition (i.e., C3 versus C4 ; N2 fixers versus nonfixers) predicted under elevated CO2 are taken into account.Key words: climate change, substrate quality, carbon dioxide, plant litter, chemical composition, decomposition.


Author(s):  
Lili Wei

Coastal wetlands are among the most carbon-rich ecosystems in the world. Litter decomposition is a major process controlling soil carbon input. Litter mixing has shown a non-additive effect on the litter decomposition of terrestrial plants particularly of those species having contrasting litter quality. But the non-additive effect has been rarely tested in coastal plants which generally having low-quality litters. We selected three common mangrove species and one saltmarsh species, co-occurring in subtropical coasts, to test whether the non-additive effect occurs when the litters of these coastal species mixing together. We are also concerned whether the changes in the decomposition rate of litter will affect the nutrient contents in waters. A litter-bag experiment was carried out in a glasshouse with single and mixed leaf litters. A non-additive effect was observed in the litter mixtures of mangrove species Aegiceras corniculatum vs. Kandelia obovata (antagonistic) and A. corniculatum vs. Avicennia marina (synergistic). Whereas, the mixture of A. corniculatum (mangrove species) and Spartina alterniflora (saltmarsh species) showed an additive effect. The strength of the non-additive effect was unrelated to the initial trait dissimilarity of litters. Instead, the decomposition rate and mass remaining of litter mixtures were strongly related to the carbon concentrations in litters. Nutrient content in waters was dependent on the decomposition rate of litter mixtures but not on the initial nutrient concentrations in litters. Despite the behind mechanisms were not yet revealed by the current study, these findings have improved our understanding of the litter decomposition of coastal species and the consequent nutrient release.


2006 ◽  
Vol 6 (10) ◽  
pp. 2911-2925 ◽  
Author(s):  
D. Chand ◽  
P. Guyon ◽  
P. Artaxo ◽  
O. Schmid ◽  
G. P. Frank ◽  
...  

Abstract. As part of the Large Scale Biosphere-Atmosphere Experiment in Amazonia – Smoke, Aerosols, Clouds, Rainfall and Climate (LBA-SMOCC) campaign, detailed surface and airborne aerosol measurements were performed over the Amazon Basin during the dry to wet season from 16 September to 14 November 2002. Optical and physical properties of aerosols at the surface, and in the boundary layer (BL) and free troposphere (FT) during the dry season are discussed in this article. Carbon monoxide (CO) is used as a tracer for biomass burning emissions. At the surface, good correlation among the light scattering coefficient (σs at 545 nm), PM2.5, and CO indicates that biomass burning is the main source of aerosols. Accumulation of haze during some of the large-scale biomass burning events led to high PM2.5 (225 μg m−3), σs (1435 Mm−1), aerosol optical depth at 500 nm (3.0), and CO (3000 ppb). A few rainy episodes reduced the PM2.5, number concentration (CN) and CO concentration by two orders of magnitude. The correlation analysis between σs and aerosol optical thickness shows that most of the optically active aerosols are confined to a layer with a scale height of 1617 m during the burning season. This is confirmed by aircraft profiles. The average mass scattering and absorption efficiencies (545 nm) for small particles (diameter Dp<1.5 μm) at surface level are found to be 5.0 and 0.33 m2 g−1, respectively, when relating the aerosol optical properties to PM2.5 aerosols. The observed mean single scattering albedo (ωo at 545 nm) for submicron aerosols at the surface is 0.92±0.02. The light scattering by particles (Δσs/Δ CN) increase 2–10 times from the surface to the FT, most probably due to the combined affects of coagulation and condensation.


1995 ◽  
Vol 25 (7) ◽  
pp. 1049-1057 ◽  
Author(s):  
Robert L. Edmonds ◽  
Ted B. Thomas

Decomposition rates and nutrient dynamics (for N, P, K, Ca, Mg, Mn, and Na) were determined for green needles of western hemlock (Tsugaheterophylla (Raf.) Sarg.) and Pacific silver fir (Abiesamabilis (Dougl.) Forb.) in an old-growth forested watershed (58 ha West Twin Creek) in the Hoh River valley, Olympic National Park, Washington. The influence of temperature and substrate chemistry on decomposition was determined. Temperature was the dominant factor controlling decomposition rates in the first year in this watershed, with the fastest decomposition at an elevation of 275 m (lower watershed) and the slowest decomposition at 725 m (upper watershed). After 12 months mass loss averaged 36% in the lower watershed and 28% in the upper watershed. There was no significant difference in decomposition rates between species. Substrate chemistry, i.e., the lignin/N ratio, became a more important factor than temperature as decomposition proceeded. After 37 months mass loss for needles averaged 61% for western hemlock and 50% for Pacific silver fir, with no difference by watershed location. After 61 months both types of substrates appeared to be approaching similar substrate chemistry and similar decomposition rates and there were no significant differences by species or watershed location. Decomposition constants (k values) after 61 months were 0.26 and 0.20 year−1 for western hemlock needles in the lower and upper watershed, respectively, and 0.22 and 0.19 year−1 for Pacific silver fir needles in the lower and upper watershed, respectively. Nitrogen was immobilized during the first 12 months of decomposition in needles of both species and then released. No other elements were immobilized during the initial (0- to 12-month) decomposition period, except for Ca in Pacific silver fir needles. However, in the 37- to 61-month period there was a considerable immobilization of Mg and Na in both species in the upper and lower watershed and K and Mn in both species in the upper watershed.


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