Tag Archives: biodiversity

National Climate Assessment rolling out now

Ignore the beautiful but dysfunctional interactive website, and instead go straight to downloading the highlights  or the full report. The documents are a treasure trove of data, documenting all of the changes in our climate that we have already witnessed and what is likely to come. The report offers data and projections by region, sector, and response strategies.


The price of gold and the loss of forests

“Everything is connected” is something we say so often in ecology that it often loses its meaning. However, this new study published today in the Proceedings of the National Academy of Sciences really exemplifies the real world impact of these connections.

Skyrocketing gold prices, driven mainly by speculators, has spurred an epidemic of illegal mining (and consequently deforestation) in the Peruvian Amazon. These mines are dangerously close to a major river system, increasing the risk of mining pollution entering the Madre de Dios River watershed. Mining and deforestation often go together, as we know very well here in the UP.

Greg Asner and his colleagues used remote sensing imagery to detect these mines and measure deforestation caused by them. The images themselves provide a powerful message. Each hectare lost to mining can support hundreds of tree species, and thousands of animal species which depend upon them. The loss of these forests and risks of pollution are difficult to calculate, and therefore difficult to balance against the fluctuating value of the gold retrieved from the mines.


Loss

Maya Lin, creator of the Vietnam Veterans’ Memorial in Washington, D.C., is developing a lovely and moving web memorial to global biodiversity loss. Moving your mouse to click different dots, you can see single stories of species that have already disappeared, or click yourself into a “wormhole” with a story about once-abundant species now drastically reduced (and – too rarely – on their way back from the brink).

I suspect that for most people, staring at the possible loss of majestic species such as Siberian tigers helps to drive the point home. Stories of flocks of billions of passenger pigeons darkening the North American skies for days succinctly captures the destruction that a million guns can do to even the most abundant of species. But for ecologists, it is the smaller, less grandiose species we have studied that pull on our heart strings. I’ve worked on two species close to the edge (the California gnatcatcher and the Cape Sable seaside sparrow), and if and when they disappear it will be forever (as the failed attempts at saving the Dusky seaside sparrow illustrate). For ecologists, the loss of “our” species inspires a unique feeling of failure among us.



Save some for the birds

In last week’s Science, a group of researchers pooled data on marine ecosystems around the world to measure the impact of fisheries on marine birds. They found that once fish and krill populations dipped below 30% of their maximum, bird populations began to suffer. Said a different way: if we want penguins, puffins, terns and kittiwakes, we’re going to have to leave them something to eat.

The study reminds me of Peter Vitousek’s famous piece (BioScience 36:368) on “Human Appropriated Net Primary Productivity” in 1986. He estimated that humans use about 40% of all of the biomass produced by plants in a given year; this claim has been supported and refuted about a dozen times since then. Postel et al. have looked at  our appropriation of water as well (estimating that we use over half of the available runoff globally). Since everything needs to eat and drink, it then becomes less surprising that we are witness to such startling losses of biodiversity (well…. perhaps we are more than just “witnessing” it!).

The difference between the “one third for the birds” study and these predecessors is policy relevance: it is probably better to know how much we can take before we do irreparable damage, than to simply know how much we are taking. Let’s see if others can follow suit with biomass, water, and land area.

Happy New Year!


The Anthropocene epoch

There is an interesting piece in this week’s Science regarding the discussions that geologists are having at their meeting this week, as to whether the epoch we are in right now should be officially called the “Anthropocene”, and if so, when it should start.

It may seem like one of those nerd debates that doesn’t really matter to normal folks, but this one really does. The article has some excellent graphics and truly frightening statistics to anchor this debate. Consider this: 80% of the Earths’ land area has been altered by humans, and 90% of the biomass represented by mammalian species is currently tied up in either human or domesticated livestock bodies. Think about that…. our bodies and our cows, goats and sheep outweigh all of the lions and tigers and bears out there, not to mention the elephants, whales, and gorillas.

Wow. That one took me a while to process.

So what does this say about our future on this planet, or even the future of our planet? Back in 1986, Peter Vitousek* sounded an alarm regarding our increasingly heavy footprint, estimating that humans soaked up about 40% of the planet’s Net Primary Productivity, a measure of how much sunlight plants convert into biomass. That doesn’t leave much left for the millions of species with which we share this rock. And unfortunately, our fate is tied up with most of those millions; if they go, there is no guarantee that we won’t go too.

*Vitousek P, Ehrlich P, Ehrlich A, Matson P. 1986. Human appropriation of the products of photosynthesis. BioScience 36:368-373.