scholarly journals Carbon Stock Variation along altitudinal gradient of Wacho Forest in Hawa Galan District, Kellem Wollega Zone, Oromia Region, Ethiopia

2020 ◽  
Author(s):  
Gezahegn Gashu ◽  
Gebre Gidey ◽  
Sime Deressa ◽  
Zame Fekansa ◽  
Halid Awoke

Abstract Background Forest ecosystem plays a crucial role in the global carbon cycle; as such, mitigating high atmospheric concentrations of carbon dioxide and other greenhouse gases by naturally taking carbon from the atmosphere through photosynthesis. Verification and accounting of carbon stock in forest ecosystem have been renowned as a potential strategy to reduce and stabilize atmospheric concentrations of greenhouse gas. Forest sequesters and store more carbon than any other terrestrial ecosystem and it is an important natural break on climate change. It acts as a carbon reservoir by storing large amount of carbon in trees, undergrowth vegetation, forest floor and soil. Result The mean carbon stock of each carbon pool was changed along altitudinal class of the study area. The largest mean above and below ground carbon stock was found in the second altitudinal class(1560.01-1643m) followed by first altitudinal class(1435-1560m) and the third altitudinal class (1643.01-1704m) of the study area. The largest mean dead tree and dead wood carbon stock was also stored in the first altitudinal class followed by the third and the second altitudinal class of the study area. The largest mean litter carbon stock was found in the first altitudinal class followed by the second and the third altitudinal class of the study area. The largest mean soil organic carbon was found in the third altitudinal class followed by the second and the first altitudinal class of the study area. Conclusions The carbon stock variation along altitudinal gradients indicated that, altitude had no a statistically significant effect on any of the carbon pools except litter carbon of the study area at 95% of confidence interval.

2020 ◽  
Author(s):  
Gezahegn Gashu ◽  
Gebre Gidey ◽  
Sime Deressa ◽  
Zame Fekansa ◽  
Halid Awoke

Abstract Background: Forest ecosystem plays a crucial role in the global carbon cycle; as such, mitigating high atmospheric concentrations of carbon dioxide and other greenhouse gases by naturally taking carbon from the atmosphere through photosynthesis. Verification and accounting of carbon stock in forest ecosystem have been renowned as a potential strategy to reduce and stabilize atmospheric concentrations of greenhouse gas. Forest sequesters and store more carbon than any other terrestrial ecosystem and it is an important natural break on climate change. It acts as a carbon reservoir by storing large amount of carbon in trees, undergrowth vegetation, forest floor and soil. Result: The mean carbon stock of each carbon pool was changed along altitudinal class of the study area. The largest mean above and below ground carbon stock was found in the second altitudinal class(1560.01-1643m) followed by first altitudinal class(1435-1560m) and the third altitudinal class (1643.01-1704m) of the study area. The largest mean dead tree and dead wood carbon stock was also stored in the first altitudinal class followed by the third and the second altitudinal class of the study area. The largest mean litter carbon stock was found in the first altitudinal class followed by the second and the third altitudinal class of the study area. The largest mean soil organic carbon was found in the third altitudinal class followed by the second and the first altitudinal class of the study area.Conclusions: The carbon stock variation along altitudinal gradients indicated that, altitude had no a statistically significant effect on any of the carbon pools except litter carbon of the study area at 95% of confidence interval.


2022 ◽  
pp. SP521-2021-149
Author(s):  
Xiangdong Zhao ◽  
Daran Zheng ◽  
He Wang ◽  
Yanan Fang ◽  
Naihua Xue ◽  
...  

AbstractThe Oceanic Anoxic Event (OAE) 1b is well documented in western Tethys, however, records in Eurasia are still lacking. Here, we carried out high-resolution organic carbon isotope (δ13Corg), total organic carbon (TOC) contents and mercury (Hg) concentrations analysis of the lacustrine sediments from the Xiagou and Zhonggou formations in the Hanxiagou section, Jiuquan Basin, northwestern China. The lacustrine δ13Corg curve presents three stages of negative excursions above the basalt layer dated at 112.4 ± 0.3 Ma in the lowermost Zhonggou Formation. The three negative δ13Corg excursions, well corresponded with the three subevents (Kilian, Paquier, and Leenhardt) of the OAE1b in Poggio le Guaine (central Italy), Vocontian Basin (SE France) and St Rosa Canyon (NE Mexico) sections, supporting the record of the terrestrial OAE 1b in the Jiuquan Basin. Five mercury enrichment (ME) intervals in Hg/TOC ratios were recognized, indicating that the pulsed volcanism from the southern Kerguelen Plateau likely triggered the OAE 1b. However, the decoupling between NIE shifts and mercury enrichments signifying other carbon reservoir (with no link to mercury) probably contributed to the global carbon cycle perturbation during the OAE 1b period. Our results provide direct evidence to link the OAE 1b and terrestrial ecosystem in the Eurasia.


Author(s):  
Mingjuan Li

AbstractThe values of forest carbon stock (CSV) and carbon sink (COV) are important topics in the global carbon cycle. We quantitatively analyzed the factors affecting changes in both for forest ecosystem in 2000−2015. With multiple linear stepwise regression analysis, we obtained the factors that had a significant impact on changes of CSV and COV, and then the impacts of these variables on CSV and COV were used for further quantitative analysis using the vector autoregressive model. Our results indicated that both stand age and afforestation area positively affect CSV and COV; however, the forest enterprise gross output value negatively affects CSV. Stand age has the largest long-term cumulative impact on CSV and COV, reaching 40.4% and 9.8%, respectively. The impact of enterprise gross output value and afforestation area on CSV and COV is the smallest, reaching 4.0% and 0.3%, respectively.


Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 130
Author(s):  
Gedion Tsegay ◽  
Xiang-Zhou Meng

Globally, there is a serious issue in carbon stock due to high deforestation and the loss of land, limited carbon storage pools in aboveground and underground forests in different regions, and increased carbon emissions to the atmosphere. This review paper highlights the impact of exclosures on above and below ground carbon stocks in biomass as a solution to globally curb carbon emissions. The data has been analyzed dependent on the Intergovernmental Panel on Climate Change (IPCC) guidelines, the Food and Agriculture Organization (FAO) Forest Resource Assessment report (FRA, 2020), and scientific journal publications mostly from the last decade, to show the research results of carbon stock and the impact of exclosures, particularly the challenges of deforestation and erosion of land and opportunities of area exclosures to provide a general outlook for policymakers. Overall, the world’s forest regions are declining, and although the forest loss rate has slowed, it has still not stopped sufficiently because the knowledge and practice of exclosures are limited. The global forest loss and carbon stock have decreased from 7.8 million ha/yr to 4.7 million ha/yr and from 668 gigatons to 662 gigatons respectively due to multiple factors that differ across the regions. However, a move toward natural rehabilitation and exclosures to reduce the emissions of Greenhouse Gas (GHGs) is needed. In the global production of carbon, the exclosure of forests plays an important role, in particular for permanent sinks of carbon.


2021 ◽  
Author(s):  
Franziska Lechleitner ◽  
Christopher C. Day ◽  
Oliver Kost ◽  
Micah Wilhelm ◽  
Negar Haghipour ◽  
...  

<p>Terrestrial ecosystems are intimately linked with the global climate system, but their response to ongoing and future anthropogenic climate change remains poorly understood. Reconstructing the response of terrestrial ecosystem processes over past periods of rapid and substantial climate change can serve as a tool to better constrain the sensitivity in the ecosystem-climate response.</p><p>In this talk, we will present a new reconstruction of soil respiration in the temperate region of Western Europe based on speleothem carbon isotopes (δ<sup>13</sup>C). Soil respiration remains poorly constrained over past climatic transitions, but is critical for understanding the global carbon cycle and its response to ongoing anthropogenic warming. Our study builds upon two decades of speleothem research in Western Europe, which has shown clear correlation between δ<sup>13</sup>C and regional temperature reconstructions during the last glacial and the deglaciation, with exceptional regional coherency in timing, amplitude, and absolute δ<sup>13</sup>C variation. By combining innovative multi-proxy geochemical analysis (δ<sup>13</sup>C, Ca isotopes, and radiocarbon) on three speleothems from Northern Spain, and quantitative forward modelling of processes in soil, karst, and cave, we show how deglacial variability in speleothem δ<sup>13</sup>C is best explained by increasing soil respiration. Our study is the first to quantify and remove the effects of prior calcite precipitation (PCP, using Ca isotopes) and bedrock dissolution (open vs closed system, using the radiocarbon reservoir effect) from the speleothem δ<sup>13</sup>C signal to derive changes in respired δ<sup>13</sup>C over time. Our approach allows us to estimate the temperature sensitivity of soil respiration (Q<sub>10</sub>), which is higher than current measurements, suggesting that part of the speleothem signal may be related to a change in the composition of the soil respired δ<sup>13</sup>C. This is likely related to changing substrate through increasing contribution from vegetation biomass with the onset of the Holocene.</p><p>These results highlight the exciting possibilities speleothems offer as a coupled archive for quantitative proxy-based reconstructions of climate and ecosystem conditions.</p>


2021 ◽  
Author(s):  
Zhe Jin ◽  
Xiangjun Tian ◽  
Rui Han ◽  
Yu Fu ◽  
Xin Li ◽  
...  

Abstract. Accurate assessment of the various sources and sinks of carbon dioxide (CO2), especially terrestrial ecosystem and ocean fluxes with high uncertainties, is important for understanding of the global carbon cycle, supporting the formulation of climate policies, and projecting future climate change. Satellite retrievals of the column-averaged dry air mole fractions of CO2 (XCO2) are being widely used to improve carbon flux estimation due to their broad spatial coverage. However, there is no consensus on the robust estimates of regional fluxes. In this study, we present a global and regional resolved terrestrial ecosystem carbon flux (NEE) and ocean carbon flux dataset for 2015–2019. The dataset was generated using the Tan-Tracker inversion system by assimilating Observing Carbon Observatory 2 (OCO-2) column CO2 retrievals. The posterior NEE and ocean carbon fluxes were comprehensively validated by comparing posterior simulated CO2 concentrations with OCO-2 independent retrievals and Total Carbon Column Observing Network (TCCON) measurements. The validation showed that posterior carbon fluxes significantly improved the modelling of atmospheric CO2 concentrations, with global mean biases of 0.33 ppm against OCO-2 retrievals and 0.12 ppm against TCCON measurements. We described the characteristics of the dataset at global, regional, and Tibetan Plateau scales in terms of the carbon budget, annual and seasonal variations, and spatial distribution. The posterior 5-year annual mean global atmospheric CO2 growth rate was 5.35 PgC yr−1, which was within the uncertainty of the Global Carbon Budget 2020 estimate (5.49 PgC yr−1). The posterior annual mean NEE and ocean carbon fluxes were −4.07 and −3.33 PgC yr−1, respectively. Regional fluxes were analysed based on TransCom partitioning. All 11 land regions acted as carbon sinks, except for Tropical South America, which was almost neutral. The strongest carbon sinks were located in Boreal Asia, followed by Temperate Asia and North Africa. The entire Tibetan Plateau ecosystem was estimated as a carbon sink, taking up −49.52 TgC yr−1 on average, with the strongest sink occurring in eastern alpine meadows. These results indicate that our dataset captures surface carbon fluxes well and provides insight into the global carbon cycle. The dataset can be accessed at https://doi.org/10.11888/Meteoro.tpdc.271317 (Jin et al., 2021).


2018 ◽  
Vol 10 (3) ◽  
pp. 639-650
Author(s):  
. Khairunnisa ◽  
Isdradjad Setyobudiandi ◽  
Mennofatria Boer

ABSTRAKSalah satu upaya untuk mengurangi emisi gas karbon pemicu pemanasan global adalah dengan memanfaatkan vegetasi pesisir seperti lamun yang dikenal dengan istilah blue carbon. Penelitian ini bertujuan untuk mengetahui stok karbon pada padang lamun di Pesisir Timur Kabupaten Bintan, Kepulauan Riau sebagai upaya dalam mengurangi pemanasan global. Penelitian dilakukan di Berakit, Malang Rapat, dan Teluk Bakau mulai Januari – Juli 2017. Parameter yang diukur dalam penelitian ini adalah biomassa, kandungan karbon, dan stok karbon pada lamun. Analisis biomassa diukur dari berat kering lamun per satuan luas yang dibagi atas bagian atas dan bawah substrat, kandungan karbon diukur dengan metode Walkley and Black, stok karbon diukur dengan memperhatikan kandungan karbon dan biomassa lamun. Hasil penelitian menunjukkan ekosistem lamun di pesisir timur Kabupaten Bintan ditumbuhi oleh C. rotundata, C. serrulata, E. acoroides, H. uninervis, H. pinifolia, H. ovalis, T. hemprichii, T. ciliatum dan S. isoetifolium dengan kondisi yang relatif baik.  Persentase biomassa dan karbon yang berada di bawah substrat lebih besar dibanding biomassa yang berada di atas substrat, sehingga ketika bagian pelepah dan daun lamun lepas baik karena tindakan manusia ataupun alam lamun masih tetap mampu menyimpan karbon. Padang lamun di pesisir sebelah timur Kabupaten Bintan memiliki potensi dalam menyerap dan menyimpan karbon yakni sebesar 2431.33 ton C dengan E. acoroides sebagai spesies yang mampu menghasilkan biomassa terbesar dan kandungan karbon tertinggi, meski jumlah tersebut tidak dapat dijadikan acuan apakah lamun memiliki potensi yang tinggi ataupun tidak karena hingga saat ini belum ada nilai standardnya. ABSTRACTOne of the solutions to reduce carbon gas emissions that triggered global warming is to utilize coastal vegetation such as seagrass that known as blue carbon. This research was aimed to determine stock carbon on seagrass in the east coast of Bintan Regency, Kepulauan Riau Province as an effort to reduce global warming.  The research was conducted in Berakit, Malang Rapat, and Teluk Bakau from January to July 2017. The parameters measured in this research were biomass, carbon content, and carbon stock on seagrass. The anylisis of the biomass was obtained from the dry weight per unit area, the carbon content was obtained by Walkley and black method, the carbon stock was obtained by the measurement of the biomass and carbon content. Based on the observation, seagrass ecosystem in east coast of Bintan was palnted by C. rotundata, C. serrulata, E. acoroides, H. uninervis, H. pinifolia, H. ovalis, T. hemprichii, T. ciliatum, dan S. isoetifolium. The below ground biomass and carbon percentation were higher that the aboveground parts so when the leaves are released either because of human or natural actions, seagrass is still able to store carbon. Seagrass beds on the east coast of Bintan Regency have the potential to absorb and store carbon which is equal to 2431.33 tons C as E. acoroides being the species which capable of producing the highest biomass and highest carbon content, although this number cannot be used as a reference whether seagrass has high potential or no because until now there has been no standard value. 


2019 ◽  
Vol 8 (2) ◽  
Author(s):  
A.M.S.K. Abeysekara ◽  
S.K. Yatigammana ◽  
K.T. Premakantha

Carbon dioxide has gained lot of attention in recent past as a greenhouse gas, and therefore it has a potential to affect the climate pattern of the world. Several anthropogenic activities are known to be responsible for the increased level of carbon in the atmosphere and disruption of the global carbon cycle. However, nature has its own mechanism of sequestering and storing the carbon in its “reservoirs”. Forest has the ability to sequester carbon in their biomass and reduce the rate of increase of atmospheric carbon dioxide. The carbon sequestered in the forest trees are mostly referred to as the biomass of a tree or a forest. It has been identified five carbon pools of the terrestrial ecosystem, involving biomass. The study was designed to estimate biomass stock and then the carbon stock of the Udawattakele Forest Reserve (7°17'58 "N, 80°38'20’’E) in Kandy, Sri Lanka. Allometric equations were used to calculate biomass of trees. The total biomass stock was estimated to be 9475.56 t ha-1 (Mega gram-Mg) and the total carbon stock was estimated to be 4,453.55 t ha-1 (Mg) in the Udawattakele Forest Reserve (UFR). This amount is equivalent to 16,344.52 Mg of carbon dioxide in the atmosphere. UFR holds a moderate amount of biomass/carbon stock and the total carbon density of natural forest and plantations was found to be 36.55 Mg ha-1 and 44.89 Mg ha-1 respectively.


2018 ◽  
Vol 6 ◽  
pp. 61-67
Author(s):  
Karishma Gubhaju ◽  
Dipesh Raj Pant ◽  
Ramesh Prasad Sapkota

Forests store significant amount of atmospheric carbon in the form of above and below ground biomass and the amount of carbon stored in forests differs along spatial continuum which provides important information regarding forest quality. This study was carried out to estimate the carbon stock of Shree Rabutar Forest of Gaurishankar Conservation Area, Dolakha, Nepal. In total, 20 circular sampling plots with an area 250 m2 were randomly laid in the study area. Ten tree species were observed in the sampling plots laid in the forest. The higher values of density, frequency, abundance and basal area were observed for Rhododendron arboreum, Alnus nepalensis, Pinus roxburghii and Pinus wallichiana. On the basis of Important Value Index, the dominant tree in the forest was Alnus nepalensis followed by Rhododendron arboreum and Pinus roxburghii. Shannon Index of general diversity of trees in the forest was 0.74 with equal value of Evenness Index, whereas the index of dominance was low (0.22) in the forest. Mean biomass of the forest was 464.01±66.71 tonha-1 contributed by above ground tree biomass (384.44 tonha-1), leaf litter, herbs and grasses biomass (2.69±0.196 tonha-1) and below ground tree biomass (76.88±11.13 tonha-1). Mean carbon stock was 262.77±30.79 tonha-1 including soil carbon stock 44.69±2.25 tonha-1. Individuals of trees with 20-30 cm DBH class were observed in maximum number, which shows that the forest has high potential to sequester carbon over time. Carbon stock estimation and forest management can be one of the potential strategies for climate change mitigation especially through carbon dioxide absorption by the forests.


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