Environmental Factors Affecting Recent Summertime Eelgrass Diebacks in the Lower Chesapeake Bay: Implications for Long-term Persistence

2008 ◽  
Vol 10055 ◽  
pp. 135-147 ◽  
Author(s):  
Kenneth A. Moore ◽  
Jessie C. Jarvis
Keyword(s):  
Environmental Factors ◽  
Chesapeake Bay ◽  
Factors Affecting

Species Responses to Grazing and Environmental-Factors in an Arid Halophytic Shrubland Community

1987 ◽  
Vol 35 (2) ◽  
pp. 135 ◽  
Author(s):  
RB Hacker
Keyword(s):  
Environmental Factors ◽  
Soil Salinity ◽  
Large Scale ◽  
Chemical Properties ◽  
Grazing Pressure ◽  
Aerial Photographs ◽  
Small Scale ◽  
Factors Affecting ◽  
Species Responses

Species responses to grazing and environmental factors were studied in an arid halophytic shrubland community in Western Australia. The grazing responses of major shrub species were defined by using reciprocal averaging ordination of botanical data, interpreted in conjunction with a similar ordination of soil chemical properties and measures of soil erosion derived from large-scale aerial photographs. An apparent small-scale interaction between grazing and soil salinity was also defined. Long-term grazing pressure is apparently reduced on localised areas of high salinity. Environmental factors affecting species distribution are complex and appear to include soil salinity, soil cationic balance, geomorphological variation and the influence of cryptogamic crusts on seedling establishment.

scholarly journals Factors affecting the abundance of age-0 Atlantic menhaden (Brevoortia tyrannus) in Chesapeake Bay

2016 ◽  
Vol 73 (9) ◽  
pp. 2238-2251 ◽  
Author(s):  
Edward D. Houde ◽  
Eric R. Annis ◽  
Lawrence W. Harding ◽  
Michael E. Mallonee ◽  
Michael J. Wilberg
Keyword(s):  
Environmental Factors ◽  
Primary Production ◽  
Chesapeake Bay ◽  
Primary Productivity ◽  
Atlantic Menhaden ◽  
Strongly Correlated ◽  
Brevoortia Tyrannus ◽  
Factors Affecting ◽  
Chl A ◽  
Low Levels

Abstract The abundance of prerecruit, age-0 Atlantic menhaden (Brevoortia tyrannus), declined to low levels in Chesapeake Bay in the 1990s, after two decades of high abundances in the 1970s–1980s. Environmental factors and trophodynamics were hypothesized to control age-0 menhaden abundance. Data on age-0 menhaden abundance from seine and trawl surveys were analysed with respect to primary productivity, chlorophyll a (Chl a), and environmental variables. Abundance from 1989 to 2004 was strongly correlated with metrics of primary production and euphotic-layer Chl a, especially during spring months when larval menhaden transform into filter-feeding, phytoplanktivorous juveniles. Correlation, principal components, and multiple regression analyses were conducted that identified factors associated with age-0 menhaden abundance. Primary production, Chl a, and variables associated with freshwater flow, e.g. Secchi disk depth and zooplankton assemblages, were correlated with age-0 menhaden abundance. Lengths of age-0 menhaden were positively related to mean levels of annual primary production. However, lengths were negatively related to age-0 menhaden abundance, indicating that growth may be density-dependent. The identified relationships suggest that numbers of menhaden larvae ingressing to Chesapeake Bay and environmental factors that subsequently control primary productivity and food for juveniles within the Bay may control recruitment levels of Atlantic menhaden.

Environmental Assessment in Manuscripts Library and Storages of Semi-Active Record at Sultanate of Oman

2013 ◽  
Vol 9 (3) ◽  
pp. 65-81
Author(s):  
Nahed Salem ◽  
Sabah Abdul-Wahab ◽  
Sappurd Ali
Keyword(s):  
Environmental Factors ◽  
Environmental Parameters ◽  
International Standards ◽  
Indoor Environments ◽  
Sultanate Of Oman ◽  
Document Collections ◽  
Factors Affecting ◽  
Archival Collection ◽  
Active Record

Indoor environmental factors have been associated with deterioration of vital library and archival assets. The assessment of environmental factors affecting the library and document collections due to their inappropriate levels was the main objective of current study. In order to fulfill this objective the measurements of indoor environmental parameters were taken in manuscripts library and documents storage buildings of various Ministries of Sultanate of Oman. The measured values of these parameters were compared with the permitted values defined in various international standards/guidelines. The results of the study showed that the observed levels of environmental factors inside these buildings were not within the stipulated limits. The quality of indoor air at the studied locations was not appropriate for long term protection and preservation of their precious collections. Hence some preventive measures must be taken to safeguard these documentary assets. Practical implications - The indoor environments of library and archival collection buildings are very important for the protection and preservation of documentary assets. The study provides very useful information about the harmful indoor environmental factors and their effects on vital library and archival collections. This work would definitely help the concerning authorities to take remedial measures to control the inappropriate levels of these factors.

scholarly journals Intestinal Helminths and the Influence of Environmental Factors on Cattle Infection in the Altai Mountains

2020 ◽  
Vol 14 (3) ◽  
pp. 53-62
Author(s):  
V. A. Marchenko ◽  
E. A. Efremova
Keyword(s):  
Environmental Factors ◽  
Summer Rainfall ◽  
Annual Rainfall ◽  
Anthropogenic Pressure ◽  
Intestinal Helminths ◽  
Altai Mountains ◽  
Factors Affecting ◽  
Average Annual Temperature ◽  
Average Annual Rainfall

The purpose of the research: comparative assessment of cattle infection with intestinal helminths in various provinces and characteristics of the relationship between abiotic and anthropogenic environmental factors with the level of infection and the number of helminths in the Altai Mountains. Materials and methods. According to the results of long-term (2010–2019) ovolarvoscopic examinations, more than 2.4 thousand heads of cattle from 7 regions of the Altai Republic characterized by extensity of infection (EI) and the number of helminth eggs in 1 g of feces (NHE/g) in animals. By correlation analysis, the association of animal EI with helminths, NHE/g and abiotic and anthropogenic environmental factors in the context of farms and regions of the Altai Mountains is shown. The following parameters are estimated: long-term average annual temperature, long-term average annual rainfall, longterm average summer temperature, long-term average summer rainfall, altitude above the sea level, population density of the host, the effect of parasiticidal treatments of animals on parasite infection. Results and discussion. It was found that animals are mostly infected with intestinal helminths in the Choy region, where the EI was 61.7% when detecting NHE/g 81.8 pcs. Minimal infection of cattle by helminths was recorded in the Kosh-Agach region – 38.8% with NHE/g of 22.9 pcs. In the whole country, EI of animals is 51.8% with an egg number of 44.1 individuals in 1 g of feces. Within the physical-geographical provinces, cattle are mostly infected in Central Altai (EI – 56.5%, NHE/g – 43.6 pcs.), to a lesser extent in Southeast Altai (EI – 38.8%, NHE/g – 22.9 pcs.). According to the results of ovoscopic examinations, it was found that the most significant factors affecting the infection of animals with intestinal helminths in farms are the long-term average annual precipitation (r = 0.60 and 0.34) and the degree of anthropogenic pressure (r = -0.52 and -0.59), in the context of districts, long-term average annual temperatures (r = 0.65 and 0.55), average annual summer rainfall (r = 0.74 and 0.65). According to larvoscopy, the most significant environmental factors affecting cattle infection are long-term average annual temperature (r = 0.62 and 0.72), long-term average annual rainfall (r = 0.76) and elevation (r = -0.71 and -0.73), in farms – the degree of anthropogenic press (r = -0.65 and -0.78).

Sign in / Sign up

Export Citation Format

Share Document