scholarly journals Holocene Fire Regime Changes in the Southern Lake Baikal Region Influenced by Climate-Vegetation-Anthropogenic Activity Interactions

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 978
Author(s):  
Chéïma Barhoumi ◽  
Marianne Vogel ◽  
Lucas Dugerdil ◽  
Hanane Limani ◽  
Sébastien Joannin ◽  
...  
Keyword(s):  
Lake Baikal ◽  
Tree Structure ◽  
Anthropogenic Activity ◽  
Human Populations ◽  
Pinus Sibirica ◽  
Fire Dynamics ◽  
The Holocene ◽  
The Past ◽  
Surface Fires ◽  
Crown Fires

Catastrophic fire years that have taken place during the last decade in Siberia, and more generally within the boreal forest, have been directly linked to global warming and had strong repercussions on boreal ecosystems and human populations. In this context the study of the past dynamics of these fires is essential for understanding their links with climate, vegetation and human activity changes on longer time scales than the last few decades. However, few studies on fire dynamics are available for Siberia, and none have been conducted for the entire Holocene period. This study presents the first fire history reconstruction of this area during the Holocene based on charcoals sequestered in sediments of two lakes located on the southern shore of Lake Baikal, in Siberia. The results show a similar trend in the two lakes, with high frequency and high peak magnitude during the Early Holocene and low magnitudes after 6500 cal. yr BP. This difference is interpreted as crown fires versus surface fires. According to pollen records (Dulikha, Vydrino, Ochkovoe) available near the studied lakes, a vegetation transition occurred at the same time. Picea obovata, which has a tree structure prone to crown fires, was dominant during the Early humid Holocene. After 6500 cal. yr BP, conditions were drier and Pinus sylvestris and Pinus sibirica became the dominant species; their tree structure favors surface fires. In addition to vegetation dynamics, the nearby pollen sequence from Dulikha has been used to provide quantitative estimates of past climate, indicating an Early to Middle Holocene climatic optimum between 8000 and 5000 cal. yr BP and an increase in temperatures at the end of the Holocene. These results have been compared to outputs from regional climate models for the Lake Baikal latitudes. Fire dynamics appear to have been more linked to the vegetation than climatic conditions. Over the past 1500 years, the greater presence of human populations has firstly resulted in an increase in the fire frequency, then in its maintenance and finally in its suppression, which may possibly have been due to very recent fire management, i.e., after ca 500 cal. BP.

Holocene fire history of the southern Lake Baikal region

2021 ◽  
Author(s):  
Marianne Vogel ◽  
Chéïma Barhoumi ◽  
Hanane Limani ◽  
Sébastien Joannin ◽  
Odile Peyron ◽  
...  
Keyword(s):  
Lake Baikal ◽  
Baikal Region ◽  
Fire History ◽  
Fire Frequency ◽  
Human Populations ◽  
Pinus Sibirica ◽  
The Holocene ◽  
The Past ◽  
Lake Baikal Region ◽  
History Of

<p><strong>Holocene fire history of the southern Lake Baikal region</strong></p><p>The catastrophic fire years that have taken place during the last decade in Siberia and in the boreal forests in general, directly linked to global warming, have had dramatic repercussions on the human populations of these regions. Past fire reconstruction studies are currently the only way to study the past dynamics of these fires and to understand their link with climate, vegetation and human activities. However, few studies of the dynamics of these fires are available in Siberia, and none have been carried out on the scale of the Holocene. This study aims to present the first reconstruction of the fire history during the Holocene based on sedimentary charcoals from two lakes localised on the southern shore of Lake Baikal, in Siberia. Two lakes have been sampled, Lake Ébène and Lake Jarod. The results showed a similar trend between the two lakes,with severe and intense crown fires during the early Holocene and less severe surface fires after 6 500 cal. yr BP. According to pollen reconstructions carried out near the studied lakes, a vegetation transition occurred at the same time. Picea obovata was dominant during the early humid Holocene. After 6 500 cal. yr BP, conditions were drier and Pinus sylvestris and Pinus sibirica became the dominant species. Over the past 1 500 years, the greater presence of human populations has firstly resulted in an increase of the fire frequency, then probably in its maintenance after 600 cal. yr BP in lake Ébène and to finish, in its suppression after 900 cal. yr BP in Lake Jarod. The decrease of fire frequency at the end of the 20th century could be explained by new fire management policies.</p>

Structural variability of mature lodgepole pine stands on gently sloping terrain in Taylor Park Basin, Colorado

1994 ◽  
Vol 24 (10) ◽  
pp. 2020-2029 ◽  
Author(s):  
Albert J. Parker ◽  
Kathleen C. Parker
Keyword(s):  
Lodgepole Pine ◽  
Strong Relationship ◽  
Dwarf Mistletoe ◽  
The Past ◽  
Surface Fires ◽  
Dead Trees ◽  
Crown Fires ◽  
Standing Dead ◽  
Standing Dead Trees ◽  
Sloping Terrain

Diameter structures, diameter–age relationships, and spatial pattern of canopy and understory layers in seven stands representative of mature lodgepole pine (Pinusconforta Dougl. ex Loud. ssp. latifolia) forests on gentle (≤5°) slopes in the Taylor Park Basin of Colorado were documented. All stands originated following crown fires 120–140 years ago, during the period of initial Euro-American presence. Two distinct structures were evident among these stands. Four stands had closed canopies (cover >70%), relatively high basal areas and tree densities, low sapling and large seedling densities, numerous standing dead trees, and even-aged diameter distributions. The other three stands had more open canopies (cover <65%), lower basal areas and tree densities, higher densities of saplings and large seedlings, and more even representation across diameter classes. Regeneration tended to occur in small patches in both types of stands. DBH showed a moderate to strong relationship to age in all stands, although suppression of bole-diameter growth was more evident in the closed stands. Structure of the closed stands exemplifies forests that have developed rapidly after canopy fire. Structure of the open stands suggests either low stocking densities following stand-originating crown fires or repetitive surface fires, perhaps reinforced by dwarf mistletoe (Arceuthobiumamericanum Nutt. ex Engelm.) infestation, that have allowed more or less continuous recruitment over the past 120–140 years.

scholarly journals 3D Insights into the Effects of Captivity on Wolf Mastication and Their Tooth Marks; Implications in Ecological Studies of Both the Past and Present

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2323
Author(s):  
Lloyd A. Courtenay ◽  
Darío Herranz-Rodrigo ◽  
José Yravedra ◽  
José Mª Vázquez-Rodríguez ◽  
Rosa Huguet ◽  
...  
Keyword(s):  
Data Science ◽  
Surface Modifications ◽  
Human Populations ◽  
Ecological Studies ◽  
The Past ◽  
Carnivore Species ◽  
Different Populations ◽  
Complex Relationships ◽  
As Stress ◽  
Tooth Marks

Human populations have been known to develop complex relationships with large carnivore species throughout time, with evidence of both competition and collaboration to obtain resources throughout the Pleistocene. From this perspective, many archaeological and palaeontological sites present evidence of carnivore modifications to bone. In response to this, specialists in the study of microscopic bone surface modifications have resorted to the use of 3D modeling and data science techniques for the inspection of these elements, reaching novel limits for the discerning of carnivore agencies. The present research analyzes the tooth mark variability produced by multiple Iberian wolf individuals, with the aim of studying how captivity may affect the nature of tooth marks left on bone. In addition to this, four different populations of both wild and captive Iberian wolves are also compared for a more in-depth comparison of intra-species variability. This research statistically shows that large canid tooth pits are the least affected by captivity, while tooth scores appear more superficial when produced by captive wolves. The superficial nature of captive wolf tooth scores is additionally seen to correlate with other metric features, thus influencing overall mark morphologies. In light of this, the present study opens a new dialogue on the reasons behind this, advising caution when using tooth scores for carnivore identification and contemplating how elements such as stress may be affecting the wolves under study.

Measuring the Selective Utilization of Animal Species by Prehistoric Human Populations

1979 ◽  
Vol 44 (1) ◽  
pp. 155-160 ◽  
Author(s):  
Bruce D. Smith
Keyword(s):  
Animal Species ◽  
Human Populations ◽  
Relative Importance ◽  
The Past

To determine the pattern of selective utilization of animal species by prehistoric human populations, it is first necessary to quantify the relative importance of species of animals in the diet of prehistoric human groups through analysis of archaeologically recovered faunal samples. These values are then compared with estimates of the relative availability of different species of animals in the environment. Such estimates of the relative availability of animal species in prehistoric habitat situations, usually quantified in terms of biomass, are obtained by projecting data from modern analog situations into the past. When attempting to reconstruct prehistoric biotic communities in this manner, it is important to be aware of a number of possible sources of bias and to evaluate and apply modern wildlife data according to a set of interrelated principles. Sources of bias and criteria for selecting modern wildlife analog data are discussed.

scholarly journals Genetic and linguistic histories in Central Asia inferred using approximate Bayesian computations

2017 ◽  
Vol 284 (1861) ◽  
pp. 20170706 ◽  
Author(s):  
Valentin Thouzeau ◽  
Philippe Mennecier ◽  
Paul Verdu ◽  
Frédéric Austerlitz
Keyword(s):  
Central Asia ◽  
Linguistic Diversity ◽  
Past History ◽  
Genetic Data ◽  
Human Populations ◽  
Language Diversity ◽  
Methodological Framework ◽  
The Past ◽  
Approximate Bayesian ◽  
Future Work

Linguistic and genetic data have been widely compared, but the histories underlying these descriptions are rarely jointly inferred. We developed a unique methodological framework for analysing jointly language diversity and genetic polymorphism data, to infer the past history of separation, exchange and admixture events among human populations. This method relies on approximate Bayesian computations that enable the identification of the most probable historical scenario underlying each type of data, and to infer the parameters of these scenarios. For this purpose, we developed a new computer program PopLingSim that simulates the evolution of linguistic diversity, which we coupled with an existing coalescent-based genetic simulation program, to simulate both linguistic and genetic data within a set of populations. Applying this new program to a wide linguistic and genetic dataset of Central Asia, we found several differences between linguistic and genetic histories. In particular, we showed how genetic and linguistic exchanges differed in the past in this area: some cultural exchanges were maintained without genetic exchanges. The methodological framework and the linguistic simulation tool developed here can be used in future work for disentangling complex linguistic and genetic evolutions underlying human biological and cultural histories.

scholarly journals Different historical generation intervals in human populations inferred from Neanderthal fragment lengths and patterns of mutation accumulation

2021 ◽  
Author(s):  
Moisès Coll Macià ◽  
Laurits Skov ◽  
Benjamin Marco Peter ◽  
Mikkel Heide Schierup
Keyword(s):  
Fragment Length ◽  
Human Populations ◽  
Female Age ◽  
Generation Interval ◽  
The Past ◽  
Geographical Regions ◽  
Neanderthal Admixture ◽  
Rate Of Decay ◽  
Out Of Africa ◽  
Insight Into

AbstractAfter the main out-of-Africa event, humans interbred with Neanderthals leaving 1-2% of Neanderthal DNA scattered in small fragments in all non-African genomes today1,2. Here we investigate the size distribution of these fragments in non-African genomes3. We find consistent differences in fragment length distributions across Eurasia with 11% longer fragments in East Asians than in West Eurasians. By comparing extant populations and ancient samples, we show that these differences are due to a different rate of decay in length by recombination since the Neanderthal admixture. In line with this, we observe a strong correlation between the average fragment length and the accumulation of derived mutations, similar to what is expected by changing the ages at reproduction as estimated from trio studies4. Altogether, our results suggest consistent differences in the generation interval across Eurasia, by up to 20% (e.g. 25 versus 30 years), over the past 40,000 years. We use sex-specific accumulations of derived alleles to infer how these changes in generation intervals between geographical regions could have been mainly driven by shifts in either male or female age of reproduction, or both. We also find that previously reported variation in the mutational spectrum5 may be largely explained by changes to the generation interval and not by changes to the underlying mutational mechanism. We conclude that Neanderthal fragment lengths provide unique insight into differences of a key demographic parameter among human populations over the recent history.

scholarly journals Ecology of the Anthropocene signals hope for consciously managing the planetary ecosystem

2021 ◽  
Vol 118 (28) ◽  
pp. e2024150118
Author(s):  
Clarence Lehman ◽  
Shelby Loberg ◽  
Michael Wilson ◽  
Eville Gorham
Keyword(s):  
Population Growth ◽  
Cultural Evolution ◽  
Human Population ◽  
Human Populations ◽  
Present Moment ◽  
Minimal Set ◽  
The Past ◽  
Food Species ◽  
Large Predators ◽  
Population Numbers

Human populations have grown to such an extent that our species has become a dominant force on the planet, prompting geologists to begin applying the term Anthropocene to recognize the present moment. Many approaches seek to explain the past and future of human population growth, in the form of narratives and models. Some of the most influential models have parameters that cannot be precisely known but are estimated by expert opinion. Here we apply a unified model of ecology to provide a macroscale summary of the net effects of many microscale processes, using a minimal set of parameters that can be known. Our models match estimates of historic and prehistoric global human population numbers and provide predictions that correspond to some of the more complicated current models. In addition to fitting the data well they reveal that, amidst enormous complexity in our human and prehuman past, three key ecological discontinuities have occurred in turn: 1) becoming dominant competitors of large predators rather than their prey, 2) becoming mutualists with food species rather than acting as predators upon them, and 3) changing from a regime of uncontrolled population growth to one of controlled fertility instead. All three processes have been interlinked with cultural evolution and all three ushered in developments of the Anthropocene. Understanding the trajectories that have delivered us to this stage can help guide prudent paths into the future.

Assessing the seasonal variability of shallow underground waters quality from a volcanic – sedimentary formation during El Niño event in Panama

2021 ◽  
Author(s):  
Mario Luis Miranda Montenegro ◽  
Ana Garcia ◽  
Raizha Batista ◽  
Obdulia de Montilla ◽  
Arkin Tapia ◽  
...  
Keyword(s):  
Drinking Water ◽  
El Niño ◽  
Urban Areas ◽  
El Nino ◽  
Anthropogenic Activity ◽  
Human Populations ◽  
Ph Values ◽  
El Niño Event ◽  
Geological Conditions ◽  
Groundwater Reserves

Abstract Providing drinking water to growing populations has become a worldwide concern. Therefore, in many countries some groundwater reserves are now being used to supply drinking water in remote urban areas. The state of these groundwater reserves is strongly influenced by the local geological conditions. Furthermore, climate change has caused a decrease in the periodicity of environmental conditions such as rainfalls, a key driver in replenishing these reserves. In 2019, the weak El Niño event affected the rainfall pattern, as well as physical and chemical quality of shallow ground waters in Panama. Within this study, the northwestern central region of Panama groundwaters have been systematically characterized during El Niño 2018 – 2019 event. Our results indicate that changes in values of physicochemical parameters such as alkalinity, pH and conductivity are related to changes in the amount of rainfall reported in the region starting from dry season (DS) to the rainy season (RS). Chloride was recorded as an indicator of anthropogenic activity and/or the effect of human populations on specific sites in the aquifer recharge zones. Lead (Pb2+), Zinc (Zn2+), Manganese (Mn2+), and Copper (Cu2+) concentrations in the groundwater were evaluated during the DS and RS 2019. Recorded data indicates sub – lethal concentrations of Pb2+, Zn2+, Mn2+ were associated to changes in alkalinity values of groundwater during the DS. While during the RS, a decrease in pH values favored the dissolution of Cu2+ and Zn2+. Our findings suggest that seasonal rainfall deficits modify shallow underground water alkalinity and pH values, inducing the redissolution of Pb2+, Zn2+, Mn2+, Cu 2+and exposing populations to sub – lethal concentrations of those microelements.

scholarly journals Mitochondrial Dysfunction in Obesity and Reproduction

Endocrinology ◽  
2020 ◽  
Vol 162 (1) ◽  
Author(s):  
Manasi Das ◽  
Consuelo Sauceda ◽  
Nicholas J G Webster
Keyword(s):  
Mitochondrial Dysfunction ◽  
Energy Production ◽  
Molecular Mechanisms ◽  
Human Populations ◽  
Metabolic Alterations ◽  
Genetic Manipulations ◽  
The Past ◽  
Calcium Buffering

Abstract Mounting evidence suggests a role for mitochondrial dysfunction in the pathogenesis of many diseases, including type 2 diabetes, aging, and ovarian failure. Because of the central role of mitochondria in energy production, heme biosynthesis, calcium buffering, steroidogenesis, and apoptosis signaling within cells, understanding the molecular mechanisms behind mitochondrial dysregulation and its potential implications in disease is critical. This review will take a journey through the past and summarize what is known about mitochondrial dysfunction in various disorders, focusing on metabolic alterations and reproductive abnormalities. Evidence is presented from studies in different human populations, and rodents with genetic manipulations of pathways known to affect mitochondrial function.

scholarly journals Future Temperature Extremes Will Be More Harmful: A New Critical Factor for Improved Forecasts

2019 ◽  
Vol 16 (20) ◽  
pp. 4015 ◽  
Author(s):  
Costas A. Varotsos ◽  
Yuri A. Mazei
Keyword(s):  
Climate Change ◽  
Temperature Change ◽  
Heat Waves ◽  
Extreme Temperature ◽  
Well Being ◽  
Early Warning Systems ◽  
Extreme Weather Events ◽  
Anthropogenic Activity ◽  
Extreme Temperature Events ◽  
The Past

There is increasing evidence that extreme weather events such as frequent and intense cold spells and heat waves cause unprecedented deaths and diseases in both developed and developing countries. Thus, they require extensive and immediate research to limit the risks involved. Average temperatures in Europe in June–July 2019 were the hottest ever measured and attributed to climate change. The problem, however, of a thorough study of natural climate change is the lack of experimental data from the long past, where anthropogenic activity was then very limited. Today, this problem can be successfully resolved using, inter alia, biological indicators that have provided reliable environmental information for thousands of years in the past. The present study used high-resolution quantitative reconstruction data derived from biological records of Lake Silvaplana sediments covering the period 1181–1945. The purpose of this study was to determine whether a slight temperature change in the past could trigger current or future intense temperature change or changes. Modern analytical tools were used for this purpose, which eventually showed that temperature fluctuations were persistent. That is, they exhibit long memory with scaling behavior, which means that an increase (decrease) in temperature in the past was always followed by another increase (decrease) in the future with multiple amplitudes. Therefore, the increase in the frequency, intensity, and duration of extreme temperature events due to climate change will be more pronounced than expected. This will affect human well-being and mortality more than that estimated in today’s modeling scenarios. The scaling property detected here can be used for more accurate monthly to decadal forecasting of extreme temperature events. Thus, it is possible to develop improved early warning systems that will reduce the public health risk at local, national, and international levels.

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