Expression of the “4.2 ka event” drought in the southern Rocky Mountains, USA

The use of the climatic anomaly known as the “4.2 ka event” as the stratigraphic division between the mid- and late Holocene has prompted debate over its impact, geographic pattern, and significance. The anomaly has primarily been described as abrupt drying, but evidence of hydroclimate change at ca. 4 ka is inconsistent among sites globally, and few sites in North America document a major drought. Climate records from the southern Rocky Mountains demonstrate the challenge with diagnosing the extent and severity of the anomaly. Dune-field chronologies and a pollen record in southeast Wyoming reveal several centuries of low moisture at around 4.2 ka and prominent low stands in lakes in Colorado suggest the drought was unique amid Holocene variability, but detailed carbonate oxygen isotope (δ18Ocarb) records from Colorado do not record it. We find new evidence from δ18Ocarb in a small mountain lake in southeast Wyoming of an abrupt reduction in effective moisture or snowpack from approximately 4.2–4 ka that coincides in time with the other evidence from the southern Rocky Mountains and the western Great Plains of regional drying at around 4.2 ka. We find that the δ18Ocarb in our record may reflect cool-season inputs into the lake, which do not appear to track the strong enrichment of heavy oxygen by evaporation during summer months today. The modern relationship differs from some widely applied conceptual models of lake-isotope systems and may indicate reduced winter precipitation rather than enhanced evaporation at ca. 4.2 ka. Inconsistencies among the North American records, particularly in δ18Ocarb trends, thus show that site-specific factors can prevent identification of the patterns of multi-century drought. However, the prominence of the drought at ca. 4 ka among a growing number of sites in the North American interior suggests it was a regionally substantial climate event amid other Holocene variability.

Climate Change Impact and Conservation on Environment

Climate-Change affecting unfavorably because of upward push in worldwide temperature alteration and that too alarmingly. Ancient Air bubbles buried in Antarctic Ice to shed more light on Global Warming. It has happened in the North-Atlantic and may happen again. According to scientists, a dangerous atmospheric deviation could prompt prolonged chill and move the Earth towards a brand new age and a new defined climate that would be an effect of the worldwide environmental change. On such conditions James White, a geography educator at Colorado University, Boulder, not engaged with the investigation, said that albeit the ice-age proof showed that degrees of CO2 and further ozone harming substances rose and fell in reaction to heating and cooling , the gases could clearly take the lead as well. Global Climate withinside the fresh past: In the 90’s decades there has stood an experience and witnessing of the extremes of various weather events. In the warmer temperature of century was recorded and a share of the majority noticeably terrible floods all in the course of the planet. The one such inconstancy is the staggering dry period in the Sahel-area which lies in South-of-Sahara desert, from 1967-1977. During the 1930’s there were severe drought that occurred in the south-western Great Plains of the U.S which was described as DUST BOWL. The after-effects of the Global-Climate-Change are severe and tell us about the various impacts. They are:- A. Crop yield or Crop failures, B. Floods, C. Migration of people. These are various influences of the Global-Climate-Change that effect the biosphere from many ways as Climate-Change directly affects the biosphere which is the only sphere wherein lifestyle exists and where life can exist.

Wheat streak mosaic virus (wheat streak).

WSMV is an obligate parasite which infects wheat and other cereal crops and causes significant losses in production throughout many regions of the world. It is not listed as an invasive species, but introduction of the virus to other regions is possible due to a low occurrence of seed transmission. It is believed that WSMV entered the USA in the late 1800s (Reitz and Heyne, 1944; Ross, 1969) from Turkey and then moved into Canada and down into the southern states of the Great Plains as well as Mexico (Sanchez-Sanchez et al., 2001). The introduction of WSMV into Argentina and Australia is reported to be due to infected seed from both Mexico and the USA (Dwyer et al., 2007). Wheat streak is now commonly found throughout many countries and is one of the most common wheat viruses throughout the Central and Western Great Plains of the USA (Burrows et al., 2009).

Contribution of Larvae Developing on Corn and Dry Beans to the Adult Population of Western Bean Cutworm in Michigan

The western bean cutworm, Striacosta albicosta (Smith) (Lepidoptera: Noctuidae), is historically a pest of both corn (Zea mays L. (Poales: Poaceae)) and dry beans (Phaseolus sp. L. (Fabales: Fabaceae)) in the western Great Plains. However, it has recently undergone an eastward range expansion establishing itself across the Corn Belt in 25 states and 4 Canadian provinces. To mitigate the effects of infestation in Michigan, foliar insecticides are used in dry beans, whereas management of the pest in corn relies more heavily on the use of Bt-expressing hybrids. In this study stable carbon isotope analysis was used to determine what crop adult moths developed on as larvae with analysis showing that very few of the adult moths developed on dry beans. These results suggest that beans and corn are not suitable as co-refuges and that mainly adults which developed on corn are contributing to the next generation of western bean cutworm in Michigan.

Contribution of larvae developing on corn and dry beans to the adult population of western bean cutworm in Michigan

The western bean cutworm, Striacosta albicosta (Smith) (Lepidoptera: Noctuidae), is historically a pest of both corn (Zea mays L.) and dry beans (Phaseolus sp L.) in the western Great Plains. However, it has recently undergone an eastward range expansion establishing itself across the Corn Belt in twenty-five states and four Canadian provinces. To mitigate the effects of infestation in Michigan, foliar insecticides are used in dry beans whereas management of the pest in corn relies more heavily on the use of Bt-expressing hybrids. In this study stable carbon isotope analysis was used to determine what crop adult moths developed on as larvae with analysis showing that very few of the adult moths developed on dry beans. These results suggest that beans and corn are not suitable as co-refuges and that mainly adults which developed on corn are contributing to the next generation of western bean cutworm in Michigan.

Staurothele nemorum sp. nov. (Ascomycota: Verrucariaceae), with a revised key to North American Staurothele s. lat.

Staurothele nemorum is described as new to science from the southern Great Plains of central North America. The species is characterized by a thin, areolate, epilithic thallus, sessile perithecia, globose to oblong hymenial algal cells and 8-spored asci. Staurothele hymenogonia is restored to the North American flora, based on material from the south-western Great Plains. An updated key to North American members of Staurothele s. lat. is provided.