What is intermediate disturbance hypothesis

In rivers, lakes, wetlands and floodplains, thepredominant agent of disturbance is flooding.

Intermediate Disturbance Hypothesis - Complexity Labs

As theoretical ecologists have moved away from approaches that are preoccupied with equilibrium, the role of spatial heterogeneity in models of population dynamics has received greater attention (Nielson 2006; Sebens 1984). In these models, patches of primary substrata are treated as fundamental structural units; patterns of spatio-temporal heterogeneity emerge with increasing regional scale. Patches are taken to be a "holes" in an otherwise homogeneous reference background. Though bounded and discrete, they are not viewed as closed systems, but rather as individual components of a larger spatio-temporal mosaic. The random colonization and founder effects that follow natural succession regimes guarantee the ongoing integrity of this larger system. At least certain species in these communities depends upon certain levels of local disturbance (Levin and Paine 1974).

Wilkinson, D.M. (1999) The disturbing history of intermediate disturbance. Oikos, 84, 145-147.

Intermediate Disturbance Hypothesis - WikiVisually

Fourth, it is important to emphasize that a commitment to constitutionalism does not consist in trying to increase the power of that particular part of the government machine or that political party or movement, which for the time being is following policies of which one happens to approve. The switch of conservative support to a strong presidency during the Reagan era is an example of this kind of misjudgement, based on the assumption that the presidency would remain under Republican control indefinitely. Thatcherite governments in Britain pursued policies which cast off traditional attitudes towards those constitutional conventions intended to limit the power of government. Thus they saw Friedrich Hayek simply as an economic guru but did not share his respect for constitutional principles. Constitutionalism is not a matter of seizing a short-term advantage; it is a belief in the need to establish and support those values in the political system which provide for stability and to maintain the procedures which protect the liberty of the individual in a democratic society. Thus it is important that opponents of the administrative state should not assume that it can be abolished. There is no way to predict how large, or how important, the administration will be in five or fifty years’ time: it may be larger, or it may be smaller, but it will be there. The priority, therefore, is to control it.

(3) Given coexistence, increasing disturbance drives the dominant extinct first.

Ruddy Turnstones build pectoral muscle after raptor scares -- To cope with changes in the environment, organisms not only show behavioral but also phenotypic adjustments. This is well established for the digestive tract. Van den Hout et al. (2006) described the first case of birds adjusting their flight machinery in response to predation risk. In an indoor experiment, Ruddy Turnstones () were subjected to an unpredictable daily appearance of either a raptor or a small gull (as a control). Ruddy Turnstones experiencing threat induced by a flying raptor model, longer than after similar passage by the gull model, refrained from feeding after this disturbance. Pectoral muscle mass, but not lean mass, responded in a course of a few days to changes in the perceived threat of predation. Pectoral muscle mass increased after raptor scares. Taking the small increases in body mass into account, pectoral muscle mass was 3.6% higher than aerodynamically predicted for constant flight performance. This demonstrates that perceived risk factors may directly affect organ size.

change is weak, which is not what might have been expected from Darwin’s hypothesis.


Intermediate Disturbance Hypothesis Discussion - …

The devil is in the details again, and the most successful community ecological studies have essentially been population ecology studies writ large for the major species in the community. Evolution rears its ugly head to confound generalization. There is not, for example, a generalized large mammal predator in every community, and the species of predators that have evolved on different continents do not all follow the same ecological rules. Ecology may be more local than we would like to believe. Perhaps Lawton (1999) was right about community ecology.

Intermediate Disturbance Hypothesis | CourseNotes

Because disturbances caused by soil frost action andanimals are frequent in many Arctic and alpine tundras, these resultsimply that disturbance could be an important factor in species diversitydifferences within and between tundra vegetation types.

intermediate disturbance hypothesis ..

Fox, J.W. (2013b) The intermediate disturbance hypothesis should be abandoned. Trends in Ecology & Evolution, 28, 86-92.

Intermediate Disturbance Hypothesis : Wikis (The Full …

Kershaw, H.M. & Mallik, A.U. (2013) Predicting plant diversity response to disturbance: Applicability of the Intermediate Disturbance Hypothesis and Mass Ratio Hypothesis. Critical Reviews in Plant Sciences, 32, 383-395.

In ecological disturbance: Intermediate disturbance hypothesis

The rocky shores of the Northeast Pacific Ocean provide an ideal setting to study ecological succession and the effects of disturbance regimes; not only are they reasonably accessible, but they are experimentally amenable in that they are geographically unbroken with flora and fauna that have overlapping ranges that are confined to the intertidal zone. These communities are open-ended, as most primary production and decomposition takes place elsewhere (Dayton 1971). Furthermore, a great majority of interspecific competitive interaction involves the struggle to claim space, which is relatively simple to analyze in this environment, owing to a two-dimensional substrate and clearly delineated bands of vertical distribution (Dayton 1971).