scholarly journals Spatiotemporal evolution and assembly processes of ammonia-oxidising prokaryotic communities in 1000 years coastal reclaimed soils

2021 ◽  
Author(s):  
Sarfraz Hussain ◽  
Yifan Yin ◽  
Senlin Liu ◽  
Shanshan Yan ◽  
Dongjie Chen ◽  
...  
Keyword(s):  
Anthropogenic Activities ◽  
Microbial Community Composition ◽  
Amoa Gene ◽  
Nitrification Rate ◽  
Coastal Marshes ◽  
Deterministic Process ◽  
Sequencing Platform ◽  
Nitrification Activity ◽  
Reclaimed Soils

Coastal marshes are transitional areas between terrestrial and aquatic ecosystems and vulnerable to climate change and anthropogenic activities. In recent decades the reclamation of coastal marshes remarkably increased and their effects on microbial communities present in coastal marshes have been studied with great interest. However, most of these studies focused on microbial community composition and diversity. The processes underlying functional community assembly and spatiotemporal effect often ignored. Therefore, community structure and assembly mechanisms of ammonia-oxidising prokaryotes in long-term reclaimed coastal marshes have not been studied. Here using qPCR and IonS5TMXL sequencing platform, we investigated spatiotemporal dynamics, assembly processes and diversity patterns in ammonia-oxidising prokaryotes in over 1000 years reclaimed coastal salt marsh soils. The taxonomic & phylogenetic diversity and composition of the ammonia-oxidizers showed apparent spatiotemporal variations along reclamation of soil. The phylogenetic null modelling-based analysis showed across all sites, the archaeal ammonia-oxidising community assembled by deterministic process (84.71%). The ammonia-oxidising bacterial community was formed more by a stochastic process in coastal marshes and at stage 60 years (|βNTI|<2), despite its relatively dominant deterministic process (55.2%). The deterministic assembly process and nitrification activity in reclaimed soils was positively correlated. Archaeal amoA gene abundance were also positively correlated with the nitrification rate. Our study revealed that during the 1000 years of reclamation coastal marshes both ammonia-oxidising communities responded differently to diversity change and assembly processes and nitrification activity. These findings provide a better understanding of how long-term reclamation affect soil N cycling and assembly dynamics of ammonia-oxidising communities.

Tertiary nitrification in pilot-plant plug-flow fixed-film reactors with long-term ammonium deficiency

1994 ◽  
Vol 29 (10-11) ◽  
pp. 61-67 ◽  
Author(s):  
M. Fruhen ◽  
K. Böcker ◽  
S. Eidens ◽  
D. Haaf ◽  
M. Liebeskind ◽  
...  
Keyword(s):  
Pilot Plant ◽  
Effective Means ◽  
Plug Flow ◽  
Nitrification Rate ◽  
Industrial Project ◽  
Transfer Processes ◽  
Fixed Film ◽  
Film Reactor ◽  
Observation Period

The objective of this study is to investigate to what extent the nitrification capacity of a pilot-plant fixed-film reactor changes during extensive periods of nutrient supply deficiency. The examined pilot-plant was an upflow reactor filled with swelling clay of medium grain size (6 to 8 mm). The experiments revealed that the maximum nitrification rate remained practically constant during the first weeks after the onset of unregulated ammonium supply. The capacity declined slowly, dropping to approximately 66% of the initial capacity after about ten weeks. Still ammonium peaks of up to 8 mg/l were readily nitrified throughout the entire period of the experiment. The reduction in nitrification capacity during the observation period did not result from decay processes of biomass but from the reactor becoming blocked and thus hampering transfer processes. It could be observed that the detached organisms attached again further up. This semi-industrial project demonstrated that a plug-flow fixed-film reactor can be used as effective means of tertiary nitrification.

scholarly journals Responses of Vertebrate Wildlife to Oil and Natural Gas Development: Patterns and Frontiers

2021 ◽  
Author(s):  
A. D. Chalfoun
Keyword(s):  
Natural Gas ◽  
Anthropogenic Activities ◽  
Spatial Scales ◽  
Habitat Type ◽  
Population Level ◽  
Low Frequencies ◽  
Natural Gas Development ◽  
The Usa ◽  
Oil And Natural Gas

Abstract Purpose of Review Anthropogenic activities can lead to the loss, fragmentation, and alteration of wildlife habitats. I reviewed the recent literature (2014–2019) focused on the responses of avian, mammalian, and herpetofaunal species to oil and natural gas development, a widespread and still-expanding land use worldwide. My primary goals were to identify any generalities in species’ responses to development and summarize remaining gaps in knowledge. To do so, I evaluated the directionality of a wide variety of responses in relation to taxon, location, development type, development metric, habitat type, and spatiotemporal aspects. Recent Findings Studies (n = 70) were restricted to the USA and Canada, and taxonomically biased towards birds and mammals. Longer studies, but not those incorporating multiple spatial scales, were more likely to detect significant responses. Negative responses of all types were present in relatively low frequencies across all taxa, locations, development types, and development metrics but were context-dependent. The directionality of responses by the same species often varied across studies or development metrics. Summary The state of knowledge about wildlife responses to oil and natural gas development has developed considerably, though many biases and gaps remain. Studies outside of North America and that focus on herpetofauna are lacking. Tests of mechanistic hypotheses for effects, long-term studies, assessment of response thresholds, and experimental designs that isolate the effects of different stimuli associated with development, remain critical. Moreover, tests of the efficacy of habitat mitigation efforts have been rare. Finally, investigations of the demographic effects of development across the full annual cycle were absent for non-game species and are critical for the estimation of population-level effects.

scholarly journals Unmapped exome reads implicate a role for Anelloviridae in childhood HIV-1 long-term non-progression

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Savannah Mwesigwa ◽  
◽  
Lesedi Williams ◽  
Gaone Retshabile ◽  
Eric Katagirya ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Diversity Index ◽  
Strong Association ◽  
Community Diversity ◽  
Added Value ◽  
Sequencing Platform ◽  
Public Health Burden ◽  
Survival Status ◽  
Significant Public Health

AbstractHuman immunodeficiency virus (HIV) infection remains a significant public health burden globally. The role of viral co-infection in the rate of progression of HIV infection has been suggested but not empirically tested, particularly among children. We extracted and classified 42 viral species from whole-exome sequencing (WES) data of 813 HIV-infected children in Botswana and Uganda categorised as either long-term non-progressors (LTNPs) or rapid progressors (RPs). The Ugandan participants had a higher viral community diversity index compared to Batswana (p = 4.6 × 10−13), and viral sequences were more frequently detected among LTNPs than RPs (24% vs 16%; p = 0.008; OR, 1.9; 95% CI, 1.6–2.3), with Anelloviridae showing strong association with LTNP status (p = 3 × 10−4; q = 0.004, OR, 3.99; 95% CI, 1.74–10.25). This trend was still evident when stratified by country, sex, and sequencing platform, and after a logistic regression analysis adjusting for age, sex, country, and the sequencing platform (p = 0.02; q = 0.03; OR, 7.3; 95% CI, 1.6–40.5). Torque teno virus (TTV), which made up 95% of the Anelloviridae reads, has been associated with reduced immune activation. We identify an association between viral co-infection and prolonged AIDs-free survival status that may have utility as a biomarker of LTNP and could provide mechanistic insights to HIV progression in children, demonstrating the added value of interrogating off-target WES reads in cohort studies.

scholarly journals Biogeochemical Controls on the Potential for Long-Term Contaminant Leaching from Soils Developing on Historic Coal Mine Spoil

Soil Systems ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 3
Author(s):  
David Singer ◽  
Elizabeth Herndon ◽  
Laura Zemanek ◽  
Kortney Cole ◽  
Tyler Sanda ◽  
...  
Keyword(s):  
Coal Mine ◽  
Solid Phase ◽  
Microbial Community Composition ◽  
Toxic Metal ◽  
Soil Formation ◽  
Mineral Weathering ◽  
Mine Spoil ◽  
Secondary Phases ◽  
Undisturbed Soil

Coal mine spoil is widespread in US coal mining regions, and the potential long-term leaching of toxic metal(loid)s is a significant and underappreciated issue. This study aimed to determine the flux of contaminants from historic mine coal spoil at a field site located in Appalachian Ohio (USA) and link pore water composition and solid-phase composition to the weathering reaction stages within the soils. The overall mineralogical and microbial community composition indicates that despite very different soil formation pathways, soils developing on historic coal mine spoil and an undisturbed soil are currently dominated by similar mineral weathering reactions. Both soils contained pyrite coated with clays and secondary oxide minerals. However, mine spoil soil contained abundant residual coal, with abundant Fe- and Mn- (oxy)hydroxides. These secondary phases likely control and mitigate trace metal (Cu, Ni, and Zn) transport from the soils. While Mn was highly mobile in Mn-enriched soils, Fe and Al mobility may be more controlled by dissolved organic carbon dynamics than mineral abundance. There is also likely an underappreciated risk of Mn transport from coal mine spoil, and that mine spoil soils could become a major source of metals if local biogeochemical conditions change.

Late Quaternary vegetation dynamics in a biodiversity hotspot, the Uluguru Mountains of Tanzania

2009 ◽  
Vol 72 (1) ◽  
pp. 111-122 ◽  
Author(s):  
Jemma Finch ◽  
Melanie J. Leng ◽  
Rob Marchant
Keyword(s):  
Environmental Changes ◽  
Vegetation History ◽  
Late Quaternary ◽  
Anthropogenic Activities ◽  
Significant Loss ◽  
Environmental Stability ◽  
Forest Composition ◽  
Eastern Arc ◽  
Uluguru Mountains

AbstractLate Quaternary vegetation history and environmental changes in a biodiverse tropical ecosystem are inferred from pollen, charcoal and carbon isotope evidence derived from a ∼ 48,000-yr sedimentary record from the Uluguru Mountains, a component of the Eastern Arc Mountains of Kenya and Tanzania. Results indicate that Eastern Arc forest composition has remained relatively stable during the past ∼ 48,000 yr. Long-term environmental stability of the Eastern Arc forests has been proposed as a mechanism for the accumulation and persistence of species during glacial periods, thus resulting in the diverse forests observed today. The pollen and isotope data presented here indicate some marked changes in abundance but no significant loss in moist forest taxa through the last glacial maximum, thereby providing support for the long-term environmental stability of the Eastern Arc. Anthropogenic activities, including burning and forest clearance, were found to play a moderate role in shaping the mosaic of forest patches and high-altitude grasslands that characterise the site today; however, this influence was tempered by the inaccessibility of the mountain.

scholarly journals Pikas and People: Human-Pika (Ochotona) interaction in the Himalaya of Nepal

2021 ◽  
Vol 22 (11) ◽  
Author(s):  
Narayan Koju ◽  
Mukesh Kumar Chalise ◽  
Randall C Kyes
Keyword(s):  
Traditional Medicine ◽  
Anthropogenic Activities ◽  
Anthropogenic Pollution ◽  
Group Discussions ◽  
Conservation Area ◽  
Collective Data ◽  
Local Residents ◽  
Folk Stories ◽  
The Himalaya

Abstract. Koju NP, Chalise MK, Kyes RC. 2021. Pikas and People: Human-Pika (Ochotona) interaction in the Himalaya of Nepal. Biodiversitas 22: 5085-5091. This study examined human-pika (Ochotona) interaction in two protected areas of Nepal: Lamtang National Park (LNP) and Api Nampa Conservation Area (ACNA). We conducted the study between 2012 and 2017 and employed a combination of three qualitative sampling methods: observation of behavior (both humans and pikas), practices, and rituals of the local residents, pilgrims, tourists, and Yarsagumba (Ophiocordyceps sinesis) collectors; collection of folk stories; and focus group discussions with local residents to investigate the nature of human-pika interaction. Based on the collective data, three general themes relating to human-pika interaction emerged: 1) the perception of pikas as a respected entity; 2) effects of anthropogenic pollution on pikas, and 3) pikas as a traditional medicine. In LNP, the pika was respected as symbol of the Buddhist monk ‘Lama’. In contrast, at ANCA, the dried meat of pika was used by local people for traditional medicine. At both locations, there is an increasing human presence resulting in increased anthropogenic pollution. This, in turn, may present a potential risk to the pikas over the long term. Further investigation is needed to address the effects of anthropogenic activities on the pika and to ensure the health and viability of the pika population.

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