Уточнить поиск
Результаты 1-4 из 4
Detection of multiple potentially pathogenic bacteria in Matang mangrove estuaries, Malaysia
2014
Ghaderpour, Aziz | Mohd Nasori, Khairul Nazrin | Chew, Li Lee | Chong, V. C. (Ving Ching) | Thong, Kwai Lin | Chai, Lay Ching
The deltaic estuarine system of the Matang Mangrove Forest Reserve of Malaysia is a site where several human settlements and brackish water aquaculture have been established. Here, we evaluated the level of fecal indicator bacteria (FIB) and the presence of potentially pathogenic bacteria in the surface water and sediments. Higher levels of FIB were detected at downstream sampling sites from the fishing village, indicating it as a possible source of anthropogenic pollution to the estuary. Enterococci levels in the estuarine sediments were higher than in the surface water, while total coliforms and E. coli in the estuarine sediments were not detected in all samples. Also, various types of potentially pathogenic bacteria, including Klebsiella pneumoniae, Serratia marcescens and Enterobacter cloacae were isolated. The results indicate that the Matang estuarine system is contaminated with various types of potential human bacterial pathogens which might pose a health risk to the public.
Показать больше [+] Меньше [-]Elemental composition, distribution and control of biogenic silica in the anthropogenically disturbed and pristine zone inter-tidal sediments of Indian Sundarbans mangrove-estuarine complex
2016
Dhame, Shreya | Kumar, Alok | Ramanathan, AL. | Chaudhari, Punarbasu
Spatial distribution and interrelationship among organic nutrients – silica and carbon – and various lithogenic elements were investigated in the surficial sediments of Matla estuary and Core Zone of Indian Sundarbans Reserve Forest using spatial analysis and multivariate statistics. Biogenic silica (BSi), an important parameter for coastal biogeochemisry, was measured using Si-time alkaline leaching method. BSi concentration ranged from 0.01% to 0.85% with higher concentrations in upstream region of Matla estuary and attenuated values towards the bay, seemingly due to changes in hydrodynamics and land use conditions. Spatial distribution of BSi did not exhibit significant correlation with sediment parameters of organic carbon (OC), elemental composition and clay content. However, it showed significant contrasting trends with total phosphorus (TP) and total silica of human influenced Matla estuary sediments as well as the dissolved silica (DSi) of its surface waters. Anthropogenic influence on sediment geochemistry is discernable with the presence of higher concentrations of organic and inorganic elements in Matla estuary than in Core Zone sediments. Spatial variation trends are often challenging to interpret due to multiple sources of input, varying energy and salinity conditions and constant physical, chemical and biological alterations occurring in the environment. Nonetheless, it is certain that anthropogenic activities have a substantial influence on biogeochemical processes of Sundarbans mangrove-estuarine complex and potentially the coastal ocean.
Показать больше [+] Меньше [-]Soil Acidification and Decline of Trees in Forests Within the Precincts of Shrines in Kyoto (Japan)
2011
Itō, Kazuo | Uchiyama, Yusuke | Kurokami, Noyuri | Sugano, Kazuki | Nakanishi, Yusuke
The historical Japanese city of Kyoto boasts a great many old Buddhist temples and Shinto shrines, many of which are surrounded by sizable forests that have long been preserved as sacred forests. However, acidic deposition has been fallen on the forests in Kyoto for many years. For this study, we conducted soil surveys and investigated the extent of decline of the trees in two Shinto shrines as historic monuments of ancient Kyoto. Our study revealed clear decline in two key tree species (Cryptomeria japonica (Japanese cedar) and Chamaecyparis obtusa (Japanese cypress)) in both shrines, with some trees showing signs of mortality. The soil was acidic, with an average pH of 4.35. Nutrient salt content too was only about one tenth the national average, with exchangeable Ca (0.52 cequiv./kg) and Mg (0.23 cequiv./kg) for 0-20 cm surface soil. The (Ca+Mg+K)/Al molar ratios were also very low, with 80% of all soil samples having a ratio of 10 or below. Such soil conditions are thought to hamper the sound growth of both Japanese cedar and Japanese cypress, and soil acidification is one of the most likely causes of the decline of temple and shrine forests in Kyoto.
Показать больше [+] Меньше [-]Comparison of microhabitats and foraging strategies between the captive-born Zhangxiang and wild giant pandas: implications for future reintroduction
2015
Lei, Miaowen | Yuan, Shibin | Yang, Zisong | Hong, Mingsheng | Yang, Xuyu | Gu, Xiaodong | Huang, Feng | Zhang, Zejun
The female giant panda Zhangxiang (pedigree number 826) was born on August 20, 2011 in Wolong Nature Reserve, China. On November 6, 2013, Zhangxiang was transported into the acclimatization enclosure in the Liziping Nature Reserve. Before Zhangxiang left the enclosure into the wild, we conducted the first study to compare microhabitats and foraging strategies between Zhangxiang in the enclosure and giant pandas in the wild. Compared with the latter, microhabitats of Zhangxiang in the enclosure are characteristic of gentler slope, more trees, higher canopy, smaller tree DBH, and lower density of living bamboos. Diet composition and foraging behaviors significantly differed between Zhangxiang and wild giant pandas, perhaps reflecting the combined consequence of environmental conditions (e.g., bamboo species) and individual status (e.g., age, mastication ability, etc.). The difference in microhabitats and foraging strategies between Zhangxiang and wild giant pandas implied that after being released into the natural habitat in the reserve, Zhangxiang will have to adapt to the environmental conditions once again. For future reintroduction, the enclosure can be extended to the Bashania spanostachya forest in the reserve, and captive giant pandas for release can thus normally transit into the wild without human intervention during acclimatization period. For other acclimatization enclosures to be constructed in the future, ecological environment inside, including topography, forests, and bamboos as well, should as possible as can match the habitat that the giant panda to-be-reinforced populations inhabit.
Показать больше [+] Меньше [-]