Ecosystem repair – why?

Can’t you just leave it alone and let nature take its course? Why try to recreate a past landscape?

An analogy comes to mind: if you drive off the road, will you get back on the road by continuing to drive in the ditch? Ecologists think of ecosystems as being on trajectories, with the implication that if you change things a bit, you might be able to get an ecosystem back on track. Removing invasive plants and re-planting or making it easier for native plants to recolonize requires active management.

Many ecosystems are fragmented and degraded. This facilitates invasion by plants and animals that displace the natives. Fragmented landscapes have more “edge” because of their geometry, and these edges are access points for disturbance that creates a point of entry for invasive species. Most if not all invasive species were originally spread by people moving them from distances they would not travel on their own, either intentionally (as garden plants or pets) or accidentally (seeds stuck to auto tires, insects in packaging, marine life in ships ballast). If we just “let nature take its course” we end up with highly degraded habitat, because invasive species will spread without management.

In the modern world where the seed rain of invasives is more or less constant (birds, animals, and humans carry seeds and plants in from other places, things blow in or get washed in, etc) it is necessary to actively manage most landscapes to some degree. Those species we have driven to extinction, and those that are reduced because of habitat loss need to be actively replaced. We have caused this problem, and we can’t expect “nature” to clean it up.

Even if there are few invasives, management is essential in systems that historically burned regularly, (whether because of lightning strikes or Indian managed burns). Fire-adapted ecosystems are not healthy without fire. Because people living in and adjacent to these landscapes have built permanent structures, they are likely not to appreciate fires next door, so this is a challenge.

See further thoughts along these lines on the page “To what past ‘look’ are you returning, and why?”

And why repair just a small remnant of a formerly vast ecosystem? What value are small areas of habitat that remain when agriculture, forestry and, most recently, development have taken most of the best quality wild areas?

First, these remnants are all we have, and they are disappearing. We need to reclaim and revitalize the gene pool of plants and animals that exist, and the landscapes they live in before they become more degraded. Even small areas – indeed even urban and suburban yards – can contribute to biodiversity and the resilience and health of our planetary environment. This matrix of human-dominated landscapes is the environment animals must move through now to get from place to place, whether migrating or dispersing to new habitats when their current one becomes too crowded or unsuitable. If they can leap-frog through the matrix, they have a better chance.

Why we care.

To lose a species forever is an irreversible and dangerous event. We don’t know what an extinct species might have contributed or how it might help us survive future changes in climate or challenges yet unknown.

Sometimes people ask if rare habitats and their plants and animals are worth saving. The reasoning goes that if they couldn’t survive on their own, maybe they are just not robust enough to adapt to changing conditions. Crucial to the concept of conservation and ecosystem health today is the difference between the loss of species when competition and predation – not human effects – are the main forces determining survival.

Evolutionary processes that resulted in stronger, healthier animals passing on their genes, are much different from wholesale destruction of habitat and species by humans capable of wiping out whole healthy populations. Too, the rate and scale of current extinction events are widely recognized to be as catastrophic as the huge mass extinctions in past geologic epochs. So much so that the term Anthropocene was coined to describe the current epoch.

So, we care about these small remnants because they are our heritage, and our safety net – the only way we have of bringing back some health to our landscape. And, they can become more valuable, more useful, if we are mindful of connecting these patches of good habitat to each other within the matrix of our farms, towns, and cities to create a larger effective habitat area, especially for migratory insects and birds. That is why everyone who lives anywhere can participate, and contribute to the healing process. It only takes one tree or a bed of native perennials for you to contribute.

On a personal level, the incomparable thrill of identifying a plant or animal I have not seen before on my land, or watching the endangered plant I placed as a seedling emerge from winter dormancy is what motivates me. Please let us share these experiences via this journal and post your comments and questions!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s