shifting baselines

[archman]

Aha, let me try and better elaborate here.

I read the article, it actualyl discussed the weakness for and against the shifting baselines idea is that since we don't know what the "baseline" is, we have no real way to work towards it.

This isn't a weakness against the validity of the theory by any means. Not knowing the original pristine habitat structure is in fact the reason we call it shifting baseline syndrome. It's a mass forgetfulness on our part, due to the effects of generations of human-derived changes.

Perhaps I am thinking about it way to philosophicly (resisted posting all of my philosophical pondering on the topic) but sure we can observe the shifting, and we can do whatever we can to try and restore to our first known baseline, but there is no solid evidence as to what the original baseline is, so how do you know if something is restored or now overpopulated?

This is one of the focal points for current interest in locating and preserving pristine habitats, like "Sherwood Forest" in the Gulf of Mexico, and deep-sea Lophelia reefs. Places like these are hoped to provide the "baselines" for similar habitats that have been heavily impacted by people. Places like the kelp forests of California are more problematic. Pristine sites are virtually nonexistent, and the historical records are ill suited in providing much of the necessary data. However, these gaps only reflect our inability to get detailed information about population stocks. There's plenty of information illustrating the vast differences between the kelp forests of today vs. those of yesteryear. We're just hazy on the specifics.

Habitat reconstruction to pristine levels is really not an option most ecologists pursue. It's simply not realistic, except in situations where the ecology is near-pristine to begin with (i.e. the Flower Garden Banks), or very small and isolated. What we DO hope to accomplish is point out to the public how much change we have ACTUALLY inflicted on an area. With that accomplished, it might be possible to slow further degradation. Outright stopping of habitat degradation (much less improvement) is not particularly likely to happen without far more regulatory support than we or other nations have.

 

[drbill]

Archman offers good points on this topic. When I was in charge of ecological restoration efforts with the Santa Catalina Island Conservancy, our goal was to minimize human caused impacts (while allowing appropriate educational and recreational access) rather than restoring a pristine ecosystem. If we could eliminate the more serious impacts (including those of introduced feral animals), we could restore a more natural (but by no means pristine) system.

Although questioned by many local residents (especially animal rights folks, hunters and others who would miss the "wildlife"- feral goats and pigs which are natives of Europe and the Middle East rather than North America), the effort was fairly successful. Rare native species not seen in as much as 100 years returned thanks to seed in the soil's seed "bank."

It is important to realize that "shifting baselines" would occur even in the absence of human beings on Earth. Ecosystems are dynamic and subject to natural events like disturbance (witness the recent tsunami or a simple hurricane). To take any single point in time as the baseline in a pristine OR a human-altered ecosystem will not give you a correct picture of the ecosystem itself WITH its "internal" dynamics.

Dr. Bill

 

[archman]

It is important to realize that "shifting baselines" would occur even in the absence of human beings on Earth. Ecosystems are dynamic and subject to natural events like disturbance (witness the recent tsunami or a simple hurricane). To take any single point in time as the baseline in a pristine OR a human-altered ecosystem will not give you a correct picture of the ecosystem itself WITH its "internal" dynamics.

That's a good point. Natural large-scale disturbance events sure can spoil your habitat. Nice thing about those is that everyone remembers what the area was like before, thus nullifying the "syndrome" part(s). The irony is that events like these get all sorts of fast-tracked public and legislative support, while small-scale, continuous changes (that are equally or more deadly to the ecology) remain under the radar. Environmental scientists working in the energy sector understand this only too well. Most of them advocate nuclear over coal any day of the week. Coal is far more harmful to the environment over the long term.

Both punctuated equilibrium and intermediate disturbance theories lean heavily on large-scale natural disturbance events.

 

[drbill]

Hmmm... what's next? A meteor or asteroid crashing to Earth!

Archman's point about small-scale continuous change is one I didn't make clear in my post about natural changes. Heck, that's one of the reasons I dive the Casino Dive Park all the time- each dive is different and the park's "ecological configuration" changes minute-to-minute! Besides, it's cheaper than doing 300-400 boat dives a year!

Dr. Bill

 

[Mako Mark]

It is important to realize that "shifting baselines" would occur even in the absence of human beings on Earth. Ecosystems are dynamic and subject to natural events like disturbance (witness the recent tsunami or a simple hurricane). To take any single point in time as the baseline in a pristine OR a human-altered ecosystem will not give you a correct picture of the ecosystem itself WITH its "internal" dynamics.

Dr. Bill

I have to agree with you there Dr Bill, having been involved with a long term restoration project, what can you compare it to??

The oposite side of shifting baselines is that a "Climax ecosystem" is a myth, the only constant is change.

 

[Mako Mark]

The only climax I've seen in an ecosystem was by my former girlfriend!

Couldn't resist (buut should have).

Dr. Bill

Ahem....

Secifically referring to apocalyptic events that occur on an up to 1000 year basis, Karakatoa, Lake Taupo, Pinatubo, and such massive volcanic events. 9.0 grade earthquakes and their ramifications, category 5-6 storms and the huge distruction that they can do on a macro scale,

but also at a micro scale, the death of a large podocarp leaves a canopy gap that in effect is a 1000 year event of similar disaster (and biotic opportunity) as the macro events.

In light of these events, there can be no baseline, and anyone who says that 1000 years is too long for this sort of comparison, has never seen a really really big tree. 1000 years can be just one generation.

 

[archman]

The oposite side of shifting baselines is that a "Climax ecosystem" is a myth, the only constant is change.

Well that's certainly not true about climax communities. Perhaps it is in reference to older contexts for what a climax community denotes. I've seen some loony stuff in lay-person's books and on TV. By making things simple, sometimes the proper definitions get the axe.

In modern terminology (the last 30+ years), a climax community in the marine environment is one in which the ecology is driven by resource partitioning, rather than environmental tolerances. The community has progressed to the point where biological competition is the main driving point for adaptation. Food resources are fully maximized. Natural emigration/immigration effects are minimal. "Niche" specialization is rampant.

"Climax communities" in marine environs are best exemplified by hermatypic reef habitats, and the deep sea benthos. On land, tropical rain forests. Species diversity must be high, although abundance may/may not be. Climax systems tend to be sheltered from both infrequent large scale environmental disturbance, and frequent medium-scale disturbance. By living in fairly static environments, the community structure becomes highly adapted (and thus narrowly specific) for that environment. This is why its so bloody important to have perfect water quality for reef aquariums; the corals have specialized to the point where their environmental tolerances are limited.

 

[lanun]

very educational. thanks for discussing this to all.

 

[Mako Mark]

"Climax communities" in marine environs are best exemplified by hermatypic reef habitats, and the deep sea benthos..

Good point, I was definately thinking of forests when I wrote that, I really wasnt considering benthic environments..

 

[drbill]

All this is scale dependent of course. Even a "climax" community as described has large-scale disturbance and recovery as well as the small-scale changes (using the geographic definitions of these scales).

Dr. Bill