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tv   Newsweek South Asia  PBS  July 21, 2013 3:00pm-3:31pm PDT

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. >>diversity is healthy. i mean when you have all this biodiversity, it generally indicates resiliency and that, that's the key to good conservation planning. the question is how do we foster resiliency, how do you keep all this biodiversity around, how do you generate it? well, we may find the answer right here. join me on today's expedition as we explore a land that has been the last refuge for so many, a land that in many respects really is an island - california. >> ♪music.
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>>roar of airplane. >>california! where better to talk diversity! >>♪music. >>there's more than just a diversity of faces in california. this is our most bio-diverse state - ridiculously so! there are over 5,860 different types of plants here, 2,153 of them are endemic - they are found nowhere else. add to this over 540 birds, 214 mammals, 77 reptiles, 47 amphibians, 83 fish...and, well, you get the picture! why? the state is big - it's huge! but there are small places here
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where diversity is really high. it's more than size. to begin to answer the question we travel to one of these diverse corners, torrey pines state reserve, just outside of san diego. so here are some really local statistics. right here in san diego county we have three million people. that makes it the fifth most populated county in the united states. in fact, three million people makes it larger than the population of 20 out of the 50 states. all these people share this place, these 2.7 million acres that make up san diego county with 2,300 species of plants. 2,300 species that makes san diego county, probably, the most bio-diverse county for plants anywhere in the country. another interesting thing about san diego county is that the people don't live everywhere. about 75% of this
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county is undeveloped. the thing is most of the undeveloped portion is over in the eastern section of the county, in the desert, on the other side of the mountains. the people live here in the coastal areas. unfortunately, a huge percentage of the non-human inhabitants of this county, a huge part of that biodiversity also lives here. 2,300 different types of plants, how do you pack that into such a small area? how is it possible that i can go from this mild climate here on the coast; to this, cool oak woodlands, well, cool this time of the year, they bake during the summer? to this - jeffrey pine forest where there's still snow on the ground. to this - white fir, incense cedar, and bigcone doug fir forests at the very peaks of the mountains where spring hasn't even thought about beginning. to this - one of the hottest and driest places in north america - all in only about 70 linear miles from
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the coast. so a large part of it has to do with topographical diversity, topography. that's just really the ups and the downs. and here in san diego county we can go from sea level here at the coast to over 6,500 feet up at the tops of the mountains, back down to sea level, even below, on the other side near the salton sea. well when you go up in elevation, temperature goes down and humidity goes up. that explains why we have such lush forests on the peaks of the mountains here. when you go over the other side, all of a sudden you are met with an extreme and abrupt change to desert, and that's because of where we set, right here on the western edge of a continent, at a very special latitude. another huge chunk of this whole problem with biodiversity has to do with that, the interplay between the land, the latitude, and this huge chunk of blue out here - the pacific.
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>>♪music. >>between 30 and 35 degrees latitude is a region of intense dryness. the reason is that the sun, which shines directly over the tropics warms air and as the warm air rises, it cools, water condenses, and then falls as rain - after it has rained out it begins to descend. this extremely dry air falls right here in what is known as the horse latitudes. during the summer months, as the earth tilts towards the sun here, the high moves northward along with the track of the sun's rays and during the winter it retreats to the south and allows storms from the pacific to track on shore- hence the rains fall here in the winter, not summer! this is called a mediterranean climate. we are really left with a backwards world here, it's moist
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and it's green in the wintertime and it's parched, hot and dry in the summertime. the challenge is that even though the moisture is available here in the wintertime, it's cooler in the wintertime, and the light levels are lower because the sun is lower on the horizon. now you don't have as much to work with light wise for photosynthesis. if you can adapt to this habitat, you are stuck here, because you have to grow in that habitat, and it doesn't exist anywhere outside mediterranean regions. that's why the mediterranean regions of the world are biodiversity hotspots. so many plants have adapted to grow just in that climate that they are full of endemics, and that shoots up the biodiversity even higher. one feature that a lot of the plants that live in mediterranean climates share in common is - they are beautiful! they have gorgeous flowers and they produce lots of them. so the one that's right in front of me here, this lotus, is a good example. i mean it's covered
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with yellow flowers, pea-shaped flowers, because this plant is in the pea family. but we also have things like sand verbenas, which are actually an abronia, they're in a different genus. here the beautiful pink abronia umbellata is in full flower even now in late winter. but if you come back in just a few weeks, this place is absolutely covered with poppies, phacelia, and just a myriad of other species. it's also incredible to think that this site only receives around 10 inches or less of rain a year. that's typical for the coastal sage scrub. ten inches of rain or less a year is usually a desert, but this place, a desert it's not. this place is dry, but it's not parched - why is that? the cold water flowing down the west side of the continent keeps the areas directly next to the coast cool. that's why the average temperature in san diego isn't that much warmer than san francisco over 400 hundred miles to the north. the cooler
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the temperature - the less evaporation. but there is another bit of nature's magic at work here. when the cold water comes into contact with hot, dry, summer air it forms fog. fog blankets these slopes during the summer, bathing them in light mist - nearly immeasurable but enough to keep it from baking like a desert! all the winter greenery means that food is available for animals at that time of the year too. and when you get those winter rains and you start to get all this flush of growth it's not just the plants that bloom, when the plants bloom and the thing greens up, the animals come out too. animals like brush rabbits, desert cottontails, california ground squirrels which are just absolutely everywhere out here. and birds - the rabbit up here, i have been watching him chew on stalks of green vegetation. now you think about a rabbit doing that, you maybe think about a ground squirrel doing that, but
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you don't usually think about things like the white-crowned sparrows that are over here acting very uncharacteristic for white-crowned sparrows for what we're used to in the east, or the california towhees that are everywhere, feeding on green vegetation, eating flowers, eating leaves. taking advantage of all the nutrients that are flushing into those plants during this odd time of the year. it's still winter, everything is green and everything is moving and wildlife, it's just everywhere. the habitat here at the coast is shrub land. it's called chaparral. here, we call it soft chaparral, or coastal sage scrub. dense, california sagebrush and true sages give it the name, and it's amazing scent. this is a place pleasant to all of the senses. >>bird chirping. >>that sound is often times
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called the sound of the chaparral, really it's almost the song of southern california, that's the sound of the wrentit. and the wrentit song, that song - bird chirping- is often described as a ping-pong ball being dropped on a table. it's a neat sound. it's a bird that you'll hear out here all day long, but you almost never see, and that's typical of the birds that we find in chaparral, not just the wrentit; but the california thrasher which actually has been giving us some nice views this morning sitting right up on top of vegetation. long, curved bill but a similar morphology to the wrentit, but all these birds have really, really short wings and long tails and they tend to be pretty drab in color, brown or gray, they don't want to show up and those short wings allow them to move through the shrubs and the long tail acts as a rudder. it's a cool bird and one of 492 species that are known from san diego county, making it the most diverse county, and...that's nice, of course that's the other sound of
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southern california - music from a passing car. red hot chili peppers i guess. but it sort of shows though uh, that there's not much of this habitat left in southern california and, and that's an important point because this habitat is vitally important for birds. >>bird chirping. >>even though this may not be a desert, it's filled with things that we think of as desert plants, and animals. there are a lot of plants here that are succulent and that's a great adaptation for growing in really dry climates. so we see lots of succulents, but some are truly special and this one's my favorite, this is shaw's agave, agave shawii, and this beautiful plant with those huge yellow clusters of flowers on this flowering stem, like all of our agaves is going to die at that growing point when it flowers, it's a determinate perennial but luckily it usually has tons of offshoots with these huge fleshy
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succulent leaves and wicked spines at the tip that will come in to keep this colony growing. and that's important because there's not that many shaw's agave left, shaw's agave is a good example of an endangered plant that we find here. california doesn't just have the highest diversity of any state it has the highest number of endangered species with over 600 found here. and this one it's here in this part of san diego county and just barely over into baja, it's a very localized endemic, just in this coastal sage scrub community. gets us to thinking about where these plants originally came from. to really understand why san diego county is really much more mexico than it is u.s. we need to go farther inland. >>♪music. >>as i move inland i leave the coastal fog behind - hard chaparral dominated by chamise coats the hillsides - it freezes here in the winter. at the top of the mountains, it is much
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cooler. over the other side, in the rain shadow, it quickly dries out. this is desert transition - a drop down further and all of a sudden i'm in the colorado desert. spring moves at break-neck speed here but it turns out that even the ground beneath our feet is on the move here in california. >>♪music. >>well this is it! this is what causes so much heartache for people who live here in this part of southern california. i'm standing pretty much directly on the san andreas fault and this is really important for southern california. what's odd here is this fault has right-lateral movement to it, and so what we're looking at here is the continental landmass of north america coming into contact with a different plate. this land over here has moved over 400 hundred miles in the last 20+ million years from where it used to be attached to mexico to
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where it is today, and that, that's one of the engines of biodiversity here in this part of california. >>♪music. >>those winter rains bring late winter and spring flowers to the desert too. the desert comes alive with flowers! every shrub - the encelia, the burrobush, the creosote bush, and then herbs everywhere. we have fagonia in full-flower out here, and lots phacelias, scorpionweeds, it's just incredible the amount of variation we find in the desert and this one, one i haven't seen before but we all know it, tobacco. did you know that tobacco is an american plant and the native americans used it and they used this one. imagine - our tobacco came from a desert heritage!
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>>bird chirping. >>on warm spring nights, desert life emerges in force. the strangest of creatures, like the desert banded gecko, are out hunting. their skin can't avoid drying out in the heat of day, so they live underground until darkness falls. perhaps even stranger are the granite night lizards with their elongated toes, made for scaling rock. many of the oddest snakes are also nocturnal like the lyre snake. this is a rear-fanged venomous species but it's no threat to humans. the bizarre shovel-nosed snake commonly crosses roads on warm nights but it's how they travel when not on pavement that's impressive! they can literally swim through the sand. tim burton must have drawn his inspiration here. the
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architects of the sand are out in force, the merriam's kangaroo rat. they're superbly adapted for life here - they never drink, all their water comes from metabolizing their food and a superb recycling system. they make intricate burrows that are often taken over and enlarged by the white-tailed antelope squirrels and these provide nighttime shelter for a colorado desert specialty - the fringe-toed lizard. this lizard is a master of the dunes. it has fringed toes for running on sand, enlarged scales that cover the ears, special eyelids, and valves over the nostrils - to keep the sand out. with all the problems that blowing sand creates it's hard to believe there are so many species that can deal with it. in fact, life thrives here. sometimes the inhabitants are just a little hard to spot! that was the
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venomous bite of the sidewinder and that's my boot - only it's not on my leg! that is why people get bitten - they step right onto a hidden snake while wearing sandals. wear boots or thick shoes to protect yourself and the snake. these are the only rattlesnakes to sidewind, apparently this minimizes their contact with the hot sand. no one is really sure what the funky eyebrows are all about! but they may act kind of like shades! it's hard to imagine there's so much life here in such a seemingly inhospitable place. sometimes lizards can tell you as much about the geology of an area as rocks can. lizards like this one, that's a banded rock lizard. he's out here sunning himself in this cool, late winter sun. if you watch that lizard, it is one of the most dexterous species around for moving on rocks. it's really well named. and it doesn't just
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move over top of the rocks and up the sides of the rocks. those specialized feet will cling right to the undersurface of rock and overhangs. we are in the peninsular range. peninsular should really kind of give it away. that peninsular refers to the baja peninsula, which which is part of mexico and really this part of california is much more mexico than it is u.s., and that lizard sort of tells us that. this lizard, like many of the lizards, that we find here in southern san diego county range mostly in mexico and barely enter the united states here. looking at the lizards here gives us yet another reason why this place is so diverse, it's a mixture of what moves up from mexico and what's moving down out of the united states. but more than that it gets us to thinking about how these things actually move. are they migrating from mexico themselves or is something else going on? why are these lizards restricted to just the parts of california that came from mexico? to answer
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this question and to really think about migration from a totally different mindset, we need to look at an even lowlier creature, one that's not found in the desert. we need to look at salamanders. the salamanders we're after are far above us here in the desert so we head back up hill and into the cool forests above 4,000 feet elevation. so, you know how they say california is full of freaks? well, they're right - when it comes to plants! i mean, imagine, in this state, we have the tallest tree on earth in the coastal redwood. and imagine that tree gets to be over 300 feet tall! how big do you think the cone is on such a giant tree? guess what -we've got one right here. let me grab one of these. whaaa! not too big is it? in fact, i guess it goes to show you can't tell the size of the cone by the height of the tree. but california redwood - not a very impressive cone. check out the little tiny tree behind me because this is truly one of the
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great freaks of california. they get to be 80, maybe 100 feet tall, but they're not a giant tree - they're small by california standards. what's impressive is the cone! and there are two from this tree right here. check those out! incredible! these are the cones of the coulter pine - the largest, heaviest cones on earth! they can get up to about 14 inches long and weigh about 9 pounds. one of the things we know is that when pines grow in hot, dry places they need to protect the seeds. and that's the function of a pinecone. so this pine grows at the lower elevations where it's really hot and droughty in the summertime so you need big, thick, scales to protect the seeds that are in this cone. that doesn't explain the giant spines though and people have had a harder time explaining that. maybe these are defenses for giant animals that are gone. things like giant ground sloth, maybe even
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mastodon, mammoth. who knows? but it truly is a freak of nature and only in california would you encounter something like this every day. well we've moved up in elevation now to about 4,600 feet and we're in a beautiful live oak forest here, or woodland we call it, because the trees are widely spaced-apart. and it happens to be the home to one of the most beautiful animals to me in the world. can you believe that? this is an ensatina, that's a large-blotched ensatina. the subspecies is klauberit's an incredible animal - it's a lungless salamander. lungless is what most of our salamanders are in the family plethodontidae and they breathe through their skin. means they have to stay moist and they have to stay cool. well, that's why we're here, to see this animal and to learn what an animal, even a salamander, can teach us about why we have so much biodiversity here in southern california.
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you'd hardly believe that this was the same species of ensatina. it is, in fact, there are seven subspecies that all look different. so why are they all considered the same species? it's because the subspecies can interbreed near the margins of their ranges but at their extremes they are essentially biologically isolated - they don't interbreed, at least not given the choice. this is a textbook case, of what's known as ring-speciation. a single species migrated south a long, long time ago; it formed a ring around the great central valley - that's not good salamander habitat - it's too hot and dry. the blotched form arose in the sierra nevadas, while the red form remained on the coast. when climates warmed and dried they became isolated on the mountain peaks, and this gives them a chance to change. then when the climate cooled, they wandered back into contact. now this process has been going on for millions and millions of
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years and the populations at the far corners are the most distinctive. and what we are seeing is speciation in action! all of the ecological islands provide a chance for all the plants and animals that enter california to do the same - to adapt - to generate biodiversity. this is a batrachoseps salamander or often times it's called a slender salamander. you can see how it gets that name; i mean it looks like a worm! well studies that looked at the life-long movements of these salamanders have shown that they may only move 4 or 5 meters from where they were born. that means they're stuck where they're at. and this salamander, this salamander, has taught us a ton about how important the complex geology of california really is. in the old days, we used to think there were only two species of slender salamanders. they all look very similar but thanks to an understanding of
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dna, which helps us determine who is related to who, we now know there are 20 species of slender salamanders. each range tends to correspond to a different geologic landmass. what's crazy is that we also know they originated in central america. because they don't move far, they rode the landmasses north from mexico and ended up here - isolated on the different pieces, which moved independently of each other. it isn't only salamanders that have moved this way, everything on the plates is doing this, but most move away from their homeland, the little sedentary salamanders don't and thus provide us evidence of how important the movement of the land has been. diverse geology and movement has also aided in the richness we see today in california. this little salamander has taught us that you don't necessarily have to move to migrate, sometimes the land moves you.
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we head back to where we began, torrey pines state reserve to visit its namesake - the rarest pine in the world. it's found only here and on one of the channel islands. it's a relict - making its last stand in california. but why here? how did it find just the right spot? what is it about this place that makes it the right spot? like most relicts, this one enjoyed a much wider range during the distant past. and as its range got smaller and smaller because the habitat, the climate was changing, it managed to find this one little corner of california where it could grow. because of that fog that comes in off the pacific during the warmer months - so then why isn't it all over the coastal sage scrub of california? it's not all over the coastal sage scrub because it can't compete. it has to have a marginal habitat and here it's provided by the sandstone cliffs and
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sandstone habitats that it's growing on. it's interesting also that this is a plant that we think speciated far to the south and rode those plates north to occupy the place where it is today. it's facing a bigger challenge maybe today than it ever has - a challenge that all these plants and animals are facing. they are now islands in a sea of humans and this tree itself is surrounded by three million of them. there's a critical balance to be met here if we're going to keep species like the torrey pine and the shaw's agave and so many others around for future generations - if we're going to protect the resilient workings those ecological interactions and the habitats that make california so special. join us next time as we explore the struggles and the success stories of the wildlife that call california home.
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to purchase a copy of expeditions with patrick mcmillan; california, an ecological island, call toll free, 1-800-553-7752 or order online at gcgcww
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[dramatic tango music] ♪ - it's not just about the photograph. it's the outdoor experience. [up-tempo percussive music] ♪ keep in mind everything that you need to know about photography-- f-stop, shutter speed, lens selection. nice photo op. we got beautiful light now. oh, my god. i'm your host, doug gardner, and your wild photo adventure starts now. captioning by captionmax thank you for joining us on another edition of wild photo adventures.


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