1 00:00:34,000 --> 00:00:38,440 Plants cover much of the land surface of our planet. 2 00:00:38,440 --> 00:00:42,880 But there is another extraordinary green world 3 00:00:42,880 --> 00:00:44,680 that is often hidden from us. 4 00:00:58,320 --> 00:01:01,880 It's one where plants have overcome huge challenges 5 00:01:01,880 --> 00:01:03,520 in order to survive. 6 00:01:11,880 --> 00:01:15,160 The world of fresh water. 7 00:01:28,840 --> 00:01:34,640 At first sight, a lake like this would seem to have everything 8 00:01:34,640 --> 00:01:37,920 that life needs in order to thrive. 9 00:01:37,920 --> 00:01:41,400 Clear, oxygen-rich water, 10 00:01:41,400 --> 00:01:44,600 plenty of dissolved nutrients and minerals 11 00:01:44,600 --> 00:01:47,160 and lots of sunlight. 12 00:01:47,160 --> 00:01:51,800 But, in fact, life in fresh water 13 00:01:51,800 --> 00:01:54,440 presents plants with huge problems. 14 00:01:57,720 --> 00:02:03,320 To succeed, plants have had to abandon many of the adaptations 15 00:02:03,320 --> 00:02:06,360 that served them so well on land 16 00:02:06,360 --> 00:02:10,440 and evolve something quite new and, doing that, 17 00:02:10,440 --> 00:02:15,440 they have created some of the most beautiful and bizarre 18 00:02:15,440 --> 00:02:18,080 and important habitats on Earth. 19 00:02:23,840 --> 00:02:27,480 There are few places where it's more difficult to make 20 00:02:27,480 --> 00:02:31,200 a permanent home than a freshwater torrent like this one. 21 00:02:51,480 --> 00:02:56,880 Violent currents drip across the riverbed, 22 00:02:56,880 --> 00:02:58,200 scouring it clean... 23 00:03:03,280 --> 00:03:07,680 ..whipping land plants from their margins 24 00:03:07,680 --> 00:03:08,920 and drowning them. 25 00:03:13,000 --> 00:03:16,800 How could any plant survive in a place like this? 26 00:03:28,920 --> 00:03:32,480 Yet, even here, some do manage to, 27 00:03:32,480 --> 00:03:35,200 quite literally, hold on. 28 00:03:39,800 --> 00:03:44,160 They can grasp the bare rock with remarkable strength. 29 00:03:50,360 --> 00:03:52,840 This ability allows plants to thrive 30 00:03:52,840 --> 00:03:55,680 in these otherwise hostile environments. 31 00:04:01,280 --> 00:04:05,560 This is the Cano Cristales river in Colombia. 32 00:04:21,280 --> 00:04:24,520 These plants are red Macarenia, 33 00:04:24,520 --> 00:04:28,600 sometimes called the Orchid of the Falls. 34 00:04:38,120 --> 00:04:41,560 They cling to the riverbed, not with their roots, 35 00:04:41,560 --> 00:04:46,040 but with their stems, glued to the rock surface by one 36 00:04:46,040 --> 00:04:48,160 of the most powerful adhesives in nature. 37 00:04:56,160 --> 00:04:58,280 The rock itself will break 38 00:04:58,280 --> 00:05:00,240 before these anchors lose their grip. 39 00:05:11,200 --> 00:05:15,680 These feathery filaments are their modified leaves, 40 00:05:15,680 --> 00:05:18,600 and they do what roots normally do - 41 00:05:18,600 --> 00:05:21,440 gather the minerals and nutrients they need 42 00:05:21,440 --> 00:05:23,040 that are dissolved in the water. 43 00:05:29,320 --> 00:05:33,360 With such spectacular colours, it's hardly surprising 44 00:05:33,360 --> 00:05:37,000 that the Cano Cristales is sometimes called 45 00:05:37,000 --> 00:05:40,160 the most beautiful river on Earth. 46 00:05:45,960 --> 00:05:49,960 But being rooted to the spot is not always the best strategy 47 00:05:49,960 --> 00:05:51,960 for living in a water world. 48 00:05:55,280 --> 00:05:58,560 This is a water lettuce, 49 00:05:58,560 --> 00:06:01,640 and it has some remarkable adaptations. 50 00:06:03,400 --> 00:06:06,840 Its roots hang free, 51 00:06:06,840 --> 00:06:09,880 so it's not anchored to the ground, 52 00:06:09,880 --> 00:06:13,360 and its leaves are thick and spongy 53 00:06:13,360 --> 00:06:16,120 and covered in fine hairs. 54 00:06:16,120 --> 00:06:19,240 So the plant itself is more or less unsinkable. 55 00:06:27,920 --> 00:06:32,000 This combination of characteristics enable the water lettuce 56 00:06:32,000 --> 00:06:36,240 to do something that almost no land plant can do. 57 00:06:36,240 --> 00:06:37,720 It can travel. 58 00:06:41,600 --> 00:06:45,800 It is an ability that becomes invaluable when, 59 00:06:45,800 --> 00:06:49,680 during the wet season, flooded rivers become great highways, 60 00:06:49,680 --> 00:06:52,720 as they do here in South America. 61 00:06:58,080 --> 00:07:02,080 This is the largest inland water world on Earth. 62 00:07:02,080 --> 00:07:03,520 The Pantanal. 63 00:07:04,960 --> 00:07:09,320 For a few months every year, it provides water plants 64 00:07:09,320 --> 00:07:12,040 with ideal conditions, 65 00:07:12,040 --> 00:07:16,760 but, all too soon, it becomes a battleground. 66 00:07:25,640 --> 00:07:29,360 Plants are racing to claim their space on the surface. 67 00:07:31,400 --> 00:07:35,840 The water lettuce rapidly expands its network of hanging roots 68 00:07:35,840 --> 00:07:38,280 so that it starts absorbing nutrients 69 00:07:38,280 --> 00:07:40,720 before other competitors arrive. 70 00:07:57,840 --> 00:08:00,240 Water hyacinth appears. 71 00:08:03,480 --> 00:08:08,160 Its leaves are carried on stalks filled with air 72 00:08:08,160 --> 00:08:11,160 that also make it virtually unsinkable. 73 00:08:16,440 --> 00:08:19,200 The race for space intensifies. 74 00:08:21,920 --> 00:08:25,680 A new competitor arrives, Ludwigia. 75 00:08:25,680 --> 00:08:29,400 It spreads by developing a chain of tiny rafts. 76 00:08:31,320 --> 00:08:34,520 And jostles for space with the densely packed leaves 77 00:08:34,520 --> 00:08:36,280 of mosaic plants. 78 00:08:43,440 --> 00:08:47,480 All are racing to claim as much sunlight as possible. 79 00:08:57,720 --> 00:09:01,280 They flower quickly before the floodwaters recede. 80 00:09:12,920 --> 00:09:16,520 And these surface dwellers also have competitors. 81 00:09:19,120 --> 00:09:22,240 Including one that has been waiting in the depths 82 00:09:22,240 --> 00:09:23,600 and is now stirring. 83 00:09:35,080 --> 00:09:37,200 It's a monster. 84 00:10:05,200 --> 00:10:07,160 It's well armed. 85 00:10:22,360 --> 00:10:27,040 It clears space for itself 86 00:10:27,040 --> 00:10:28,880 by wielding one of its buds. 87 00:10:30,680 --> 00:10:32,160 Like a club. 88 00:10:38,240 --> 00:10:42,000 And now it dominates the surface. 89 00:11:01,200 --> 00:11:04,880 This is a leaf of the giant water lily. 90 00:11:25,960 --> 00:11:29,800 It expands by over 20 centimetres a day 91 00:11:29,800 --> 00:11:31,520 and eventually measures 92 00:11:31,520 --> 00:11:33,200 more than two metres across. 93 00:11:38,560 --> 00:11:43,800 Its immense leaves are supported by a network of air-filled struts 94 00:11:43,800 --> 00:11:47,280 and protected by spines two centimetres long. 95 00:11:52,080 --> 00:11:56,240 The leaves float high in the water and their surfaces are dotted 96 00:11:56,240 --> 00:12:01,080 with tiny holes, drains, that help them ensure that rainwater 97 00:12:01,080 --> 00:12:03,480 doesn't accumulate and sink them. 98 00:12:17,640 --> 00:12:22,400 Nutrients from the fertile mud below are carried up by tubes 99 00:12:22,400 --> 00:12:26,080 in its stem to fuel the leaf's expansion. 100 00:12:34,040 --> 00:12:37,520 Over the next few months, the lily will produce 101 00:12:37,520 --> 00:12:40,560 some 40 or so of these gigantic leaves. 102 00:12:50,480 --> 00:12:55,680 And as each one reaches the surface and expands, more and more light 103 00:12:55,680 --> 00:12:59,400 is taken from those plants that are trying to grow beneath. 104 00:13:12,280 --> 00:13:15,120 Competitors are pushed aside. 105 00:13:38,800 --> 00:13:41,600 Some are crushed, 106 00:13:41,600 --> 00:13:43,160 or skewered. 107 00:14:20,640 --> 00:14:24,640 Eventually, its immense leaves press their margins 108 00:14:24,640 --> 00:14:26,880 against one another, 109 00:14:26,880 --> 00:14:30,600 totally cutting off the light from the plants beneath them. 110 00:14:33,640 --> 00:14:36,680 The battle is over. 111 00:14:36,680 --> 00:14:39,200 And victory is total. 112 00:14:58,680 --> 00:15:02,480 The frozen water world of Lake Akan in northern Japan. 113 00:15:06,960 --> 00:15:11,040 Home to one of the strangest and most primitive of plants. 114 00:15:14,520 --> 00:15:20,240 It's an alga, like those that appear so mysteriously in our ponds. 115 00:15:23,840 --> 00:15:27,080 But this one is truly extraordinary. 116 00:15:33,400 --> 00:15:38,160 Each spring, the melting ice releases soft, velvety balls 117 00:15:38,160 --> 00:15:43,120 of interwoven threads called Marimos. 118 00:15:46,760 --> 00:15:48,840 This one is small. 119 00:15:48,840 --> 00:15:50,560 No bigger than a walnut. 120 00:15:52,200 --> 00:15:54,480 But there are lots of them here. 121 00:16:00,440 --> 00:16:04,640 They attract the attention of visiting whooper swans. 122 00:16:33,120 --> 00:16:38,120 But there is one way for the Marimo to escape from the danger, 123 00:16:38,120 --> 00:16:40,200 and it depends on a change in the weather. 124 00:16:45,120 --> 00:16:49,960 Fortunately, in the spring, winds sweep across the lake... 125 00:16:52,120 --> 00:16:57,440 ..creating currents that carry some of the Marimos beyond the reach 126 00:16:57,440 --> 00:16:59,080 of hungry swans. 127 00:17:02,560 --> 00:17:05,360 It's the start of a remarkable journey. 128 00:17:22,880 --> 00:17:26,760 They are gently carried back and forth by the currents 129 00:17:26,760 --> 00:17:31,200 so that the Marimos become more and more spherical. 130 00:17:37,520 --> 00:17:41,160 And, slowly, they travel into deeper water. 131 00:17:53,960 --> 00:17:58,400 Here, there are great numbers of them, certainly many millions. 132 00:18:00,040 --> 00:18:03,280 Some are the size of basketballs. 133 00:18:09,560 --> 00:18:11,840 They're safe from swans, 134 00:18:11,840 --> 00:18:14,120 and the water is still shallow enough 135 00:18:14,120 --> 00:18:16,720 for some sunlight to reach them. 136 00:18:16,720 --> 00:18:18,720 It seems a perfect home. 137 00:18:20,120 --> 00:18:22,960 And so it is... 138 00:18:22,960 --> 00:18:24,120 ..almost. 139 00:18:26,440 --> 00:18:31,320 The snag is that these waters also carry a fine sediment 140 00:18:31,320 --> 00:18:34,160 that can clog the Marimo's surface, 141 00:18:34,160 --> 00:18:36,480 cutting off the all-important light. 142 00:18:40,040 --> 00:18:43,280 But the Marimos are not entirely immobile. 143 00:18:52,800 --> 00:18:54,280 They dance. 144 00:19:03,240 --> 00:19:07,480 The winds blowing over the lake's surface create currents 145 00:19:07,480 --> 00:19:11,920 beneath that are sufficiently strong to move the Marimos. 146 00:19:19,600 --> 00:19:22,160 They rub against each other. 147 00:19:22,160 --> 00:19:25,560 And in just a couple of hours of gentle movement, 148 00:19:25,560 --> 00:19:27,760 they're all clean once more. 149 00:19:34,320 --> 00:19:37,960 As they spin, every part of their surface 150 00:19:37,960 --> 00:19:40,600 gets enough time in the sunlight to keep growing. 151 00:19:59,240 --> 00:20:02,080 This is the heart of the Amazon. 152 00:20:19,640 --> 00:20:23,360 There are water worlds here that are so remote that, even today, 153 00:20:23,360 --> 00:20:25,480 few people have ever seen them. 154 00:20:28,640 --> 00:20:33,200 This barely explored tributary is the Rio Claro. 155 00:20:34,720 --> 00:20:38,280 And here, when conditions are just right, it's possible 156 00:20:38,280 --> 00:20:41,320 to witness a rare and remarkable spectacle. 157 00:20:52,280 --> 00:20:57,480 The river is so crystal clear that its bed is bathed in sunlight. 158 00:21:04,080 --> 00:21:09,120 A magical landscape of miniature mountains and valleys. 159 00:21:23,360 --> 00:21:28,200 It's carpeted by pipewort, fanwort 160 00:21:28,200 --> 00:21:30,440 and star grasses. 161 00:21:40,480 --> 00:21:43,240 As the sun climbs in the sky... 162 00:21:45,360 --> 00:21:49,840 ..bubbles of gas appear. 163 00:21:49,840 --> 00:21:52,520 Evidence of photosynthesis. 164 00:22:03,800 --> 00:22:06,240 Deep inside the plant cells, 165 00:22:06,240 --> 00:22:08,840 tiny structures called chloroplasts 166 00:22:08,840 --> 00:22:10,920 move towards the light. 167 00:22:14,920 --> 00:22:18,560 They absorb carbon dioxide and use the sun's power 168 00:22:18,560 --> 00:22:23,080 to synthesise the sugars that the plant needs to grow. 169 00:22:27,600 --> 00:22:31,160 And as a by-product, they release oxygen. 170 00:22:34,080 --> 00:22:38,520 The gas that we and all other animals must have 171 00:22:38,520 --> 00:22:40,760 in order to breathe. 172 00:23:02,320 --> 00:23:07,160 Now, in late afternoon, bubbles of oxygen make the river water 173 00:23:07,160 --> 00:23:09,400 fizz like champagne. 174 00:23:57,840 --> 00:24:01,280 The plants can become so buoyant with gas 175 00:24:01,280 --> 00:24:04,680 that they rise to the surface, 176 00:24:04,680 --> 00:24:06,680 even carrying the bedrock with them. 177 00:24:18,000 --> 00:24:20,720 Only in this remote water world 178 00:24:20,720 --> 00:24:24,160 can this spectacular natural wonder be seen. 179 00:24:33,680 --> 00:24:35,720 Eastern Venezuela. 180 00:24:39,120 --> 00:24:43,240 Here, rectangular table mountains known as tepuis 181 00:24:43,240 --> 00:24:45,680 stand above the tropical forest. 182 00:24:50,760 --> 00:24:54,440 There are more than 50 such isolated mountain plateaus here, 183 00:24:54,440 --> 00:24:57,240 each home to a unique community of plants. 184 00:25:02,320 --> 00:25:06,600 Downpours are so torrential that no soil can accumulate 185 00:25:06,600 --> 00:25:09,320 on their broad, rocky summits, 186 00:25:09,320 --> 00:25:12,600 and some plants living up here have to find their nutrients 187 00:25:12,600 --> 00:25:14,320 from another source. 188 00:25:21,840 --> 00:25:24,680 These are Bromeliads. 189 00:25:29,200 --> 00:25:33,600 Their leaves are shaped like a funnel and collect rainwater, 190 00:25:33,600 --> 00:25:35,720 which accumulates in the centre. 191 00:25:41,320 --> 00:25:46,200 This small pond is colonised by all kinds of tiny animals. 192 00:25:54,920 --> 00:25:58,560 And it is their bodies, when they die, that provide 193 00:25:58,560 --> 00:26:01,040 some of the nutrients the Bromeliads need. 194 00:26:03,320 --> 00:26:07,920 This makes a good partnership in which both parties can thrive. 195 00:26:09,160 --> 00:26:11,000 But... 196 00:26:11,000 --> 00:26:13,840 ..it can be exploited 197 00:26:13,840 --> 00:26:15,240 by a plant predator. 198 00:26:45,960 --> 00:26:50,000 This probing stem belongs to a plant called a bladderwort. 199 00:26:52,040 --> 00:26:54,920 It, too, is in need of nutrients. 200 00:27:03,640 --> 00:27:08,280 And a well-stocked Bromeliad pool is just the place to find them. 201 00:27:11,760 --> 00:27:15,080 This one is full of aquatic animals. 202 00:27:42,080 --> 00:27:44,640 The bladderwort begins to change... 203 00:27:47,080 --> 00:27:49,320 ..into a hunter. 204 00:27:51,520 --> 00:27:54,640 It develops bladders 205 00:27:54,640 --> 00:27:58,520 and removes sufficient of the water within them 206 00:27:58,520 --> 00:28:00,920 to create a partial vacuum. 207 00:28:04,960 --> 00:28:09,600 Each bladder has a trap door beside it with trigger hairs. 208 00:28:12,240 --> 00:28:15,440 Now all the bladderwort has to do... 209 00:28:17,600 --> 00:28:20,080 ..is to bide its time. 210 00:28:39,720 --> 00:28:42,720 It only takes one touch 211 00:28:42,720 --> 00:28:45,120 for the trap door to snap open... 212 00:28:47,840 --> 00:28:50,120 ..and suck in its prey. 213 00:28:57,160 --> 00:29:00,000 It's all over in a millisecond. 214 00:29:10,200 --> 00:29:14,200 And after it has fed, a bladderwort has enough energy 215 00:29:14,200 --> 00:29:17,080 to produce another tendril 216 00:29:17,080 --> 00:29:20,040 to search for another Bromeliad pool. 217 00:29:35,520 --> 00:29:39,200 Swamps and bogs are also poor in nutrients. 218 00:29:42,080 --> 00:29:46,320 So several plants that live in such places catch insects too, 219 00:29:46,320 --> 00:29:48,040 if they can. 220 00:30:00,680 --> 00:30:06,400 The leaves of Sundews are covered with long, red hairs, 221 00:30:06,400 --> 00:30:08,520 each tipped with a droplet. 222 00:30:27,880 --> 00:30:30,840 These glistening globules are, 223 00:30:30,840 --> 00:30:32,840 in fact, glue. 224 00:30:49,560 --> 00:30:55,000 Once the Sundews detect the taste of their victim's body, 225 00:30:55,000 --> 00:30:58,400 they flood it with digestive enzymes. 226 00:31:08,240 --> 00:31:11,160 The little body disintegrates. 227 00:31:15,600 --> 00:31:19,080 And the Sundew gets the nutrients it needs. 228 00:31:25,080 --> 00:31:28,600 Another plant has an even more elaborate way 229 00:31:28,600 --> 00:31:29,680 of catching a meal. 230 00:31:36,720 --> 00:31:40,440 The Venus Flytrap has leaves that are lined 231 00:31:40,440 --> 00:31:42,280 with interlocking teeth. 232 00:31:47,640 --> 00:31:51,400 It attracts insects by producing a sweet perfume, 233 00:31:51,400 --> 00:31:53,240 just as a flower does. 234 00:31:55,720 --> 00:31:58,560 It, too, has a hair trigger. 235 00:32:10,720 --> 00:32:13,520 And another insect is caught. 236 00:32:26,800 --> 00:32:30,240 But the technique is more complex than it might seem. 237 00:32:34,200 --> 00:32:37,600 The Venus Flytrap has a problem. 238 00:32:37,600 --> 00:32:40,840 It needs to avoid false alarms, 239 00:32:40,840 --> 00:32:45,880 snapping shut on something inedible, like a raindrop 240 00:32:45,880 --> 00:32:48,560 or a little bit of twig. 241 00:32:48,560 --> 00:32:52,200 That would be a waste of both time and energy. 242 00:32:52,200 --> 00:32:55,040 So how does it avoid that? 243 00:32:55,040 --> 00:32:58,760 Well, it does it by counting. 244 00:32:58,760 --> 00:33:01,120 If I touch this one, 245 00:33:01,120 --> 00:33:03,120 sensitive hair just there... 246 00:33:05,760 --> 00:33:07,640 ..no reaction. 247 00:33:07,640 --> 00:33:11,880 That could be a false alarm, but the plant remembers that 248 00:33:11,880 --> 00:33:13,920 for 20 seconds. 249 00:33:13,920 --> 00:33:17,600 And if I touch it a second time within that time, 250 00:33:17,600 --> 00:33:21,400 then that's much more likely to be worth eating. 251 00:33:21,400 --> 00:33:22,560 And so... 252 00:33:25,120 --> 00:33:26,200 ..it closes. 253 00:33:29,360 --> 00:33:34,920 So far, so good, but now it needs to be absolutely certain 254 00:33:34,920 --> 00:33:37,680 that it's got something worth eating, 255 00:33:37,680 --> 00:33:40,040 so it continues counting. 256 00:33:40,040 --> 00:33:45,440 Only after it has totted up five separate touches to those hairs 257 00:33:45,440 --> 00:33:50,840 will it give the final squeeze and then begin to produce the liquid 258 00:33:50,840 --> 00:33:54,720 from the surface of the leaf, which will dissolve the body 259 00:33:54,720 --> 00:33:56,560 of its unfortunate victim. 260 00:33:59,640 --> 00:34:03,680 The Flytrap now has enough energy to produce flowers 261 00:34:03,680 --> 00:34:07,120 and attract pollinating insects. 262 00:34:17,240 --> 00:34:23,400 Wind and insects between them pollinate virtually all land plants, 263 00:34:23,400 --> 00:34:27,160 but neither method can be used by plants that live 264 00:34:27,160 --> 00:34:29,360 entirely underwater. 265 00:34:29,360 --> 00:34:31,800 So some lead double lives. 266 00:34:35,280 --> 00:34:39,720 A chalk stream in southern England, and swaying in the current 267 00:34:39,720 --> 00:34:43,080 is a plant for which these rivers are famous. 268 00:34:44,240 --> 00:34:49,200 This is water-crowfoot, a kind of aquatic buttercup. 269 00:34:49,200 --> 00:34:53,040 For most of the year, it is underwater. 270 00:34:53,040 --> 00:34:56,520 And if I take this underwater camera... 271 00:34:59,560 --> 00:35:03,720 ..you can see its floppy stems grow horizontally. 272 00:35:03,720 --> 00:35:07,080 That reduces the risk of being swept away by the current. 273 00:35:10,400 --> 00:35:14,160 But each spring, when it's time to flower, it produces 274 00:35:14,160 --> 00:35:16,200 something crucially different... 275 00:35:18,640 --> 00:35:23,640 ..a stem that is stiff enough to resist the current 276 00:35:23,640 --> 00:35:26,800 and lift its flowers into the air above. 277 00:35:47,120 --> 00:35:50,720 And now, of course, they can get help from insects. 278 00:36:06,960 --> 00:36:09,600 So every year, in part, at least, 279 00:36:09,600 --> 00:36:13,040 water-crowfoot becomes a land plant... 280 00:36:16,160 --> 00:36:20,280 ..and provides us with one of the loveliest natural spectacles 281 00:36:20,280 --> 00:36:22,000 of the early English summer. 282 00:36:31,760 --> 00:36:35,800 Water-crowfoot is not the only water plant to lift its flowers 283 00:36:35,800 --> 00:36:36,800 above the surface. 284 00:36:42,720 --> 00:36:45,560 Plants do so all around the world. 285 00:36:51,240 --> 00:36:54,080 From the swamps of the Pantanal... 286 00:36:58,960 --> 00:37:02,680 ..to the lakes of Thailand, 287 00:37:02,680 --> 00:37:05,680 they all burst into spectacular bloom. 288 00:37:16,120 --> 00:37:20,080 Once they've been pollinated, they produce seeds. 289 00:37:32,320 --> 00:37:35,080 And now their flowers have done their job, 290 00:37:35,080 --> 00:37:39,760 some return to a life under water. 291 00:37:45,320 --> 00:37:49,760 Now they must ensure that some of their seeds 292 00:37:49,760 --> 00:37:53,400 will find suitable places in which to germinate. 293 00:38:06,960 --> 00:38:13,400 Bullrushes every year produce these long, brown, velvety objects. 294 00:38:14,760 --> 00:38:17,360 Look what happens when I break one open. 295 00:38:21,040 --> 00:38:25,040 It contains almost a quarter of a million seeds. 296 00:38:33,360 --> 00:38:36,880 Each seed is attached to a delicate parachute. 297 00:38:43,560 --> 00:38:47,440 Even the slightest breeze will lift it and may carry it 298 00:38:47,440 --> 00:38:49,880 for very long distances indeed. 299 00:38:52,200 --> 00:38:56,360 So even though suitable stretches of fresh water are few 300 00:38:56,360 --> 00:39:00,280 and far between, there's a good chance that at least one 301 00:39:00,280 --> 00:39:02,560 will end up in a place where it can grow. 302 00:39:11,720 --> 00:39:15,280 Much bigger seeds, of course, can't travel by air. 303 00:39:23,480 --> 00:39:25,840 A river can provide transport, 304 00:39:25,840 --> 00:39:30,720 but it's a one-way journey downstream 305 00:39:30,720 --> 00:39:32,880 that often ends up in the sea. 306 00:39:36,200 --> 00:39:38,240 And that's not ideal. 307 00:39:40,880 --> 00:39:46,160 So how can any riverside plant avoid this and travel upstream? 308 00:39:48,840 --> 00:39:51,880 Here, along the Bonito River in Brazil, 309 00:39:51,880 --> 00:39:56,120 a variety of trees manage to do exactly that. 310 00:40:03,360 --> 00:40:07,760 They embed their seeds in the middle of soft, sweet fruit. 311 00:40:24,920 --> 00:40:28,920 Monkeys, such as these capuchins, 312 00:40:28,920 --> 00:40:32,280 make a meal of them just as soon as they're ripe. 313 00:40:37,240 --> 00:40:41,240 But monkeys are very wasteful feeders. 314 00:40:41,240 --> 00:40:45,680 And what's not eaten ends up in the river 315 00:40:45,680 --> 00:40:48,200 and is washed away. 316 00:41:02,440 --> 00:41:04,360 But not all. 317 00:41:22,680 --> 00:41:27,560 In the fruiting season, hundreds of Piraputanga fish 318 00:41:27,560 --> 00:41:29,480 gather beneath these trees. 319 00:41:38,520 --> 00:41:42,920 But the Piraputanga want more than the monkeys' leftovers. 320 00:41:45,400 --> 00:41:50,080 The brightly coloured fruits are clearly visible, even to the fish 321 00:41:50,080 --> 00:41:51,280 in the water below. 322 00:42:00,800 --> 00:42:03,640 And some manage to claim them 323 00:42:03,640 --> 00:42:05,600 even before a monkey does. 324 00:42:19,520 --> 00:42:22,280 This isn't a skill mastered by just one particularly 325 00:42:22,280 --> 00:42:25,000 successful acrobatic fish. 326 00:42:25,000 --> 00:42:28,200 Many of the Piraputanga can do this. 327 00:42:33,720 --> 00:42:36,720 Nor is this a disaster for the tree. 328 00:42:42,880 --> 00:42:44,320 Far from it. 329 00:42:50,280 --> 00:42:53,640 These Piraputanga are migratory, 330 00:42:53,640 --> 00:42:57,240 heading many miles upriver to spawn. 331 00:43:05,240 --> 00:43:08,920 The trees, by enticing the fish to eat their fruits, 332 00:43:08,920 --> 00:43:12,200 have a perfect means of transport for their seeds. 333 00:43:13,760 --> 00:43:19,200 With luck, the seeds will be deposited many miles upstream. 334 00:43:37,080 --> 00:43:40,440 The ability to colonise new habitats 335 00:43:40,440 --> 00:43:45,400 has allowed one group of flowering plants to venture out of fresh water 336 00:43:45,400 --> 00:43:49,920 and into a world that may look the same to us, 337 00:43:49,920 --> 00:43:53,160 but for a plant is crucially different. 338 00:43:56,400 --> 00:43:58,840 The much greater, saltier world... 339 00:44:00,360 --> 00:44:01,880 ..the sea. 340 00:44:04,960 --> 00:44:10,400 This is a fruit from one of the most important plants on the Earth today. 341 00:44:11,560 --> 00:44:13,080 Seagrass. 342 00:44:21,000 --> 00:44:24,800 This particular one is floating off the coast of Formentera 343 00:44:24,800 --> 00:44:26,320 in the Mediterranean. 344 00:44:38,680 --> 00:44:43,440 100,000 years ago, a seagrass seed like this 345 00:44:43,440 --> 00:44:46,160 sank to the sea floor just here. 346 00:45:01,200 --> 00:45:03,000 And, eventually, it produced... 347 00:45:04,640 --> 00:45:06,080 ..a great meadow. 348 00:45:10,560 --> 00:45:15,000 A meadow that is still flourishing today. 349 00:45:18,240 --> 00:45:20,960 It did so by cloning itself. 350 00:45:24,280 --> 00:45:27,240 Now over ten miles across, 351 00:45:27,240 --> 00:45:29,760 it's not only one of the largest living 352 00:45:29,760 --> 00:45:32,080 organisms on Earth, 353 00:45:32,080 --> 00:45:34,120 it's also one of the oldest. 354 00:45:42,080 --> 00:45:46,640 And it supports a rich community of many kinds of animals. 355 00:45:52,000 --> 00:45:55,200 It's become a kind of marine savannah. 356 00:46:00,520 --> 00:46:03,840 Over 1,000 species now live here. 357 00:46:03,840 --> 00:46:07,720 Some, like these elegantly camouflaged pipe fish, 358 00:46:07,720 --> 00:46:10,120 live nowhere else but amongst the seagrass. 359 00:46:20,640 --> 00:46:23,880 Seagrass fringes many of the world's coasts. 360 00:46:31,640 --> 00:46:33,640 Turtles depend upon it, too. 361 00:46:38,720 --> 00:46:42,360 And so do Dugong - animals that are sometimes called, 362 00:46:42,360 --> 00:46:45,240 very appropriately, sea cows. 363 00:46:53,760 --> 00:46:58,200 Today, seagrass plays a critical role in maintaining the health 364 00:46:58,200 --> 00:46:59,880 of our planet. 365 00:47:02,080 --> 00:47:05,120 It creates stores of carbon around its roots 366 00:47:05,120 --> 00:47:07,560 at an enormous rate. 367 00:47:07,560 --> 00:47:11,400 35 times faster, in fact, than plants that live on the floor 368 00:47:11,400 --> 00:47:13,240 of a tropical rainforest. 369 00:47:16,880 --> 00:47:19,160 Here in Formentera, 370 00:47:19,160 --> 00:47:22,360 it's possible to see, beneath the living seagrass, 371 00:47:22,360 --> 00:47:25,040 layer upon layer of trapped carbon 372 00:47:25,040 --> 00:47:29,400 that the plants have accumulated over the past 2,000 years. 373 00:47:36,400 --> 00:47:41,080 Seagrass, however, is easily destroyed by human disturbance. 374 00:47:41,080 --> 00:47:45,120 A third of the world's underwater meadows have already been lost, 375 00:47:45,120 --> 00:47:47,320 and many more are in decline. 376 00:47:55,720 --> 00:48:00,440 Biologists are now striving to not only protect the remaining meadows, 377 00:48:00,440 --> 00:48:02,200 but to restore them. 378 00:48:05,400 --> 00:48:08,080 One plant at a time. 379 00:48:15,160 --> 00:48:18,240 Seagrass could be a valuable ally 380 00:48:18,240 --> 00:48:20,680 in our fight against climate change. 381 00:48:24,720 --> 00:48:28,960 Today, water worlds everywhere are under threat. 382 00:48:34,320 --> 00:48:37,800 Many of their inhabitants are disappearing 383 00:48:37,800 --> 00:48:40,560 without us even being aware of their existence. 384 00:48:48,880 --> 00:48:53,040 The plants that grow in water are probably the least noticeable. 385 00:48:53,040 --> 00:48:55,600 They're certainly the least studied. 386 00:48:55,600 --> 00:48:59,520 But the more you know about the problems of living in that way, 387 00:48:59,520 --> 00:49:02,720 the greater the wonder of their success. 388 00:49:04,440 --> 00:49:08,000 Surely they deserve more of our attention 389 00:49:08,000 --> 00:49:09,440 and, most importantly, 390 00:49:09,440 --> 00:49:10,840 our care. 391 00:49:27,640 --> 00:49:31,600 This vast wetland is the Pantanal. 392 00:49:31,600 --> 00:49:35,560 The Water World's team are heading to a plant battlefield. 393 00:49:36,880 --> 00:49:40,040 The home of Brazil's giant water lily. 394 00:49:42,760 --> 00:49:45,480 This is like seeing the end of a war. 395 00:49:45,480 --> 00:49:47,360 There are leaves growing on top of each other, 396 00:49:47,360 --> 00:49:49,800 flowers going through leaves. 397 00:49:49,800 --> 00:49:51,080 Unbelievable! 398 00:49:53,520 --> 00:49:58,000 To capture this story in all its detail would take over a year 399 00:49:58,000 --> 00:50:02,440 and require a unique Green Planet approach, both filming here, 400 00:50:02,440 --> 00:50:05,480 and, in a parallel mini Pantanal, 401 00:50:05,480 --> 00:50:08,800 in deepest, darkest Devon. 402 00:50:12,440 --> 00:50:16,520 This is the unique world of specialist time lapse cameraman 403 00:50:16,520 --> 00:50:18,080 Tim Shepherd. 404 00:50:21,000 --> 00:50:25,800 Tim has the reputation of being able to think like a plant. 405 00:50:26,840 --> 00:50:30,720 It's absolutely crucial that you get the plant really happy. 406 00:50:30,720 --> 00:50:34,160 And to make the giant lily feel totally at home, 407 00:50:34,160 --> 00:50:37,800 Tim must build a little piece of Brazilian wetland. 408 00:50:39,880 --> 00:50:42,640 First, a 10,000 litre tank. 409 00:50:45,960 --> 00:50:50,560 Hundreds of bricks, almost 1,000 kilos of soil 410 00:50:50,560 --> 00:50:52,960 and countless cups of tea later, 411 00:50:52,960 --> 00:50:54,840 the foundations are complete. 412 00:50:56,440 --> 00:50:59,040 So far, so good. 413 00:50:59,040 --> 00:51:04,160 Now time to prepare for the new green pellet camera system. 414 00:51:04,160 --> 00:51:07,680 We're trying to assemble the main gantry framework 415 00:51:07,680 --> 00:51:10,880 so that we can mount the moving rig on top of it. 416 00:51:10,880 --> 00:51:13,640 So it's a bit of a fiddle to get all the screws 417 00:51:13,640 --> 00:51:15,800 in all the right places, basically. 418 00:51:17,200 --> 00:51:20,680 After a few weeks, the building works are complete. 419 00:51:22,080 --> 00:51:24,160 The flood can now begin. 420 00:51:31,440 --> 00:51:34,600 Tim needs to be sure everything in the room is heated 421 00:51:34,600 --> 00:51:36,440 to tropical temperatures... 422 00:51:41,200 --> 00:51:44,120 ..before the star of the scene can move in. 423 00:51:46,880 --> 00:51:52,200 Carefully grown at the Royal Botanic Gardens at Kew, especially for us. 424 00:51:56,640 --> 00:52:00,120 Everything depends on this one plant. 425 00:52:00,120 --> 00:52:03,360 There will be no time for a second attempt. 426 00:52:05,000 --> 00:52:07,760 And even more important for Tim 427 00:52:07,760 --> 00:52:11,080 to keep his guest happy and healthy. 428 00:52:11,080 --> 00:52:13,680 This big monster need a lot of feeding. 429 00:52:13,680 --> 00:52:17,960 We found we need about five sand bags full of compost 430 00:52:17,960 --> 00:52:22,000 every two or three weeks, so we just sort of lower them in 431 00:52:22,000 --> 00:52:24,040 and stick them down by the roots. 432 00:52:24,040 --> 00:52:26,040 There you go. 433 00:52:26,040 --> 00:52:29,520 Whilst the Devon giant settles in, 434 00:52:29,520 --> 00:52:34,200 the Pantanal crew are continuing to get their shots. 435 00:52:34,200 --> 00:52:37,440 Time to see some giant water lilies underwater. 436 00:52:37,440 --> 00:52:40,280 And I hope there's no anaconda. 437 00:52:46,880 --> 00:52:49,400 Ooh! Mission accomplished! 438 00:52:52,840 --> 00:52:54,880 The pressure is now on Tim. 439 00:52:58,480 --> 00:53:03,240 After months of pampering, the giant lily is ready for action. 440 00:53:05,480 --> 00:53:09,920 First thing to film is a leaf spike rising up from the depths. 441 00:53:12,400 --> 00:53:15,040 Luckily, there are no anacondas here. 442 00:53:17,480 --> 00:53:20,640 The special camera weighs over 40 kilos. 443 00:53:20,640 --> 00:53:23,440 It's suddenly become less heavy, which is good. 444 00:53:23,440 --> 00:53:27,400 The new rig means Tim will be able to follow 445 00:53:27,400 --> 00:53:29,800 the emerging plant in any direction. 446 00:53:35,080 --> 00:53:37,160 Wow, fancy! 447 00:53:38,760 --> 00:53:41,040 The technology is working well, 448 00:53:41,040 --> 00:53:44,880 but nature is starting to derail Tim's plans. 449 00:53:44,880 --> 00:53:47,040 We're tangled up in all these weeds. 450 00:53:48,960 --> 00:53:53,000 What happens is we've got a bit of an ecosystem developing here 451 00:53:53,000 --> 00:53:57,280 and, before you know it, you get masses and masses of algae 452 00:53:57,280 --> 00:53:59,680 growing in amongst it all. 453 00:53:59,680 --> 00:54:02,200 Cor! 454 00:54:02,200 --> 00:54:06,280 Think I've just released some anaerobic gases there. 455 00:54:06,280 --> 00:54:09,160 No, not me, the algae! 456 00:54:10,480 --> 00:54:14,520 State of the art tools help keep the algae at bay. 457 00:54:18,320 --> 00:54:19,320 Eurgh! 458 00:54:25,720 --> 00:54:29,160 Just in time for Tim to film lift-off. 459 00:54:41,560 --> 00:54:44,400 That's quite nice coming out of the water, look at that! 460 00:54:44,400 --> 00:54:47,840 Tim's focus can now shift to the battle that's starting to take place 461 00:54:47,840 --> 00:54:49,000 on the surface. 462 00:54:52,760 --> 00:54:56,320 I'm trying to film this new bud coming out on this lily leaf. 463 00:54:56,320 --> 00:55:00,200 Give or take about three days to grow from where it is now. 464 00:55:00,200 --> 00:55:03,120 Somewhere in this zone between these two other leaves. 465 00:55:03,120 --> 00:55:05,280 I want that to last about ten seconds. 466 00:55:05,280 --> 00:55:08,600 Ten seconds is about 250 frames. 467 00:55:08,600 --> 00:55:11,200 That works out about one frame every 20 minutes. 468 00:55:13,080 --> 00:55:16,720 But plants don't read scripts. 469 00:55:16,720 --> 00:55:20,400 It's nature, it doesn't always do what you think it's going to do. 470 00:55:26,600 --> 00:55:30,080 We've had a few false starts where the leaf has swung out of shot 471 00:55:30,080 --> 00:55:31,560 and gone somewhere else. 472 00:55:37,440 --> 00:55:40,040 Or it just grows a lot quicker than you thought. 473 00:55:43,760 --> 00:55:46,360 It's a challenge to get things right. 474 00:55:46,360 --> 00:55:50,520 But with the combination of Tim's expertise and the new camera system, 475 00:55:50,520 --> 00:55:53,520 results are starting to look good. 476 00:55:53,520 --> 00:55:56,520 I think the difference now with this series is we can bring 477 00:55:56,520 --> 00:56:01,240 the plants much more to life as characters and tell their story 478 00:56:01,240 --> 00:56:03,200 in a much more dynamic way. 479 00:56:05,440 --> 00:56:10,680 It's great to be able to follow them around much more with the way 480 00:56:10,680 --> 00:56:12,560 you'd film an animal behaving. 481 00:56:20,080 --> 00:56:24,640 These rigs have given us a whole new realm of possibilities. 482 00:56:24,640 --> 00:56:27,640 After over a year of filming and recording 483 00:56:27,640 --> 00:56:30,240 100,000 separate images, 484 00:56:30,240 --> 00:56:35,080 the secret life of the giant water lily and the battle of the Pantanal 485 00:56:35,080 --> 00:56:36,920 has been revealed. 486 00:56:43,120 --> 00:56:45,840 Next time on The Green Planet, 487 00:56:45,840 --> 00:56:49,280 the ever changing seasonal world, 488 00:56:49,280 --> 00:56:53,080 full of hunters, tricksters 489 00:56:53,080 --> 00:56:55,000 and unlikely alliances. 490 00:56:58,080 --> 00:57:02,720 Plants here are in a race against the clock. 491 00:57:02,720 --> 00:57:05,000 Timing is everything. 492 00:57:07,640 --> 00:57:11,280 The Open University has produced a poster 493 00:57:11,280 --> 00:57:16,040 that explores the vital role that plants have for our planet. 494 00:57:16,040 --> 00:57:18,760 To order your free copy, call... 495 00:57:22,240 --> 00:57:23,640 ..or go to... 496 00:57:27,720 --> 00:57:30,440 ..and follow the links to the Open University.