Global distribution of biodiversity
Current time:0:00Total duration:5:54
What is a biodiversity hotspot?
- [Instructor] What we're gonna talk about right now is something called a biodiversity hotspot. How do you figure out what the places are on earth that deserve our special focus, that deserve attention that they need to protect them for future generations? It's obvious that the earth is in trouble and we can't save the entire planet all at once. We need to have a focus. We can't do triage on an entire planet. We've limited resource. We have limited time. We're running out of time to protect many of these places. So what are the criteria that we use to try and figure out what those hotspots really are that need that special attention and protection? Back in 1988, ancient history to some of us and in fact might be pre-history to others there was a scientist by the name of Norman Myers who wrote a really important paper that analyzed different types of geological, climatological and uniqueness criteria to come up with concept of a hotspot. Scientists who look at this problem and decided eventually that there really were two main criteria that were gonna lead to what Conservation International now recognizes as a biodiversity hotspot. One criterion was that there had to be at least 1500 endemic species of plants. We'll get back to the idea of endemism in a moment. There also had to be an additional factor that made the area unique and deserving of our focus. There had to be more than 70% of the original habitat already lost which highlighted the need to designate this place as a hotspot. Well why plants? Plants, particularly in terrestrial environments are crucial. Animals go where the plants are. Plants are the primary producers. They're at the base of food webs. Life attracts other life and it depends on other life. Now let's get back to that idea of endemism. An endemic species is a species that's found in a certain area and nowhere else on earth. In other words, endemism is a measure of how unique and irreplaceable something is. An example of an endemic organism that resonates with people, people love tortoises. If you think about the Galapagos Islands for example, most islands have their own special type of tortoise. It lives there, and nowhere else. So if something happens to wipe out the tortoises on that island, those tortoises are gone forever. They're not found anyplace else. They were irreplaceable. At the moment Conservation International formally recognizes 34 biodiversity hotspot areas on earth. The interesting thing about this is that less than three percent of the earth's land surface area is represented by these hotspots. So we're talking about some very, very special places indeed. There are other ways to think about these special places on earth besides hotspots. Some of these concepts are used to help recognize larger geographical units of land and water that have unique assemblages of species or distinct environmental conditions that make them worthy of our special attention. I think it's really important that we recognize that the hotspot idea is much more than a conservation tool. It's actually become a powerful scientific tool. Because hotspots are a blood pressure cuff for planet Earth. You can go back and keep measuring the effects on these different places due to human activity or environmental change of various kinds and go through the science of measuring the pressure on biodiversity. In a sense, hotspots are almost like avatars. They're like representatives for other endangered areas on the planet that might not necessarily meet this special criteria of 1500 endemic species of plants and more than 70% of the original habitat lost and yet they are still obviously critical and important places for lots of organisms to live. You need to think about hotspots as a network of places on Earth that are interconnected. Not just single units that protect small pieces of biodiversity but that help preserve biodiversity in a great many other habitats and other hotspots as well. And lots of conservation organizations, government agencies and even concerned people like all of us can use these hotspots to better help direct the resources to the places that require our greatest attention. Above all, we need to remember one overriding principle. That we focus on protecting the highest number of species that we can. Especially the ones that are most threatened. That's what this hotspot concept is trying to get to. We want to enhance our ability to protect species richness. That way, we can boost the stability and resilience of ecosystems. So I think that for me these hotspots really do carry that special signal and are really worthy of the special effort that's been developed over the last few decades to monitor to them, to provide the good, solid science that helps us not just to define them but to monitor and promote their health down the road and to employ those concepts to draw people in, to develop that people power that's really necessary to move forward with the protection of life on Earth.
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