scholarly journals Lianas reduce carbon accumulation and storage in tropical forests

2015 ◽  
Vol 112 (43) ◽  
pp. 13267-13271 ◽  
Author(s):  
Geertje M. F. van der Heijden ◽  
Jennifer S. Powers ◽  
Stefan A. Schnitzer
Keyword(s):  
Tropical Forests ◽  
Large Scale ◽  
Net Primary Production ◽  
Carbon Dynamics ◽  
Carbon Accumulation ◽  
Carbon Uptake ◽  
Woody Vines ◽  
Significant Difference ◽  
Agent Of Change ◽  
The Impact

Tropical forests store vast quantities of carbon, account for one-third of the carbon fixed by photosynthesis, and are a major sink in the global carbon cycle. Recent evidence suggests that competition between lianas (woody vines) and trees may reduce forest-wide carbon uptake; however, estimates of the impact of lianas on carbon dynamics of tropical forests are crucially lacking. Here we used a large-scale liana removal experiment and found that, at 3 y after liana removal, lianas reduced net above-ground carbon uptake (growth and recruitment minus mortality) by ∼76% per year, mostly by reducing tree growth. The loss of carbon uptake due to liana-induced mortality was four times greater in the control plots in which lianas were present, but high variation among plots prevented a significant difference among the treatments. Lianas altered how aboveground carbon was stored. In forests where lianas were present, the partitioning of forest aboveground net primary production was dominated by leaves (53.2%, compared with 39.2% in liana-free forests) at the expense of woody stems (from 28.9%, compared with 43.9%), resulting in a more rapid return of fixed carbon to the atmosphere. After 3 y of experimental liana removal, our results clearly demonstrate large differences in carbon cycling between forests with and without lianas. Combined with the recently reported increases in liana abundance, these results indicate that lianas are an important and increasing agent of change in the carbon dynamics of tropical forests.

scholarly journals Carbon Stock and Sequestration Potential of an Agroforestry System in Sabah, Malaysia

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 210 ◽  
Author(s):  
Normah Awang Besar ◽  
Herawandi Suardi ◽  
Mui-How Phua ◽  
Daniel James ◽  
Mazlin Bin Mokhtar ◽  
...  
Keyword(s):  
Global Warming ◽  
Tropical Forest ◽  
Tropical Forests ◽  
Oil Palm ◽  
Carbon Stock ◽  
Agroforestry System ◽  
Agroforestry Systems ◽  
Sequestration Potential ◽  
Significant Difference ◽  
The Impact

Total aboveground carbon (TAC) and total soil carbon stock in the agroforestry system at the Balung River Plantation, Sabah, Malaysia were investigated to scientifically support the sustaining of natural forest for mitigating global warming via reducing carbon in the atmosphere. Agroforestry, monoculture, and natural tropical forests were investigated to calculate the carbon stock and sequestration based on three different combinations of oil palm and agarwood in agroforestry systems from 2014 to 2018. These combinations were oil palm (27 years) and agarwood (seven years), oil palm (20 years) and agarwood (seven years), and oil palm (17 years) and agarwood (five years). Monoculture oil palm (16 years), oil palm (six years), and natural tropical forest were set as the control. Three randomly selected plots for agroforestry and monoculture plantation were 0.25 ha (50 × 50 m), respectively, whereas for the natural tropical forest it was 0.09 ha (30 × 30 m). A nondestructive sampling method followed by the allometric equation determined the standing biomass. Organic and shrub layers collected in a square frame (1 × 1 m) were analyzed using the CHN628 series (LECO Corp., MI, USA) for carbon content. Soil bulk density of randomly selected points within the three different layers, that is, 0 to 5, 5 to 10, and 10 to 30 cm were used to determine the total ecosystem carbon (TEC) stock in each agroforestry system which was 79.13, 85.40, and 78.28 Mg C ha−1, respectively. The TEC in the monoculture oil palm was 76.44 and 60.30 Mg C ha−1, whereas natural tropical forest had the highest TEC of 287.29 Mg C ha−1. The forest stand had the highest TEC capacity as compared with the agroforestry and monoculture systems. The impact of planting systems on the TEC showed a statistically significant difference at a 95% confidence interval for the various carbon pools among the agroforestry, monoculture, and natural tropical forests. Therefore, the forest must be sustained because of its higher capacity to store carbon in mitigating global warming.

scholarly journals Impact of Coronavirus Disease 2019 on Clinical Characteristics in Patients With Lung Cancer: A Large Single-Centre Retrospective Study

2021 ◽  
Vol 11 ◽  
Author(s):  
Yu Zhang ◽  
Jie Li ◽  
Zhi-Ke Li ◽  
Xiyue Yang ◽  
Jie Bai ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Physical Examination ◽  
Clinical Characteristics ◽  
Large Scale ◽  
Demographic Data ◽  
Continuous Variables ◽  
Newly Diagnosed ◽  
Epidemic Period ◽  
Significant Difference ◽  
The Impact

Lung cancer is the most common cancer malignancy worldwide. With the continuous spread of the coronavirus disease 2019 (COVID-19) globally, it is of great significance to explore the impact of this disease on the clinical characteristics of lung cancer. Thus, we aimed to investigate whether the COVID-19 pandemic had any influence on the clinical characteristics and diagnosis of patients with lung cancer. We collected clinical and demographic data of patients who were newly diagnosed with lung cancer at our hospital between February 2019 and July 2020. Overall, 387 patients with lung cancer were divided into two groups for analysis: epidemic group (from February to July 2020) and pre-epidemic group (from February to July 2019). The source of diagnosis and clinical characteristics of the two groups were analysed. T-test and Mann-Whitney U were used for continuous variables, and Chi-squared or Fisher’s exact test for categorical variable. We found that during the epidemic period, 110 cases of lung cancer were incidentally diagnosed during COVID-19 screening, accounting for 47.6% of all newly diagnosed lung cancer cases at our hospital. The proportions of patients who were diagnosed based on symptoms and physical examination in the epidemic group were 34.2 and 18.2%, respectively, while that in the pre-epidemic group were 41.7 and 58.3%, respectively. There was significant difference in the source of diagnosis between the two groups. In a subgroup analysis of the epidemic group, the average tumour volume of the patients diagnosed with COVID-19 screening was significantly smaller than that of the patients diagnosed with symptoms and physical examination. In conclusion, the continuation of the COVID-19 pandemic may impact the screening and clinical characteristics of lung cancer and require large-scale and longer-term observation.

scholarly journals Remote sensing of the impact of flash drought events on terrestrial carbon dynamics over China

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Miao Zhang ◽  
Xing Yuan ◽  
Jason A. Otkin
Keyword(s):  
Remote Sensing ◽  
Soil Moisture ◽  
Large Scale ◽  
Structural Changes ◽  
Terrestrial Ecosystems ◽  
Northern China ◽  
Carbon Dynamics ◽  
Western China ◽  
Terrestrial Carbon ◽  
The Impact

Abstract Background Flash drought poses a great threat to terrestrial ecosystems and influences carbon dynamics due to its unusually rapid onset and increasing frequency in a warming climate. Understanding the response of regional terrestrial carbon dynamics to flash drought requires long-term observations of carbon fluxes and soil moisture at a large scale. Here, MODIS satellite observations of ecosystem productivity and ERA5 reanalysis modeling of soil moisture are used to detect the response of ecosystems to flash drought over China. Results The results show that GPP, NPP, and LAI respond to 79–86% of the flash drought events over China, with highest and lowest response frequency for NPP and LAI, respectively. The discrepancies in the response of GPP, NPP, and LAI to flash drought result from vegetation physiological and structural changes. The negative anomalies of GPP, NPP, and LAI occur within 19 days after the start of flash drought, with the fastest response occurring over North China, and slower responses in southern and northeastern China. Water use efficiency (WUE) is increased in most regions of China except for western regions during flash drought, illustrating the resilience of ecosystems to rapid changes in soil moisture conditions. Conclusions This study shows the rapid response of ecosystems to flash drought based on remote-sensing observations, especially for northern China with semiarid climates. Besides, NPP is more sensitive than GPP and LAI to flash drought under the influence of vegetation respiration and physiological regulations. Although the mean WUE increases during flash drought over most of China, western China shows less resilience to flash drought with little changes in WUE during the recovery stage. This study highlights the impacts of flash drought on ecosystems and the necessity to monitor rapid drought intensification.

Cropland carbon uptake delayed by 2019 U.S. Midwest floods

2020 ◽  
Author(s):  
Yi Yin ◽  
Branden Byrne ◽  
Junjie Liu ◽  
Paul Wennberg ◽  
Philipp Köhler ◽  
...  
Keyword(s):  
Large Scale ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Gross Primary Production ◽  
Early Summer ◽  
Satellite Observations ◽  
Mitigation Strategies ◽  
Carbon Uptake ◽  
Vegetation Activity ◽  
The Impact

<p>While large-scale floods directly impact human lives and infrastructures, they also profoundly impact agricultural productivity. New satellite observations of vegetation activity and atmospheric CO<sub>2</sub> offer the opportunity to quantify the effects of such extreme events on cropland carbon sequestration, which are important for mitigation strategies. Widespread flooding during spring and early summer 2019 delayed crop planting across the U.S. Midwest. As a result, satellite observations of solar-induced chlorophyll fluorescence (SIF) from TROPOspheric Monitoring Instrument (TROPOMI) and Orbiting Carbon Observatory (OCO-2) reveal a shift of 16 days in the seasonal cycle of photosynthetic activity relative to 2018, along with a 15% lower peak photosynthesis. We estimate the 2019 anomaly to have led to a reduction of -0.21 PgC in gross primary production (GPP) in June and July, partially compensated in August and September (+0.14 PgC). The extension of the 2019 growing season into late September is likely to have benefited from increased water availability and late-season temperature. Ultimately, this change is predicted to reduce the crop yield over most of the midwest Corn/Soy belt by ~15%. Using an atmospheric transport model, we show that a decline of ~0.1 PgC in the net carbon uptake during June and July is consistent with observed CO<sub>2</sub> enhancements from Atmospheric Carbon and Transport - America (ACT-America) aircraft and OCO-2. This study quantifies the impact of floods on cropland productivity and demonstrates the potential of combining SIF with atmospheric CO<sub>2</sub> observations to monitor regional carbon flux anomalies.</p>

scholarly journals Effects of large-scale floating (solar photovoltaic) platforms on hydrodynamics and primary production in a coastal sea from a water column model

Ocean Science ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 195-208
Author(s):  
Thodoris Karpouzoglou ◽  
Brigitte Vlaswinkel ◽  
Johan van der Molen
Keyword(s):  
Primary Production ◽  
Water Column ◽  
Large Scale ◽  
Net Primary Production ◽  
Biogeochemical Model ◽  
Solar Photovoltaic ◽  
Column Model ◽  
Coastal Sea ◽  
Floating Platforms ◽  
The Impact

Abstract. An improved understanding of the effects of floating solar platforms on the ecosystem is necessary to define acceptable and responsible real-world field implementations of this new marine technology. This study examines a number of potential effects of offshore floating solar photovoltaic (PV) platforms on the hydrodynamics and net primary production in a coastal sea for the first time. Three contrasting locations within the North Sea (a shallow and deeper location with well-mixed conditions and a seasonally stratifying location) have been analysed using a water column physical–biogeochemical model: the General Ocean Turbulence Model coupled with the European Regional Seas Ecosystem Model – Biogeochemical Flux Model (GOTM-ERSEM-BFM). The results show strong dependence on the characteristics of the location (e.g. mixing and stratification) and on the density of coverage with floating platforms. The overall response of the system was separated into contributions by platform-induced light deficit, shielding by the platforms of the sea surface from wind and friction induced by the platforms on the currents. For all three locations, light deficit was the dominant effect on the net primary production. For the two well-mixed locations, the other effects of the platforms resulted in partial compensation for the impact of light deficit, while for the stratified location, they enhanced the effects of light deficit. For up to 20 % coverage of the model surface with platforms, the spread in the results between locations was relatively small, and the changes in net primary production were less than 10 %. For higher percentages of coverage, primary production decreased substantially, with an increased spread in response between the sites. The water column model assumes horizontal homogeneity in all forcings and simulated variables, also for coverage with floating platforms, and hence the results are applicable to very-large-scale implementations of offshore floating platforms that are evenly distributed over areas of at least several hundreds of square kilometres, such that phytoplankton remain underneath a farm throughout several tidal cycles. To confirm these results, and to investigate more realistic cases of floating platforms distributed unevenly over much smaller areas with horizontally varying hydrodynamic conditions, in which phytoplankton can be expected to spend only part of the time underneath a farm and effects are likely to be smaller, spatial detail and additional processes need to be included. To do so, further work is required to advance the water column model towards a three-dimensional modelling approach.

scholarly journals Economics- and policy-driven organic carbon input enhancement dominates soil organic carbon accumulation in Chinese croplands

2018 ◽  
Vol 115 (16) ◽  
pp. 4045-4050 ◽  
Author(s):  
Yongcun Zhao ◽  
Meiyan Wang ◽  
Shuijin Hu ◽  
Xudong Zhang ◽  
Zhu Ouyang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Large Scale ◽  
Management Practices ◽  
Cropping Systems ◽  
Crop Productivity ◽  
Extensive Study ◽  
Soil Survey ◽  
Carbon Accumulation ◽  
The Impact

China’s croplands have experienced drastic changes in management practices, such as fertilization, tillage, and residue treatments, since the 1980s. There is an ongoing debate about the impact of these changes on soil organic carbon (SOC) and its implications. Here we report results from an extensive study that provided direct evidence of cropland SOC sequestration in China. Based on the soil sampling locations recorded by the Second National Soil Survey of China in 1980, we collected 4,060 soil samples in 2011 from 58 counties that represent the typical cropping systems across China. Our results showed that across the country, the average SOC stock in the topsoil (0–20 cm) increased from 28.6 Mg C ha−1 in 1980 to 32.9 Mg C ha−1 in 2011, representing a net increase of 140 kg C ha−1 year−1. However, the SOC change differed among the major agricultural regions: SOC increased in all major agronomic regions except in Northeast China. The SOC sequestration was largely attributed to increased organic inputs driven by economics and policy: while higher root biomass resulting from enhanced crop productivity by chemical fertilizers predominated before 2000, higher residue inputs following the large-scale implementation of crop straw/stover return policy took over thereafter. The SOC change was negatively related to N inputs in East China, suggesting that the excessive N inputs, plus the shallowness of plow layers, may constrain the future C sequestration in Chinese croplands. Our results indicate that cropland SOC sequestration can be achieved through effectively manipulating economic and policy incentives to farmers.

scholarly journals Marine biogeochemical cycling and oceanic CO<sub>2</sub> uptake simulated by the NUIST Earth System Model version 3

2019 ◽  
Author(s):  
Yifei Dai ◽  
Long Cao ◽  
Bin Wang
Keyword(s):  
Primary Production ◽  
Large Scale ◽  
Net Primary Production ◽  
Earth System Model ◽  
System Model ◽  
Upper Ocean ◽  
Carbon Uptake ◽  
Co2 Uptake ◽  
Earth System ◽  
Cmip5 Model

Abstract. In this study, we evaluate the performance of Nanjing University of Information Science and Technology Earth System Model, version 3 (hereafter NESM v3) in simulating the marine biogeochemical cycle and CO2 uptake. Compared with observations, NESM v3 reproduces reasonably well the large-scale patterns of upper ocean biogeochemical fields including nutrients, alkalinity, dissolved inorganic, chlorophyll, and net primary production. The model also reasonably reproduces current-day oceanic CO2 uptake, the total CO2 uptake is 149 PgC from 1850 to 2016. In the 1ptCO2 experiment, the NESM v3 produced carbon-climate (γ=-7.9 PgC/K) and carbon-concentration sensitivity parameters (β=0.8 PgC/ppm) are comparable with CMIP5 model results. The nonlinearity of carbon uptake in the NESM v3 accounts for 10.3% of the total carbon uptake, which is within the range of CMIP5 model results (3.6%~10.6%). Some regional discrepancies between model simulations and observations are identified and the possible causes are investigated. In the upper ocean, the simulated biases in biogeochemical fields are mainly associated with the shortcoming in simulated ocean circulation. Weak upwelling in the Indian Ocean suppresses the nutrient entrainment to the upper ocean, therefore reducing the biological activities and resulting in underestimation of net primary production and chlorophyll concentration. In the Pacific and the Southern Ocean, high-nutrient and low-chlorophyll result from the strong iron limitation. Alkalinity shows high biases in high-latitude oceans due to the strong convective mixing. The major discrepancy in biogeochemical fields is seen in the deep Northern Pacific. The simulated high concentration of nutrients, alkalinity and dissolved inorganic carbon water is too deep due to the excessive deep ocean remineralization. Despite these model-observation discrepancies, it is expected that the NESM v3 can be employed as a useful modeling tool to investigate large scale interactions between the ocean carbon cycle and climate change.

scholarly journals Measurement and Analysis of Differences in The Impact of The Implementation of Large-Scale Social Restrictions (PSBB) Based on The Mann Whitney Test

2021 ◽  
Vol 1 ◽  
pp. 75-86
Author(s):  
Bambang Budiarto
Keyword(s):  
Large Scale ◽  
Descriptive Analysis ◽  
Whitney Test ◽  
The Third ◽  
Statistical Measurement ◽  
Mann Whitney Test ◽  
Employment Factors ◽  
Significant Difference ◽  
Measurement And Analysis ◽  
The Impact

This research is a non-parametric statistical measurement form which use the Mann Whitney Test. The aim is to determine whether or not there are differences in the impact of the implementation of the PSBB as a result of Covid-19 pandemic in the Surabaya, Gresik and Sidoarjo areas through the distribution of questionnaires and interviews, a sample of 134 people who were distributed in the 3 regions obtained. From the results of repeated simulations, measurements and testing to answer existing hypotheses, it can be seen that there are 3 things that are the conclusions of this study. The first conclusion, that there is no difference in the impact of the PSBB implementation in the Sidoarjo and Surabaya areas, which use α = 5%, the value obtained Zcount = -0.65745 is higher than Ztabel = +/- 1.96. It is in the receiving area which means H0 or the hypothesis that there is no difference in the impact of the PSBB implementation between Sidoarjo and Surabaya areas cannot be rejected. The second conclusion, that there are differences in the impact of the PSBB implementation in the Surabaya and Gresik areas with the result that the value of Zcount = -2.28792 is lower than Ztable. The same thing happened in the third test, there was a significant difference in the impact of the PSBB implementation in Sidoarjo and Gresik areas. Furthermore, in the descriptive analysis, there are several factors were found which effect the three tests result, as follows: geographic, demographic, social, cultural and employment factors.

scholarly journals Strategic Change and the Improvement of Organizational Performance: A Study Based On Meta-Analysis

CONVERTER ◽  
2021 ◽  
pp. 153-168
Author(s):  
Junjie Wu, Et al.
Keyword(s):  
Organizational Performance ◽  
Large Scale ◽  
Strategic Change ◽  
Meta Analysis ◽  
Data Types ◽  
Moderating Factors ◽  
Significant Difference ◽  
Meta Regression ◽  
The Impact ◽  
The Relationship

Objectives: In order to explore the factors that lead to the difference of outcome between strategic change and organizational performance.Methods: This paper takes the correlation coefficient between strategic change and organizational performance as the effect value, and conducts Meta integration analysis and Meta regression analysis on 23 important literatures involving 7225 enterprise samples from 2008 to 2018.Results: Firstly, the meta-integration method is used to estimate the overall results of existing empirical studies. The results show that strategic change is significantly positively correlated with organizational performance. Second, there are too many moderating factors that lead to different conclusions of research on strategic change-organizational performance. Therefore, Meta regression method is used to explore the impact of 10 moderating factors on the relationship between the two. First, positive strategic change has a better moderating effect; Second, compared with small and medium-sized enterprises, the performance of strategic change of large-scale enterprises is better; Third, the more recent the year of publication, the less supportive the relationship between strategic change and organizational performance; Fourth, there is no significant difference between data types and the relationship between strategic change and organizational performance, but data time span has a significant negative moderating effect.Conclusions: This study shows that the quantitative literature study of meta analysis not only helps to resolve the existing theoretical disputes, but also helps to explore new theoretical studies in the context of COVID-19 epidemic in the future, meanwhile, it also provides a novel framework for quantitative literature analysis.

scholarly journals The impact of lateral carbon fluxes on the European carbon balance

2008 ◽  
Vol 5 (5) ◽  
pp. 1259-1271 ◽  
Author(s):  
P. Ciais ◽  
A. V. Borges ◽  
G. Abril ◽  
M. Meybeck ◽  
G. Folberth ◽  
...  
Keyword(s):  
Carbon Balance ◽  
Large Scale ◽  
Food Product ◽  
Carbon Fluxes ◽  
Carbon Accumulation ◽  
Main Process ◽  
Carbon Budgets ◽  
Lateral Transport ◽  
Gaseous Species ◽  
The Impact

Abstract. To date, little is known about the impact of processes which cause lateral carbon fluxes over continents, and from continents to oceans on the CO2 – and carbon budgets at local, regional and continental scales. Lateral carbon fluxes contribute to regional carbon budgets as follows: Ecosystem CO2 sink=Ecosystem carbon accumulation+Lateral carbon fluxes. We estimated the contribution of wood and food product trade, of emission and oxidation of reduced carbon species, and of river erosion and transport as lateral carbon fluxes to the carbon balance of Europe (EU-25). The analysis is completed by new estimates of the carbon fluxes of coastal seas. We estimated that lateral transport (all processes combined) is a flux of 165 Tg C yr−1 at the scale of EU-25. The magnitude of lateral transport is thus comparable to current estimates of carbon accumulation in European forests. The main process contributing to the total lateral flux out of Europe is the flux of reduced carbon compounds, corresponding to the sum of non-CO2 gaseous species (CH4, CO, hydrocarbons, ...) emitted by ecosystems and exported out of the European boundary layer by the large scale atmospheric circulation.

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