scholarly journals TEM as an Important Tool to Study Aquatic Microorganisms and their Relationships with Ecological Processes

10.5772/61804 ◽  
2016 ◽  
Author(s):  
Thiago P. Silva ◽  
Juliana P. Gamalier ◽  
Rossana C.N. Melo
Keyword(s):  
Ecological Processes ◽  
Aquatic Microorganisms

scholarly journals Agricultural pressures impair trophic link between aquatic microorganisms and invertebrates

2021 ◽  
Author(s):  
Rody Blom ◽  
Henrik Barmentlo ◽  
Maarten Schrama ◽  
Ellard Hunting
Keyword(s):  
Organic Matter ◽  
Ecosystem Health ◽  
Agricultural Practices ◽  
Ecological Processes ◽  
Aquatic Biodiversity ◽  
Microbial Decomposition ◽  
Aquatic Microorganisms ◽  
Human Practices ◽  
Aquatic Food ◽  
Trophic Linkages

Decadal declines in aquatic ecosystem health prompted monitoring efforts and studies on effects of human practices on aquatic biodiversity, yet a consideration of ecological processes and trophic linkages is increasingly required to develop an in-depth understanding of aquatic food webs and its vulnerability to human activities. Here, we test in laboratory incubations using natural organic matter whether agricultural practices have an effect on two interacting ecological processes (i.e., decomposition and invertebrate growth) as the relevant temporal components of the trophic linkage between aquatic microbial communities and aquatic invertebrates. We further assess whether these altered trophic interactions are visible on ecologically relevant scales. We observed clear patterns in agricultural constraints on microbial decomposition, which coincided with reduced invertebrate growth and an unexpected increase in invertebrate consumption of organic matter. Similar differences in invertebrate length depending on land use were observed in our field survey, thereby providing important clues on the relevance and vulnerability of interdependent processes that can serve to improve future forays in monitoring ecosystem health.

Adoption Decision and Sustainable Utilization of Soil Conservation Technologies: Empirical Evidence from North West Ethiopia

2019 ◽  
Vol 10 ◽  
pp. 1853-1863
Author(s):  
Kassaye Gurebiyaw Legese ◽  
Taye Melese ◽  
Tadie Mire ◽  
Abebe Birara ◽  
Kefale Eniyew
Keyword(s):  
Water Conservation ◽  
Soil Conservation ◽  
Sampling Technique ◽  
Household Survey ◽  
Ecological Processes ◽  
Related Factors ◽  
Severe Problem ◽  
North West ◽  
Household Heads ◽  
North Gondar Zone

Soil is a crucial and precious natural resource that govern numerous ecological processes. However, in Ethiopia particularly in north Gondar zone, soil erosion is a severe problem and a major cause of the decline of agricultural productivity. The adoption and diffusion of soil and water conservation practices (SWC), as a way to tackle this challenge, has become an important issue in the development policy agenda in the zone. Therefore, this study was to identify factors affecting Soil conservation investments in the North Gondar zone. Data was collected through interviewed schedule, filed observation and focus group discussion. The multistage sampling technique was employed to select 206 sample households.  Both descriptive and econometrics model was used to analyze the collected data. A multivariate profit (MPV) model was used to analyze the effect of demographic, socioeconomic, market, institutional and biophysical related factors on the interdependent investment decisions of SWC practices using household survey. The MPV model analysis indicates that farmers invest a combination of practices at parcel level by considering substitution and complementarity effects of the practices. The results also revealed that age of household heads, literacy status of household heads, off-farm activity, distance of farmlands from homesteads, tropical livestock unit, and access to training were influence farmers’ investments in SWC practices. The overall results indicate that the identified physical, socioeconomic, and institutional factors influence promote or hinder investments in SWC practice so, policymakers should take into consideration these various factors in designing and implementing SWC policies and Programmers.

Prominence of environmental and anthropogenic agents on the occurrence of coral reef bleaching syndrome and coral diseases

2024 ◽  
Vol 74 (10) ◽  
pp. 6139-2024
Author(s):  
MICHAŁ SCHULZ ◽  
ALEKSANDRA ŁOŚ ◽  
PATRYCJA SKOWRONEK ◽  
ANETA STRACHECKA
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Oil Spills ◽  
Global Scale ◽  
Ecological Processes ◽  
Coral Diseases ◽  
Rapid Changes ◽  
Anthropogenic Threats ◽  
Negative Factors ◽  
Main Relationship

Coral reefs are the most productive ecosystems on Earth. They ensure the conservation of biodiversity and are a live habitat for 25% of all marine organisms. The main relationship on the coral reef is the symbiosis between corals and algae from the genus Symbiodinium (commonly called zooxanthellae). The authors of this publication have characterized and described the factors limiting the occurrence of coral reefs, including: water temperature, salinity, access to sunlight, contamination, physicochemical and hydromechanical parameters of water. Moreover anthropogenic threats to coral reefs have been specified, including diving tourism, ecological disasters (e.g. oil spills) and the development of marine aquaristics. Rapid changes in the basic living conditions are dangerous for corals and their symbionts and may cause the unsuitability of the new environment resulting in diseases such as coral bleaching. Corals bleaching is a disease associated with the break of the coral and algae relationship which results in a coral reef death on a global scale. Awareness of these negative factors, often related to human activity, may allow us to better understand the ecological processes that are the basis of reef functioning and might enable us to prevent and oppose to the changes and ecological recessions of coral reefs.

The lake ecosystem simulation program

1995 ◽  
Vol 31 (8) ◽  
pp. 367-370
Author(s):  
J. Heringa ◽  
H. Hylkema ◽  
M. Kroes ◽  
E. Ludden ◽  
P. G. van Schaick Zillesen
Keyword(s):  
Mathematical Model ◽  
Water Resources ◽  
Computer Program ◽  
Water Resources Management ◽  
Lake Ecosystem ◽  
Original Research ◽  
Ecological Processes ◽  
Resources Management ◽  
Lake Ecology ◽  
Ecosystem Simulation

The computer program LAKE simulates a shallow lake ecosystem. The program is based on a mathematical model. In the model the most important aspects of several models for water resources management are integrated (Collins and Wlosinski, 1988; Jørgensen, 1976; Jørgensen et al., 1978; Scheffer, 1988). Furthermore, the model describes several ecological processes that have not yet been described by lake-ecosystem models so far. In the computer program, the mathematical model and an advanced, object oriented, user interface are combined. Following this approach the use of the original research models was extended to a use for the purpose of teaching lake ecology. We suggest that the same approach may be followed to open research models to other groups concerned with water resources management, such as management authorities, industry, agricultural extension, nature conservation and recreation.

Towards evolutionary agroecology

2018 ◽  
Vol 6 (14) ◽  
pp. 51 ◽  
Author(s):  
Kristin L. Mercer
Keyword(s):  
Social Dynamics ◽  
Agricultural Systems ◽  
Short Term ◽  
Ecological Processes ◽  
Genetic Analyses ◽  
Holistic Perspective ◽  
Evolutionary Study ◽  
Quantitative Genetic ◽  
Field Evolution

Agroecology derives much of its strength from interactions between disciplines that produce a holistic perspective on agricultural systems and issues.  Although ongoing integration of social dynamics into agroecology has strengthened the field, evolution and genetics have not been embraced to the same degree, despite the fact that they have been are discussed in some common agroecology texts.  I argue that the field of agroecology could extend its reach and depth by embracing the evolutionary study of agroecosystems.  Areas of evolutionary inquiry with relevance to agriculture focus on long or short term processes, encompass a range of scales, incorporate molecular or quantitative genetic analyses, and explore ecological processes to differing degrees.

Kalahari Cheetahs

2017 ◽  
Author(s):  
Gus Mills ◽  
Margaret Mills
Keyword(s):  
Reproductive Success ◽  
Spatial Ecology ◽  
Prey Selection ◽  
Arid Ecosystems ◽  
Foraging Success ◽  
Ecological Processes ◽  
Demographic Groups ◽  
Important Prey ◽  
Hunting Behaviour ◽  
The Impact

This book demonstrates how cheetahs are adapted to arid savannahs like the southern Kalahari, and makes comparisons with other areas, especially the Serengeti. Topics dealt with are: demography and genetic status; feeding ecology, i.e. methods used for studying diet, diets of different demographic groups, individual diet specializations of females, prey selection, the impact of cheetah predation on prey populations, activity regimes and distances travelled per day, hunting behaviour, foraging success and energetics; interspecific competition; spatial ecology; reproductive success and the mating system; and conservation. The major findings show that cheetahs are well adapted to arid ecosystems and are water independent. Cheetah density in the study area was stable at 0.7/100 km2 and the population was genetically diverse. Important prey were steenbok and springbok for females with cubs, gemsbok, and adult ostrich for coalition males, and steenbok, springhares, and hares for single animals. Cheetahs had a density-dependent regulatory effect on steenbok and springbok populations. Females with large cubs had the highest overall food intake. Cheetahs, especially males, were often active at night, and competition with other large carnivores, both by exploitation and interference, was slight. Although predation on small cubs was severe, cub survival to adolescence was six times higher than in the Serengeti. There was no difference in reproductive success between single and coalition males. The conservation priority for cheetahs should be to maintain protected areas over a spectrum of landscapes to allow ecological processes, of which the cheetah is an integral part, to proceed unhindered.

Environmental DNA

2018 ◽  
Author(s):  
Pierre Taberlet ◽  
Aurélie Bonin ◽  
Lucie Zinger ◽  
Eric Coissac
Keyword(s):  
Graduate Students ◽  
Feeding Habits ◽  
Environmental Dna ◽  
Research Field ◽  
Background Information ◽  
Ecological Processes ◽  
Biodiversity Research ◽  
Dna Metabarcoding ◽  
Standard Information

Environmental DNA (eDNA), i.e. DNA released in the environment by any living form, represents a formidable opportunity to gather high-throughput and standard information on the distribution or feeding habits of species. It has therefore great potential for applications in ecology and biodiversity management. However, this research field is fast-moving, involves different areas of expertise and currently lacks standard approaches, which calls for an up-to-date and comprehensive synthesis. Environmental DNA for biodiversity research and monitoring covers current methods based on eDNA, with a particular focus on “eDNA metabarcoding”. Intended for scientists and managers, it provides the background information to allow the design of sound experiments. It revisits all steps necessary to produce high-quality metabarcoding data such as sampling, metabarcode design, optimization of PCR and sequencing protocols, as well as analysis of large sequencing datasets. All these different steps are presented by discussing the potential and current challenges of eDNA-based approaches to infer parameters on biodiversity or ecological processes. The last chapters of this book review how DNA metabarcoding has been used so far to unravel novel patterns of diversity in space and time, to detect particular species, and to answer new ecological questions in various ecosystems and for various organisms. Environmental DNA for biodiversity research and monitoring constitutes an essential reading for all graduate students, researchers and practitioners who do not have a strong background in molecular genetics and who are willing to use eDNA approaches in ecology and biomonitoring.

Larval Transport in the Coastal Zone: Biological and Physical Processes

2018 ◽  
Keyword(s):  
Simulation Models ◽  
Population Connectivity ◽  
Larval Transport ◽  
Larval Abundance ◽  
Transport Mechanisms ◽  
Larval Behavior ◽  
Physical Processes ◽  
Ecological Processes ◽  
Emergent Technologies ◽  
Advection Diffusion

Larval transport is fundamental to several ecological processes, yet it remains unresolved for the majority of systems. We define larval transport, and describe its components, namely, larval behavior and the physical transport mechanisms accounting for advection, diffusion, and their variability. We then discuss other relevant processes in larval transport, including swimming proficiency, larval duration, accumulation in propagating features, episodic larval transport, and patchiness and spatial variability in larval abundance. We address challenges and recent approaches associated with understanding larval transport, including autonomous sampling, imaging, -omics, and the exponential growth in the use of poorly tested numerical simulation models to examine larval transport and population connectivity. Thus, we discuss the promises and pitfalls of numerical modeling, concluding with recommendations on moving forward, including a need for more process-oriented understanding of the mechanisms of larval transport and the use of emergent technologies.

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