Role of forest fires in Holocene stand-scale dynamics in the unmanaged taiga forest of northwestern Russia

The Holocene ◽  
2014 ◽  
Vol 24 (11) ◽  
pp. 1503-1514 ◽  
Author(s):  
Niina Kuosmanen ◽  
Keyan Fang ◽  
Richard HW Bradshaw ◽  
Jennifer L Clear ◽  
Heikki Seppä
Keyword(s):  
Forest Fires ◽  
Siberian Larch ◽  
Wavelet Coherence ◽  
Individual Tree ◽  
Study Region ◽  
Taiga Forest ◽  
The Impact ◽  
Wavelet Coherence Analysis ◽  
Northwestern Russia

Fossil pollen, conifer stomata, and charcoal records for the last 10,000 years were studied from three small hollow sites (Larix Hollow, Mosquito Hollow, and Olga Hollow) located at the modern western range limit of Siberian larch ( Larix sibirica) in northwestern Russia to investigate the role of forest fires in stand-scale dynamics of taiga vegetation. Wavelet coherence analysis was utilized to reveal the significance of fire on the vegetation composition at different timescales by assessing the phase and strength of the relationship between forest fires and most common boreal tree taxa in a time–frequency window. Pollen and stomata data show that all of the modern-day common tree taxa, including Norway spruce ( Picea abies) and Siberian larch, have been present in the study region since the early Holocene. The absence of charcoal layers at Mosquito Hollow suggests that this site has acted as a fire-free refugium with continuous dominance of spruce throughout the Holocene. Meanwhile, the Larix Hollow record indicates frequent local fire events and as a consequence, a more variable tree species composition. The wavelet coherence results show that the impact of forest fires on vegetation varies from short-term (<200-year periods) changes in individual tree taxa to long-term (400–800 years) changes in forest composition, such as the expansion of spruce population after local high-intensity fires around 7500–7000 cal. yr BP and the increase in abundance of birch and alder during periods of high fire frequency. Our results suggest that Holocene fire histories can be markedly different within a small geographical area, demonstrating the importance of site-specific factors in the local fire regime in the unmanaged taiga forest.

scholarly journals Exploring the Influence of Daily Climate Variables on Malaria Transmission and Abundance of Anopheles arabiensis over Nkomazi Local Municipality, Mpumalanga Province, South Africa

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Gbenga J. Abiodun ◽  
Kevin Y. Njabo ◽  
Peter J. Witbooi ◽  
Abiodun M. Adeola ◽  
Trevon L. Fuller ◽  
...  
Keyword(s):  
South Africa ◽  
Malaria Transmission ◽  
Anopheles Arabiensis ◽  
Climatic Factors ◽  
Time Lag ◽  
Wavelet Coherence ◽  
Study Region ◽  
Mosquito Abundance ◽  
The Impact ◽  
Wavelet Coherence Analysis

The recent resurgence of malaria incidence across epidemic regions in South Africa has been linked to climatic and environmental factors. An in-depth investigation of the impact of climate variability and mosquito abundance on malaria parasite incidence may therefore offer useful insight towards the control of this life-threatening disease. In this study, we investigate the influence of climatic factors on malaria transmission over Nkomazi Municipality. The variability and interconnectedness between the variables were analyzed using wavelet coherence analysis. Time-series analyses revealed that malaria cases significantly declined after the outbreak in early 2000, but with a slight increase from 2015. Furthermore, the wavelet coherence and time-lagged correlation analyses identified rainfall and abundance of Anopheles arabiensis as the major variables responsible for malaria transmission over the study region. The analysis further highlights a high malaria intensity with the variables from 1998–2002, 2004–2006, and 2010–2013 and a noticeable periodicity value of 256–512 days. Also, malaria transmission shows a time lag between one month and three months with respect to mosquito abundance and the different climatic variables. The findings from this study offer a better understanding of the importance of climatic factors on the transmission of malaria. The study further highlights the significant roles of An. arabiensis on malaria occurrence over Nkomazi. Implementing the mosquito model to predict mosquito abundance could provide more insight into malaria elimination or control in Africa.

scholarly journals Rhythmic Features of Movement Synchrony for Bonding Individuals in Dyadic Interaction

2019 ◽  
Vol 44 (1) ◽  
pp. 173-193 ◽  
Author(s):  
Ken Fujiwara ◽  
Masanori Kimura ◽  
Ikuo Daibo
Keyword(s):  
Hierarchical Linear Modeling ◽  
Dyadic Interaction ◽  
Wavelet Coherence ◽  
Linear Modeling ◽  
Theoretical Contribution ◽  
Bonding Effect ◽  
Slow Tempo ◽  
Movement Synchrony ◽  
The Impact

Abstract This study examined ways in which rhythmic features of movement contribute to bonding between individuals. Though previous studies have described synchrony as a form of social glue, this research extends those findings to consider the impact of fast versus slow tempo on movement synchrony. This two-part experiment examined dyadic interactions as they occurred between same-sex strangers (Study 1) and friends (Study 2). Participants were video-recorded as they engaged in 5- or 6-min chats, and synchrony was evaluated using wavelet transform via calculations of cross-wavelet coherence. Study 1 employed regression commonality analysis and hierarchical linear modeling and found that among various frequency bands, rapport between individuals was positively associated with synchrony under 0.025 Hz (i.e., slower than once every 40 s) and 0.5–1.5 Hz (i.e., once every 0.67–2 s). On the contrary, Study 2 determined that synchrony of 0.5–1.5 Hz was not impactful among friend dyads and only predictive of the motivation to cultivate a friendly relationship during interactions with strangers. These results indicate the existence of a distinctive rhythm for bonding individuals, and the role of pre-existing friendship as a moderator of the bonding effect of synchrony. However, the role of relative phase (i.e., timing of movement; same versus opposite timing) remains unclear, as the ratio of in- and anti-phase patterning had no significant influence on perceived rapport and motivation to develop relationships. On the basis of the research results, a theoretical contribution is proposed to the study of interpersonal coordination.

scholarly journals Exploring the Impact of Climate Variability on Malaria Transmission Using a Dynamic Mosquito-Human Malaria Model

2018 ◽  
Vol 10 (1) ◽  
pp. 88-100 ◽  
Author(s):  
Gbenga J. Abiodun ◽  
Peter J. Witbooi ◽  
Kazeem O. Okosun ◽  
Rajendra Maharaj
Keyword(s):  
Climate Variability ◽  
Malaria Transmission ◽  
Malaria Incidence ◽  
Principal Component ◽  
Wavelet Coherence ◽  
Human Malaria ◽  
Kwazulu Natal ◽  
The Impact ◽  
Wavelet Coherence Analysis ◽  
Malaria Model

Introduction: The reasons for malaria resurgence mostly in Africa are yet to be well understood. Although the causes are often linked to regional climate change, it is important to understand the impact of climate variability on the dynamics of the disease. However, this is almost impossible without adequate long-term malaria data over the study areas. Methods: In this study, we develop a climate-based mosquito-human malaria model to study malaria dynamics in the human population over KwaZulu-Natal, one of the epidemic provinces in South Africa, from 1970-2005. We compare the model output with available observed monthly malaria cases over the province from September 1999 to December 2003. We further use the model outputs to explore the relationship between the climate variables (rainfall and temperature) and malaria incidence over the province using principal component analysis, wavelet power spectrum and wavelet coherence analysis. The model produces a reasonable fit with the observed data and in particular, it captures all the spikes in malaria prevalence. Results: Our results highlight the importance of climate factors on malaria transmission and show the seasonality of malaria epidemics over the province. Results from the principal component analyses further suggest that, there are two principal factors associated with climates variables and the model outputs. One of the factors indicate high loadings on Susceptible, Exposed and Infected human, while the other is more correlated with Susceptible and Recovered humans. However, both factors reveal the inverse correlation between Susceptible-Infected and Susceptible-Recovered humans respectively. Through the spectrum analysis, we notice a strong annual cycle of malaria incidence over the province and ascertain a dominant of one year periodicity. Consequently, our findings indicate that an average of 0 to 120-day lag is generally noted over the study period, but the 120-day lag is more associated with temperature than rainfall. This is consistence with other results obtained from our analyses that malaria transmission is more tightly coupled with temperature than with rainfall in KwaZulu-Natal province.

scholarly journals IMPACT OF TRADE OPENNESS ON ENVIRONMENT IN CHINA

2020 ◽  
Vol 21 (4) ◽  
pp. 1185-1202 ◽  
Author(s):  
Wen Jun ◽  
Hamid Mahmood ◽  
Muhammad Zakaria
Keyword(s):  
Carbon Emission ◽  
Trade Openness ◽  
Wavelet Coherence ◽  
Coherence Analysis ◽  
Pollution Haven Hypothesis ◽  
Causality Test ◽  
Pollution Haven ◽  
Analysis Phase ◽  
The Impact ◽  
Wavelet Coherence Analysis

The study investigates the impact of trade openness on pollution in China by applying wavelet-coherence analysis, phase-difference technique and Breitung and Candelon (2006) causality test. The estimated results provide some dynamic association between trade openness and pollutant variables. The results indicate that trade openness has increased pollution in China especially after 2001 when China became member of WTO. It suggests that “pollution haven hypothesis” exists in China. These results imply that trade openness has increased exports which has increased domestic production by increasing the scale of industries, which in turn has increased pollution in the country. The findings of spectral domain causality test show that trade openness causes carbon emission both in short, medium and long runs. It indicates that trade openness forecast carbon emissions in China. The results suggest that China should take suitable measures while following trade openness policy to avoid pollution.

scholarly journals WOMEN’S ROLE IN MITIGATION AND DISASTER MANAGEMENT

2021 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Lilik Sumarni ◽  
Endang Rudiatin
Keyword(s):  
Climate Change ◽  
Natural Disasters ◽  
Disaster Management ◽  
Forest Fires ◽  
Disaster Mitigation ◽  
London School ◽  
Close Link ◽  
Role Of Women ◽  
The Impact

The impact of climate change caused by global warming is currently one of the trending topics in various media and it is an extremely serious threat to human security. Forest fires, floods, landslides and changes in lifestyles to survive natural disasters are the very significant contributing factors to poverty rates in various parts of the world. The London School of Economics and Political Science conducted a study of 141 countries affected by disasters in the 1981-2002 period and found a close link between natural disasters and women's socioeconomic status. Data from the National Agency for Disaster Management (BNPB) states that women have 14 times of risk for becoming victims of disasters compared to adult men. Women become the most victimized because women prioritize children and their families rather than saving themselves. Although women bear more risks to climate change, women can also have the principal opportunity and role in implementing climate change mitigation adaptation, namely by making women actors in disaster mitigation and drivers of change in parallel to their strong responsibilities to their families. By providing adequate knowledge for women about adaptation and mitigation of disasters, the women can turn themselves to be the strategic activists in coping with disasters for communities living in disaster-prone areas.This study is a comparative discussion of three research results to obtain an overview and find solutions to women's problems from the consequences of climate change, which is a study by changing women from being the most victims of natural disasters to becoming the driving actor for families and communities in overcoming disaster and her ability to survive the post-disaster situation. The conclusion is the three levels of gender roles related to climate change to increase women's adaptive capacity. An adaptation strategy needs the form of 1. Increasing the role of women in the political arena. It is a crucial issue because women's rights can be protected by their presence and role, as well as women in guarding policies. 2. Increasing the role of women in the realm of education. Education is no less important than politics because education will provide a foundation for understanding and self-confidence, bargaining and personal branding for women so that their presence in society will be recognized and will no longer be discriminated. 3. Cultural reconstruction based on gender equality is very important because so far, the notion of patriarchy is still inherent in our culture. Many perspectives are cooptated on the statement that superior (men) are stronger then give rise women mythos that is said to be weak (women). In reality, the presence of women is still fundamental to the aspect of maintaining the economy and education for the continuation and the quality of the life in the society.

scholarly journals Effect of Structural Funds on Housing Market Sustainability Development—Correlation, Regression and Wavelet Coherence Analysis

Risks ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 182
Author(s):  
Łukasz Mach ◽  
Karina Bedrunka ◽  
Anna Kuczuk ◽  
Marzena Szewczuk-Stępień
Keyword(s):  
Positive Impact ◽  
Research Process ◽  
Global Scale ◽  
Real Estate Market ◽  
Wavelet Coherence ◽  
Time Variability ◽  
Coherence Analysis ◽  
Structural Funds ◽  
The Impact ◽  
Wavelet Coherence Analysis

Effective acquisition of funds, including European Union (EU) funds, designated for example, creating economic and social processes, may have a real impact on the elimination of the negative outcomes of the current position of the EU on the global scale. The aim of the research is to indicate the impact of spending funds from the Regional Operational Program of the Opolskie Voivodeship 2014–2020 (ROP OV) on a key macroeconomic area of the economy, i.e., the housing development sector in the region. The practical aim is to formulate recommendations and solutions that can offer guidelines for more effective spending of EU funds and their effect on the macroeconomic dimensions of the economy. The article proposes an innovative approach to linking EU payments in the region with the real estate market. The results of the research and the analyses made on this basis showed a positive impact of the payments made from the ROP OV on selected macroeconomic indicators, i.e., the number of permits issued for the construction of new apartments and the number of currently implemented housing investments. The obtained results should be used in the decision-making process at the level of regional and national authorities responsible for the payment of EU funds. In this article, prior to the research process, a literature review was made. It covered various aspects of the evolution and development of research in the area of regional development. The research process was based on innovative methods of time variability analysis, correlation between the investigated determinants and coherence analysis for the studied dimensions. Data on payments from the ROP OV concern the years 2015–2020.

scholarly journals The impact of Mediterranean oscillations on periodicity and trend of temperature in the valley of the Nisava River: A fourier and wavelet approach

2017 ◽  
Vol 21 (3) ◽  
pp. 1389-1398
Author(s):  
Natasa Martic-Bursac ◽  
Branislav Bursac ◽  
Vladan Ducic ◽  
Aleksandar Radivojevic ◽  
Nenad Zivkovic ◽  
...  
Keyword(s):  
Wavelet Transforms ◽  
Spectral Component ◽  
Power Spectra ◽  
Dominant Mode ◽  
River Valley ◽  
Wavelet Coherence ◽  
Mediterranean Oscillation ◽  
The Impact ◽  
Wavelet Coherence Analysis ◽  
Individual Series

Periodicity of temperature on three stations in the Nisava River valley in period 1949-2014, has been analyzed by means of Fourier and wavelet transforms. Combined periodogram based on fast Fourier transform shows considerable similarity among individual series and identifies significant periods on 2.2, 2.7, 3.3, 5, 6-7, and 8.2 years in all datasets. Wavelet coherence analysis connects strongest 6-7 years spectral component to Mediterranean oscillation, starting in 1980s. Combined periodogram of Mediterranean oscillation index reveals 6-7 years spectral component as a dominant mode in period 1949-2014. Wavelet power spectra and partial combined periodograms show absence of 6-7 years component before 1975, after which this component becomes dominant in the spectrum. Consistency between alternation in temperature trend in the Nisava River valley and change in periodicity of Mediterranean oscillation was found.

scholarly journals FORECAST OF THE STRUCTURE OF SHELTERBELTS IN THE CENTRAL SIBERIA TAKING INTO ACCOUNT AGRONOMIC CHARACTERISTICS OF PLANTATIONS

2017 ◽  
Vol 7 (1) ◽  
pp. 6-16
Author(s):  
Вараксин ◽  
Gennadiy Varaksin ◽  
Вайс ◽  
Andrey Vays ◽  
Шевелев ◽  
...  
Keyword(s):  
Normal Distribution ◽  
Forest Fires ◽  
Siberian Larch ◽  
Average Diameter ◽  
Weibull Function ◽  
Individual Tree ◽  
Central Siberia ◽  
Shelter Belts ◽  
Forest Belts ◽  
The Republic

The study of the structure was based on a series of distribution by the steps of the thickness. Measurements were carried out in forest shelter belts of the southern part of Central Siberia. Plots were laid on the territory of the Republic of Khakassia (Ust- Abakan, Bay, Shirinsky, Shushensky districts), Krasnoyarsk territory (Minusinsk district) and the Republic of Tuva (Kyzylskiy district). Approximation of distribution rows by diameter has been implemented by two functions: normal distribution and Weibull distribution. With respect to protective forest belts for most forest stands, structure by diameter is more adequately approximated by normal distribution, indicating the symmetry rows. But at this, function of Weibull is characterized by high correlation of its ratios with parameters of plantations, in particular with average diameter and normalized variability. Based on the study of the structure of the plantings in diameter, the optimal agro-technical indicators for the cultivation of plantations presented a variety of wood species, were revealed. It is recommended to divide rows into two groups, before forecasting the series. The first category reflects the influence of the internal (growth) processes: growth, mortality, movement of trees on the steps. These rows can be predicted taking into account the average diameter of tree stand and theoretical density (square of nutrition of individual tree). The second group of rows was formed under the influence of external factors (supplement, renewal, felling, and forest fires).These rows are forecasted using the average diameter and standard deviation of trees. For the prediction of the structure of the stands of Siberian larch, silver birch, Siberian elm and black poplar, model based on the Weibull function, were obtained.

scholarly journals A Methodology for the Fast Comparison of Streamwater Diurnal Cycles at Two Monitoring Points

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2524 ◽  
Author(s):  
Andrei-Emil Briciu ◽  
Adrian Graur ◽  
Dinu Iulian Oprea ◽  
Constantin Filote
Keyword(s):  
Diurnal Cycle ◽  
Specific Conductivity ◽  
Wavelet Coherence ◽  
Discrete Wavelet ◽  
Monitoring Point ◽  
Diurnal Cycles ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
The Impact ◽  
Wavelet Coherence Analysis

There are numerous streamwater parameters that exhibit a diurnal cycle. However, the shape of this cycle has a huge variation from one parameter to another and from one monitoring point to another on the same river. Important variations also occur at the same point during some events, such as high waters. Water level, specific conductivity, dissolved oxygen, oxidation reduction potential, and pH of the Suceava River were monitored for 365 days (2018–2019, hourly sampling frequency) in order to assess the upstream-downstream changes in the diurnal cycle of these parameters, some of these changes being caused by the impact of Suceava city, which is located between the selected monitoring points. The multiresolution analysis of the maximal overlap discrete wavelet transform and the wavelet coherence analysis were combined in a flexible methodology that helped in comparing the upstream and downstream shapes of the diurnal cycle. The methodology allowed for a fast comparison of diurnal profiles during periods of high waters or baseflow. Notable changes were observed in the moments of diurnal maxima and minima.

scholarly journals ROLE OF REMOTE SENSING AND GEOGRAPHIC INFORMATION SYSTEM TO ANALYZE THE IMPACT OF CLIMATE CHANGE ON FOREST ECOSYSTEMS

2015 ◽  
Vol 3 (8) ◽  
pp. 61-68
Author(s):  
Shahid Mohommad ◽  
Shambhu Prasad Joshi
Keyword(s):  
Climate Change ◽  
Remote Sensing ◽  
Information System ◽  
Geographic Information System ◽  
Forest Ecosystem ◽  
Forest Fires ◽  
Geographic Information ◽  
Substantial Impact ◽  
The Impact

Climate change is an inevitable process impacting the forest ecosystem. Various impacts like treeline shift, forest fires, and Species distribution are due to the effect of climate change. Green House Gases concentration in the atmosphere is increasing day by day due to anthropogenic activities. The pace of climate change is very alarming which will have the substantial impact on the forest ecosystem. Role of remote sensing and geographic information system in observing the forest ecosystem was reviewed. Spatio-temporal analysis of change in forest structure can be proficiently done with the help of remote sensing and geographic information system. Climate Change Mitigation programmes like Reducing Emissions from Deforestation and Forest Degradation (REDD-plus) can be implemented with the help of remote sensing and geographic information system. Baseline data generation using remote sensing and geographic information system can be useful in designing the policies for forest management and monitoring.

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