The link between climate change and biodiversity of lacustrine inhabitants and terrestrial plant communities of the Uvs Nuur Basin (Mongolia) during the last three millennia

The Holocene ◽  
2021 ◽  
pp. 095968362110190
Author(s):  
Natalia Rudaya ◽  
Larisa Nazarova ◽  
Larisa Frolova ◽  
Olga Palagushkina ◽  
Vasiliy Soenov ◽  
...  

The paper is focused on changes in biodiversity, the environment, and human activity in the Uvs Nuur Basin during the last three millennia based on biological and geochemical proxies from the lake Bayan Nuur. Regions with high biodiversity and relatively low anthropogenic pressures are typically the most vulnerable to both climate change and human activities. One such area is the Uvs Nuur Basin located on the north of the Great Lake Depression of Mongolia. The main objective of this study is to assess changes in the past biodiversity of the lake’s microflora and microfauna, and surrounding vegetation biodiversity in the Uvs Nuur Basin, and to determine the main drivers of diversity change. Based on the analysis of pollen and chironomids we conclude that the most humid and afforested phase was between 1400 and 1800 CE. We assume that the Little Ice Age in the Uvs Nuur Basin was humid with mean annual precipitation ca. 305 mm/year and mean July temperature about 13°C. Conversely, the warmest and most arid period was between 650 and 1350 CE with mean annual precipitation ca. 280 mm/year and mean July temperature of about 16°C, attributed to the Medieval Warm Period. The biodiversity of terrestrial plants, chironomids, and Cladocera positive react to changes in annual precipitation and July temperature, whereas diatoms do not correlate directly to the climatic factors. The diversity and the evenness of plants are strongly correlated with the change in the leading biomes. The calculated species turnover suggests no significant changes in plant and Cladocera taxa composition, but significant changes in diatom and chironomid communities. This may be explained by the instability of lake ecology due to the fluctuation of the salinity and acidity of the water. An additional aim was to assess if dung fungi in lacustrine sediments reflect changes in human population density around the lake. We found that neither historical sources of human presence nor the influx of coprophilous fungi are correlated with the inferred climate changes. Coprophilous fungi can be used as individual or additional sources of assessment for the peopling and human-related herbivore density including overgrazing of the studied area.

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1962
Author(s):  
Zhilong Zhao ◽  
Yue Zhang ◽  
Zengzeng Hu ◽  
Xuanhua Nie

The alpine lakes on the Tibetan Plateau (TP) are indicators of climate change. The assessment of lake dynamics on the TP is an important component of global climate change research. With a focus on lakes in the 33° N zone of the central TP, this study investigates the temporal evolution patterns of the lake areas of different types of lakes, i.e., non-glacier-fed endorheic lakes and non-glacier-fed exorheic lakes, during 1988–2017, and examines their relationship with changes in climatic factors. From 1988 to 2017, two endorheic lakes (Lake Yagenco and Lake Zhamcomaqiong) in the study area expanded significantly, i.e., by more than 50%. Over the same period, two exorheic lakes within the study area also exhibited spatio-temporal variability: Lake Gaeencuonama increased by 5.48%, and the change in Lake Zhamuco was not significant. The 2000s was a period of rapid expansion of both the closed lakes (endorheic lakes) and open lakes (exorheic lakes) in the study area. However, the endorheic lakes maintained the increase in lake area after the period of rapid expansion, while the exorheic lakes decreased after significant expansion. During 1988–2017, the annual mean temperature significantly increased at a rate of 0.04 °C/a, while the annual precipitation slightly increased at a rate of 2.23 mm/a. Furthermore, the annual precipitation significantly increased at a rate of 14.28 mm/a during 1995–2008. The results of this study demonstrate that the change in precipitation was responsible for the observed changes in the lake areas of the two exorheic lakes within the study area, while the changes in the lake areas of the two endorheic lakes were more sensitive to the annual mean temperature between 1988 and 2017. Given the importance of lakes to the TP, these are not trivial issues, and we now need accelerated research based on long-term and continuous remote sensing data.


Botany ◽  
2010 ◽  
Vol 88 (4) ◽  
pp. 409-428 ◽  
Author(s):  
Curtis R. Björk

A region of contrastively wetter and milder climate occurs in inland northwest North America, separated from similar climates of the Pacific coast by 200–400 km. Researchers have long noted that numerous vascular plants divide their ranges between the interior wetbelt and coastal regions, although many such disjunctions have hitherto gone undocumented. Here I summarize all vascular plants shared between coastal and interior wetbelt regions, disjunct by at least 200 km. These disjunct taxa are assigned to north-coast and south-coast lists according to whether the coastal portions of the ranges occur primarily north or south of the southern limits of maximum continental glaciation. A list of interior wetbelt endemic taxa is also presented, focusing on those that occur at forested elevations. Presence/absence for coastal disjunct and endemic taxa were assigned to grid of 1° × 1° latitude–longitude cells. Using this grid, concentrations of disjunct and endemic taxa were detected, and total values per cell were tested in linear regression for a relationship to mean annual precipitation. In total, 116 coastal disjunct taxa were detected, 31 of them north-coastal and 85 south-coastal. Interior wetbelt endemic and subendemic taxa total 95, and of these, 46 were found primarily at forested elevations. North-coast taxa were found over a wide latitudinal range both north and south of the glacial limits, and their distribution had a weak positive relationship with annual precipitation. South-coast and endemic taxa were found mostly south of the glacial limits, and their distribution did not correlate to annual precipitation. The greatest concentrations of south coastal disjunct and endemic taxa occurred in the Clearwater region of north-central Idaho; a region noted by previous researchers to be a likely ice-age refugium for wet-climate dependent plants and animals. Inferences are made from these patterns, both for biogeographical understanding of the roles played by the interior wetbelt and some regions connecting to the coast, as well as for preservation of biodiversity and ecosystem continuity.


2011 ◽  
Vol 137 ◽  
pp. 286-290 ◽  
Author(s):  
Xi Chun ◽  
Mei Jie Zhang ◽  
Mei Ping Liu

The objective of this study is to analyse the climate changing patterns chronologically for exposing the coincident relationships between the lake area fluctuation and the climate change in Qehan lake of Abaga county of Inner Mongolia. The results show that there’s highly interrelation between the changes of the lake area and the climatic factors here, the annual average temperature and annual evaporation are negatively interrelate to the lake area fluctuation, and the annual precipitation interrelate to it is positive. The lake area has descended about 75 km2 during the nearly past 40 years. There were about two considerable lake expansions in 1973, 1998 through the generally lake area descending process.


2021 ◽  
Author(s):  
Yutong Lin ◽  
Yuan Lai ◽  
Songbo Tang ◽  
Zhangfen Qin ◽  
Jianfeng Liu ◽  
...  

Abstract Purpose Leaf elemental stoichiometry is indicative of plant nutrient limitation, community composition, ecosystem function. Understanding the variations of leaf carbon (C), nitrogen (N), and phosphorus (P) stoichiometry at genus-level across large geographic regions and identifying their driving factors are important to predict species’ distribution range shifts affected by climate change.MethodsHere, we determined the patterns of leaf concentrations ([ ]) and ratios ( / ) of C, N, P of five deciduous oaks species (Quercus) across China covering ~ 20 latitude (~21–41˚ N) and longitude (~99–119˚ E) degrees, and detected their relationships with climatic, edaphic variables. ResultsLeaf [C], [N] and N/P, C/P significantly increased, while leaf [P] and C/N decreased with the increasing latitude. Leaf stoichiometry except for leaf [C] had no significant trends along the longitude. Climatic variables, i.e. mean annual temperature, mean annual precipitation, the maximum temperature of the warmest month, temperature seasonality, aridity index, and the potential evapo-transpiration were the determinants of the geographic patterns of leaf C, N, P stoichiometry. The mean annual precipitation and the maximum temperature of the warmest month indirectly regulated leaf C/N, C/P and N/P via altering leaf [P]. Edaphic variables had non-significant effects on leaf C, N, and P stoichiometry at the broad geographic range.ConclusionsClimatic variables have more important effects than edaphic properties on leaf C, N, P stoichiometry of the studied deciduous Quercus species, which imply the ongoing climate change will alter nutrient strategies and potentially shift the distribution range of this eurytopic species.


Author(s):  
В.А. Усольцев ◽  
И.С. Цепордей ◽  
А.А. Осмирко ◽  
В.Ф. Ковязин ◽  
В.П. Часовских ◽  
...  

Биомасса лесов является ключевой экосистемной составляющей и важным компонентом глобального углеродного цикла. Разработка моделей биомассы, чувствительных к изменению климата, ведется сегодня на уровнях как древостоев, так и модельных деревьев. Однако все текущие исследования подобного рода выполняются в пределах ограниченных экорегионов. Сформированная авторами база данных о биомассе насаждений подрода Pinus L., произрастающего в Евразии, в количестве 2460 пробных площадей использована в качестве основы для выявления трансконтинентальных закономерностей. Предпринята первая попытка разработать гармонизированную по структуре биомассы модель аддитивной по фракционному составу биомассы насаждений двухвойных сосен, изменяющейся по трансевразийским гидротермическим градиентам, а именно, по среднегодовым осадкам и средней январской температуре воздуха. Гармонизация обеспечена аддитивностью фракционного состава, когда суммарная биомасса стволов, ветвей, хвои и корней, полученная по «фракционным» уравнениям, равняется значению биомассы, полученной по общему уравнению. Показано, что в холодных климатических поясах увеличение осадков приводит к снижению биомассы большинства фракций, а в теплых – к ее увеличению. Соответственно во влагообеспеченных районах повышение температуры вызывает увеличение биомассы, а в засушливых – ее снижение. Геометрическая интерпретация полученной модели представлена «пропеллеро-образной» поверхностью, что согласуется с аналогичными закономерностями, ранее установленными в России на локальном и региональном уровнях. Предложенная модель аддитивной структуры биомассы сосновых древостоев дает возможность прогнозировать изменение структуры биомассы, связанное с одновременным повышением или понижением температуры января и годичных осадков. Forest biomass is a key ecosystem part and an important component of the global carbon cycle. Modelling of biomass, sensitive to climate change, is fulfiled up-to-date at levels as forest stands and sample trees. However, all current studies of this matter are carried out within limited ecoregions. The database on forest biomass of the subgenus Pinus L. in Eurasia in a number of 2460 sample plots compiled by the authors is the basis for revealing transcontinental regularities. The first attempt is made to develop a biomass structure model harmonized by means of additive component composition algorithm describing biomass change in trans-Eurasian hydrothermal gradients, namely, mean annual precipitation and mean January air temperature. Additivity of biomass component composition means that the total of biomass components (stems, branches, foliage, roots) derived from component equations is equal to the result obtained using the common biomass equation. It is stated that in cold climatic zones any increase in precipitation leads to corresponding decrease in the biomass values, but in warm zones – to its increase. In wet areas, the rise in temperature causes an increase of biomass values, but in arid areas – their reductions. Geometric view of this model represented by a «propeller-shaped» surface is consistent with the results, formerly revealed by the other authors in Russia on local and regional levels. The proposed transcontinental model of additive structure of forest biomass gives a possibility to predict the change of biomass structure in relation to simultaneous increase or decrease of January temperature and annual precipitation. The development of such models for basic forest-forming species grown in Eurasia enables to forecast any changes in the biological productivity of forest cover of Eurasia in relation to climate change.


2015 ◽  
Vol 63 (2) ◽  
pp. 134-144 ◽  
Author(s):  
Nejc Bezak ◽  
Alja Horvat ◽  
Mojca Šraj

Abstract The detailed analysis of individual flood event elements, including peak discharge (Q), flood event volume (V), and flood event duration (D), is an important step for improving our understanding of complex hydrological processes. More than 2,500 flood events were defined based on the annual maximum (AM) peak discharge from 50 Slovenian gauging stations with catchment areas of between 10 and 10,000 km2. After baseflow separation, the stations were clustered into homogeneous groups and the relationships between the flood event elements and several catchment characteristics were assessed. Different types of flood events were characteristic of different groups. The flashiness of the stream is significantly connected with mean annual precipitation and location of the station. The results indicate that some climatic factors like mean annual precipitation and catchment related attributes as for example catchment area have notable influence on the flood event elements. When assessing the dependency between the pairs of flood event elements (Q, V, D), the highest correlation coefficients were obtained for the Q-V pair. The smallest correlations or no correlations were observed between the Q and D variables.


Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3557
Author(s):  
Zhaoyang Li ◽  
Yidan Cao ◽  
Jie Tang ◽  
Yao Wang ◽  
Yucong Duan ◽  
...  

The southwest of Songnen Plain, Northeast China, has an arid climate and is a typical concentrated distribution area of saline-alkali soil. The terrain here is low-lying, with many small, shallow lakes that are vulnerable to climate change. This paper used Landsat satellite remote sensing images of this area from 1985 to 2015 to perform interpretation of lake water bodies, to classify the lakes according to their areas, and to analyze the spatial dynamic characteristics of lakes in different areas. During the 30 years from 1985 to 2015, the number of lakes in the study area decreased by 71, and the total lake area decreased by 266.85 km2. The decrease was more serious in the east and northeast, and the appearance and disappearance of lakes was drastic. The Mann–Kendall test method was used to analyze trends in meteorological factors (annual mean temperature, annual precipitation, and annual evaporation) in the study area and perform mutation tests. Through correlation analysis and multiple generalized linear model analysis, the response relationship between lake change and climate change was quantified. The results showed that the average temperature in the area is rising, and the annual precipitation and evaporation are declining. Temperature and precipitation mainly affected lakes of less than 1 km2, with a contribution rate of 31.2% and 39.4%, and evaporation had a certain correlation to the total lake area in the study area, with a contribution rate of 60.2%. Small lakes are susceptible to climatic factors, while large lakes, which are mostly used as water sources, may be influenced more by human factors. This is the problem and challenge to be uncovered in this article. This research will help to improve our understanding of lake evolution and climate change response in saline-alkali areas and provide scientific basis for research into lakes’ (reservoirs’) sustainable development and protection.


2020 ◽  
Vol 6 (2) ◽  
pp. 15-32
Author(s):  
Vladimir Andreevich Usoltsev ◽  
Seyed Omid Reza Shobairi ◽  
Ivan Stepanovich Tsepordey

A comparative discussion on advantages and disadvantages of natural stands and plantations, including their productivity and resistance, began from the moment of first forest plantings and continues to this day. In the context, progressive replacement of natural forests by plantations, the question of how that will change the carbon storage capacity of forest cover when replacing natural forests with planted ones in a changing climate becomes extremely relevant. This article presents the first attempt to answer this question at the transcontinental level on a special case for two-needles pine trees (subgenus Pinus L.). The research was carried out using the database compiled by the authors on the tree biomass allocation structure for major tree species of Eurasia, in particular, the 1880 and 1967 data of naturally regenerated and planted sample pine trees, respectively. Multi-factor regression models were calculated after combining the matrix of initial data on the structure of tree biomass with the mean temperature of January and mean annual precipitation; their adequacy indices allow us to consider them reproducible. It is found that the aboveground biomass of equal-sized and equal-aged natural and planted trees increases with the rise in the temperature in the month of January and annual precipitation. This pattern is only partially valid for the branches’ biomass. Iit has a specific character for the foliage one. The biomass of all components of planted trees is higher than that of natural trees, but the percentage excess varies among different components and depends on the level of January’s temperature, but does not depend at all on the level of annual precipitation. The uncertainties of estimations, as well as the nature of the obtained regularities, are discussed in the text.


2004 ◽  
Vol 359 (1442) ◽  
pp. 243-254 ◽  
Author(s):  
Clive Gamble ◽  
William Davies ◽  
Paul Pettitt ◽  
Martin Richards

A link between climate change and human evolution during the Pleistocene has often been assumed but rarely tested. At the macro–evolutionary level Foley showed for hominids that extinction, rather than speciation, correlates with environmental change as recorded in the deep sea record. Our aim is to examine this finding at a smaller scale and with high–resolution environmental and archaeological archives. Our interest is in changing patterns of human dispersal under shifting Pleistocene climates during the last glacial period in Europe. Selecting this time frame and region allows us to observe how two hominid taxa, Neanderthals and Crô–Magnons, adapted to climatic conditions during oxygen isotope stage 3. These taxa are representative of two hominid adaptive radiations, termed terrestrial and aquatic , which exhibited different habitat preferences but similar tolerances to climatic factors. Their response to changing ecological conditions was predicated upon their ability to extend their societies in space and time. We examine this difference further using a database of all available radiocarbon determinations from western Europe in the late glacial. These data act as proxies for population history, and in particular the expansion and contraction of regional populations as climate changed rapidly. Independent assessment of these processes is obtained from the genetic history of Europeans. The results indicate that climate affects population contraction rather than expansion. We discuss the consequences for genetic and cultural diversity which led to the legacy of the Ice Age: a single hominid species, globally distributed.


2021 ◽  
Author(s):  
Christopher Spence ◽  
Zhihua He ◽  
Kevin R. Shook ◽  
Balew A. Mekonnen ◽  
John W. Pomeroy ◽  
...  

Abstract. Significant challenges from changes in climate and land-use face sustainable water use in the Canadian Prairies ecozone. The region has experienced significant warming since the mid 20th Century, and continued warming of an additional 2 °C by 2050 is expected. This paper aims to enhance understanding of climate controls on Prairie basin hydrology through numerical model experiments. It approaches this by developing a basin classification–based virtual modeling framework for a portion of the Prairie region, and applying the modelling framework to investigate the hydrological sensitivity of one Prairie basin class (High Elevation Grasslands) to changes in climate. High Elevation Grasslands dominate much of central and southern Alberta and parts of southwestern Saskatchewan with outliers in eastern Saskatchewan and western Manitoba. The experiments revealed that High Elevation Grasslands snowpacks are highly sensitive to changes in climate, but that this varies geographically. Spring maximum snow water equivalent in grasslands decreases 8% per degree °C of warming. Climate scenario simulations indicated a 2 °C increase in temperature requires at least an increase of 20% in mean annual precipitation for there to be enough additional snowfall to compensate for enhanced melt losses. The sensitivity in runoff is less linear and varies substantially across the study domain; simulations using 6 °C of warming and a 30% increase in mean annual precipitation yields simulated decreases in annual runoff of 40% in climates of the western Prairie but 55% increases in climates of eastern portions. These results can be used to identify those areas of the region that are most sensitive to climate change, and highlight focus areas for monitoring and adaptation. The results also demonstrate how a basin classification–based virtual modeling framework can be applied to evaluate regional scale impacts of climate change with relatively high spatial resolution, in a robust, effective and efficient manner.


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