scholarly journals Litterfall, Decomposition and Nutrient Release in Sacred Forests of Western Odisha, India.

2020 ◽  
Author(s):  
Antaryami Pradhan ◽  
Niranjan Behera

Abstract Background Recognizing that litterfall and decomposition are key ecosystem functions for ecosystem stability in a terrestrial ecosystem, litterfall and decomposition in four sacred forests were studied from western part of Odisha. The present study focuses on the detailed aspects of litter dynamics, decomposition and consequent release of nutrients to the forest floor. The results obtained in this study will be beneficial in understanding the ecosystem functioning associated with nutrient cycling, which helps in determining possible management strategies for optimization of ecosystem functioning and productivity of these sacred forests. Results Litterfall and standing litter showed a seasonal pattern with most of the litter accumulated during the dry seasons and lowest in the rainy season. However, no significant difference was observed between the litterfall patterns of the sacred forests. The annual turnover rate (KL) was found to be in the range of 3.59/yr to 4.22/yr in studied sacred forests. The litter decomposition study was performed by litter bag technique and almost 95% of mass loss was observed within a period of 6 months. Such fast decomposition leads to faster rate of nutrient release across the sites. The studied elements can be set in the following order as regards to their return to the topsoil during decomposition in the order of K (Potassium) > N (Nitrogen) > P (Phosphorus). The approximate amount of nutrient released to the forest soil is quantified in the range of 184.76 to 33.61kg/ha of NPK (Nitrogen, Phosphorus and Potassium) in different sacred forests.Conclusion Such nutrient release and dynamics in sacred forests, may contribute an effective nutrient flow to the topsoil as well as to the surrounding agricultural landscapes boosting agricultural productivity and sustainability. This signifies the role of sacred forests in rendering an important ecological service in terms of nutrient cycling.

2002 ◽  
Vol 6 (6) ◽  
pp. 999-1005 ◽  
Author(s):  
C. L. Biles ◽  
D. M. Paterson ◽  
R. B. Ford ◽  
M. Solan ◽  
D. G. Raffaelli

Abstract. The effect of community structure on the functioning of the ecosystem is an important issue in ecology due to continuing global species loss. The influence of infaunal community structure on the functioning of marine systems is proposed here to act primarily through bioturbation of the sediment. Nutrient concentration in the water column, generated by release from the sediment, was used as a measure of ecosystem functioning. In situ and laboratory experiments showed a significant difference in nutrient concentrations with different species treatments. Bioturbation profiles showing the incorporation of tracer particles also differed between communities with different dominant species. The behavioural differences between infaunal species, generating different modes and rates of bioturbation, are therefore proposed to influence nutrient release. The presence and quantity of bioturbating infauna also influenced the amount of sediment suspended in the water column. The increase in surface area available for microbial activity may generate an increase in nutrient cycling. Abiotic influences on sediment structure, such as flow, may have a similar effect on nutrient concentration. Annular flumes used in both laboratory and in situ experiments to generate flow conditions produced a significant increase in ammonia (NH4-N) production in macrofaunal treatments. Flow may influence the behaviour of macrofaunal species, causing changes in NH4-N production through modifying bioturbation of the sediment. Keywords: bioturbation, community structure, ccosystem functioning, estuaries, flow, infauna


2020 ◽  
Author(s):  
Yudi M. Lozano ◽  
Carlos A. Aguilar-Trigueros ◽  
Gabriela Onandia ◽  
Stefanie Maaß ◽  
Tingting Zhao ◽  
...  

AbstractMicroplastics in soils have become an important threat for terrestrial systems, which can be exacerbated by drought as microplastics may affect soil water content. Thus, the interaction between these two factors may alter ecosystem functions such as litter decomposition, stability of soil aggregates, as well as functions related to nutrient cycling. Despite this potential interaction, we know relatively little about how microplastics, under different soil water conditions, affect ecosystem functions and ecosystem multifunctionality.To address this gap, we carried out a controlled-environment study using grassland plant communities. We applied the two factors microplastic fibers (absent, present) and soil water conditions (well-watered, drought), in all possible combinations in a factorial experiment. At harvest, we measured multiple ecosystem functions linked to nutrient cycling, litter decomposition, and soil aggregation and as terrestrial systems provide these functions simultaneously, we also assessed ecosystem multifunctionality.Our results showed that the interaction between microplastic fibers and drought affected ecosystem functions and multifunctionality. Overall, drought had negatively affected nutrient cycling by decreasing potential enzymatic activities and increasing nutrient leaching, while microplastic fibers had a positive impact on soil aggregation and nutrient retention by diminishing nutrient leaching. Microplastic fibers also impacted enzymatic activities, soil respiration and ecosystem multifunctionality, but importantly, the direction of these effects depended on soil water status (i.e., they decreased under well watered conditions, but tended to increase or had similar effects under drought conditions). Litter decomposition had a contrary pattern.Synthesis and applications. As soil water content is affected by climate change, our results suggest that areas with sufficiency of water would be negatively affected in their ecosystem functioning as microplastics increase in the soil; however, in areas subjected to drought, microplastics would have a neutral or slightly positive effect on ecosystem functioning.


Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 419
Author(s):  
Jordi Sardans ◽  
Josep Peñuelas

Potassium, mostly as a cation (K+), together with calcium (Ca2+) are the most abundant inorganic chemicals in plant cellular media, but they are rarely discussed. K+ is not a component of molecular or macromolecular plant structures, thus it is more difficult to link it to concrete metabolic pathways than nitrogen or phosphorus. Over the last two decades, many studies have reported on the role of K+ in several physiological functions, including controlling cellular growth and wood formation, xylem–phloem water content and movement, nutrient and metabolite transport, and stress responses. In this paper, we present an overview of contemporary findings associating K+ with various plant functions, emphasizing plant-mediated responses to environmental abiotic and biotic shifts and stresses by controlling transmembrane potentials and water, nutrient, and metabolite transport. These essential roles of K+ account for its high concentrations in the most active plant organs, such as leaves, and are consistent with the increasing number of ecological and agricultural studies that report K+ as a key element in the function and structure of terrestrial ecosystems, crop production, and global food security. We synthesized these roles from an integrated perspective, considering the metabolic and physiological functions of individual plants and their complex roles in terrestrial ecosystem functions and food security within the current context of ongoing global change. Thus, we provide a bridge between studies of K+ at the plant and ecological levels to ultimately claim that K+ should be considered at least at a level similar to N and P in terrestrial ecological studies.


Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 672
Author(s):  
Sandoval Carpinelli ◽  
Adriel Ferreira da Fonseca ◽  
Pedro Henrique Weirich Neto ◽  
Santos Henrique Brant Dias ◽  
Laíse da Silveira Pontes

Residue decomposition from cattle dung is crucial in the nutrient cycling process in Integrated Crop–Livestock Systems (ICLS). It also involves the impact of the presence of trees exerted on excreta distribution, as well as nutrient cycling. The objectives of this research included (i) mapping the distribution of cattle dung in two ICLS, i.e., with and without trees, CLT and CL, respectively, and (ii) quantification of dry matter decomposition and nutrient release (nitrogen—N, phosphorus—P, potassium—K, and sulphur—S) from cattle dung in both systems. The cattle dung excluded boxes were set out from July 2018 to October 2018 (pasture phase), and retrieved after 1, 7, 14, 21, 28, 56 and 84 days (during the grazing period). The initial concentrations of N (~19 g kg−1), P (~9 g kg−1), K (~16 g kg−1), and S (~8 g kg−1) in the cattle dung showed no differences. The total N, P, K and S released from the cattle dung residues were less in the CLT system (2.2 kg ha−1 of N; 0.7 kg ha−1 of P; 2.2 kg ha−1 of K and 0.6 kg ha−1 of S), compared to the CL (4.2 kg ha−1 of N; 1.4 kg ha−1 of P; 3.6 kg ha−1 of K and 1.1 kg ha−1 of S). Lesser quantities of cattle dung were observed in the CLT (1810) compared to the CL (2652), caused by the lower stocking rate, on average, in this system (721 in the CL vs. 393 kg ha−1 in the CLT) because of the reduced amount of pasture in the CLT systems (−41%), probably due to light reduction (−42%). The density of the excreta was determined using the Thiessen polygon area. The CL system revealed a higher concentration of faeces at locations near the water points, gate and fences. The CLT affects the spatial distribution of the dung, causing uniformity. Therefore, these results strengthen the need to understand the nutrient release patterns from cattle dung to progress fertilisation management.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Dolbeth ◽  
O. Babe ◽  
D. A. Costa ◽  
A. P. Mucha ◽  
P. G. Cardoso ◽  
...  

AbstractMarine heatwaves are increasing worldwide, with several negative impacts on biological communities and ecosystems. This 24-day study tested heatwaves' effect with distinct duration and recovery periods on benthic estuarine communities' diversity and contribution to ecosystem functioning experimentally. The communities were obtained from a temperate estuary, usually subjected to high daily thermal amplitudes. Our goal was to understand the communities' response to the thermal change, including the community descriptors and behavioural changes expected during heat extremes. We measured community composition and structural changes and the bioturbation process and nutrient release as ecosystem functioning measurements. Overall, our findings highlight the potential tolerance of studied estuarine species to the temperature ranges tested in the study, as community composition and structure were similar, independently of the warming effect. We detected a slight trend for bioturbation and nutrient release increase in the communities under warming, yet these responses were not consistent with the heatwaves exposure duration. Overall, we conclude on the complexity of estuarine communities’ contribution to functioning under warming, and the importance of scalable experiments with benthic organisms' responses to climate variability, accommodating longer time scales and replication. Such an approach would set more efficient expectations towards climate change mitigation or adaptation in temperate estuarine ecosystems.


2019 ◽  
Author(s):  
Fons van der Plas ◽  
Thomas Schröder-Georgi ◽  
Alexandra Weigelt ◽  
Kathryn Barry ◽  
Sebastian Meyer ◽  
...  

ABSTRACTEarth is home to over 350,000 vascular plant species1 that differ in their traits in innumerable ways. Yet, a handful of functional traits can help explaining major differences among species in photosynthetic rate, growth rate, reproductive output and other aspects of plant performance2–6. A key challenge, coined “the Holy Grail” in ecology, is to upscale this understanding in order to predict how natural or anthropogenically driven changes in the identity and diversity of co-occurring plant species drive the functioning of ecosystems7, 8. Here, we analyze the extent to which 42 different ecosystem functions can be predicted by 41 plant traits in 78 experimentally manipulated grassland plots over 10 years. Despite the unprecedented number of traits analyzed, the average percentage of variation in ecosystem functioning that they jointly explained was only moderate (32.6%) within individual years, and even much lower (12.7%) across years. Most other studies linking ecosystem functioning to plant traits analyzed no more than six traits, and when including either only six random or the six most frequently studied traits in our analysis, the average percentage of explained variation in across-year ecosystem functioning dropped to 4.8%. Furthermore, different ecosystem functions were driven by different traits, with on average only 12.2% overlap in significant predictors. Thus, we did not find evidence for the existence of a small set of key traits able to explain variation in multiple ecosystem functions across years. Our results therefore suggest that there are strong limits in the extent to which we can predict the long-term functional consequences of the ongoing, rapid changes in the composition and diversity of plant communities that humanity is currently facing.


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.


2015 ◽  
Vol 12 (15) ◽  
pp. 4565-4575 ◽  
Author(s):  
C. Sanz-Lázaro ◽  
T. Valdemarsen ◽  
M. Holmer

Abstract. Increasing ocean temperature due to climate change is an important anthropogenic driver of ecological change in coastal systems. In these systems sediments play a major role in nutrient cycling. Our ability to predict ecological consequences of climate change is enhanced by simulating real scenarios. Based on predicted climate change scenarios, we tested the effect of temperature and organic pollution on nutrient release from coastal sediments to the water column in a mesocosm experiment. PO43− release rates from sediments followed the same trends as organic matter mineralization rates, increased linearly with temperature and were significantly higher under organic pollution than under nonpolluted conditions. NH4+ release only increased significantly when the temperature rise was above 6 °C, and it was significantly higher in organic polluted compared to nonpolluted sediments. Nutrient release to the water column was only a fraction from the mineralized organic matter, suggesting PO43− retention and NH4+ oxidation in the sediment. Bioturbation and bioirrigation appeared to be key processes responsible for this behavior. Considering that the primary production of most marine basins is N-limited, the excess release of NH4+ at a temperature rise > 6 °C could enhance water column primary productivity, which may lead to the deterioration of the environmental quality. Climate change effects are expected to be accelerated in areas affected by organic pollution.


2021 ◽  
pp. 1-5
Author(s):  
George N. Furey ◽  
Sean M. Smukler ◽  
Andrew Riseman

Increasing the functional diversity of cover crop polycultures has potential to modify nutrient cycling. Aboveground tissue from rye (Secale cereale), vetch (Vicia villosa subsp. dasycarpa), and chicory (Cichorium intybus) was arranged in litterbags, and rates of nutrient supply were measured. A control, monocultures of each species, a biculture of rye:vetch, and a polyculture of rye:vetch:chicory were compared. Increasing functional diversity through reducing the quantity of rye tissue by 30% to include 10% chicory and 20% vetch increased the total amount of nitrogen released by 257%.


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