Editing Ecology (section)

== Complexity ==
{{Main|Complexity}}
{{See also|Emergence}}

Complexity is understood as a large computational effort needed to piece together numerous interacting parts exceeding the iterative memory capacity of the human mind. Global patterns of biological diversity are complex. This [[biocomplexity]] stems from the interplay among ecological processes that operate and influence patterns at different scales that grade into each other, such as transitional areas or [[ecotones]] spanning landscapes. Complexity stems from the interplay among levels of biological organization as energy, and matter is integrated into larger units that superimpose onto the smaller parts. "What were wholes on one level become parts on a higher one."<ref name="Novikoff45"/>{{rp|209}} Small scale patterns do not necessarily explain large scale phenomena, otherwise captured in the expression (coined by Aristotle) 'the sum is greater than the parts'.<ref name="Schneider01"/><ref name="Molnar04"/>{{Cref2|E}}

"Complexity in ecology is of at least six distinct types: spatial, temporal, structural, process, behavioral, and geometric."<ref name="Loehle04"/>{{rp|3}} From these principles, ecologists have identified [[emergence|emergent]] and [[Self-organization#Biology|self-organizing]] phenomena that operate at different environmental scales of influence, ranging from molecular to planetary, and these require different explanations at each [[integrative level]].<ref name="Lovelock03" /><ref name="Odum1977"/> Ecological complexity relates to the dynamic resilience of ecosystems that transition to multiple shifting steady-states directed by random fluctuations of history.<ref name="Holling01"/><ref name="Carpenter01"/> Long-term ecological studies provide important track records to better understand the complexity and resilience of ecosystems over longer temporal and broader spatial scales. These studies are managed by the International Long Term Ecological Network (LTER).<ref name="urlWelcome to ILTER – ILTER"/> The longest experiment in existence is the [[Park Grass Experiment]], which was initiated in 1856.<ref name="Siverton06"/> Another example is the [[Hubbard Brook Experimental Forest|Hubbard Brook study]], which has been in operation since 1960.<ref>{{cite web |url=http://www.hubbardbrook.org/ |title=Hubbard Brook Ecosystem Study Front Page |access-date=16 March 2010 |url-status=live |archive-url=https://web.archive.org/web/20100324131250/http://www.hubbardbrook.org/ |archive-date=24 March 2010}}</ref>

=== Holism ===
{{Main|Holism}}

Holism remains a critical part of the theoretical foundation in contemporary ecological studies. Holism addresses the [[Biological organisation|biological organization]] of life that [[Systems biology|self-organizes]] into layers of emergent whole systems that function according to non-reducible properties. This means that higher-order patterns of a whole functional system, such as an [[ecosystem]], cannot be predicted or understood by a simple summation of the parts.<ref name="Liu09"/> "New properties emerge because the components interact, not because the basic nature of the components is changed."<ref name="Odum05"/>{{rp|8}}

Ecological studies are necessarily holistic as opposed to [[reductionistic]].<ref name="Levins80" /><ref name="Odum1977"/><ref name="Mikkelson10"/> Holism has three scientific meanings or uses that identify with ecology: 1) the mechanistic complexity of ecosystems, 2) the practical description of patterns in quantitative reductionist terms where correlations may be identified but nothing is understood about the causal relations without reference to the whole system, which leads to 3) a [[metaphysics|metaphysical]] hierarchy whereby the causal relations of larger systems are understood without reference to the smaller parts. Scientific holism differs from [[mysticism]] that has appropriated the same term. An example of metaphysical holism is identified in the trend of increased exterior thickness in shells of different species. The reason for a thickness increase can be understood through reference to principles of natural selection via predation without the need to reference or understand the [[biomolecular]] properties of the exterior shells.<ref name="Wilson88"/>