Ecosystems

Description:

To understand something new, it's our nature to compare it to something familiar, particularly through the use of analogy and metaphor. As a formal method, we can nearly always learn more about something by rigorously comparing it to something else. In a sense, it can be anything else - for example, the greater the dissimilarity, the greater the mental stretch to find similarities.

The idea is to broaden thinking around a topic, to promote creativity and discovery by "making the familiar strange" (synectics), in some cases to subtly introduce new strategies and options.

Suppose that principles of conservation biology, chemistry and physics can be applied to organizations. How might organizations appear through these metaphorical lenses, and might these slanted vantage points offer some insight merely by connecting two diverse sets of principles, thereby making the familiar strange and the strange familiar? The following investigation does not imply that these very different worlds are identical or even similar. However, there may be phenomenon that are perhaps analogous.

By carefully crafting metaphors around recent reports from the scientific literature, we can use the excercise as way to expose people to concepts that they might otherwise not have an opportunity to learn about. The metaphor module is a great opportunity to engage people in the wonder of Nature.

"You've got to use metaphor to explain science, it's part of a process of giving people a feel for the subject." James Lovelock, originator of the Gaia Hypothesis

metaphor

noun

Pronunciation: 'me-t&-"for also -f&r

Etymology: Middle French or Latin; Middle French metaphore, from Latin metaphora, from Greek, from metapherein to transfer, from meta- + pherein to bear -- more at BEAR

Date: 1533

1 : a figure of speech in which a word or phrase literally denoting one kind of object or idea is used in place of another to suggest a likeness or analogy between them (as in drowning in money); broadly : figurative language -- compare SIMILE

2 : an object, activity, or idea treated as a metaphor : SYMBOL

(from the Encyclopaedia Britannica Dictionary, http://members.eb.com/cgi-bin/dictionary?va=metaphor)

Figure of speech that implies comparison between two unlike entities, as distinguished from simile, an explicit comparison signalled by the words "like" or "as."

The distinction is not simple. The metaphor makes a qualitative leap from a reasonable, perhaps prosaic comparison, to an identification or fusion of two objects, to make one new entity partaking of the characteristics of both. Many critics regard the making of metaphors as a system of thought antedating or bypassing logic.

Metaphor is the fundamental language of poetry, although it is common on all levels and in all kinds of language. Many words were originally vivid images, although they exist now as dead metaphors whose original aptness has been lost--for example, "daisy" (day's eye). Other words, such as "nightfall," are dormant images. In addition to single words, everyday language abounds in phrases and expressions that once were metaphors. "Time flies" is an ancient metaphorical expression. When a poet says "The Bird of Time has but a little way / To flutter--and the Bird is on the Wing" (The Rub‡iy‡t of Omar Khayyam), he is constructing a new metaphor on the foundations of an older, stock metaphor. When Tennessee Williams entitles his play Sweet Bird of Youth, he, too, is referring to that Bird of Time that flies. Thus, metaphorical language develops continuously in complexity just as ordinary language does.

"metaphor" Encyclopaedia Britannica Online (http://members.eb.com/bol/topic?eu=53596&sctn=1&pm=1) [Accessed 24 August 2000].

"On average, greater diversity leads to greater productivity in plant communities, greater nutrient retention in ecosystems and greater ecosystem stability." "An average plot containing one plant species is less than half as productive as an average plot containing 24-32 species." The greater stability of more diverse ecosystems results from several factors: (Tilman, 2000)

• Species tend to respond somewhat independently to environmental variability.
• Species within a trophic level often compete for resources, which causes their abundances to negatively covary. Thus, when one species declines, another is freed from competition and increases. This reduces the variability of the community as a whole.

"Diversity increases the chance that the species that are better able to handle particular conditions are present." (Tilman, 2000)

"The greater productivity of higher diversity communities occurs because, in such heterogeneous habitats, each species is a superior performer in only a portion of sites. " (Tilman, 2000)

Productivity is an increasing function of plant species diversity. Much of nature appears to operate under a free-market economy, structured by the efficiencies of open competition among species, rather than an economy structured by pre-emption and other monopolistic strategies.

Diverse plant communities often have a greater variety of positive and complementary interactions and so outperform any single species, and have more chance of having the right species in the right place at the right time.

(Also see Tilman et al., 1997)

Diversity in one group of organisms can also promote diversity of associated groups, for example between mycorrhizas and plants, or plants and insects. (van der Heijden et al., 1988, Mychorrhizal fungal diversity determines plant biodiversity, ecosystem variability and productivity)

Within an ecosystem, diversity tends to be positively correlated with ecosystem stability. This correlation does not necessarily extend to population-level stability, however. (McCann, 2000)

Diversity cannot be maintained by variation alone. Rather, it requires both the existence of flux or variability in ecosystems and populations capable of differentially exploiting this flux or variability.

"... recent advances indicate that diversity can be expected, on average, to give rise to ecosystem stability. The evidence also indicates that diversity is not the driver of this relationship; rather, ecosystem stability depends on the ability for communities to contain species, or functional groups, that are capable of differential response."

The hypothesis that "greater connectance drives community and ecosystem stability - seems a strong possibility provided most pathways are constructed from weak interactions that mute the potentially destabilizing roles of a few strong consumer-resource interactions."

"The larger the number of functionally similar species in a community, the greater the probability that at least some of these species will survive stochastic or directional changes in environment and maintain the current properties of the ecosystem." (Chapin et al., 2000)

As an ecosystem, a rich ValueWeb™ will be much more robust than a "supply chain" due to the myriad of interconnections that provide feedback to the different players within the web. A rich ValueWeb will be better at self regulating, i.e., keeping an individual player from growing out of control and upsetting the balance of the web as a whole.

This could lead to a discussion of ecosystem evolution, rather than evolution of the individual players.

There are any number of connections we can make between the ecosystem characteristics to the left and their manifestations in the ValueWeb. Many of these will be most powerful if they're tailored for the specific client/challenge.

Seems to be saying that diversity is defined by interspecific interactions, not intraspecific interactions. It's the local scale interactions between producers, customers, investors and management that define the diversity of the ValueWeb, as opposed to producer - producer or customer - customer interactions.

This (and just about everything else in this section) suggests that a ValueWeb dominated by a Mega Corp. is inherently not as robust and viable as a ValueWeb composed of complex assemblages of competing and cooperating entities. A Mega Corp. cannot have interspecific interactions.

One could say that the finer grained, the higher the fractal dimension of the ValueWeb, the greater the ability of the ValueWeb to leverage the power of it's diversity.

"Most ecosystem processes are non-additive functions of the traits of two or more species, because interactions among species, rather than simple presence or absence of species, determines ecosystem characteristics. Species interactions, including mutualism, trophic interactions (predation, parasitism and herbivory) and competition may affect ecosystem processes directly by modifying pathways of energy and material flow or indirectly by modifying the abundances or traits of species with strong ecosystem effects."

"Many of these interactions have a high degree of specificity, which increases the probability that loss of a given species will have cascading effects on the rest of the system."

(Chapin et al., 2000)

"The underlying mechanisms of coexistence can greatly influence how diversity affects ecosystem processes." Consider plant species that coexist by exploiting the fact that each grows optimally in different soil pH and temperature regimes. Such niche differentiation causes the predicted productivity of plant communities to be an increasing function of plant diversity. (Tilman, 2000)

• Presence of several varieties in a mixture provides a physical barrier to the spread of pathogens.
• The immune systems of plants may be stimulated by the action of pathogens to which they are not directly susceptible.
• Leads to a damping of the development of epidemics within a field, with an increase in the complexity of the pathogen population, which can slow the adaptation of the pathogen to the mixture.

The stability of yields from variety mixtures likely results from combined restriction of biotic and abiotic (temperature, drought, etc.) stresses.

"The limitless potential for pathogen spread in monocultures leads to rapid selection of pathogens that can overcome resistant crop varieties and survive in the presence of fungicides." (Wolfe, 2000)

While there seems to be more and more evidence to support the connection between biodiversity and ecosystem health, there is currently a big debate in the ecological community over this issue.

"... weakly interacting species stabilize community dynamics by damping strong, potentially destabilizing consumer-resource interactions."

"... decreasing biodiversity will be accompanied by increases in average interaction strengths within ecosystems, and a concomitant decrease in ecosystem stability." (McCann, 2000)

"Much of ecological theory is based on the underlying assumption of equilibrium population dynamics. Although this assumption is aesthetically pleasing, in that it suggest the balance of nature is infinitely precise, an alternative and viable ecological perspective exists. As real populations are variable, it is possible that the persistence of complex communities depends to some degree on population fluxes (that is, fairly regular waxing and waning of a population's density). Such background population variability, whether driven by biotic or abiotic processes, can provide species with the opportunity to respond differentially to their environment. In turn, these differential species responses weaken the destructive potential of competitive exclusion." (McCann, 2000)

"Before Hubble's sharp view, most scientists viewed the universe as timeless; things changed so slowly outside our own solar system that researchers rarely considered the possibility of movies. Now, with Hubble, pictures taken of the universe today won't necessarily look the same as those snapped a few months from now." For a great animation, click here.

We could bring up specific biological examples such as lemmings, cicada and others.

" ... the evidence points to variable population densities that sum to produce a relatively constant biomass at the community level."

Definitions of stability in ecology can be generally classified into two categories: definitions that are based on a system's dynamic stability, and stability definitions that are based on a systems ability to defy change.

This is a very interesting point that I think we can do some interesting things with. Much of science over the past couple hundred years has been permeated by the idea of gradualism and equilibrium dynamics. As suggested by the quote to the left, however, this view is shifting. Concepts such as punctuated equilibrium, mass extinctions caused by asteroids, and perhaps chaos and complexity science could be used to talk about this shifting paradigm.

Could look at vantage points. From a distance, averaged over 10 years, an ecosystem/ValueWeb could appear to be in a stable equilibrium. From the vantage point of 2 year cycles however, one might see very large population changes.

Could be related to Kelly's Rule 8, "No Harmony, All Flux", and the idea of "churn."

The Weak-Interaction Effect (McCann, 2000)

In the past decade, ecologists have replaced the idea of the linear food chain with the view that food webs are highly interconnected assemblages.

"... increasing diversity can increase food-web stability under one condition: the distribution of consumer-resource interaction strengths must be skewed towards weak interaction strengths."

Communities with lower mean interaction strength have been found to be more resistant to invasion.

A strong consumer-resource interaction is potentially destabilizing.

"... decreasing biodiversity will tend to increase the overall mean interaction strength, and thus increase the probability that ecosystems undergo destabilizing dynamics and collapses."

"... weakly interacting species stabilize community dynamics by damping strong, potentially destabilizing consumer-resource interactions."

"... decreasing biodiversity will be accompanied by increases in average interaction strengths within ecosystems, and a concomitant decrease in ecosystem stability."

(McCann, 2000)

As mentioned above, the emphasis is on high frequency low amplitude interactions.

What are the implications for PatchWorks Designs?

Variation in interaction strength may be important in generating landscape-scale variation that promotes the maintenance of diversity.

However, "... diversity cannot be maintained by variation alone. Rather, maintenance of diversity requires the two following components: the existence of flux or variability in ecosystems; and populations capable of differentially exploiting this flux or variability." (McCann, 2000)

Themes of recursion and requisite variety immediately come to mind.

Not surprisingly, without some mechanism to leverage the variety, it is useless.

Despite the importance of these weak interactions, experiments also show that the removal or addition of a single key species can have pronounced impacts on the dynamics and persistence of the ecosystem populations.

The challenge is identifying the key players and the key interactions in the ValueWeb. Where are the tipping points?

Recent experimental results support the idea of group selection, that natural selection can operate on the level of groups, such as diverse ecosystems, just as it does on individuals.

"Group selection holds that natural selection operates on groups, such as diverse ecosystems, just as it does on individuals, to select traits that lead to higher reproductive success." "The mini-ecosystems showed evidence of passing traits to 'offspring' ecosystems."

"... selected cages of hens that as a whole yielded more eggs than other caged groups. This approach boosted egg laying to 160 percent of the original strain's and produced milder-mannered hens."

S. Milius, Science News.

What defines a "mature" ecosystem?

Relates to one of the Kelly's Rule 5: "Feed the Web First; Members prosper as the Net Prospers".

What defines a "mature" Value Web?

Mechanisms of Coexistence

What are the mechanisms of coexistence? In general, coexistence requires trade-offs in the abilities of species to deal with factors that constrain fitness and abundance. There are many potential constraints and tradeoffs Species may coexist because of interspecific tradeoffs (1) between their competitive abilities and their dispersal abilities; (2) between their competitive abilities and their susceptibility to disease, herbivory or predation; (3) between their abilities to live off average conditions and their abilities to exploit resource pulses; or (4) between their abilities to compete for alternative resources in a heterogeneous landscape. (Tilman, 2000)

This point is getting to the fact that there is only a finite supply of resources. There are a variety of strategies that species can take to deal with the constraints of limited resources. The particular strategy depends upon a particular series of tradeoffs.

"Consider a case in which interspecific interactions are based on direct antagonism and not on efficiency of resource use. Because greater diversity increases the chance that a competitively superior but lower-yielding species would be present, productivity would, on average, be a decreasing function of diversity."

This seems like a finite view of resource utilization. This view is no longer valid in the "network" economy, is it still valid in nature? What are the assumptions? Resources available to an ecosystem are certainly finite, question is, what is the meta-strategy used by the ecosystem, direct antagonism or maximizing resource utilization?

What does Kelly have to say here?

One important factor here is scale of resources. Need to make sure that one's vantage point is broad enough to include all relevant interactions/exchanges. What level are you optimizing over? At the level of species, it might seem that a group of organisms has made certain less than optimal tradeoffs, yet moving a couple levels out it becomes clear that it was not really a tradeoff, but a trade-up.

Players within the ValueWeb have to get away from the the traditional ways they've defined there relationships with others, be they "competitors," "suppliers," "customers," etc.

For example ... Recognizing that while on one hand I compete for the same customers as you and so we could be considered competitors, on the other hand you bring additional suppliers and customers into the ValueWeb and so strengthen the entire system.

Perhaps this could lead to a discussion of Wacker and Taylor's paradoxes.

"Any attempt to measure biodiversity quickly runs into the problem that it is a fundamentally multidimensional concept: it cannot be reduced sensible to a single number." "... we should probably be relieved that the variety of life cannot be expressed along a single dimension." (Purvis and Hector)

"It has long been argued that species should be treated as dynamic evolutionary units, rather than as types." (Margules and Pressey, 2000)

Important to convey the idea that representing a ValueWeb by a series of numbers (how big is it?, how many players?, how diverse is it?, etc.) is an inherently simplifying process. Not sure how best to explain what I mean. Like building a model. You choose your model based on which elements of the real thing you want to represent. The model represents a simplification. If you weren't looking for a simplification you would use the real thing.

Idea of complementarity is an interesting notion. (Margules and Pressey, 2000)

" Complementarity is a measure of the extent to which an area, or set of areas, contributes unrepresented features to an existing area or set of areas. ... it can be thought of as the number of unrepresented species (or other biodiversity features) that a new area adds."

"An area with high complementarity will not necessarily be the richest."

Complementarity recognizes that "the potential contributions of an area to a set of targets is dynamic ... . In contrast, more traditional measures of conservation value such as species richness or number of rare species are unresponsive to changing targets."

Resistance to invasion

"Vulnerability to invasion is governed more strongly by the traits of resident and invading species than by species richness per se."

"... the effect of species diversity on vulnerability to invasion depends on the components of diversity involved (richness, evenness, composition, and species interactions..."

(Chapin et al., 2000)

Four broad characteristics of global patterns of biodiversity (Gaston, 2000):

1. No single mechanism adequately explains all examples of a given pattern,
2. Observed patterns vary with spatial scale,
3. Processes operating at regional scales influence patterns observed at local ones,
4. The relative balance of causal mechanisms means that there will inevitably be variations in and exceptions to any given pattern.

Observation: High proportions of terrestrial and freshwater species occur in the tropics. Moving from high to low latitudes the average species richness within a sampling area increases.

More than 25 different mechanisms have been suggested for generating these patterns in species richness, including explanations based on chance, historical perturbation, environmental stability, habitat heterogeneity, productivity and interspecific interactions. Many of these mechanisms are not mutually exclusive, and others merely offer different levels of explanation.

A sole explanation is insufficient.

The assumption that where a pattern is common to many taxa it must result from the same single mechanism has been widely held but there is little evidence for it.

(Gaston, 2000)

What is the relationship between the "area" of the Value Web and it's vibrancy?

What mechanisms do we invoke to explain various patterns in the ValueWeb around us? We must always keep in mind that correlation does not indicate causation!

The greater the energy availability, the more biomass that can be supported in an area. This relationship is not universally observed, however. There is in fact a growing speculation that in many situations the species-energy relationships may not be causal.

Many taxa use only a very small proportion of the total energy available in an area ... or at least the energy that is being measured.

"Greater energy availability is assumed to enable a greater biomass to be supported in an area. In turn, this enables more individual organisms to coexist, and thus more species at abundances that enable them to maintain viable populations. The result is an increase in species richness with energy availability."

"Complex patterns of causality suggest an important connection between species-energy theory and debates over the ecosystem function of biodiversity."

However, there are problems with the linkages between energy availability and species richness.

(Gaston, 2000)

Can it be said that the greater the wealth (energy) in a Value Web, the more vibrant it is.

How do we measure the health of the ValueWeb?

"... levels of species richness have not been produced directly by present environmental conditions, as processes of speciation and extinction do not operate on these time scales."

(Gaston, 2000)

Unintended Consequences

"... unlikely that the path of causality is simple."(Gaston, 2000)

See specific examples on page 237 and 240 in Chapin et al., 2000.

Simply knowing that a species is present or absent is insufficient to predict its impact on ecosystems.

Timing can be crucial. See article on recovery of ecosystems from after Mt. St. Helens eruption. Because eruption took place in early spring, when many plants and animals were still covered by a thick layer of snow, recovery has been much quicker than if the eruption had taken place just a month later.

http://www.sciencemag.org/cgi/content/full/288/5471/1578

How is your organization using timing to your advantage? disadvantage?

Clearly a rich thread here that can be tied to AND Maps, scenarios, etc.

In Systematic Conservation Planning, a 6 step process for systematic conservation planning is presented.

"The process is not unidirectional - there will be many feedbacks and reasons for revised decisions."

"... planners, rather than proceeding as if certain, must learn to deal explicitly with uncertainty in ways that minimize the chances of a serious mistake."

"Some threats arise for reasons that can be understood only with the benefit of hindsight, but this is no reason not to improve foresight ...."

(Margules and Pressey, 2000)

Think about Bryan's quote (and the Stages of an Enterprise model in general) in the context of a tree in the rainforest. The mature tree may last for centuries, but there's always the possibility for a storm or disease to strike it down early.

The tree will feed and support vast ecosystems of other plants, insects and animals.

(expand further)

"The mature phase of the enterprise may last a period of months or centuries. The many rebirths the organization has had may continue to feed and support its original manifestation, but chances are that the enterprise, at some point, begins a final collapse which leads to its demise. Sometimes the final collapse denotes simply the age of the enterprise, or the wearing out of an idea or set of processes. Other times, however, organizational stubbornness or blindness will precipitate the fall, and in such cases there lies opportunity for a turnaround, leading the enterprise back to the entrepreneurial button and new life." B.S.C. from "Looping and Leaping"

"The parasitic fluke Microphallus piriformes has a problem. To complete its life cycle it needs to travel between two hosts: the rough periwinkle, a seashore mollusc) and the herring gull. In the normal run of things, these species have little to do with each other. But the cunning parasite has a way of making introductions." (Whitfield, 2000)

Aparantly, parasitized periwinkles show a greater tendency to crawl upwards, into positions where they are more vulnerable to being eaten by gulls.

"This change in behavior happens only when the infection is mature and the fluke is ready to switch hosts. In the early stages, infected periwinkles behave nomally; after all, the parasite doesn't want its home to perish from desiccation or predation too early."

A story of a parasitic wasp species that chemically reprograms its spider host to weave a special web for its own ends. (Eberhard, 2000)

"... the mechanism employed by the larva to manipulate the spider's behavior is fast-acting, apparently chemical, and has long-term effects."

Lichens are a very interesting type of organism that could be developed into a metaphor, either within the Ecosystem classification or perhaps on their own.

Lichens aren't animals or plants, but rather are composite organisms that go by the names of the fungal partners. In addition to representatives of the fungal kingdom, lichens include members of the protist kingdom and sometimes also include a cyanobacteria, from yet another kingdom. Whether this combination creates a mutually supportive partnership or slavery depends on the species involved, as well as on who is describing the combination.

Lichens make up the dominant vegetation on 8 percent of land on Earth.

"Lichens face a considerable challenge in reproducing and dispersing, since they have to coordinate the mechanics of several organisms. Getting the reproductive bits of the right partners to the right place - with partners from two or three kingdoms - makes the human mating game look laughably simple." (Milius, Science News, Vol. 158, pg 140, 2000)

Misc.

A Value Web is a network.

"The distinguishing characteristic of networks is that they contain no clear center and no clear outside boundaries. Within a network everything is potentially equidistant from everything else." Kelly, pg. 65

Stem Cells - Latest news: a good resource page from New Scientist

http://www.newscientist.com/nsplus/insight/clone/stem/stem.html