scholarly journals Cenários de mudanças climáticas influenciando a germinação e vigor de sementes de Mimosa tenuiflora e Cenostigma pyramidalis

2021 ◽  
Vol 1 (54) ◽  
pp. 62
Author(s):  
Maria do Carmo Learth Cunha ◽  
Thiago Costa Ferreira ◽  
Roberta Patrícia De Sousa Silva
Keyword(s):  
Water Stress ◽  
Relative Humidity ◽  
Climate Changes ◽  
Climatic Changes ◽  
Reference Scenario ◽  
Plant Seeds ◽  
Caatinga Biome ◽  
Alternating Temperature ◽  
Stress Combinations ◽  
Mimosa Tenuiflora

<span class="fontstyle0">Climatic changes occurring on the planet can cause problems in the physiological behavior of plant seeds from the Caatinga biome. The objective of this research was to evaluate a reference scenario to climate changes in the germination and vigor of Mimosa tenuiflora and Cenostigma pyramidalis seeds. For this, different treatments of environmental stress (combinations of temperature, relative humidity, luminous intensities, and water stresses) were tested on seeds of M. tenuiflora and C. pyramidalis. Using Gerbox boxes with vermiculite substrate, the assays were assembled in CRD, and evaluated for variations related to germination and seed and seedlings vigor. The results obtained were obtained by ANOVA and by the Scott-Knott means test. The germination and vigor of M. tenuiflora seeds and seedlings were reduced after a temperature of 30°C. C. pyramidalis seeds germinated only under conditions of alternating temperature, absence of water stress and cannot tolerate temperatures above 30°C. Climatic changes can affect the germination and vigor of the studied species. Research with this theme must be carried out to improve the management of these species in relation to the effects of climate changes.</span> <br /><br />

scholarly journals Effect of relative humidity on evaporation rates in Nabatieh Region

2018 ◽  
Vol 19 (1) ◽  
pp. 59-66
Author(s):  
Nasser Farhat ◽  
Keyword(s):  
Water Stress ◽  
Relative Humidity ◽  
Inverse Relationship ◽  
Climate Changes ◽  
Climatic Factors ◽  
Prevailing Wind ◽  
Climatic Parameters ◽  
Factors Affecting ◽  
Daily Evaporation ◽  
General Climate

Relative humidity affects evaporation, whichisin turn is affected by several climatic parameters. This effect is on the increaseas a result of climate changes, especially increasedtemperature.Nabatiyeh region, insouth Lebanon, was selected for this study, even thoughcomprehensive climaterecords are not available. Instead, data from an experimentalmeteorological station capable of providing all climatic parameters digitally, which includes an evaporation basin of the form A, was used.This study providedexplanations of the general climate in the study area.This includesaverage annual temperature, precipitation and evaporation. Factors affecting relative humiditywere determined.It was found that theevaporationvalueschanged by thechangingdirection of the prevailing wind,andfluctuating higher valueswere recorded in autumn, due to the south-eastern dry winds, which lead to a fluctuation in the amount of daily evaporation.An inverse relationship between relative humidity and evaporationwas observed, with significant correlation between them. The net effect of relative humidity onevaporationwas investigated in this studyby comparing data in two days in which the values of other climatic factors affecting evaporation were the same. It was found that the amount of daily evaporation increased by 80% when the relative humidity declined to 53%.Most likely, in the coming years, the region is moving towards more water stress in light of changes in climatic parameters.

Paraburkholderia spp. are the main rhizobial microsymbionts of Mimosa tenuiflora (Willd.) Poir. in soils of the Brazilian tropical dry forests (Caatinga biome)

2021 ◽  
pp. 126208
Author(s):  
Marcos André Moura Dias ◽  
Claudia Silva Gomes Bomfim ◽  
Dalila Ribeiro Rodrigues ◽  
Aleksandro Ferreira da Silva ◽  
Jéssica Caroline Souza Santos ◽  
...  
Keyword(s):  
Tropical Dry Forests ◽  
Dry Forests ◽  
Caatinga Biome ◽  
Mimosa Tenuiflora

scholarly journals Geomorphological indicators of large-scale climatic changes in the Eastern Bolivian lowlands

2006 ◽  
Vol 61 (2) ◽  
pp. 120-134 ◽  
Author(s):  
J. May
Keyword(s):  
South America ◽  
Large Scale ◽  
Climate Changes ◽  
Landscape Evolution ◽  
Spatial Scales ◽  
Climatic Changes ◽  
Climatic Conditions ◽  
Fluvial Erosion ◽  
Paleoclimatic Significance ◽  
Bolivian Lowlands

Abstract. This study provides an inventory of geomorphological landforms in Eastern Bolivia at different spatial scales. Landforms and associated processes are interpreted and discussed regarding landscape evolution and paleoclimatic significance. Thereby, preliminary conclusions about past climate changes and the geomorphic evolution in Eastern Bolivia can be provided. Fluvial and aeolian processes are presently restricted to a few locations in the study area. A much more active landscape has been inferred from large-scale Channel shifts and extensive paleodune Systems. Mobilization. transport and deposition of Sediments are thought to be the result of climatic conditions drier than today. However. there are also indications of formerly wetter conditions such as fluvial erosion and paleolake basins. In conclusion, the documentation and interpretation of the manifold landforms has shown to contain a considerable amount of paleoecological information, which might serve as the base for further paleoclimatic research in the central part of tropical South America.

scholarly journals Hydrological and Climatic Changes in Deserts of China since the Late Pleistocene

2010 ◽  
Vol 73 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Xiaoping Yang ◽  
Louis A. Scuderi
Keyword(s):  
Climate Changes ◽  
Climatic Changes ◽  
Western China ◽  
Special Issue ◽  
Monsoon Climate ◽  
Complex Interactions ◽  
Aeolian Dunes ◽  
The Last Glacial Maximum ◽  
Dryland Rivers ◽  
The Last Glacial

Large areas in western China were wetlands or less arid between 40 and 30 ka, corresponding to the “Greatest Lake Period” on the adjacent Tibetan Plateau. During the last glacial maximum, some of these western Chinese deserts again experienced wetter conditions; however, at the same time the sandy lands in the eastern Chinese desert belt experienced an activation of aeolian dunes. While interpretations of the mid-Holocene environment in the deserts of China are controversial, it is quite likely that it was more humid not only in the eastern areas influenced by monsoon climate systems but also in the western deserts where moisture is currently associated with westerlies. Evaluation of lacustrine records in the lakes recharged by dryland rivers and the complex interactions of these systems, as well as other paleoenvironmental proxies such as the Artemisia/Chenopodiaceae ratio, should be interpreted with greater caution. Facing the highlighted uncertainties in our understanding of climate changes in Chinese deserts, it is hoped that this special issue will improve our knowledge considerably.

Assessment of the Current and Expected by mid-XXI Century Climatic Changes at the Major Reservoirs Catchments of Russian Hydro Power Stations

2014 ◽  
pp. 60-71
Author(s):  
Keyword(s):  
Integrated Assessment ◽  
Climate Changes ◽  
Climatic Changes ◽  
Hydro Power ◽  
Hydrological Conditions ◽  
Power Stations ◽  
Hydropower Stations ◽  
Operational Modes

The paper presents an integrated assessment of trends in changing of climatic and hydrological conditions in contemporary period and for the 2041–2060 period within the zone of major national hydropower stations in order to specify operational modes and to prevent unfavorable consequences of climate changes for hydropower stations.

scholarly journals Mapping Maize Water Stress Based on UAV Multispectral Remote Sensing

2019 ◽  
Vol 11 (6) ◽  
pp. 605 ◽  
Author(s):  
Liyuan Zhang ◽  
Huihui Zhang ◽  
Yaxiao Niu ◽  
Wenting Han
Keyword(s):  
Water Stress ◽  
High Resolution ◽  
Relative Humidity ◽  
Air Temperature ◽  
Vegetation Index ◽  
Multispectral Imagery ◽  
Crop Water ◽  
Significant Difference ◽  
Maturation Stages ◽  
Crop Water Stress

Mapping maize water stress status and monitoring its spatial variability at a farm scale are a prerequisite for precision irrigation. High-resolution multispectral images acquired from an unmanned aerial vehicle (UAV) were used to evaluate the applicability of the data in mapping water stress status of maize under different levels of deficit irrigation at the late vegetative, reproductive and maturation growth stages. Canopy temperature, field air temperature and relative humidity obtained by a handheld infrared thermometer and a portable air temperature/relative humidity meter were used to establish a crop water stress index (CWSI) empirical model under the weather conditions in Ordos, Inner Mongolia, China. Nine vegetation indices (VIs) related to crop water stress were derived from the UAV multispectral imagery and used to establish CWSI inversion models. The results showed that non-water-stressed baseline had significant difference in the reproductive and maturation stages with an increase of 2.1 °C, however, the non-transpiring baseline did not change significantly with an increase of 0.1 °C. The ratio of transformed chlorophyll absorption in reflectance index (TCARI) and renormalized difference vegetation index (RDVI), and the TCARI and soil-adjusted vegetation index (SAVI) had the best correlations with CWSI. R2 values were 0.47 and 0.50 for TCARI/RDVI and TCARI/SAVI at the reproductive and maturation stages, respectively; and 0.81 and 0.80 for TCARI/RDVI and TCARI/SAVI at the late reproductive and maturation stages, respectively. Compared to CWSI calculated by on-site measurements, CWSI values retrieved by VI-CWSI regression models established in this study had more abilities to assess the field variability of crop and soil. This study demonstrates the potentiality of using high-resolution UAV multispectral imagery to map maize water stress.

scholarly journals O Papel das Oleaginosas em um Cenário de Mudanças Climáticas no Semiárido Brasileiro (The Role of Oilseeds in a Climate Change Scenario in the Brazilian Semiarid)

2013 ◽  
Vol 5 (6) ◽  
pp. 1426
Author(s):  
João Nildo S. Vianna ◽  
Marcelo Castro Pereira ◽  
Laura M.G. Duarte ◽  
Magda E. Wehrmann
Keyword(s):  
Climate Change ◽  
Water Stress ◽  
Climate Changes ◽  
Climate Change Scenario ◽  
Geographic Location ◽  
Semiarid Region ◽  
Change Scenario ◽  
Brazilian Semiarid ◽  
Family Agriculture

Este trabalho tem por objetivo avaliar, ainda que de forma preliminar, os efeitos limitantes das mudanças climáticas na produção de oleaginosas agro-energética no semiárido brasileiro, nomeadamente a redução dos índices pluviométricos e aumento de temperatura. Para alcançar este objetivo usa-se como referência a evolução de variáveis climáticas, por meio da série histórica entre 1973 e 2010, e projeções futuras tendo por base os cenários de mudanças climáticas, desenvolvidos para o nordeste brasileiro até 2100. O recorte geográfico é a região de Irecê, no semiárido da Bahia, tradicional reduto da agricultura familiar e grande produtor de alimentos consorciado com oleaginosas. O estudo mostra que as culturas tradicionais de oleaginosas estão próximas aos limites de exigências hídricas, pelo que, para enfrentar as mudanças nos padrões climáticos, vai ser necessário um melhoramento genético das culturas tradicionais para que essa espécies consigam tolerar as restrições hídricas. Preconizando-se igualmente a introdução de espécies mais rústicas e com maior resistência ao estresse hídrico. Palavras-Chave: Agricultura Familiar, Vulnerabilidade e Adaptação às Mudanças Climáticas, Biodiesel, Semiárido.  The Role of Oilseeds in a Climate Change Scenario in the Brazilian Semiarid  ABSTRACT The present study aims to evaluate the effects of climate changes on the production of oilseed and energy crops in the Brazilian semiarid region. The study is based on the analysis of past climate, by evaluating a historic series of rain and temperature from 1973 to 2010. This historic series is, then, compared to a future climate prediction, based on climatic change scenarios developed for the Brazilian northeast until 2100. The geographic location of the study is the Irecê area of the State of Bahia, in the semi-arid northeast. That is a traditional family agriculture area with a strong food crop and oilseeds production. The study shows that traditional oilseed crops are being cultivated near the limits of their water needs. In order to face the climate changes, such crops would need to be genetically improved to increase their tolerance to water stress. An option would be to introduce species with higher level of tolerance to water stress. Keywords: family agriculture, vulnerability and adaptation to climate changes, biodiesel, semiarid.

scholarly journals Climate Changes and the Imperatives of All Round-a-Year Human Activity in the Arctic

2015 ◽  
pp. 9-18
Author(s):  
L. Voronkov
Keyword(s):  
Energy Supply ◽  
Climate Changes ◽  
Climatic Changes ◽  
Arctic Climate ◽  
The Arctic ◽  
Financial Resources ◽  
Human Society ◽  
Human Beings ◽  
Earth’S Climate ◽  
The Impact

The author questions the indisputability of the Arctic’s existing climate change assessments and insists on the need to adjust the Arctic strategies of states to different scenarios of such changes. While not denying the impact of human society on the Earth’s climate, the author believes to be important not to limit research on its changes by exclusively natural-scientific aspects, but to include considerations concerning the influence of peculiarities of human society’s development on the climate. He thinks it is important to take into account the combine impact of the changing nature of contemporary industrial activity, of sources for energy supply, the on-going processes of building of “smart” economy and its innovative development, demographic changes, improvement of human capital as well as the impact of increased environmental consciousness of human beings on the global and Arctic climate. Despite the observed climatic changes in the Arctic, it remains ice-covered the major part of the year. Any commercially justified human activities in the Arctic must be based on the need to maintain a year-round exploitation of its resources and possibilities and to create the appropriate infrastructure, machinery and equipment. The author comes to the conclusion that the need to resolve these problems requires considerable financial resources and time.

scholarly journals Postglacial Fire Frequency and its Relation to Long Term Vegetational and Climatic Changes in Yellowstone Park

1991 ◽  
Vol 15 ◽  
pp. 276-279
Author(s):  
Cathy Whitlock ◽  
Sarah Millspaugh
Keyword(s):  
Environmental Change ◽  
Climate Changes ◽  
Fire Frequency ◽  
Climatic Changes ◽  
Term Effect ◽  
Environmental Perturbations ◽  
Long Term Effect ◽  
Primary Agent ◽  
Pollen Records

The paleoecologic record provides unique insights into the response of coinmunities to environmental perturbations of different duration and intensity. Climate is a primary agent of environmental change and its long-term effect on the vegetation of the Yellowstone region is revealed in a network of pollen records. Fire frequency is controlled by climate, and as climate changes so too does the importance of fire in shaping and maintaining spatia\l patterns of vegetation. The prehistoric record of Yellowstone's northern range, for example, shows the response of vegetation to an absence of major fires in the last 150 years (Whitlock et al. 1991; Engstrom et al. 1991). In longer records spanning the last 14,000 year8, periods of frequent fires are suggested • by sediments containing high percentages of fire-adapted trees and high amounts of charcoal (Bamosky et al. 1987).

Sign in / Sign up

Export Citation Format

Share Document