scholarly journals Euphorbia tirucalli (Indian-tree spurge).

Author(s):  
Julissa Rojas-Sandoval

Abstract E. tirucalli is a many-branched succulent plant widely commercialized as an ornamental, hedge plant, potted plant and for soil conservation (Orwa et al., 2009; USDA-ARS, 2016). It has escaped from cultivation and once naturalized, it often grows forming thickets mostly in disturbed sites, abandoned gardens, deciduous forests, semiarid sites, and along roadsides (Little et al., 1974; PIER, 2016). This species grows very fast, and produces a lot of biomass even under very marginal soil and extreme climatic conditions (Mwine and Damme, 2011). In invaded areas, it is propagating vegetatively by cuttings and stem fragments (Little et al., 1974; PIER, 2016). Currently, this species is listed as invasive in Hawaii and Cuba (Oviedo Prieto et al., 2012; PIER, 2016), but is listed as potentially invasive on many islands in the Pacific and in tropical and subtropical areas of Asia (Nguyen and Sosef, 1999; Flora of China Editorial Committee, 2016; PIER, 2016).

2020 ◽  
Author(s):  
Julissa Rojas-Sandoval

Abstract Ipomoea indica is a vine that has been widely cultivated as a garden ornamental across tropical, subtropical and warm temperate regions of the world (Randall, 2017; USDA-ARS, 2017). It is an aggressive and opportunistic colonizer of open and disturbed habitats that has escaped from cultivation to become widely naturalized in disturbed areas near gardens, coastal areas, forest edges, and along roadsides and waterways. This species spreads by seeds, stolons, and stem fragments and when growing under favourable environmental conditions (e.g., full sun, ample moisture and fertile soil) it can spread very rapidly, smothering all other vegetation growing nearby. Its rapidly growing stolons can form dense mats over the ground, while its climbing habit enables it to compete successfully with trees and shrubs on the edges of forests and along riparian zones. Its twining stems also choke adjacent seedlings and smother young trees and shrubs in the understory (Wagner et al., 1999; Csurches, 2016). Currently, I. indica is listed as invasive in Australia, New Zealand, China, southern Africa, Europe, the West Indies, and on many islands in the Pacific Region (Smith, 2010 BioNET-EAFRINET, 2017; DAISIE, 2017; Flora of China Editorial Committee, 2017; GRIIS, 2017; PIER, 2017; Queensland Government, 2017).


2020 ◽  
Vol 8 (Spl-2-AABAS) ◽  
pp. S292-S297
Author(s):  
Alexander Leonidovich Mikhailov ◽  
◽  
Olga Arnoldovna Timofeeva ◽  
Uliana Aleksandrovna Ogorodnova ◽  
Nikita Sergeevich Stepanov ◽  
...  

The current study was conducted to estimate the effect of soil and growth climatic conditions on the vitamin content of red clover (Trifolium pratense L.). Further, in vitamins, the content of ascorbic acid and vitamin A (provitamin – carotene) was estimated from the aerial parts of the clover. Ascorbic acid is a powerful antioxidant, antiviral, and antitumor vitamin while vitamin A is a useful vitamin for eyesight. Ascorbic acid content in the red clover tissues was determining potassium hexacyanoferrate method while Provitamin A and total carotenoid was estimated by spectrophotometric method. Results of the study revealed that the highest content of vitamins C was found in the plant grown under the climatic conditions of the southern taiga subzone of the Atninsky and in the zone of deciduous forests (Apastovsky and Kamsko-Ustinsky districts) while the plant is grown under the coniferous-deciduous forests (Zelenodolsky district) climatic conditions are a rich source of vitamin A. From the results of the study, it can conclude the soil and growing conditions especially temperature regime and soil moisture affected the level of vitamins in red clover.


2021 ◽  
Author(s):  
Julissa Rojas-Sandoval ◽  
Pedro Acevedo-Rodríguez

Abstract C. rutidosperma is a common herb that grows as a weed in disturbed and ruderal habitats, principally in areas with humid and hot environmental conditions. It is often found as a weed of disturbed ground, roadsides, gardens, crops and abandoned lands, and has also been found growing as an epiphyte on trees, stone walls and cliff faces. This species is included in the Global Compendium of Weeds (Randall, 2012) where it is considered to have moderate economic impacts in a wide range of crops, due to its scrambling habit that smothers and stunts young crop plants. C. rutidosperma has been listed as invasive in China, Malaysia, India, Thailand, Vietnam, Australia, and the Domican Republic (Waterhouse and Mitchell, 1998; Kairo et al., 2003; Flora of China Editorial Committee, 2014, USDA-ARS, 2014). This species has had considerable environmental impacts in South East Asia and Australia. C. rutidosperma also has the potential to be moderately problematic in intensive cropping areas, greenhouses and nurseries.


2018 ◽  
Vol 31 (15) ◽  
pp. 6189-6207 ◽  
Author(s):  
Scott B. Power ◽  
François P. D. Delage

Increases in greenhouse gas emissions are expected to cause changes both in climatic variability in the Pacific linked to El Niño–Southern Oscillation (ENSO) and in long-term average climate. While mean state and variability changes have been studied separately, much less is known about their combined impact or relative importance. Additionally, studies of projected changes in ENSO have tended to focus on changes in, or adjacent to, the Pacific. Here we examine projected changes in climatic conditions during El Niño years and in ENSO-driven precipitation variability in 36 CMIP5 models. The models are forced according to the RCP8.5 scenario in which there are large, unmitigated increases in greenhouse gas concentrations during the twenty-first century. We examine changes over much of the globe, including 25 widely spread regions defined in the IPCC special report Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX). We confirm that precipitation variability associated with ENSO is projected to increase in the tropical Pacific, consistent with earlier research. We also find that the enhanced tropical Pacific variability drives ENSO-related variability increases in 19 SREX regions during DJF and in 18 during JJA. This externally forced increase in ENSO-driven precipitation variability around the world is on the order of 15%–20%. An increase of this size, although substantial, is easily masked at the regional level by internally generated multidecadal variability in individual runs. The projected changes in El Niño–driven precipitation variability are typically much smaller than projected changes in both mean state and ENSO neutral conditions in nearly all regions.


Manoa ◽  
2019 ◽  
Vol 31 (1) ◽  
pp. 70-71
Author(s):  
Ling Yu ◽  
Michelle Yeh

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Edvinas Stonevicius ◽  
Gintautas Stankunavicius ◽  
Egidijus Rimkus

The climate continentality or oceanity is one of the main characteristics of the local climatic conditions, which varies with global and regional climate change. This paper analyzes indexes of continentality and oceanity, as well as their variations in the middle and high latitudes of the Northern Hemisphere in the period 1950–2015. Climatology and changes in continentality and oceanity are examined using Conrad’s Continentality Index (CCI) and Kerner’s Oceanity Index (KOI). The impact of Northern Hemisphere teleconnection patterns on continentality/oceanity conditions was also evaluated. According to CCI, continentality is more significant in Northeast Siberia and lower along the Pacific coast of North America as well as in coastal areas in the northern part of the Atlantic Ocean. However, according to KOI, areas of high continentality do not precisely correspond with those of low oceanity, appearing to the south and west of those identified by CCI. The spatial patterns of changes in continentality thus seem to be different. According to CCI, a statistically significant increase in continentality has only been found in Northeast Siberia. In contrast, in the western part of North America and the majority of Asia, continentality has weakened. According to KOI, the climate has become increasingly continental in Northern Europe and the majority of North America and East Asia. Oceanity has increased in the Canadian Arctic Archipelago and in some parts of the Mediterranean region. Changes in continentality were primarily related to the increased temperature of the coldest month as a consequence of changes in atmospheric circulation: the positive phase of North Atlantic Oscillation (NAO) and East Atlantic (EA) patterns has dominated in winter in recent decades. Trends in oceanity may be connected with the diminishing extent of seasonal sea ice and an associated increase in sea surface temperature.


1992 ◽  
Vol 37 (1) ◽  
pp. 42-59 ◽  
Author(s):  
James C. Chatters ◽  
Karin A. Hoover

AbstractAn understanding of the response of a fluvial system to past climatic changes is useful for predicting its response to future shifts in temperature and precipitation. To determine the response of the Columbia River system to previous climatic conditions and transitions, a well-dated sequence of floodplain development in the Wells Reservoir region was compared with the paleoenvironmental history of the Columbia River Basin. Results of this comparison indicate that aggradation episodes, occurring approximately 9000-8000, 7000-6500, 4400-3900, and 2400-1800 yr B.P., coincided with climatic transitions that share certain characteristics. The inferred climates associated with aggradation had at least moderate rates of precipitation that occurred mainly in winter coupled with moderate winter temperatures. Such conditions would have resulted in the buildup of snowpacks and a high frequency of rain-on-snow events. The warming and precipitation increases predicted for the Pacific Northwest under most CO2-doubling scenarios are likely to repeat these conditions, which could increase the frequency of severe, sediment-laden floods in the Columbia River Basin.


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