1 00:00:37,560 --> 00:00:40,360 David Attenborough: The relationship between plants 2 00:00:40,480 --> 00:00:42,880 and humans is extraordinary. 3 00:00:45,240 --> 00:00:48,280 We've been adapting to each other 4 00:00:48,400 --> 00:00:51,280 for as long as we've been on the planet. 5 00:00:53,800 --> 00:00:57,800 We rely upon plants for almost everything. 6 00:00:57,920 --> 00:00:59,760 The air we breathe, 7 00:00:59,880 --> 00:01:01,440 the water we drink, 8 00:01:01,560 --> 00:01:03,120 the food we eat, 9 00:01:03,240 --> 00:01:05,360 much of the clothes we wear, 10 00:01:05,480 --> 00:01:07,040 and in some parts of the world, 11 00:01:07,160 --> 00:01:09,640 the very buildings in which we live. 12 00:01:11,160 --> 00:01:15,000 But that relationship is now changing. 13 00:01:16,400 --> 00:01:18,560 How it changes next 14 00:01:18,680 --> 00:01:23,080 will shape the future of our green planet. 15 00:01:36,840 --> 00:01:40,480 Some plants have the ability to live alongside us... 16 00:01:43,400 --> 00:01:46,600 Even when we make it extremely difficult 17 00:01:46,720 --> 00:01:48,840 for them to do so. 18 00:01:51,080 --> 00:01:53,840 This is piccadilly circus 19 00:01:53,960 --> 00:01:56,000 in the heart of London. 20 00:01:56,120 --> 00:01:58,480 It would be difficult to imagine 21 00:01:58,600 --> 00:02:01,880 a more hostile place for a plant. 22 00:02:03,440 --> 00:02:06,920 And yet, even here, 23 00:02:07,040 --> 00:02:09,400 plants will find a way. 24 00:02:19,840 --> 00:02:25,440 Plants like this may seem to follow us wherever we go. 25 00:02:28,680 --> 00:02:31,640 We call them - perhaps a little unkindly - 26 00:02:31,760 --> 00:02:33,200 weeds. 27 00:02:36,880 --> 00:02:40,840 In fact, these plants are pioneers, 28 00:02:40,960 --> 00:02:44,680 the ones that are most able to take advantage 29 00:02:44,800 --> 00:02:47,880 of new habitats, even very harsh ones. 30 00:02:52,800 --> 00:02:56,200 This wall is at least 100 years old. 31 00:02:56,320 --> 00:02:58,520 It's like a sheer cliff face, 32 00:02:58,640 --> 00:03:00,840 with no sign of soil. 33 00:03:01,920 --> 00:03:06,040 And yet, this Ivy-leaved toadflax thrives here. 34 00:03:07,200 --> 00:03:08,680 How? 35 00:03:10,080 --> 00:03:12,320 The plant grows towards the light, 36 00:03:12,440 --> 00:03:14,720 with its flowers facing outwards 37 00:03:14,840 --> 00:03:16,360 to attract pollinators. 38 00:03:17,680 --> 00:03:20,400 But once they've succeeded in doing that 39 00:03:20,520 --> 00:03:22,840 and the seed pods have started to develop, 40 00:03:22,960 --> 00:03:24,800 its behaviour changes. 41 00:03:26,720 --> 00:03:28,840 Now the pods turn 42 00:03:28,960 --> 00:03:31,400 and grow away from the light, 43 00:03:31,520 --> 00:03:34,400 seeking the darkest place they can find. 44 00:03:34,520 --> 00:03:37,000 A crevice, perhaps, 45 00:03:37,120 --> 00:03:38,320 like this one. 46 00:03:43,360 --> 00:03:46,080 It's all the toadflax needs. 47 00:03:47,160 --> 00:03:51,120 It can now germinate and start to produce a new plant. 48 00:04:08,640 --> 00:04:11,800 Other pioneers have a different strategy. 49 00:04:11,920 --> 00:04:15,960 They, instead, distribute their seeds far and wide 50 00:04:16,080 --> 00:04:17,880 in great numbers. 51 00:04:18,000 --> 00:04:22,600 Sow thistles are masters of this trick. 52 00:04:22,720 --> 00:04:27,640 Each of its seeds is equipped with a tiny downy parachute 53 00:04:27,760 --> 00:04:30,360 which will catch the slightest breeze. 54 00:04:32,520 --> 00:04:35,480 And they can travel extraordinary distances. 55 00:04:37,360 --> 00:04:39,920 They can rise a mile high in the sky 56 00:04:40,040 --> 00:04:42,720 and reach places hundreds of miles away 57 00:04:42,840 --> 00:04:44,720 from the parent plant. 58 00:04:48,480 --> 00:04:51,360 The seeds only need to find the tiniest chink... 59 00:04:52,680 --> 00:04:54,120 And they can take hold. 60 00:04:58,560 --> 00:05:02,280 We barely notice many of these plant invaders. 61 00:05:04,360 --> 00:05:07,560 But here, in the heart of Hong Kong, 62 00:05:07,680 --> 00:05:09,400 strangler fig seeds 63 00:05:09,520 --> 00:05:12,840 that landed on a stone wall generations ago 64 00:05:12,960 --> 00:05:18,160 have spread their flexible branching roots far and wide. 65 00:05:21,920 --> 00:05:24,880 They can be anchored so firmly 66 00:05:25,000 --> 00:05:27,560 that they become a part of the city's architecture. 67 00:05:31,320 --> 00:05:35,840 This is, perhaps, the ultimate weed. 68 00:05:39,280 --> 00:05:42,800 But there are places where the extraordinary abilities 69 00:05:42,920 --> 00:05:46,280 of fig trees have created a very different relationship 70 00:05:46,400 --> 00:05:48,280 with human beings. 71 00:05:48,400 --> 00:05:50,520 (Birds call) 72 00:06:01,760 --> 00:06:04,640 Meghalaya, in northeast India... 73 00:06:06,600 --> 00:06:08,360 A high-altitude plateau 74 00:06:08,480 --> 00:06:11,560 riven by dizzying/y steep valleys. 75 00:06:15,080 --> 00:06:17,800 It's home to the khasi people... 76 00:06:21,760 --> 00:06:23,200 Who've learned how to use 77 00:06:23,320 --> 00:06:26,160 the remarkable properties of fig trees 78 00:06:26,280 --> 00:06:29,120 to help them live in such difficult country. 79 00:06:33,160 --> 00:06:34,800 As in Hong Kong, 80 00:06:34,920 --> 00:06:38,280 the tree's numerous roots anchor it firmly, 81 00:06:38,400 --> 00:06:41,480 here, to steep mountainsides. 82 00:06:44,120 --> 00:06:48,760 These roots can grow up to 2. 5cm a day. 83 00:06:48,880 --> 00:06:51,080 They are unusually strong, 84 00:06:51,200 --> 00:06:52,360 flexible 85 00:06:52,480 --> 00:06:56,640 and can develop into a multitude of shapes. 86 00:06:58,480 --> 00:07:02,360 The khasi persuade them to provide them with stairs. 87 00:07:08,720 --> 00:07:10,360 The monsoon season brings 88 00:07:10,480 --> 00:07:12,920 a seemingly insurmountable challenge 89 00:07:13,040 --> 00:07:14,480 for khasi communities. 90 00:07:14,600 --> 00:07:16,600 (Thunder rumbles) 91 00:07:19,120 --> 00:07:22,320 This is the wettest place in the world. 92 00:07:23,920 --> 00:07:28,720 Nearly 30cm of rain can fall in a day. 93 00:07:37,840 --> 00:07:40,600 Rivers become lethal torrents, 94 00:07:40,720 --> 00:07:42,840 dividing communities from each other. 95 00:07:44,800 --> 00:07:48,560 This is when the relationship between fig trees and the khasi 96 00:07:48,680 --> 00:07:50,560 becomes most important. 97 00:07:52,840 --> 00:07:56,840 They deliberately plant fig trees near the rivers. 98 00:07:56,960 --> 00:07:58,640 When they're mature enough 99 00:07:58,760 --> 00:08:01,240 to have developed many hanging roots, 100 00:08:01,360 --> 00:08:05,360 shining star kongthaw begins working with them. 101 00:08:25,560 --> 00:08:29,080 He guides the roots through bamboo tubes 102 00:08:29,200 --> 00:08:32,080 that are pointed towards the opposite river bank. 103 00:08:50,800 --> 00:08:53,800 These strands will combine as they grow, 104 00:08:53,920 --> 00:08:56,280 sharing nutrients and resources, 105 00:08:56,400 --> 00:09:00,520 and becoming stronger than a lone strand could ever be. 106 00:09:27,760 --> 00:09:29,480 As the years pass, 107 00:09:29,600 --> 00:09:33,800 the growing roots become a living bridge. 108 00:09:52,560 --> 00:09:55,920 As they grow, they become ever stronger 109 00:09:56,040 --> 00:09:57,720 and more stable. 110 00:10:20,920 --> 00:10:24,960 This unusual relationship has allowed the people here 111 00:10:25,080 --> 00:10:29,080 to thrive in an otherwise challenging landscape. 112 00:10:44,920 --> 00:10:46,840 But there are plants 113 00:10:46,960 --> 00:10:49,160 that have found a deeper partnership with us, 114 00:10:49,280 --> 00:10:53,720 and in doing so, have changed landscapes across the globe. 115 00:10:57,280 --> 00:10:59,960 It began over 10,000 years ago 116 00:11:00,080 --> 00:11:03,800 with plants that we found especially good to eat. 117 00:11:05,720 --> 00:11:09,800 At first, this relationship created challenges of its own. 118 00:11:11,400 --> 00:11:14,040 Many of the ancestral grasses, 119 00:11:14,160 --> 00:11:16,480 like these wild oats from Israel, 120 00:11:16,600 --> 00:11:19,640 have a trick to ensure that their seeds 121 00:11:19,760 --> 00:11:22,560 are planted in the perfect place. 122 00:11:22,680 --> 00:11:25,280 Each seedhead, at the top, 123 00:11:25,400 --> 00:11:29,480 carries two long bristles called awns, 124 00:11:29,600 --> 00:11:32,920 and when a seed drops to the ground, 125 00:11:33,040 --> 00:11:36,760 these awns do something truly extraordinary. 126 00:12:15,200 --> 00:12:16,800 They walk. 127 00:12:22,680 --> 00:12:26,640 The awns twist as they dry out during the day, 128 00:12:26,760 --> 00:12:28,440 and then, when they get wet... 129 00:12:31,120 --> 00:12:33,720 They untwist. 130 00:12:35,960 --> 00:12:38,680 Tiny hairs grip onto the ground, 131 00:12:38,800 --> 00:12:41,680 keeping the individual moving forward. 132 00:12:48,000 --> 00:12:51,400 In this way, the seeds work their way along the ground 133 00:12:51,520 --> 00:12:55,200 until, eventually, they find a rock to hide under 134 00:12:55,320 --> 00:12:57,600 or a crack to drill into. 135 00:13:03,560 --> 00:13:06,560 This adaptation is useful for the plant 136 00:13:06,680 --> 00:13:08,160 but not for us. 137 00:13:09,560 --> 00:13:11,040 It's hard to collect seeds 138 00:13:11,160 --> 00:13:13,120 when they drop off and walk away. 139 00:13:14,760 --> 00:13:17,800 So our ancestors selected plants 140 00:13:17,920 --> 00:13:20,720 whose seeds don't drop off, 141 00:13:20,840 --> 00:13:22,160 don't have legs 142 00:13:22,280 --> 00:13:25,040 and don't Bury themselves out of reach. 143 00:13:27,840 --> 00:13:30,880 They also selected those individuals 144 00:13:31,000 --> 00:13:35,040 which put their energy into developing much larger seeds. 145 00:13:36,400 --> 00:13:38,080 Close relationships like this 146 00:13:38,200 --> 00:13:41,440 have developed all over the world... 147 00:13:42,800 --> 00:13:47,040 Producing the plants that are now our crops. 148 00:13:51,240 --> 00:13:53,000 This may seem a poor deal 149 00:13:53,120 --> 00:13:54,480 from the point of view of plants, 150 00:13:54,600 --> 00:13:55,920 butnotso. 151 00:13:56,040 --> 00:13:57,880 We eat their seeds 152 00:13:58,000 --> 00:14:00,000 but, in return, 153 00:14:00,120 --> 00:14:02,520 we Cherish and cultivate them 154 00:14:02,640 --> 00:14:07,440 and now they are widespread and far more abundant 155 00:14:07,560 --> 00:14:09,280 than their wild ancestors. 156 00:14:14,840 --> 00:14:16,760 You might call this 157 00:14:16,880 --> 00:14:20,480 a bargain between ourselves and plants, 158 00:14:20,600 --> 00:14:22,120 and over the years 159 00:14:22,240 --> 00:14:24,680 it's proved extraordinarily powerful. 160 00:14:34,320 --> 00:14:35,800 In the beginning... 161 00:14:37,360 --> 00:14:40,240 The bargain operated on a small scale. 162 00:14:48,760 --> 00:14:53,040 Plant, tend, and harvest by hand 163 00:14:53,160 --> 00:14:55,280 in small patches. 164 00:14:58,640 --> 00:15:00,200 Over time, 165 00:15:00,320 --> 00:15:04,960 these plants produced more food increasingly efficiently... 166 00:15:09,760 --> 00:15:14,200 And the partnerships became more exclusive. 167 00:15:17,760 --> 00:15:20,240 We started doing more and more 168 00:15:20,360 --> 00:15:23,920 for a small number of chosen species. 169 00:15:31,800 --> 00:15:33,640 These few persuaded us 170 00:15:33,760 --> 00:15:35,600 to eliminate their competitors... 171 00:15:37,120 --> 00:15:39,240 Cure their diseases, 172 00:15:39,360 --> 00:15:41,520 poison their enemies... 173 00:15:44,160 --> 00:15:46,360 And keep them well watered, 174 00:15:46,480 --> 00:15:50,360 even when other species face drought. 175 00:15:51,720 --> 00:15:56,160 Fewer and fewer plant species, like soy, wheat and rice, 176 00:15:56,280 --> 00:15:59,160 now occupy more and more land. 177 00:16:01,120 --> 00:16:03,520 So now whole landscapes 178 00:16:03,640 --> 00:16:06,440 are dominated by a single species of plant. 179 00:16:10,080 --> 00:16:11,680 A monoculture. 180 00:16:17,480 --> 00:16:21,200 This is the central valley of California, 181 00:16:21,320 --> 00:16:24,560 the biggest orchard in the world. 182 00:16:26,240 --> 00:16:30,320 A million acres of just one type of tree. 183 00:16:31,520 --> 00:16:32,960 Almonds. 184 00:16:41,120 --> 00:16:43,880 Each flower, if it's fertilised 185 00:16:44,000 --> 00:16:46,000 by pollen from a different almond tree... 186 00:16:47,080 --> 00:16:50,000 Will produce an almond nut. 187 00:17:01,680 --> 00:17:04,360 The flowers' patterns and scent have evolved 188 00:17:04,480 --> 00:17:05,960 to attract insects 189 00:17:06,080 --> 00:17:09,560 and bribe them to do that job for them. 190 00:17:09,680 --> 00:17:12,360 The pollen doesn't have to move far. 191 00:17:12,480 --> 00:17:14,760 It just has to reach a neighbouring tree. 192 00:17:19,160 --> 00:17:24,080 There are about 20,000 flowers on each tree... 193 00:17:27,600 --> 00:17:31,560 And 140 million trees. 194 00:17:34,200 --> 00:17:37,040 That is billions of flowers, 195 00:17:37,160 --> 00:17:39,240 all calling out at once. 196 00:17:43,240 --> 00:17:46,080 But here, the beauty of the blossom is wasted. 197 00:17:46,200 --> 00:17:49,240 To make way for these almond trees, 198 00:17:49,360 --> 00:17:52,000 the land was, in effect, wiped clean. 199 00:17:55,320 --> 00:17:58,680 Countless wild species of plants and animals 200 00:17:58,800 --> 00:18:03,200 were removed, including, critically, pollinators. 201 00:18:05,280 --> 00:18:07,600 So now the flowers need help, 202 00:18:07,720 --> 00:18:09,560 and lots of it. 203 00:18:37,920 --> 00:18:39,560 (Buzzing) 204 00:18:44,200 --> 00:18:46,360 40 billion honeybees... 205 00:18:47,680 --> 00:18:51,480 Trucked in from all over the United States. 206 00:18:58,840 --> 00:19:02,160 The orchard is only in bloom for a few weeks, 207 00:19:02,280 --> 00:19:06,760 so the almonds need the bees to get to work immediately. 208 00:19:22,920 --> 00:19:26,440 Each bee can visit thousands of blossoms a day. 209 00:19:29,200 --> 00:19:32,280 And while they take most of the pollen they collect 210 00:19:32,400 --> 00:19:33,440 back to the hive, 211 00:19:33,560 --> 00:19:37,640 they also drop some pollen at each stop. 212 00:19:37,760 --> 00:19:39,360 And so, with luck, 213 00:19:39,480 --> 00:19:42,880 the flowers are all eventually fertilised. 214 00:19:44,640 --> 00:19:46,880 Day after day, 215 00:19:47,000 --> 00:19:49,360 the process is repeated. 216 00:20:02,480 --> 00:20:05,280 Flower after flower. 217 00:20:10,120 --> 00:20:12,280 Tree after tree. 218 00:20:30,840 --> 00:20:36,560 By the time the petals fall, two-and-a-half trillion flowers 219 00:20:36,680 --> 00:20:38,680 have been successfully pollinated 220 00:20:38,800 --> 00:20:41,160 and will now grow into 221 00:20:41,280 --> 00:20:43,160 two-and-a-half trillion almonds. 222 00:20:45,440 --> 00:20:49,560 This type of intensive, streamlined agriculture 223 00:20:49,680 --> 00:20:53,080 produces amazingly high yields. 224 00:20:57,120 --> 00:20:59,560 But monocultures are fragile. 225 00:21:01,200 --> 00:21:03,520 While they can function effectively 226 00:21:03,640 --> 00:21:05,400 when conditions remain stable, 227 00:21:05,520 --> 00:21:07,480 it only takes a small change 228 00:21:07,600 --> 00:21:10,280 to create catastrophe. 229 00:21:23,160 --> 00:21:25,400 Lodgepole pine. 230 00:21:27,320 --> 00:21:29,440 A very valuable timber tree 231 00:21:29,560 --> 00:21:32,400 grown extensively in western Canada. 232 00:21:35,280 --> 00:21:37,960 Millions of acres of the same species, 233 00:21:38,080 --> 00:21:40,240 all the same age 234 00:21:40,360 --> 00:21:41,800 and the same size. 235 00:21:44,800 --> 00:21:47,440 For centuries, lodgepole forests 236 00:21:47,560 --> 00:21:50,320 have lived in a natural balance with their enemies, 237 00:21:50,440 --> 00:21:53,200 including this one. 238 00:21:54,360 --> 00:21:56,720 The mountain pine beetle. 239 00:22:00,480 --> 00:22:04,920 In summer, female beetles start hunting for a suitable nursery 240 00:22:05,040 --> 00:22:07,160 in which to lay their eggs. 241 00:22:14,600 --> 00:22:18,320 The ideal site is a mature lodgepole pine, 242 00:22:18,440 --> 00:22:22,000 with bark thick enough to feed a female's brood 243 00:22:22,120 --> 00:22:24,760 and, critically, to protect them 244 00:22:24,880 --> 00:22:27,400 from the bitter cold of the coming winter. 245 00:22:32,760 --> 00:22:35,280 Once under the bark, 246 00:22:35,400 --> 00:22:37,200 she tunnels upwards... 247 00:22:39,960 --> 00:22:42,360 Laying her eggs as she goes. 248 00:22:47,760 --> 00:22:49,600 A single female beetle 249 00:22:49,720 --> 00:22:51,920 can lay 100 eggs in a season. 250 00:23:07,080 --> 00:23:09,400 When the larvae hatch, 251 00:23:09,520 --> 00:23:13,200 they grow by feeding on the inside of the bark. 252 00:23:14,640 --> 00:23:18,440 As they do, they damage the channels 253 00:23:18,560 --> 00:23:20,400 that transport water and nutrients 254 00:23:20,520 --> 00:23:22,120 between the roots and needles. 255 00:23:35,480 --> 00:23:36,800 For centuries, 256 00:23:36,920 --> 00:23:40,280 the freezing northern winters killed the majority of larvae 257 00:23:40,400 --> 00:23:43,520 so tree and beetle remained in balance, 258 00:23:43,640 --> 00:23:46,920 but now, with the climate changing, 259 00:23:47,040 --> 00:23:50,800 the winters aren't cold enough to control the beetle numbers. 260 00:23:53,200 --> 00:23:55,320 Needles turning red 261 00:23:55,440 --> 00:23:58,720 are a sure sign that the trees are dying. 262 00:24:07,800 --> 00:24:11,760 The beetle plague spreads like wildfire across a landscape 263 00:24:11,880 --> 00:24:15,760 covered by a monoculture of similarly vulnerable trees. 264 00:24:19,200 --> 00:24:22,840 Since the first mass outbreak 40 years ago, 265 00:24:22,960 --> 00:24:25,120 trillions of trees in North America 266 00:24:25,240 --> 00:24:28,120 have been killed by the mountain pine beetle. 267 00:24:33,840 --> 00:24:37,560 Loss of plant diversity makes any habitat 268 00:24:37,680 --> 00:24:40,520 more vulnerable to changing conditions. 269 00:24:42,840 --> 00:24:45,120 Now, with climate changing so fast, 270 00:24:45,240 --> 00:24:50,280 we 're losing plant diversity just when we need it the most. 271 00:24:52,120 --> 00:24:55,040 Two out of five plants 272 00:24:55,160 --> 00:24:57,440 are now facing extinction. 273 00:24:57,560 --> 00:25:01,200 Of course, the loss of any one species 274 00:25:01,320 --> 00:25:03,920 is in itself a tragedy. 275 00:25:04,040 --> 00:25:08,160 But such a loss erodes the stability 276 00:25:08,280 --> 00:25:10,000 of a whole ecosystem, 277 00:25:10,120 --> 00:25:15,240 and that should be of great concern for all of us. 278 00:25:17,840 --> 00:25:21,000 We need an insurance policy. 279 00:25:22,400 --> 00:25:25,840 A hedge against extinction. 280 00:25:27,240 --> 00:25:31,200 This is kew's millennium seed bank. 281 00:25:33,640 --> 00:25:38,680 Packets of seed arrive here from all over the world. 282 00:25:39,840 --> 00:25:43,440 These are from a relative of the yucca plant 283 00:25:43,560 --> 00:25:45,640 which grows in central Mexico 284 00:25:45,760 --> 00:25:49,200 on the slopes of volcanos and nowhere else. 285 00:25:52,560 --> 00:25:58,000 Most of the seeds are from plants that are threatened. 286 00:25:58,120 --> 00:26:00,520 Some, indeed, have gone extinct 287 00:26:00,640 --> 00:26:02,600 since their seeds arrived here. 288 00:26:02,720 --> 00:26:06,200 But here, at least, those seeds are safe. 289 00:26:10,120 --> 00:26:12,880 When they arrive, they're processed 290 00:26:13,000 --> 00:26:17,080 and sealed into airtight jars. 291 00:26:18,880 --> 00:26:20,960 The seeds are then brought underground 292 00:26:21,080 --> 00:26:23,120 to be stored in a vault, 293 00:26:23,240 --> 00:26:24,600 like this one, 294 00:26:24,720 --> 00:26:27,000 at minus 20 degrees centigrade. 295 00:26:33,080 --> 00:26:35,160 Since the bank was founded, 296 00:26:35,280 --> 00:26:40,240 2 billion seeds, from 40,000 different species, 297 00:26:40,360 --> 00:26:42,640 have been brought and stored here. 298 00:26:51,760 --> 00:26:55,160 Because a seed contains everything it needs 299 00:26:55,280 --> 00:26:57,400 to start a new plant, 300 00:26:57,520 --> 00:26:59,040 each and every one of them 301 00:26:59,160 --> 00:27:02,000 represents a little grain of hope. 302 00:27:16,520 --> 00:27:20,160 Hope that one day we will make it possible 303 00:27:20,280 --> 00:27:25,480 for the seeds of these rarities to grow in the wild once again. 304 00:27:29,400 --> 00:27:32,080 The seed bank certainly gives us options 305 00:27:32,200 --> 00:27:36,000 when a species becomes rare or even extinct. 306 00:27:42,240 --> 00:27:45,360 But around the world, people are trying ways 307 00:27:45,480 --> 00:27:48,320 to keep natural plant populations healthy 308 00:27:48,440 --> 00:27:49,760 where they should be - 309 00:27:49,880 --> 00:27:52,120 in the wild. 310 00:28:00,560 --> 00:28:02,560 Hawaii. 311 00:28:05,280 --> 00:28:08,520 90% of the plant species here 312 00:28:08,640 --> 00:28:11,800 are found nowhere else in the world. 313 00:28:16,400 --> 00:28:19,360 Many are threatened by a plant invader 314 00:28:19,480 --> 00:28:21,800 called miconia. 315 00:28:25,440 --> 00:28:27,920 It was brought to the island of Maui 316 00:28:28,040 --> 00:28:30,640 in the '70s as an ornamental plant. 317 00:28:32,000 --> 00:28:33,440 In its native Mexico, 318 00:28:33,560 --> 00:28:34,720 it grows in balance 319 00:28:34,840 --> 00:28:36,520 with a rich variety of predators, 320 00:28:36,640 --> 00:28:39,040 competitors and diseases. 321 00:28:45,800 --> 00:28:49,360 It grows taller than most Hawaiian native vegetation, 322 00:28:49,480 --> 00:28:51,680 and little can grow beneath it. 323 00:29:01,200 --> 00:29:02,800 On the island of Maui, 324 00:29:02,920 --> 00:29:04,840 with nothing to keep it in check, 325 00:29:04,960 --> 00:29:07,840 it creates a stifling monoculture. 326 00:29:11,040 --> 00:29:13,600 Miconia, it would appear, 327 00:29:13,720 --> 00:29:15,960 is doing very well for itself. 328 00:29:19,560 --> 00:29:23,520 But today, it's under attack. 329 00:29:28,160 --> 00:29:31,400 On level ground, a single dedicated team 330 00:29:31,520 --> 00:29:34,920 can keep miconia in check. 331 00:29:42,600 --> 00:29:44,320 But, unfortunately, 332 00:29:44,440 --> 00:29:46,080 this plant can spread to places 333 00:29:46,200 --> 00:29:48,960 impossible for people to reach on foot. 334 00:29:54,960 --> 00:29:57,640 Just one plant can produce 335 00:29:57,760 --> 00:30:00,320 around 10 million seeds a year - 336 00:30:00,440 --> 00:30:03,680 enough to cover this entire landscape. 337 00:30:06,040 --> 00:30:07,760 With so much at stake, 338 00:30:07,880 --> 00:30:11,680 the team have come up with an extraordinary plan. 339 00:30:56,040 --> 00:30:58,840 It's too dangerous to land here. 340 00:31:01,400 --> 00:31:03,120 But they don't need to. 341 00:31:10,600 --> 00:31:12,480 A marksman with great skill 342 00:31:12,600 --> 00:31:16,960 can shoot the miconia with paintballs full... 343 00:31:17,080 --> 00:31:18,840 Of herbicide. 344 00:31:21,720 --> 00:31:25,680 A perfect shot is one that hits the stem, 345 00:31:25,800 --> 00:31:29,920 so ensuring that the herbicide spreads throughout the plant. 346 00:31:41,280 --> 00:31:43,400 (Indistinct radio chatter) 347 00:31:43,520 --> 00:31:45,720 The method is so precise 348 00:31:45,840 --> 00:31:48,960 that with careful flying and accurate aim, 349 00:31:49,080 --> 00:31:50,640 they can kill the intruders... 350 00:31:51,680 --> 00:31:55,160 Without damaging any wild plants. 351 00:32:26,160 --> 00:32:28,480 Destroying alien invaders 352 00:32:28,600 --> 00:32:31,960 is not the only way to help the native plants here. 353 00:32:34,360 --> 00:32:35,640 (Birdsong) 354 00:32:40,040 --> 00:32:44,560 This is waikamoi preserve, the last surviving fragment 355 00:32:44,680 --> 00:32:47,360 of a high-altitude Hawaiian rainforest... 356 00:32:47,480 --> 00:32:51,320 And home to one of the world's rarest plants. 357 00:32:55,280 --> 00:32:56,520 Holokea. 358 00:32:59,280 --> 00:33:04,240 There are only 57 fully grown individuals left in the wild. 359 00:33:08,360 --> 00:33:12,200 Their peculiar flowers evolved to suit the beak of a bird 360 00:33:12,320 --> 00:33:15,760 found only in Hawaii - the 'i'iwi. 361 00:33:18,000 --> 00:33:20,320 The bird is now so rare itself 362 00:33:20,440 --> 00:33:24,760 that today these partners seldom, if ever, meet. 363 00:33:27,280 --> 00:33:30,680 So the chances of holokea getting pollinated 364 00:33:30,800 --> 00:33:32,200 are very slim. 365 00:33:33,840 --> 00:33:39,240 But a strange new partnership might just save it. 366 00:33:39,360 --> 00:33:44,960 I look at losing a plant as flying in a plane 367 00:33:45,080 --> 00:33:46,920 and taking a screw out. 368 00:33:47,040 --> 00:33:49,080 Yeah, the plane will fly, 369 00:33:49,200 --> 00:33:50,720 and you might be able to 370 00:33:50,840 --> 00:33:52,400 take a couple screws out 371 00:33:52,520 --> 00:33:53,920 and keep flying, 372 00:33:54,040 --> 00:33:57,040 but eventually, you're going to crash. 373 00:34:07,040 --> 00:34:08,960 Hank knows where to find 374 00:34:09,080 --> 00:34:12,280 every one of the last 57 plants. 375 00:34:13,760 --> 00:34:18,160 And he returns every year to act as their pollinator. 376 00:34:19,200 --> 00:34:23,760 We have to step in and play that role as... 377 00:34:23,880 --> 00:34:25,680 Pollinator, matchmaker. 378 00:34:34,800 --> 00:34:37,840 Hank collects the pollen from the male flower 379 00:34:37,960 --> 00:34:42,200 and dusts it onto a female flower of a different plant. 380 00:34:45,040 --> 00:34:47,320 He's currently their life support, 381 00:34:47,440 --> 00:34:51,360 but his goal is for holokea to thrive without him. 382 00:34:52,840 --> 00:34:54,680 So before he leaves, 383 00:34:54,800 --> 00:34:58,200 he plays the call of the 'i'iwi bird. 384 00:34:58,320 --> 00:35:00,760 (Birds calling) 385 00:35:11,240 --> 00:35:14,320 Hank hopes the sound will attract the living birds, 386 00:35:14,440 --> 00:35:17,720 and if they come, that they will reconnect 387 00:35:17,840 --> 00:35:19,280 with the last holokea 388 00:35:19,400 --> 00:35:22,280 and rekindle their vital relationship. 389 00:35:25,120 --> 00:35:27,560 (Birds calling) 390 00:35:34,880 --> 00:35:38,080 I believe all species are important. 391 00:35:41,000 --> 00:35:44,160 And I believe we have a duty to act. 392 00:35:50,480 --> 00:35:54,880 We need to act not only in the wild places, 393 00:35:55,000 --> 00:35:57,600 but even in those where we live 394 00:35:57,720 --> 00:35:59,200 and where we farm. 395 00:35:59,320 --> 00:36:01,200 (Water running) 396 00:36:05,440 --> 00:36:06,760 Like much of the world, 397 00:36:06,880 --> 00:36:10,400 Kenya is losing thousands of native trees annually, 398 00:36:10,520 --> 00:36:15,400 ones that local people rely on for so much, especially fuel. 399 00:36:19,480 --> 00:36:20,960 But here, people have come up 400 00:36:21,080 --> 00:36:23,160 with an ingenious way to reverse 401 00:36:23,280 --> 00:36:26,120 some of that loss around them. 402 00:36:26,240 --> 00:36:28,680 (Machinery whirring) 403 00:36:34,080 --> 00:36:37,120 At a factory in the outskirts of Nairobi, 404 00:36:37,240 --> 00:36:41,480 workers collect and sort waste charcoal dust. 405 00:36:45,640 --> 00:36:50,000 Seeds of carefully selected native trees 406 00:36:50,120 --> 00:36:53,360 are mixed with the dust. 407 00:36:55,560 --> 00:36:59,800 This carbon coat will protect the seeds from hungry animals 408 00:36:59,920 --> 00:37:02,120 until the rains arrive. 409 00:37:11,520 --> 00:37:15,000 These are seed balls. 410 00:37:29,200 --> 00:37:30,960 In the village of kibwezi, 411 00:37:31,080 --> 00:37:33,600 acacia trees are becoming scarce, 412 00:37:33,720 --> 00:37:36,200 cut down by previous generations 413 00:37:36,320 --> 00:37:37,680 to make charcoal. 414 00:37:37,800 --> 00:37:40,920 (Children chattering) 415 00:37:58,960 --> 00:38:01,320 But the students at this school 416 00:38:01,440 --> 00:38:05,280 make forest restoration child's play. 417 00:38:23,240 --> 00:38:26,360 The nutrients in the dissolving char dust 418 00:38:26,480 --> 00:38:28,800 will give each little seed a good start. 419 00:38:36,000 --> 00:38:38,440 If only a handful of these seeds grow into a tree, 420 00:38:38,560 --> 00:38:41,280 the effort has been well worth it. 421 00:38:42,760 --> 00:38:45,600 Every mature acacia tree can itself produce 422 00:38:45,720 --> 00:38:48,240 thousands of seeds a year. 423 00:38:53,120 --> 00:38:56,400 13 million seed balls have been distributed 424 00:38:56,520 --> 00:38:58,280 in Kenya alone. 425 00:39:01,120 --> 00:39:05,200 And the methods by which they are dispersed... 426 00:39:08,160 --> 00:39:12,480 Are ever more inventive, to say the least. 427 00:39:25,640 --> 00:39:29,600 This technique is being repeated around the globe. 428 00:39:29,720 --> 00:39:32,600 A seed-ball-making workshop. 429 00:39:32,720 --> 00:39:37,640 People are choosing seeds of local native plants, 430 00:39:37,760 --> 00:39:39,600 giving them a little initial help, 431 00:39:39,720 --> 00:39:42,920 and bringing some wild plants back 432 00:39:43,040 --> 00:39:44,600 into the world around them. 433 00:39:49,880 --> 00:39:51,720 But is it possible, 434 00:39:51,840 --> 00:39:54,920 even in our most extreme monocultures, 435 00:39:55,040 --> 00:39:58,040 to invite a bit of wildness in? 436 00:39:59,920 --> 00:40:03,400 And with it, a bit of resilience? 437 00:40:05,760 --> 00:40:10,520 I have two different kinds of forage growing in my orchard. 438 00:40:10,640 --> 00:40:13,120 The yellow that you see behind me 439 00:40:13,240 --> 00:40:15,600 is a variety of different mustards, 440 00:40:15,720 --> 00:40:17,560 and then after the bloom, 441 00:40:17,680 --> 00:40:20,640 we're going to see some clover blossom. 442 00:40:22,960 --> 00:40:27,480 This mix of plants means the bees can feed 443 00:40:27,600 --> 00:40:30,560 before and after the brief almond bloom. 444 00:40:30,680 --> 00:40:34,360 They also get a more balanced, healthier diet. 445 00:40:35,440 --> 00:40:38,600 In the meantime, it's going to provide habitat 446 00:40:38,720 --> 00:40:40,880 for all sorts of insects, and the bees, 447 00:40:41,000 --> 00:40:42,440 probably some rabbits. 448 00:40:44,680 --> 00:40:47,440 It's a step towards establishing a better, 449 00:40:47,560 --> 00:40:49,080 more stable system. 450 00:40:50,960 --> 00:40:52,520 It's about finding balance. 451 00:40:52,640 --> 00:40:54,440 That's what we're trying to do here. 452 00:40:54,560 --> 00:40:56,400 Find a balance. 453 00:40:59,760 --> 00:41:03,320 Can humanity globally find a new balance 454 00:41:03,440 --> 00:41:04,960 between wild plants 455 00:41:05,080 --> 00:41:07,680 and those we have domesticated? 456 00:41:11,320 --> 00:41:13,720 Around half the usable land on earth 457 00:41:13,840 --> 00:41:15,760 is taken up by agriculture. 458 00:41:17,200 --> 00:41:19,200 Do we really need that much? 459 00:41:20,600 --> 00:41:21,920 Maybe not. 460 00:41:23,720 --> 00:41:26,200 It's a remarkable fact, 461 00:41:26,320 --> 00:41:31,000 but around 80% of all cultivated land 462 00:41:31,120 --> 00:41:36,240 is used for raising livestock for us to eat. 463 00:41:38,080 --> 00:41:40,320 Raising animals can be a sustainable way 464 00:41:40,440 --> 00:41:43,880 to create food, but in many places, 465 00:41:44,000 --> 00:41:46,600 plants can produce the same amount of protein 466 00:41:46,720 --> 00:41:50,040 on a fraction of the land that animals need. 467 00:41:52,840 --> 00:41:55,200 What could it mean for wild plants 468 00:41:55,320 --> 00:41:58,120 if the global balance between plant eating 469 00:41:58,240 --> 00:42:00,080 and meat eating shifted? 470 00:42:02,520 --> 00:42:04,320 It may sound odd, 471 00:42:04,440 --> 00:42:07,240 but the more plants we eat, 472 00:42:07,360 --> 00:42:10,880 the more space there will be for wild plants. 473 00:42:14,600 --> 00:42:17,640 Remarkably, it's possible to restock 474 00:42:17,760 --> 00:42:21,400 even highly degraded land with wild plants. 475 00:42:28,080 --> 00:42:30,800 In Brazil, the needs of cattle ranching 476 00:42:30,920 --> 00:42:33,440 drive most deforestation. 477 00:42:40,240 --> 00:42:44,120 30 years ago, the owners of one former cattle ranch 478 00:42:44,240 --> 00:42:48,560 wanted to restore their land to the Atlantic rainforest 479 00:42:48,680 --> 00:42:50,800 that once covered it. 480 00:42:52,440 --> 00:42:55,800 They had no idea if it could be done. 481 00:42:57,160 --> 00:42:59,400 The land was so bare and eroded. 482 00:43:01,080 --> 00:43:04,240 But they were determined to try. 483 00:43:06,200 --> 00:43:08,120 First, they cleared the introduced 484 00:43:08,240 --> 00:43:11,280 African cattle grasses, invasive plants 485 00:43:11,400 --> 00:43:14,040 that outcompete most of the native plants. 486 00:43:21,240 --> 00:43:25,040 The grasses were replaced by seedlings 487 00:43:25,160 --> 00:43:26,760 grown from seeds gathered 488 00:43:26,880 --> 00:43:29,960 in nearby remnants of Atlantic rainforest. 489 00:43:38,720 --> 00:43:42,000 The earth institute, or instituto terra, 490 00:43:42,120 --> 00:43:46,000 as the ranch is known now, was encouraged by early success 491 00:43:46,120 --> 00:43:49,560 and expanded its scope and ambition. 492 00:44:07,360 --> 00:44:11,200 In five years, trees covered the land again. 493 00:44:12,960 --> 00:44:14,720 And within ten, it was clear 494 00:44:14,840 --> 00:44:16,920 something remarkable was happening. 495 00:44:19,360 --> 00:44:21,240 (Birdsong) 496 00:44:21,360 --> 00:44:23,040 (Insects buzzing) 497 00:44:23,160 --> 00:44:25,280 (Animals calling) 498 00:44:37,320 --> 00:44:39,440 When rain falls, 499 00:44:39,560 --> 00:44:42,800 it now no longer simply runs off the land, 500 00:44:42,920 --> 00:44:44,600 leaving it parched. 501 00:44:48,080 --> 00:44:51,120 Instead, it clings to the plants, 502 00:44:51,240 --> 00:44:53,960 to every root, stem and leaf... 503 00:44:55,800 --> 00:44:59,600 And then slowly filters to the forest floor. 504 00:45:02,520 --> 00:45:05,600 And so previously dry streams 505 00:45:05,720 --> 00:45:09,360 burst into life for the first time in decades. 506 00:45:14,600 --> 00:45:17,800 The institute never introduced animals or plants 507 00:45:17,920 --> 00:45:19,640 other than the trees. 508 00:45:25,160 --> 00:45:28,480 The animals came back on their own. 509 00:45:30,800 --> 00:45:33,400 Small ones came first. 510 00:45:50,040 --> 00:45:52,240 And then, very recently, 511 00:45:52,360 --> 00:45:55,600 camera traps left in the forest 512 00:45:55,720 --> 00:46:00,560 captured images beyond the hopes of everyone involved. 513 00:46:03,560 --> 00:46:05,200 A maned wolf. 514 00:46:06,520 --> 00:46:10,000 An animal that is being driven from its native habitat 515 00:46:10,120 --> 00:46:14,600 by deforestation, drawn to its favourite plant, 516 00:46:14,720 --> 00:46:17,080 the wolf fruit tree. 517 00:46:20,600 --> 00:46:22,040 Not only that... 518 00:46:22,160 --> 00:46:24,640 (High-pitched barks) 519 00:46:27,240 --> 00:46:29,000 A puma. 520 00:46:31,560 --> 00:46:33,720 With cubs! 521 00:46:42,840 --> 00:46:47,360 The arrival of these precious top predators and their young 522 00:46:47,480 --> 00:46:49,800 shows what can happen 523 00:46:49,920 --> 00:46:52,480 when we make space for wild plants. 524 00:46:58,080 --> 00:47:02,160 We have for centuries robbed wild plants 525 00:47:02,280 --> 00:47:05,080 of the space and time they need to thrive. 526 00:47:07,400 --> 00:47:11,440 That has certainly not been to their benefit. 527 00:47:12,680 --> 00:47:16,240 Nor, ultimately, is it to ours. 528 00:47:21,760 --> 00:47:25,440 Our relationship with plants has changed throughout history. 529 00:47:25,560 --> 00:47:28,120 And now it must change again. 530 00:47:28,240 --> 00:47:30,760 Whether it's what we eat and cultivate 531 00:47:30,880 --> 00:47:33,040 or whether it's what we like, 532 00:47:33,160 --> 00:47:35,520 we must now work with plants, 533 00:47:35,640 --> 00:47:38,760 and make the world a little greener, 534 00:47:38,880 --> 00:47:40,560 a little Wilder. 535 00:47:48,520 --> 00:47:53,480 If we do this, our future will be healthier, 536 00:47:53,600 --> 00:47:55,960 and safer, 537 00:47:56,080 --> 00:47:59,400 and in my experience, at any rate, happier. 538 00:47:59,520 --> 00:48:03,360 Plants are, after all, our most ancient allies, 539 00:48:03,480 --> 00:48:07,760 and, together, we can make this an even greener planet. 540 00:48:21,720 --> 00:48:24,520 Throughout the human episode, 541 00:48:24,640 --> 00:48:27,640 the green planet crew sought to capture the lives of plants 542 00:48:27,760 --> 00:48:29,880 confronted with the human world. 543 00:48:31,320 --> 00:48:32,960 But they also heard the stories 544 00:48:33,080 --> 00:48:37,160 of people deeply connected to the plants around them... 545 00:48:39,240 --> 00:48:41,560 Such as those at the front line 546 00:48:41,680 --> 00:48:43,560 of the battle to save Hawaii's 547 00:48:43,680 --> 00:48:47,880 native endangered plants from invasive species. 548 00:48:49,000 --> 00:48:51,160 If we don't get a handle on miconia, 549 00:48:51,280 --> 00:48:53,400 we could lose everything 550 00:48:53,520 --> 00:48:56,080 that makes Hawaii special and unique. 551 00:48:58,280 --> 00:48:59,960 But before the green planet team 552 00:49:00,080 --> 00:49:02,280 could start work, they had to undertake 553 00:49:02,400 --> 00:49:04,640 some rigorous preparation. 554 00:49:05,920 --> 00:49:07,120 We're going into somewhere 555 00:49:07,240 --> 00:49:09,400 that has very... it's a very sensitive ecosystem, 556 00:49:09,520 --> 00:49:11,480 they're trying to protect it from invasives. 557 00:49:11,600 --> 00:49:16,120 Filming in a place so ravaged by invasive species 558 00:49:16,240 --> 00:49:20,080 meant they had to be 100% sure that they were not spreading 559 00:49:20,200 --> 00:49:23,320 any non-native stowaways themselves. 560 00:49:23,440 --> 00:49:27,600 They had to scrub and disinfect every item of equipment. 561 00:49:32,040 --> 00:49:35,040 With kit clean, the team first focus on filming 562 00:49:35,160 --> 00:49:37,240 the rare holokea plant... 563 00:49:41,840 --> 00:49:43,680 Accessible only on foot. 564 00:49:50,440 --> 00:49:53,960 There are few pristine areas like this left in Hawaii. 565 00:49:55,960 --> 00:50:00,520 Only 40% of the land still has native vegetation... 566 00:50:01,600 --> 00:50:04,640 Most of it wiped out by invasive species 567 00:50:04,760 --> 00:50:06,200 like miconia. 568 00:50:10,960 --> 00:50:12,720 Next on the list 569 00:50:12,840 --> 00:50:16,520 was to film the team waging war on miconia, 570 00:50:16,640 --> 00:50:19,280 known locally as the purple plague. 571 00:50:21,200 --> 00:50:24,440 For crewmember aja, the work is not just 572 00:50:24,560 --> 00:50:27,760 a physical battle against this invasive species - 573 00:50:27,880 --> 00:50:30,280 it's deeply personal. 574 00:50:30,400 --> 00:50:32,000 I've been to the pristine area, 575 00:50:32,120 --> 00:50:35,520 so I know what it looks like and feels like, you know, 576 00:50:35,640 --> 00:50:37,520 to be in the presence 577 00:50:37,640 --> 00:50:41,240 of all that mana and spirituality. 578 00:50:44,800 --> 00:50:46,560 Those aren't just plants. 579 00:50:48,600 --> 00:50:51,440 Those are ancestors' spirits, you know? 580 00:50:51,560 --> 00:50:55,160 Controlling these invasive plants is a relentless job, 581 00:50:55,280 --> 00:51:00,040 and aja is not just doing this for native Hawaiian ecosystems, 582 00:51:00,160 --> 00:51:03,080 but also to protect her ancestral relationship 583 00:51:03,200 --> 00:51:05,760 to this fragile landscape. 584 00:51:05,880 --> 00:51:08,600 So going to do this, it feels good just to hack them, 585 00:51:08,720 --> 00:51:11,240 and pull them out and be like, "yeah, ok, take that," 586 00:51:11,360 --> 00:51:13,640 you know? We can sort of fight back. 587 00:51:13,760 --> 00:51:17,640 Aja's fierce passion to protect these native forests 588 00:51:17,760 --> 00:51:19,720 is evident. 589 00:51:19,840 --> 00:51:22,360 But the purple plague has spread 590 00:51:22,480 --> 00:51:25,400 to places aja could never reach on foot. 591 00:51:26,720 --> 00:51:29,200 Taking to the sky is the only way 592 00:51:29,320 --> 00:51:33,200 to reach the front line of this battleground. 593 00:51:35,160 --> 00:51:39,160 With only enough fuel to stay airborne for two hours, 594 00:51:39,280 --> 00:51:41,000 the window for capturing this aerial battle 595 00:51:41,120 --> 00:51:43,360 is uncomfortably small. 596 00:51:44,960 --> 00:51:48,080 We have one day of doing the heli operations. 597 00:51:48,200 --> 00:51:51,160 The weather could completely mess us up 598 00:51:51,280 --> 00:51:53,560 if we get a system that comes in. 599 00:51:53,680 --> 00:51:56,080 Heli-to-heli is always dangerous and difficult. 600 00:51:57,360 --> 00:51:59,720 This flight is not just tense for lis. 601 00:51:59,840 --> 00:52:02,600 For plant sniper Brooke mahnken, 602 00:52:02,720 --> 00:52:03,920 these short flights 603 00:52:04,040 --> 00:52:07,880 represent his only opportunity to hold back the invasion. 604 00:52:08,000 --> 00:52:11,760 Brooke: Miconia left unchecked can be terribly damaging. 605 00:52:11,880 --> 00:52:13,000 The potential for 606 00:52:13,120 --> 00:52:15,320 one seeding plant, 607 00:52:15,440 --> 00:52:17,440 if it were to get far away from the population, 608 00:52:17,560 --> 00:52:19,880 reach maturity and put seeds out, 609 00:52:20,000 --> 00:52:23,400 then it's starting a whole new infestation. 610 00:52:23,520 --> 00:52:25,920 And once it occupies that entire area, 611 00:52:26,040 --> 00:52:27,960 then it's completely wiped it out. 612 00:52:32,200 --> 00:52:34,920 The helicopter is really important 613 00:52:35,040 --> 00:52:37,200 because you can fly in extreme terrain 614 00:52:37,320 --> 00:52:39,280 with these, like, 1,000-foot cliffs, 615 00:52:39,400 --> 00:52:42,120 and find miconia that there would be no other way 616 00:52:42,240 --> 00:52:44,480 to get to these plants. 617 00:52:45,920 --> 00:52:49,000 The miconia team are used to the aerial challenges 618 00:52:49,120 --> 00:52:51,280 of this battle, but for producer lis, 619 00:52:51,400 --> 00:52:54,560 the pre-flight talk from the helicopter pilot 620 00:52:54,680 --> 00:52:56,840 brings home the lengths that this team go to 621 00:52:56,960 --> 00:52:59,960 in order to complete their work. 622 00:53:00,080 --> 00:53:01,800 So you're just going to be in the back here, 623 00:53:01,920 --> 00:53:04,000 and it's a hurricane in the back seat. 624 00:53:04,120 --> 00:53:05,560 Literally a hurricane. 625 00:53:05,680 --> 00:53:08,080 So nothing loose, you don't want to put an arm, a head, 626 00:53:08,200 --> 00:53:09,720 a leg or a hand out. 627 00:53:09,840 --> 00:53:11,480 It's just going to blow behind you. 628 00:53:11,600 --> 00:53:13,280 You don't want to stick your head out 629 00:53:13,400 --> 00:53:15,840 because if the headset comes off, 630 00:53:15,960 --> 00:53:18,600 then it's into the tail rotor and then it's bye-bye, Maui. 631 00:53:20,240 --> 00:53:21,880 Pre-flight checks completed, 632 00:53:22,000 --> 00:53:24,200 the clock is now ticking to get into the air. 633 00:53:28,360 --> 00:53:30,600 Lis: This matters so much to everyone here. 634 00:53:30,720 --> 00:53:32,840 I definitely feel the pressure to get this right. 635 00:53:39,520 --> 00:53:43,960 The first thing I want to do is get some close-ups of the hbt, 636 00:53:44,080 --> 00:53:47,120 because that's going to be the most challenging thing. 637 00:53:47,240 --> 00:53:49,880 Pilot: Let's go find some plants, please. 638 00:53:51,080 --> 00:53:54,440 To get within shooting distance of the plants, 639 00:53:54,560 --> 00:53:56,520 the helicopter pilot must carefully manoeuvre 640 00:53:56,640 --> 00:53:59,080 into one of the area's deepest canyons. 641 00:54:01,680 --> 00:54:03,080 Pilot: See this light-coloured rock? 642 00:54:03,160 --> 00:54:04,536 - Brooke: Yep. - Pilot: Follow that up 643 00:54:04,560 --> 00:54:07,480 to the right to see it. 644 00:54:08,600 --> 00:54:10,480 The target is in sight. 645 00:54:10,600 --> 00:54:12,680 Brooke: Yeah, there he is. 646 00:54:15,480 --> 00:54:18,160 Brooke: Ok, I'm, uh... I'm live and ready. 647 00:54:18,280 --> 00:54:21,360 With high winds gusting up from the waterfall, 648 00:54:21,480 --> 00:54:24,360 getting into position is tricky enough in one helicopter, 649 00:54:24,480 --> 00:54:25,960 let alone two. 650 00:54:27,480 --> 00:54:29,880 To give Brooke the best chance of hitting the miconia, 651 00:54:30,000 --> 00:54:33,320 the pilot must get him within 20 metres of the plant, 652 00:54:33,440 --> 00:54:35,560 and ideally at eye level. 653 00:54:35,680 --> 00:54:39,400 Any missed shot threatens to become friendly fire, 654 00:54:39,520 --> 00:54:42,160 harming the species he aims to protect. 655 00:54:42,280 --> 00:54:43,480 - Ready? - Yes. 656 00:54:43,600 --> 00:54:44,840 Here we go. 657 00:54:47,880 --> 00:54:49,840 Brooke must strike the stem of the plant 658 00:54:49,960 --> 00:54:53,360 to have the best chance of completely killing it. 659 00:54:55,440 --> 00:54:58,080 - (Cheering) - Oh, my god! Nice one! 660 00:55:05,880 --> 00:55:08,960 Yeah, it worked really, really well. Thanks, guys. 661 00:55:09,080 --> 00:55:11,960 This has been a successful mission 662 00:55:12,080 --> 00:55:13,480 for both teams. 663 00:55:13,600 --> 00:55:16,880 The pilot's skills and Brooke's sharp-shooting 664 00:55:17,000 --> 00:55:18,840 have saved another patch of forest, 665 00:55:18,960 --> 00:55:22,240 and lis is relieved that she has the shots she needs 666 00:55:22,360 --> 00:55:23,920 to do the story justice. 667 00:55:24,040 --> 00:55:25,840 It's over! 668 00:55:25,960 --> 00:55:27,360 It's over. 669 00:55:27,480 --> 00:55:28,960 It just looked amazing. 670 00:55:29,080 --> 00:55:30,400 Lots of... 671 00:55:30,520 --> 00:55:31,640 Yeah, it looks good. 672 00:55:31,760 --> 00:55:33,040 It looks good. 673 00:55:33,800 --> 00:55:37,520 For Brooke and aja, however, their work doesn't stop. 674 00:55:37,640 --> 00:55:41,320 Just holding back the tide of invasive species in Hawaii 675 00:55:41,440 --> 00:55:43,680 is more than a lifetime's work. 676 00:55:43,800 --> 00:55:47,600 But aja believes that her fight is worthwhile. 677 00:55:47,720 --> 00:55:50,320 Everything we do is for the next generation, 678 00:55:50,440 --> 00:55:52,400 just like our ancestors and kupunas. 679 00:55:52,520 --> 00:55:55,840 It wasn't for them, it was for the next generation. 680 00:55:55,960 --> 00:55:58,720 And just to have my kids going to areas, like, 681 00:55:58,840 --> 00:56:02,160 where they can see there's still natives, 682 00:56:02,280 --> 00:56:04,240 where we don't have to go through 683 00:56:04,360 --> 00:56:07,360 all this invasive vegetation. 684 00:56:07,480 --> 00:56:09,200 (Camera shutter clicks) 685 00:56:10,960 --> 00:56:13,800 You know, it's not just my responsibility, 686 00:56:13,920 --> 00:56:16,000 it's everyone's responsibility. 687 00:56:19,360 --> 00:56:21,880 You know, the earth takes care of us, 688 00:56:22,000 --> 00:56:25,000 so we have to do the same. We can't just... let it go by. 689 00:56:28,560 --> 00:56:30,040 We've got to take care, too.