Tuesday, September 24, 2013

Habitat preservation and its role in conservation

Baby snapping turtle, from the Sparkill Creek, Sparkill, New York.
 Photograph by the author, 2012.

In the last post, we examined the nature of species invasion over geologic time scales, explained the relative implications of biodiversity on macroscopic and microscopic scales, and discussed the fact that human beings are not, overall, in control of their own species extinction events anymore... the events, that is, that are causing them to render so many species extinct, and vastly accelerating the rate of species invasion worldwide.

 Because human politics and societies are fundamentally fractured and contentious, and because economic activity provides nearly limitless incentives for environmental violations, worldwide consensus of any kind on the destruction of the biosphere is, relatively speaking, a fantasy.  Catastrophes on an unimaginable scale would have to rise before any real consensus could be reached. Failing that, we are left with an examination of the best approaches that actually stand a chance of working.

 Prevention of species invasion

 While this is, in theory, an excellent idea, it has turned out to be completely impractical. Despite the proliferation of an endless series of laws regarding import and export of animals and plants, designed to limit species invasion, the accelerated scale with which materials and human beings are moving around the planet has resulted in the wholesale distribution of alien species into new niches. It is likely that every week, some 10 or 20 new species that will ultimately be deemed invasive find their way to new areas they were never seen in before; and these are only the species we can see. The blending of the microbial communities that form the understory of this activity is, no doubt, far more intense and pervasive, and much more difficult to measure.

The point is that species invasion is a fact that has to be lived with now. Whether experts, biologists, conservationists, fish and wildlife enforcement agents, or the general public like it or not, species invasion will continue to take place and accelerate. This is a fact. Arguing about it is very nearly pointless, because while the arguments take place, the invasions go on. And on. And on.  Globalization virtually ensures it, and no government or private organization has the resources to control this in any credible manner.

 Given that the situation is, for all intents and purposes, uncontrollable, an endless series of expensive responses intended to control it–when it is, already, definitely uncontrollable–are very nearly pointless. While the most spectacularly destructive examples of invasion involving insect species may be worth trying to counteract, in many cases, probably the majority of cases, human beings will simply have to make an accommodation with the new status quo as it arrives.

 Elimination of invasive species

 An impractical step to take, for the reasons described above. One of the principal features of invasive species is that by the time they are labeled as invasive, they are insanely successful. That is, they have managed to take over a large portion of the ecosystem they migrated to. A rule of thumb here is that by the time a species is on the radar screen as invasive, it's too late to eliminate it. We have seen this again and again:  the Japanese beetleKudzu in the southern United States, mile a minute vine  in the Hudson River Valley, and  the Burmese python in the Everglades are just a few examples. These plants and animals are here to stay; efforts to eliminate them are pointless.

 While elimination of invasive species may be achievable in specific, limited locations over short periods of time, lessons have shown us that such control measures are simply holding actions. In the end, invaded ecosystems become new and different ecosystems that have to be dealt with on their own terms. Trying to turn them back to the conditions they began with is almost always nearly impossible. As such, spending large sums of money, whether taxpayer or donated, to control invasive species is a waste of time, unless the species represent dire threats to agricultural activities or represent major health threats to human populations.

 Preservation of habitat

 Because species evolution is a fluid series of events over long periods of time, human attempts to control it through the micromanagement of species interaction within given environments is not only (as I point out above) doomed to failure, it distracts us from the more compelling and urgent matter of the overall health of the biosphere itself. Species cannot be preserved individually if their habitat, collectively, degrades; and preservation of habitat in the face of the many significant threats human beings bring with their relentless expansion on the planet surface becomes not only the greater challenge, but the one that it is more necessary to manage properly. Rather than focusing on the gain or loss of individual species, whether native or invasive, human beings need to focus on the negative impacts they themselves are having on habitats, and what can be done to correct that.

Negative impacts on habitat

 Let's examine some of the more alarming affects human beings are having on habitat worldwide.

Fracturing of habitat

Over the last 3000 to 5000 years, humans have divided the habitable and arable landscape into progressively smaller portions. This process accelerated dramatically over the last 300 to 500 years, and took a dramatic turn for the worse with the introduction of the automobile and the division of the landscape into millions of fractional environments, separated from one another by highways, fences, dams, and other physical obstacles to the migration and interaction of wildlife. Extension of city life into large suburban areas exacerbated the issue.  Almost all of this has taken place in the most fertile and habitable regions of the planet.

Climate change

 Human beings have pumped vast amounts of carbon dioxide into the planetary atmosphere, along with innumerable other airborne pollutants such as lead, other heavy metals, and particulate pollutants that affect the breathable quality of air around every major city. Global temperatures are climbing, which will definitely have a negative impact on many existing habitats. Under ordinary circumstances, creatures would in many cases be able to migrate to more suitable areas, but the fracturing of the landscape by development has had a negative impact on the ability of species to relocate. This will make transitions for many species far more difficult.

Waterway pollution

 Almost without exception, every chemical product manufactured by man is eventually discharged into waterways, ultimately reaching the ocean. This is a major issue which will acquire much more detailed treatment in future posts, but the bottom line is that chemical pollution represents the single greatest danger to man's biological health on the planet, this for multiple reasons. The first and most immediate reason is that man needs clean water to drink; a significant percentage of the world water is on its way to being too contaminated to use for that purpose. Contamination of water also affects the wildlife that inhabits it, and its usability for agricultural purposes. In perhaps one of the greatest ironies, contaminated water is no longer suitable for use in chemical processes.


 Man's real estate development in coastal and riverine environments has resulted in enormous tracts of land that are paved, landscaped, or otherwise altered so that water runs off them easily. This has vastly accelerated the amount of pollutant bearing runoff that reaches the waterways. It degrades existing underground water tables, since the water no longer percolates through the soil or rock into the reservoir; and it results in the portage of innumerable microbial contaminants such as e coli and other inimical bacteria into the waterways.

Soil erosion and destruction

 Poor soil conservation practices across most of the planet destroy soils at a much faster rate than they are created. This is of particular concern in tropical areas, where soils may be poor to begin with and are often thin and underdeveloped. Soils in temperate climates have not, however, avoided this problem, because they've been subject to far more intensive agriculture for much longer, and in many cases, soils in developed countries have already been so badly damaged that the majority of the original soil base is compromised.

Species depletion and ecosystem collapse

 Man's effect on local ecosystems has been dramatic and catastrophic. Many keystone species have been destroyed, destroying entire industries (such as the Pacific West Coast salmon fisheries) along with them.

Chemical pollution

 Probably the most inimical and underappreciated issue facing mankind today. Over the last 100 years, the number of novel wide-application industrial and agricultural chemicals, biocides, medicines, and toxins has multiplied a thousandfold or more, with little or no adequate scientific studies to predict the  medium or long-term effects of these chemicals on the environment.


 Habitats worldwide are under siege from multiple directions. Preservation of habitat in sound, unpolluted condition in sufficient areas to allow fluid species interaction, migration, and reproduction without constant interference from human beings has become a major challenge for environmentalists and conservationists. There is no point to preserving individual species under any conditions whatsoever if habitat preservation is not achieved. As such, attempts to control invasive species or propagate native ones tend to be quixotic when measured against the need for habitat preservation.

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