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