|
Ecological Threshold
Ecological threshold is the point at which a relatively small change or disturbance in external conditions causes a rapid change in an ecosystem. When an ecological threshold has been passed, the ecosystem may no longer be able to return to its state by means of its inherent resilience . Crossing an ecological threshold often leads to rapid change of ecosystem health. Ecological threshold represent a non-linearity of the responses in ecological or biological systems to pressures caused by human activities or natural processes. Critical load, regime shift, critical transition and tipping point are examples of other closely related terms. Characteristics Thresholds can be characterized as points or as zones. Zone-type thresholds imply a gradual shift or transition from one state to another rather than an abrupt change at a specific point. Ecological thresholds have caught attention because many cases of catastrophic worsening of conditions have proved to be difficult or nearly im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disturbance (ecology)
In ecology, a disturbance is a temporary change in environmental conditions that causes a pronounced change in an ecosystem. Disturbances often act quickly and with great effect, to alter the physical structure or arrangement of biotic and abiotic elements. A disturbance can also occur over a long period of time and can impact the biodiversity within an ecosystem. Major ecological disturbances may include fires, flooding, storms, insect outbreaks and trampling. Earthquakes, various types of volcanic eruptions, tsunami, firestorms, impact events, climate change, and the devastating effects of human impact on the environment (anthropogenic disturbances) such as clearcutting, forest clearing and the introduction of invasive species can be considered major disturbances. Not only invasive species can have a profound effect on an ecosystem, but also naturally occurring species can cause disturbance by their behavior. Disturbance forces can have profound immediate effects on ecosystem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panarchy (ecology)
A social-ecological system consists of 'a bio-geo-physical' unit and its associated social actors and institutions. Social-ecological systems are complex and adaptive and delimited by spatial or functional boundaries surrounding particular ecosystems and their context problems.Glaser, M., Krause, G., Ratter, B., and Welp, M. (2008) Human-Nature-Interaction in the Anthropocene. Potential of Social-Ecological Systems Analysis. ebsite Available from: ssessed: 28 Feb 2020/ref> Definitions A social-ecological system can be defined as:Redman, C., Grove, M. J. and Kuby, L. (2004). Integrating Social Science into the Long Term Ecological Research (LTER) Network: Social Dimensions of Ecological Change and Ecological Dimensions of Social Change. Ecosystems Vol.7(2), pp. 161-171.(p. 163) # A coherent system of biophysical and social factors that regularly interact in a resilient, sustained manner; # A system that is defined at several spatial, temporal, and organisational scales, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gaia Hypothesis
The Gaia hypothesis (), also known as the Gaia theory, Gaia paradigm, or the Gaia principle, proposes that living organisms interact with their inorganic surroundings on Earth to form a synergistic and self-regulating, complex system that helps to maintain and perpetuate the conditions for life on the planet. The hypothesis was formulated by the chemist James Lovelock and co-developed by the microbiologist Lynn Margulis in the 1970s. Lovelock named the idea after Gaia, the primordial goddess who personified the Earth in Greek mythology. The suggestion that the theory should be called "the Gaia hypothesis" came from Lovelock's neighbour, William Golding. In 2006, the Geological Society of London awarded Lovelock the Wollaston Medal in part for his work on the Gaia hypothesis. Topics related to the hypothesis include how the biosphere and the evolution of organisms affect the stability of global temperature, salinity of seawater, atmospheric oxygen levels, the maintenance of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tipping Point (climatology)
In Climatology, climate science, a tipping point is a critical threshold that, when crossed, leads to large and often irreversible changes in the climate system. If tipping points are crossed, they are likely to have severe impacts on human society. Tipping behaviour is found across the climate system, in ecosystems, ice sheets, and the circulation of the ocean and atmosphere. Tipping points are often, but not necessarily, abrupt. For example, with average global warming somewhere between 0.8 and 3 °C, the Greenland ice sheet passes a tipping point and is doomed, but the melt would take place over millennia. Tipping points are possible at today's global warming of just over 1 °C above preindustrial times, and highly probable above 2 °C of global warming. The Geologic record, geological record shows many abrupt changes that suggest tipping points may have been crossed in ancient times. It is possible that some tipping points are close to being crossed or have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflection Point
In differential calculus and differential geometry, an inflection point, point of inflection, flex, or inflection (British English: inflexion) is a point on a smooth plane curve at which the curvature changes sign. In particular, in the case of the graph of a function, it is a point where the function changes from being concave (concave downward) to convex (concave upward), or vice versa. For the graph of a function of differentiability class (''f'', its first derivative ''f, and its second derivative ''f'''', exist and are continuous), the condition ''f'' = 0'' can also be used to find an inflection point since a point of ''f'' = 0'' must be passed to change ''f'''' from a positive value (concave upward) to a negative value (concave downward) or vice versa as ''f'''' is continuous; an inflection point of the curve is where ''f'' = 0'' and changes its sign at the point (from positive to negative or from negative to positive). A point where the second derivative vanishes but do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catastrophe Theory
In mathematics, catastrophe theory is a branch of bifurcation theory in the study of dynamical systems; it is also a particular special case of more general singularity theory in geometry. Bifurcation theory studies and classifies phenomena characterized by sudden shifts in behavior arising from small changes in circumstances, analysing how the qualitative nature of equation solutions depends on the parameters that appear in the equation. This may lead to sudden and dramatic changes, for example the unpredictable timing and magnitude of a landslide. Catastrophe theory originated with the work of the French mathematician René Thom in the 1960s, and became very popular due to the efforts of Christopher Zeeman in the 1970s. It considers the special case where the long-run stable equilibrium can be identified as the minimum of a smooth, well-defined potential function (Lyapunov function). In the late 1970s, applications of catastrophe theory to areas outside its scope began to b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carrying Capacity
The carrying capacity of an environment is the maximum population size of a biological species that can be sustained by that specific environment, given the food, habitat, water, and other resources available. The carrying capacity is defined as the environment's maximal load, which in population ecology corresponds to the population equilibrium, when the number of deaths in a population equals the number of births (as well as immigration and emigration). The effect of carrying capacity on population dynamics is modelled with a logistic function. Carrying capacity is applied to the maximum population an environment can support in ecology, agriculture and fisheries. The term carrying capacity has been applied to a few different processes in the past before finally being applied to population limits in the 1950s. The notion of carrying capacity for humans is covered by the notion of sustainable population. At the global scale, scientific data indicates that humans are living beyon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santa Fe Institute
The Santa Fe Institute (SFI) is an independent, nonprofit theoretical research institute located in Santa Fe, New Mexico, United States and dedicated to the multidisciplinary study of the fundamental principles of complex adaptive systems, including physical, computational, biological, and social systems. The institute is ranked 24th among the world's "Top Science and Technology Think Tanks" and 24th among the world's "Best Transdisciplinary Research Think Tanks" according to the 2020 edition of the ''Global Go To Think Tank Index Reports'', published annually by the University of Pennsylvania. The institute consists of a small number of resident faculty and postdoctoral researchers, a large group of external faculty whose primary appointments are at other institutions, and a number of visiting scholars. The institute is advised by a group of eminent scholars, including several Nobel Prize-winning scientists. Although theoretical scientific research is the institute's primary focu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resilience Alliance
The Resilience Alliance is an interdisciplinary network of scientists and practitioners that analyze the integrated dynamic of people and nature from a social-ecological system perspective. It was established in 1999 and is supported by an international network of member institutions that includes universities, government, and non-government agencies. The Resilience Alliance publishes the journal ''Ecology and Society ''Ecology and Society'' (formerly ''Conservation Ecology'') is a quarterly open access interdisciplinary academic journal published by the Resilience Alliance. It covers an array of disciplines from the natural sciences, social sciences, and the ...''. In 2007, the Resilience Alliance Young Scholars (RAYS) was established under Resilience Alliance. This network was established with a purpose of developing the next generation of resilience scientists from around the world. Cambridge University Press. Edited by Reinette Biggs, Maja Schlüter and Michael L. Schoon.Pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time Series
In mathematics, a time series is a series of data points indexed (or listed or graphed) in time order. Most commonly, a time series is a sequence taken at successive equally spaced points in time. Thus it is a sequence of discrete-time data. Examples of time series are heights of ocean tides, counts of sunspots, and the daily closing value of the Dow Jones Industrial Average. A time series is very frequently plotted via a run chart (which is a temporal line chart). Time series are used in statistics, signal processing, pattern recognition, econometrics, mathematical finance, weather forecasting, earthquake prediction, electroencephalography, control engineering, astronomy, communications engineering, and largely in any domain of applied science and engineering which involves temporal measurements. Time series ''analysis'' comprises methods for analyzing time series data in order to extract meaningful statistics and other characteristics of the data. Time series ''forecasting' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hysteresis
Hysteresis is the dependence of the state of a system on its history. For example, a magnet may have more than one possible magnetic moment in a given magnetic field, depending on how the field changed in the past. Plots of a single component of the moment often form a loop or hysteresis curve, where there are different values of one variable depending on the direction of change of another variable. This history dependence is the basis of memory in a hard disk drive and the remanence that retains a record of the Earth's magnetic field magnitude in the past. Hysteresis occurs in ferromagnetic and ferroelectric materials, as well as in the deformation of rubber bands and shape-memory alloys and many other natural phenomena. In natural systems it is often associated with irreversible thermodynamic change such as phase transitions and with internal friction; and dissipation is a common side effect. Hysteresis can be found in physics, chemistry, engineering, biology, and economics. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
