Conclusions on the role of salt-affected soils in primary succession on the Tanana River floodplain, interior Alaska

1993 ◽  
Vol 23 (5) ◽  
pp. 1015-1018 ◽  
Author(s):  
K. Van Cleve ◽  
J. Yarie ◽  
L.A. Viereck ◽  
C.T. Dyrness
Keyword(s):  
Organic Matter ◽  
Plant Community ◽  
Ecosystem Processes ◽  
Future Research ◽  
Ecosystem Structure ◽  
River Floodplain ◽  
Interior Alaska ◽  
Floodplain Ecosystems ◽  
Salt Affected Soils

Results of the study of salt-affected soils on the Tanana River floodplain in interior Alaska raised a number of key issues that are important to resolve with future research in this fluvial environment. The results emphasized the prominent role of plant succession in ecosystem structure and function in northern boreal forests. For example, alder plays a crucial role in organic matter and nitrogen dynamics in floodplain ecosystems. This plant species has an impact on ecosystem processes in successional stages beyond its period of dominance on the floodplain. The potential facilitative nature of nitrogen accumulation, mediated by alder, to plant community development during and subsequent to the alder phase of succession should be examined in future studies. Organic matter chemistry and soil temperature appeared to be more important controls of soil processes than high soil salt content. Moreover, secondary plant chemicals may play a role in determining rates of soil nitrification in these floodplain ecosystems. The importance of ion balance to plant nutrition and primary production in salt-affected soils is an important topic for future research. Groundwater may be a unique source of water and nutrients to floodplain plant communities. The magnitude of water flux to the rooting zone in relation to terrace elevation and river level and its importance to plant growth is a significant consideration in the semiarid environment of interior Alaska. The established plant community indicates which species are successful in this environment. Optimum species-terrace combinations may exist that maximize productivity through use of unique moisture and nutrient supplies associated with a shallow water table. Results of this work suggested that new research initiatives are crucial to advance the fundamental understanding of controls of ecosystem processes and as a base of information to support forest resource management.

Introduction and overview of a study dealing with the role of salt-affected soils in primary succession on the Tanana River floodplain, interior Alaska

1993 ◽  
Vol 23 (5) ◽  
pp. 879-888 ◽  
Author(s):  
K. Van Cleve ◽  
L.A. Viereck ◽  
G.M. Marion
Keyword(s):  
Primary Succession ◽  
Forest Type ◽  
Potential Evapotranspiration ◽  
Soil Formation ◽  
Substantial Contribution ◽  
Vegetation Development ◽  
River Floodplain ◽  
Interior Alaska ◽  
Salt Affected Soils

This paper provides an overview of the environmental setting, rationale, and organization of a multidisciplinary research program designed to examine the role of salt-affected soils in primary succession on the Tanana River floodplain of interior Alaska. The papers included in this series report results of studies designed to examine the controls of salt-affected soil formation and vegetation development and their interaction in this fluvial environment. The association of pedogenic salts and forests is largely restricted to northern latitudes where both low precipitation and moderate potential evapotranspiration occur simultaneously. In contrast with upland secondary-successional sites, where fire is the principal determinant of forest type distribution and successional change, ecosystem processes on the floodplain are determined by the fluvial nature of the environment. Consequently, the research presented an opportunity to evaluate some of the markedly contrasting controls of development that exist between forests in the two topographic locations. This study makes a substantial contribution to our understanding of how soil and vegetation interact on interior Alaskan floodplains to give rise to productive, commercially valuable forests.

scholarly journals Housekeeping in the Hydrosphere: Microbial Cooking, Cleaning, and Control under Stress

Life ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 152
Author(s):  
Bopaiah Biddanda ◽  
Deborah Dila ◽  
Anthony Weinke ◽  
Jasmine Mancuso ◽  
Manuel Villar-Argaiz ◽  
...  
Keyword(s):  
Organic Matter ◽  
Remote Control ◽  
Bacterial Biomass ◽  
Vital Role ◽  
Ecosystem Structure ◽  
Heterotrophic Microbes ◽  
And Function ◽  
And Control ◽  
Ecosystem Structure And Function

Who’s cooking, who’s cleaning, and who’s got the remote control within the waters blanketing Earth? Anatomically tiny, numerically dominant microbes are the crucial “homemakers” of the watery household. Phytoplankton’s culinary abilities enable them to create food by absorbing sunlight to fix carbon and release oxygen, making microbial autotrophs top-chefs in the aquatic kitchen. However, they are not the only bioengineers that balance this complex household. Ubiquitous heterotrophic microbes including prokaryotic bacteria and archaea (both “bacteria” henceforth), eukaryotic protists, and viruses, recycle organic matter and make inorganic nutrients available to primary producers. Grazing protists compete with viruses for bacterial biomass, whereas mixotrophic protists produce new organic matter as well as consume microbial biomass. When viruses press remote-control buttons, by modifying host genomes or lysing them, the outcome can reverberate throughout the microbial community and beyond. Despite recognition of the vital role of microbes in biosphere housekeeping, impacts of anthropogenic stressors and climate change on their biodiversity, evolution, and ecological function remain poorly understood. How trillions of the smallest organisms in Earth’s largest ecosystem respond will be hugely consequential. By making the study of ecology personal, the “housekeeping” perspective can provide better insights into changing ecosystem structure and function at all scales.

Ecosystem functions and the work of soft sediments

2021 ◽  
pp. 121-136
Author(s):  
Simon F. Thrush ◽  
Judi E. Hewitt ◽  
Conrad A. Pilditch ◽  
Alf Norkko
Keyword(s):  
Organic Matter ◽  
Ecosystem Services ◽  
Ecosystem Function ◽  
Ecosystem Processes ◽  
Ecosystem Dynamics ◽  
Ecosystem Metabolism ◽  
Ecosystem Functions ◽  
Habitat Creation ◽  
New Methods

This chapter describes various aspects of how we can define ecosystem function and situations ecosystem function in a continuum from ecosystem processes to services. Illustrating that functions are about connections, the chapter uses examples of productivity, organic matter decomposition, ecosystem metabolism, habitat creation and foodwebs. Changes in the contributions of function to ecosystem dynamics are considered. Sedimentary ecosystems are multifunctional, requiring the development of new methods to assess this aspect of sediments and trait-based approaches are discussed. The role of ecosystem functions in underpinning ecosystem services is described to ensure that valuation and mapping exercises do not lose sight of the foundational role of ecosystem functions.

Community Ecology of Stream Fishes: Concepts, Approaches, and Techniques

2010 ◽  
Keyword(s):  
Organic Matter ◽  
Water Column ◽  
Primary Productivity ◽  
Ecosystem Processes ◽  
Context Dependency ◽  
Stream Fishes ◽  
Invertebrate Communities ◽  
Disturbance Regimes ◽  
Mesocosm Experiments

<em>Abstract</em>.—Stream fishes can have strong top-down and bottom-up effects on ecosystem processes. However, the dynamic nature of streams constrains our ability to generalize these effects across systems with different disturbance regimes and species composition. To evaluate the role of fishes following disturbance, we used a series of field and mesocosm experiments that quantified the influence of grazers and water column minnows on primary productivity, periphyton structure, organic matter pools, and invertebrate communities following either scouring floods or drying of prairie streams. Results from individual experiments revealed highly significant effects of fishes, but the direction or magnitude of effects varied among experiments. Meta-analyses across experiments indicated that grazers consistently reduced the relative amount of fine benthic organic matter (FBOM) and chironomid abundance within 2 weeks after disturbances. However, effect sizes (log response ratios) were heterogeneous across experiments for algal biomass and algal filament lengths measured more than 4 weeks after a disturbance and potentially associated with system productivity and grazer densities. A similar analysis of 3–4 experiments using water column minnows only found a consistent trend of decreasing FBOM in fish treatments relative to controls when measured less than 2 weeks after disturbances and increase in gross primary productivity measured more than 4 weeks after disturbance. These results, along with those of others, were used to develop a conceptual framework for predicting the potential role of fishes in streams following disturbances (flood and drying). Both theoretical and empirical research shows that recovery of stream ecosystem processes will depend on the resilience of autotrophic and heterotrophic communities following disturbance. Fish effects may vary among functional groups but are generally predicted to be greatest during early stages of succession when algal and invertebrate communities are less complex and their biomass is low relative to fish biomass. Our analysis underscores the context dependency of consumer effects on ecosystem structure and function in nonequilibrium conditions and suggests that factors regulating fish densities and colonization of algal and invertebrate taxa need to be evaluated to predict the consequences of biodiversity loss in streams with variable or human-modified disturbance regimes.

Plant community responses to wildfire may be contingent upon historical disturbance regimes

2019 ◽  
Author(s):  
Jesse Miller ◽  
Hugh Safford
Keyword(s):  
Plant Community ◽  
Multiple Scales ◽  
Spatial Scales ◽  
Fire Regimes ◽  
Plant Species Richness ◽  
Future Research ◽  
Ecosystem Structure ◽  
Community Responses ◽  
Ecological Disturbance ◽  
Disturbance Regimes

Ecological disturbance is a major driver of ecosystem structure and evolutionary selection, and theory predicts that disturbance frequency and / or intensity should determine its effects on communities. However, adaptations of species pools to different historical disturbance regimes are rarely considered in the search for generalizable community responses to disturbance. To explore how disturbance severity affects plant diversity patterns, we review studies of understory plant community responses to wildfire in conifer forests of western North America across a gradient of departure from historical fire regimes. We find that post-fire plant species richness may generally be maximized at disturbance severities that match the predominant historical disturbance regime in a given ecosystem. Studies that examined multiple spatial scales indicate that plant community responses to fire are likely to be scale-dependent, suggesting that post-disturbance monitoring should consider community responses at multiple scales. Our review highlights that considering adaptations to historical disturbance regimes may improve the ability to predict disturbance effects on communities. We discuss future research needs; quantitative studies that compare community responses to fire at multiple scales across different historical fire regimes would be particularly useful. Ultimately, considering disturbance as a multivariate problem is likely to lead to greater inference than traditional bivariate approaches.

Coping Humor as a Mediator Between Emotional Intelligence and Job Satisfaction

2017 ◽  
Vol 16 (3) ◽  
pp. 155-159 ◽  
Author(s):  
Peizhen Sun ◽  
Jennifer J. Chen ◽  
Hongyan Jiang
Keyword(s):  
Job Satisfaction ◽  
Emotional Intelligence ◽  
Future Research ◽  
Satisfaction Scale ◽  
Primary School Teachers ◽  
Mediating Role ◽  
Regulation Of Emotion ◽  
The Relationship ◽  
Overall Job Satisfaction

Abstract. This study investigated the mediating role of coping humor in the relationship between emotional intelligence (EI) and job satisfaction. Participants were 398 primary school teachers in China, who completed the Wong Law Emotional Intelligence Scale, Coping Humor Scale, and Overall Job Satisfaction Scale. Results showed that coping humor was a significant mediator between EI and job satisfaction. A further examination revealed, however, that coping humor only mediated two sub-dimensions of EI (use of emotion and regulation of emotion) and job satisfaction. Implications for future research and limitations of the study are discussed.

Public Administration in the Islamic World: Considering the Importance of Religion, its Values and Culture

2019 ◽  
Vol 19 (2) ◽  
pp. 23-38
Author(s):  
Daniel Hummel
Keyword(s):  
Public Administration ◽  
Core Values ◽  
Comparative Perspective ◽  
Religious Values ◽  
Future Research ◽  
Islamic World ◽  
Salient Region ◽  
The People ◽  
Comparative Public Administration

A small but growing area of public administration scholarship appreciates the influence of religious values on various aspects of government. This appreciation parallels a growing interest in comparative public administration and indigenized forms of government which recognizes the role of culture in different approaches to government. This article is at the crossroads of these two trends while also considering a very salient region, the Islamic world. The Islamic world is uniquely religious, which makes this discussion even more relevant, as the nations that represent them strive towards legitimacy and stability. The history and core values of Islam need to be considered as they pertain to systems of government that are widely accepted by the people. In essence, this is being done in many countries across the Islamic world, providing fertile grounds for public administration research from a comparative perspective. This paper explores these possibilities for future research on this topic.

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