scholarly journals Response of pollen diversity to the climate-driven altitudinal shift of vegetation in the Colombian Andes

2006 ◽  
Vol 362 (1478) ◽  
pp. 253-262 ◽  
Author(s):  
Chengyu Weng ◽  
Henry Hooghiemstra ◽  
Joost F Duivenvoorden

Change in diversity of fossil pollen through time is used as a surrogate for biodiversity history. However, there have been few studies to explore the sensitivity of the measured pollen diversity to vegetation changes and the relationship between pollen diversity and plant diversity. This paper presents results of a study to assess the relationship between pollen diversity and relative abundance of pollen from different altitudinal vegetation belts (subandean forest, Andean forest, subparamo and grassparamo) in three records from the tropical Andes in Colombia. The results indicated that plant diversity in the vegetation declined with altitude and pollen diversity is positively correlated to the abundance of pollen from lower altitude vegetation belts and negatively correlated to that from the grassparamo. These results, therefore, suggest that pollen diversity coarsely reflects the diversity of the surrounding vegetation. Using this interpretation, we were able to predict changes in plant diversity over the past 430 000 years in the Colombian Andes. Results indicated that under warmer climatic conditions, more species-diverse vegetation of low elevation moved upslope to contribute more pollen diversity to the study sites, and under colder conditions, species-poor grassparamo moved downslope and observed pollen diversity was lower. This study concludes that fossil pollen diversity may provide an important proxy to reconstruct the temporal changes in plant diversity.

MAUSAM ◽  
2021 ◽  
Vol 68 (4) ◽  
pp. 655-662
Author(s):  
RANBIR SINGH RANA ◽  
MANMOHAN SINGH ◽  
RANU PATHANIA ◽  
S. K. UPADHYAY ◽  
VAIBHAV KALIA

The study examined the impacts of changing climate on productivity of temperate fruit crops          viz., plum, pear, peach and apricot in Himachal Pradesh based on climate information and farmers’ perception. Three study sites representing different elevations viz., Shimla, Kullu and Palampur were selected to relate the chill units with temperate fruit productivity. The climate element distribution over the period in each study site revealed an increase in the mean temperature to the tune of 0.050, 0.019 and 0.046 °C per year in Shimla, Palampur and Kullu respectively in the past 3 to 4 decade. The rate of decrease of rainfall per year during winter season was -9.86 mm in Shimla, -11.1 mm in Kullu and -8.6 mm in Palampur leading to a decrease in chill accrual. The chill units calculated using the UTAH model showed a decline of more than 4.97 chill units per year during December month, 0.64 units per year in January and 3.75 units per year in February month in past 26 year period in Shimla district. The decrease of 1.73, 1.84 and 1.65 chill units every year during December, January and February months were observed at Kullu. The decrease of chill units during December to February ranged from -2.8 to -12.8 per year in Palampur were also observed. The significance of the slope of chill units was worked out using Mann-Kendall trend test which indicated no significant trend for the December month for Kullu region and January and February months at Shimla. Significant decreasing trends in chill units for January to February months for Kullu, December month for Shimla and December to February months were observed at Palampur. The indications of changes in climate have also been supported by the farmers’ perception in Kullu, Kangra and Shimla districts accounting a reduction in snowfall with an increase in temperature in past 20 to 30 years affecting the chill accumulation. The temperate fruits pear, peach, plum and apricot showed significant increase in the production at the rate of 0.172, 0.064, 0.018 and 0.018 t/ha per year during the past two and half  decade respectively. Thus, the decreasing trends in cumulative chill units due to increase in temperature and reduction in rainfall in all locations varied from sub temperate climate in mid hills to temperate in high hills did not affect the productivity of temperate fruits in Himachal Pradesh and a promising replacement for apple shifting region in the face of climate change.  


1997 ◽  
Vol 48 (1) ◽  
pp. 15-28 ◽  
Author(s):  
Karin F. Helmens ◽  
Rene W. Barendregt ◽  
Randolph J. Enkin ◽  
Judith Baker ◽  
Paul A.M. Andriessen

Two sections exposing a Late Pliocene–Pleistocene sedimentary sequence in the marginal valleys of the Bogotá Basin (Colombian Andes, South America) were sampled for paleomagnetic analysis. Magnetostratigraphy and fission-track dates of tephra beds provide a detailed geochronologic calibration for the sedimentary basin. Measurements of magnetic susceptibility complement the regional environmental record provided by lithological and palynological evidence. Sedimentation in the Bogota Basin started in the early part of the Gauss Chron at ca. 3.2 myr. The oldest recorded sediments belong to the Guasca Member of the Upper Tilatá Formation. They were deposited in a lacustrine/paludal environment, near the end of the tectonic uplift in the Bogotá area, and/or under Pliocene climatic conditions that were warmer than today. Repeated climate cooling associated with glaciations in the surrounding mountains resulted in the deposition of a fluvial–lacustrine complex referred to as the Subachoque Formation. The first glaciation is placed near the Gauss/Matuyama polarity reversal at 2.6 myr. A lithologic change in the Subachoque Formation marked by coarser-grained fluvial deposits and a possible increase in amplitude of the magnetic susceptibility signal occurs near the Matuyama/Brunhes boundary at 0.8 myr, indicating a shift toward higher magnitude climate oscillations.


GeroPsych ◽  
2020 ◽  
Vol 33 (4) ◽  
pp. 246-251
Author(s):  
Gozde Cetinkol ◽  
Gulbahar Bastug ◽  
E. Tugba Ozel Kizil

Abstract. Depression in older adults can be explained by Erikson’s theory on the conflict of ego integrity versus hopelessness. The study investigated the relationship between past acceptance, hopelessness, death anxiety, and depressive symptoms in 100 older (≥50 years) adults. The total Beck Hopelessness (BHS), Geriatric Depression (GDS), and Accepting the Past (ACPAST) subscale scores of the depressed group were higher, while the total Death Anxiety (DAS) and Reminiscing the Past (REM) subscale scores of both groups were similar. A regression analysis revealed that the BHS, DAS, and ACPAST predicted the GDS. Past acceptance seems to be important for ego integrity in older adults.


2019 ◽  
pp. 121-143
Author(s):  
Riccardo Resciniti ◽  
Federica De Vanna

The rise of e-commerce has brought considerable changes to the relationship between firms and consumers, especially within international business. Hence, understanding the use of such means for entering foreign markets has become critical for companies. However, the research on this issue is new and so it is important to evaluate what has been studied in the past. In this study, we conduct a systematic review of e-commerce and internationalisation studies to explicate how firms use e-commerce to enter new markets and to export. The studies are classified by theories and methods used in the literature. Moreover, we draw upon the internationalisation decision process (antecedents-modalities-consequences) to propose an integrative framework for understanding the role of e-commerce in internationalisation


Author(s):  
Nina TERREY ◽  
Sabine JUNGINGER

The relationship that exists between design, policies and governance is quite complex and presents academic researchers continuously with new opportunities to engage and explore aspects relevant to design management. Over the past years, we have witnessed how the earlier focus on developing policies for design has shifted to an interest in understanding the ways in which design contributes to policy-making and policy implementation. Research into policies for design has produced insights into how policy-making decisions can advance professional impact and opportunities for designers and the creative industries. This research looked into how design researchers and design practitioners themselves can benefit from specific policies that support design activities and create the space for emerging design processes.


2019 ◽  
pp. 42-44
Author(s):  
I.V. GUSAROV ◽  
V.A. OSTAPENKO ◽  
T.V. NOVIKOVА

Впервые в мире создана популяция зубров на территории 60 градусов северной широты. В новых климатических условиях разведения и сохранения зубров определены и проанализированы факторы существования вида на севере Европейской части РФ. Выявлены признаки, динамика численности, которые являются составной частью системы, предназначенной для управления биоразнообразием. Интродукция, являясь процессом введения в экосистему нехарактерных для нее видов, может усиливать изменения биоценозов как положительно, так и отрицательно. Насколько быстро и успешно проходит процесс адаптации заселенного вида, и усматривается его влияние на окружающую среду зависит дальнейшее существование зубров и в целом биоразнообразия. В статье обсуждаются вопросы взаимоотношения зубров с другими видами копытных и хозяйственной деятельностью человека, а также дальнейшим использованием зубров в сельскохозяйственном производстве. Пластичность зубров, выявление изменений и их анализ при вселении видов в новые условия обитания необходимы не только для определения развития или деградации биоценозов и в целом экосистемы, но и прогноза социально-экономических последствий интродукции как одного из методов сохранения редких и исчезающих видов фауны.For the first time in the world, a bison population has been created in an area of 60 degrees north latitude. In the new climatic conditions of breeding and preservation of bison, the factors of the species existence in the north of the European part of the Russian Federation are identified and analyzed. The signs, dynamics of abundance, which are an integral part of the system designed to manage biodiversity are identified, since the preservation of biological diversity on the planet is one of the main problems of our time. Introduction, being the process of introducing non-typical species into an ecosystem, can enhance changes in biocenoses, both positively and negatively. The question posing sounds especially when it comes to such a large hoofed animal as the European bison. How quickly and successfully the process of adaptation of the universe takes place and its environmental impact is seen depends on the continued existence of bison and biodiversity in general. The article discusses the relationship of bison with other types of ungulates and human activities, as well as the further use of bison in agricultural production. How these issues will be resolved positively depends on the future of these animals. Thus, the plasticity of bison, the identification of changes and their analysis, with the introduction of species into new habitat conditions is necessary not only to determine the development or degradation of biocenoses and the ecosystem as a whole, but also to predict the socio-economic consequences due to the introduction as one of the methods of preserving rare and endangered species of fauna.


2020 ◽  
Vol 4 (4(13)) ◽  
pp. 31-50
Author(s):  
Shiyu Zhang ◽  

Over the past decade, bilateral relations between China and Russia have attracted the attention of the whole world. As neighbors and rapidly developing countries, China and Russia are becoming increasingly important in the international arena. The strategic partnership and interaction between China and Russia occupy a significant place in the politics of both countries. Cooperation is developing dynamically in various fields, primarily in politics. After 2012, a change of government took place in China and Russia, which brought new changes to international relations. Studying the involvement of the media in this process can clarify their impact on international relations, in particular, their role in the relationship between China and Russia.


Author(s):  
Суусар Искендерова

Аннотация: Исследование проблемы фольклоризма является наиболее актуальной в современной науке о фольклоре. На разных этапах развития художественной литературы для формирования индивидуального творчества писателя особенно значимым становятся фольклорные жанры, сюжетные мотивы и художественные средства. В статье рассматривается связь письменной литературы и фольклора, особенно точка зрения проблеме фольклоризма в прошлом и их анализ. Термин «фольклоризм» начал использоваться советскими исследователями учеными как научный термин еще в 1930-х гг. Термин «фольклоризм» используется в различных сферах культуры, а в этой статье мы будем рассматривать в литературе. Несмотря на то, что на протяжении многих лет этот вопрос изучается литературоведами, фольклористами, все -таки нет единого теоретического определения понятия. Ключевые слова: фольклор, фольклоризм, литература, культура, письменная литература, художественная литература, оседлый народ, пословицы и поговорки, фольклорные песни. Аннотация: Көркөм адабияттын өнүгүүсүнүн ар кайсы баскычтарында сүрөткердин жеке чыгармачылыгынын калыптанышы үчүн фольклордук жанрлар, сюжеттер, мотивдер жана көркөм каражаттар айрыкча мааниге ээ. Макалада жазма адабият менен фольклордук карым-катышы, айрыкча фольклоризм маселеси жөнүндө мурдагы көз караштарга кайрылып, аларга талдоо жүргүзүү менен бирге автор өз байкоолорунда келтирет. “Фольклоризм” деген илимий термин 1930-жылы баштап колдонула баштаган. “Фольклоризм” термини маданияттын түрдүү сфераларында кеңири колдо- нулат, бул жерде адабияттагы колдонулушун каралат. Макалада адабий материал менен фольклордук байланышын терең түшүнүү үчүн адабий фольклоризм маселесинин талаштуу жактары каралат. Түйүндүү сөздөр: фольклор, фольклоризм, адабият, маданият, жазма адабият, көркөм адабият, көчмөн калк, макал-лакап, фольклордук ырлар. Annotation: The study of the problem of folklore is the most relevant in the modern science of folklore. At various stages in the development of fiction, folklore genres, plot motifs, and artistic means become especially significant for the formation of the writer's individual creativity. The article examines the relationship between written literature and folklore, especially the point of view of the problem of folklorism in the past and their analysis. The term "folklorism" began to be used by Soviet scholars as a scientific term back in the 1930s. The term "folklorism" is used in various fields of culture, and in this article we will consider in the literature. Despite the fact that for many years this issue has been studied by literary scholars, folklorists, all the same there is no single theoretical definition of the concept. Keywords: folklore, folklorism, literature, culture, written literature, fiction, settled people, proverbs and sayings, folk songs.


2020 ◽  
Vol 17 (9) ◽  
pp. 1084-1101
Author(s):  
Tingjuan Wu ◽  
Xu Yao ◽  
Guan Wang ◽  
Xiaohe Liu ◽  
Hongfei Chen ◽  
...  

Background: Oleanolic Acid (OA) is a ubiquitous product of triterpenoid compounds. Due to its inexpensive availability, unique bioactivities, pharmacological effects and non-toxic properties, OA has attracted tremendous interest in the field of drug design and synthesis. Furthermore, many OA derivatives have been developed for ameliorating the poor water solubility and bioavailability. Objective: Over the past few decades, various modifications of the OA framework structure have led to the observation of enhancement in bioactivity. Herein, we focused on the synthesis and medicinal performance of OA derivatives modified on A-ring. Moreover, we clarified the relationship between structures and activities of OA derivatives with different functional groups in A-ring. The future application of OA in the field of drug design and development also was discussed and inferred. Conclusion: This review concluded the novel achievements that could add paramount information to the further study of OA-based drugs.


Author(s):  
Michael C. Rea

This chapter provides a detailed characterization of the various meanings of the term “divine hiddenness,” carefully and rigorously articulates the version of the problem of divine hiddenness that has dominated contemporary philosophical discussion for the past twenty-five years, and then explains the relationship between that problem and the problem of evil.


Sign in / Sign up

Export Citation Format

Share Document