scholarly journals Effects of uprooted treefalls and their microsites on decomposition rate and nutrient release of litters in Picea koraiensis-Abies nephrolepis-Pinus koraiensis forest

2021 ◽  
Vol 41 (24) ◽  
Author(s):  
陈佳,段文标,曲美学,王亚飞,杨习锋,孟思静 CHEN Jia
2020 ◽  
Vol 100 (1) ◽  
pp. 11-25 ◽  
Author(s):  
Guoyong Yan ◽  
Xiongde Dong ◽  
Binbin Huang ◽  
Honglin Wang ◽  
Ziming Hong ◽  
...  

We conducted a field experiment with four levels of simulated nitrogen (N) deposition (0, 2.5, 5, and 7.5 g N m−2 yr−1, respectively) to investigate the response of litter decomposition of Pinus koraiensis (PK), Tilia amurensis (TA), and their mixture to N deposition during winter and growing seasons. Results showed that N addition significantly increased the mass loss of PK litter and significantly decreased the mass loss of TA litter throughout the 2 yr decomposition processes, which indicated that the different responses in the decomposition of different litters to N addition can be species specific, potentially attributed to different litter chemistry. The faster decomposition of PK litter with N addition occurred mainly in the winter, whereas the slower decomposition of TA litter with N addition occurred during the growing season. Moreover, N addition had a positive effect on the release of phosphorus, magnesium, and manganese for PK litter and had a negative effect on the release of carbon, iron, and lignin for TA litter. Decomposition and nutrient release from mixed litter with N addition showed a non-additive effect. The mass loss from litter in the first winter and over the entire study correlated positively with the initial concentration of cellulose, lignin, and certain nutrients in the litter, demonstrating the potential influence of different tissue chemistries.


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.


2020 ◽  
Vol 40 (4) ◽  
Author(s):  
苑丹阳 YUAN Danyang ◽  
赵慧颖 ZHAO Huiying ◽  
李宗善 LI Zongshan ◽  
朱良军 ZHU Liangjun ◽  
国淼 GUO Miao ◽  
...  

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 ◽  
Author(s):  
Cheryl Batistel ◽  
Gerald Jurasinski ◽  
Hendrik Schubert

&lt;p&gt;Global mean sea level had been rising and accelerating in the last decades affecting coastal wetlands that are important carbon stores since they are susceptible to fluctuating water levels. Climate-change-driven sea-level rise, which is predicted to reach about one to two meters by 2100, may lead to dramatic shifts in the vegetation composition of coastal wetlands consequently influencing ecosystem functions including photosynthetic activity, biomass production, litter decomposability, and ultimately the pattern and rates of nutrient cycling, carbon storage, and greenhouse gas exchange. In this regard, aside from water level, changes in salinity that may especially influence the decomposition of dead plant material are also of prime concern.&lt;/p&gt;&lt;p&gt;Here, we provide a comparative evaluation of the decomposition rates of the dominant macrophytes in different nearby freshwater and brackish peatlands. We assumed that the degradability of leaf litter differs among species due to the difference in chemical composition. Two peatland sites, Schutower Moor (freshwater) and Diedrichshagen Moor (brackish) were selected to compare the decomposition rate and nutrient release of &lt;em&gt;Phragmites australis&lt;/em&gt;, &lt;em&gt;Carex&lt;/em&gt; sp. and &lt;em&gt;Schoenoplectus tabernaemontanii &lt;/em&gt;as influenced by salinity. We used the litterbag method using senescent leaves or stem parts (for &lt;em&gt;S. tabernaemontanii&lt;/em&gt;) of the macrophytes that were collected in late autumn. We deposited 30 litterbags per species per site and retrieved 5 of these per site after 1, 2, 4, 6, 8 and 12 months, respectively.&lt;/p&gt;&lt;p&gt;Regardless of site and species, the highest mass loss occurred in the first 35 days of decomposition with a strong decrease thereafter with almost flat slopes. The initial decay rates of the same species did not differ significantly between sites. However, the initial mass loss of the &lt;em&gt;S. tabernaemontanii&lt;/em&gt; litter was significantly higher than the other species. This species has the highest decay coefficient of 0.008 d&lt;sup&gt;-1&lt;/sup&gt; and 0.006 d&lt;sup&gt;-1&lt;/sup&gt; in freshwater and brackish sites, respectively. These decay rates are up to four times faster compared to the other species resulting in empty litterbags a year after deployment indicating the complete decomposition of&amp;#160;&lt;em&gt;S. tabernaemontanii &lt;/em&gt;while other species had between 40% to 60% dry mass remaining. Initially, the carbon and nitrogen contents of &lt;em&gt;S. tabernaemontanii &lt;/em&gt;were significantly lower than those of the other species while its initial sulfur content was significantly higher than of the other species.&amp;#160;&lt;em&gt;S. tabernaemontanii &lt;/em&gt;retained a relatively high amount of nitrogen, phosphorus, sulfur and magnesium throughout decomposition compared to the other species. This keeps the C:N, C:P, C:S, C:Mg and N:P ratios nearly constant from the start to the end of the study suggesting continuous microbial activities due to the availability of such nutrients in the detritus of&amp;#160;&lt;em&gt;S. tabernaemontanii&lt;/em&gt;. This confirms that&amp;#160;&lt;em&gt;P. australis&lt;/em&gt;&amp;#160;and&amp;#160;&lt;em&gt;Carex&lt;/em&gt;&amp;#160;sp. contribute to the formation of peat while&amp;#160;&lt;em&gt;S. tabernaemontanii&amp;#160;&lt;/em&gt;does not.&amp;#160;&amp;#160;&lt;/p&gt;&lt;p&gt;Litter quality showed to be a more important factor affecting decomposition than the little difference in salinity between sites (e.g. annual average of 3psu) that did not significantly affect the decomposition rate of macrophyte litter. Therefore, future similar studies should consider comparing sites with higher salinity levels.&lt;/p&gt;


2021 ◽  
Vol 4 ◽  
Author(s):  
Kaie Kriiska ◽  
Krista Lõhmus ◽  
Jane Frey ◽  
Endla Asi ◽  
Naima Kabral ◽  
...  

Litter decomposition is a key process that drives carbon and nutrient cycles in forest soils. The decomposition of five different substrate types was analyzed in hemiboreal coniferous forests, focusing on the mass loss and nutrient (N, P, and K) release of fine roots (FR) and needle litter in relation to the initial substrate and soil chemistry. A litterbag incubation experiment with site-specific FR and needle litter and three standard substrates (green and rooibos tea, α-cellulose) was carried out in four Norway spruce and four Scots pine-dominated stands in Estonia. Substrate type was the primary driver of mass loss and the decay rate of different substrates did not depend on the dominant tree species of the studied stands. Alpha-cellulose lost 98 ± 1% of the mass in 2-years, while the FR mass loss was on average 23 ± 2% after 3-years of decomposition. The FR decomposition rate could be predicted using a corresponding model of green tea, although the rate of FR decomposition is approximately five times lower than the rate of green tea in the first 3-years. The annual decomposition rate of the needle litter is rather constant in hemiboreal coniferous forests in the first 3 years. The initial substrate of fine roots or needle litter and soil chemistry jointly had a significant effect on mass loss in the later stage of decomposition. The critical N concentration for N release was lower for pine FR and needle litter (0.9–1.3% and 0.7–1.1%) compared to spruce (1.2–1.6% and 1.5–1.9%, respectively). The release rate of K depended on the initial K of substrate, while the release of N and P was significantly related to the initial C:N and N:P ratios, respectively. The results show the central role of soil and substrate initial chemistry in the decomposition of fine roots and needle litter across hemiboreal forests, especially at later stage (after 2 years) of decomposition. The slower decomposition and higher retention of N in the fine roots relative to needle litter suggests that fine roots have a substantial role in the carbon and nitrogen accumulation in boreal and hemiboreal forest ecosystems.


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