Week 6: Fragile ecosystems

Introduction

Figure 1 Farming on the Loess Plateau

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Farming on the Loess Plateau in Chine changed the entire ecosystem. This photo shows the parched groud and yellow-leaved scrub in a farmed area of the plateau.

Figure 1 Farming on the Loess Plateau

We bring the last five weeks together, looking at issues of large scale management and conservation, concluding with a study of the Galápagos archipelago World Heritage Site.

1 Gorillas and tourism

Bwindi Impenetrable National Park in Uganda was formed in an attempt to protect the jungle in the area, one of Africa’s richest ecosystems, from human activities. Initially it was preserved in a hostile way, with local residents forcibly evicted and barred from future entry into the park. This sparked angry protest from local communities, and there were violent clashes as a result.

Figure 2 A mountain gorilla in the Bwindi National Park

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A mountain gorilla in the Bwindi National Park.

Figure 2 A mountain gorilla in the Bwindi National Park

An integrated conservation development programme was conceived to protect the area without alienating local communities, who had been dependent on the resources available in the forests and jungle for their livelihood.

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Gorillas and tourism

DR. GLADYS KALEMA-ZIKUSOKA

The gorillas are very important. And mountain gorillas are one of our closest living relatives. We share 98.4% genetic material. And when you go out to see them, it's very therapeutic. They look into the eye. And you feel like you're connecting with a close relative. There's only over 700 gorillas left in the world.

NARRATOR

Mountain gorillas are one of the world's most endangered species, teetering on the edge of extinction for decades. Today, they survive only in the forests of Central Africa, where they have endured years of civil war, habitat loss, and poaching for bush meat.

TUGUMISIRIZE YESE

We used to see the gorillas. There were very few, but those few, people never feared killing them. They are vermin like other vermin. They were killed. They were poached. There was no problem

NARRATOR

Half of the world's remaining population of mountain gorillas is found here, in Bwindi Impenetrable National Park in Uganda. But as the park lies in the heart of one of the most densely populated parts of Africa, it's continually under threat from people eager to use the forest's rich resources.

CHARITY BWIZA

The population pressure is increasing. And the population in southwestern Uganda is the highest in Uganda. And it is also said it is the highest in Africa. But the land is not increasing.

NARRATOR

To deal with this threat, the Fortress Conservation approach was adopted in Bwindi. This aimed for the total exclusion of people and their activities from the forest, enforced by armed rangers.

JAMES BYAMUKAMA

Originally the communities were allowed to access a number of resources. They would access firewood. They would get mushrooms. They would get wild meat. They would get bamboo shoots - bamboo and many hand craft products. And when it was made a national park, then these rights were removed. The removal of any of the forest's products was stopped. And this implied that the communities lost all what they would get as contribution to their livelihood. And therefore, the communities came out in rage.

CHARITY BWIZA

Communities used to set fire intentionally to the protected area. Then communities used to fight with the law enforcement. So the communities were really, really very hostile.

NARRATOR

As conservation by force wasn't working, a new approach was needed. This conflict had to be resolved. For gorillas to have a sustainable future, local people needed to be involved in their conservation rather than excluded from the forest.

JAMES BYAMUKAMA

A question had come - conserving for who? Therefore, we had to make a shift from that fortress approach to an integrated conservation and development approach and put the people into conservation.

NARRATOR

The integrated conservation and development approach works by linking wildlife conservation with the welfare of the people around the park.

MOSES MAPESA

We had to review and rethink the strategy to look into to how to make these conservation areas more relevant to the people who live close to them or who even have ancestral claims to the land. And that is how the whole notion of integrated conservation and development programmes started.

ALASTAIR MCNEILAGE

One initiative designed to reduce the conflict was also what we call the multiple use programme. The idea was to take account of the fact that, actually, some of the things that people want from the forest - small amounts of medicinal plants, weaving materials - could actually be harvested without having a major impact on the forest itself. The quantities they need may be quite small. The resources may be plants which grow quite quickly and are easily renewed. And allowing the communities to access those resources could be used as a strategy to give them something back

MAN

Wild yams help us live longer and remain resistant to diseases. That’s the main reason we like them.

WOMAN

I gather enough material to weave three baskets, and I keep one to use in the home and sell two.

MAN

When the forest was closed there were problems, but since, we’ve been able to access things we need. We’ve collaborated with the park officials and there have been no problems.

TUGUMISIRIZE YESE

Some non-government organisations, even the government, have tried to improve the nature of the people neighbouring that gorilla so that they shouldn't at any time point a finger at the gorilla.

NARRATOR

Communities were helped to develop a new livelihood activities to replace those lost from their restricted access to the park.

CHARITY BWIZA

We are finding different variances of community projects, like bee keeping and like mushroom growing. People used to go into the park to harvest wild mushroom, so we started funding individuals and groups to grow mushrooms.

TUGUMISIRIZE YESE

They give me the materials - the sterilising drums, the drier. After helping me with such, then they give me knowledge, enough knowledge to grow mushrooms.

NARRATOR

Now, conservation was actually benefiting the local communities, and their view of gorillas and the forest began to change.

TUGUMISIRIZE YESE

Do I need to go to the park to look for mushrooms to supply the hotels? The mushrooms are here.

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Contributors to this video include G. Kalema-Zikusoka, T. Yese, C. Bwiza, J. Byamukama, M. Mapesa.

The Bwindi population of mountain gorillas is one of only two known. The population in Virunga national park in the DRC (Democratic Republic of Congo) has recently been surveyed, since the video was made. A census of the population in Bwindi was started in 2018. The previous census in 2012 showed that there were over 400 individuals. In the Virunga national park the 2018 census showed that there were 604 individuals in 41 social groups. This is an increase on the 2010 census figure of 480. So, although these figures are encouraging, around 1000 mountain gorillas in two locations represent a species and ecosystem in extreme danger. As a comparison, the populations of the critically endangered Western lowland gorilla are estimated to total 100,000 individuals.

The population census of the mountain gorillas is being carried out by teams of researchers. They search the trails used by gorillas and the areas in which the animals ‘nest’ at night. Fecal samples are collected so that DNA analysis can be carried out to determine the individual’s identity and their relationship with other social groups. The researchers also record family movement patterns. Of course, while the researchers are working they are looking out for poaching activities.

The crucial point of the development programme was to involve communities in the increased tourist interest in the park and its gorilla population.

Figure 3 Tourists with a mountain gorilla, a photograph that illustrates graphically the tension between conservation and tourism.

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Tourists with a mountain gorilla, a photograph that illustrates graphically the tension between conservation and tourism. The tourists are only a couple of metres away from the gorilla and are wearing brightly coloured clothing.

Figure 3 Tourists with a mountain gorilla, a photograph that illustrates graphically the tension between conservation and tourism.

As you watch the next film, reflect on why the Bwindi Park was established, and how this affected the local population. What difference has the establishment of the park made to the ecosystems there? Consider whether the economic activities around the park make enough of a difference to the local communities around the park

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Gorillas and tourists

ALASTAIR MCNEILAGE

At the same time, another organisation was starting up, a gorilla tourism programme trying to find ways that the forest could generate income sustainably without being harvested, without being cut down, without killing animals. So that that provided income both to pay for the management of the park itself, pay for all the salaries of the rangers and the guides and the park staff and the maintenance of the forest, but also to generate income for the local communities.

FEMALE TOURIST

It's amazing. You never see anything like this.

NARRATOR

Now, gorilla tourism is seen as the answer to conservation. It's based on the simple economic principle that there is more money to be made from tourist dollars than from selling of natural resources.

MOSES MAPESA

We stopped timber companies or timber harvesting in Bwindi, and we earn a lot more money from the great apes tourism, from the gorilla tourism, than we would ever earn from timber production.

TUGUMISIRIZE YESE

We respect the gorilla because of tourism. It's a bigger income to our country. And what's also very wonderful about the gorilla tourism beginning is that the local communities' perceptions of conservation have changed significantly because they now see the gorillas as a sustainable source of income for them.

NARRATOR

Revenue from tourism trickles down to communities via job creation and extra trade, but there is also a scheme that puts a percentage of park entrance fees directly into the hands of local people.

ENOCK TURYAGYENDA

You know, there is some little money, which normally comes in the parishes every year. We call it revenue sharing. That money comes from UWA. It is the money, which these whites normally contribute to visit to this park to help the citizens who live around the park.

GHAD KANYANGYEYO

In the beginning, everything like wildlife to me it was useless, because there was nothing I was benefiting from them. Many local people were just taking anything as if it was nothing. And then they would chop the trees down. It would kill the animals and all, but now things have changed. Everybody is now putting pressure on conservation because we are benefiting from more life. Everybody is benefiting from tourism.

NARRATOR

Any long term plan needed to be profitable and offer sustainable livelihoods to local communities. Gorilla tourism has done this with some surprising results. In 2006, a census found a total of 340 gorillas in the park, an astonishing 12% increase in the population over the preceding decade.

MOSES MAPESA

We can begin to talk about a very positive trend in the conservation of Bwindi and the gorillas specifically. We have seen a steady rise in the gorilla population, and habitat is still large enough to accommodate a few more gorilla families.

NARRATOR

But is the integrated conservation and development approach supported by the money from tourism really sustainable? Is it the answer to saving the gorillas?

ALASTAIR MCNEILAGE

What doesn't always work as well, which perhaps is a bit unrealistic, is to think that through these ICD projects, you're going to improve people's livelihoods so much. I mean, you're talking about maybe helping people to move from being very poor to poor, but they're still poor. And so just because they may be able to cultivate more crops and raise some goats doesn't mean to say that they still don't have great needs, which could still be met by getting resources from the park.

JAMES BYAMUKAMA

You cannot be in charge of the minds of the people. The needs of the people keep changing day by day. And they are quite many people around here, for example, who still feel, even if you give them alternatives or substitutes for bushmeat, who still feel that bushmeat is what they need. What do we do with them? We still have to get back into the forest to trap. So I think Fortress Conservation and integrated conservation development approaches have to be combined. And the kind of management that brings about that is what we call adaptive management. You adapt the management according to the situation.

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2 China’s Loess Plateau

Maximise

Figure 4 China’s Loess Plateau

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A map showing the location of the Loess Plateau in North Central China. The most northerly boundary of the plateau is roughly on the same latitude as Beijing. To the North and West of the plateau lies the Gobi desert.

Figure 4 China’s Loess Plateau

China’s Loess Plateau is a region that stretches for 640,000 square kilometres across north central China. It is an example of an ecosystem that has been ravaged by human activities, such as agriculture.

In 2015, The UN (United Nations) produced a report on food and agriculture which found that one third of the planet’s soils are damaged. Erosion, contamination and saltwater have all taken their toll. This is not a new phenomenon. In 1900 agriculture on the Great Plains of the US (United States) expanded substantially. In doing so it depleted the soil of moisture so that when, in the 1930s, there were several prolonged droughts, the dry soil was swept away by wind. Dust storms disrupted life and ruined farmland.Start of Media Content

Figure 5 Farmer walking in dust storm

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A farmer and his two sons during a dust storm; Cimarron County, Oklahoma. A black and white photograph taken in 1936.

Figure 5 Farmer walking in dust storm

The Loess plateau suffered in a similar way. In 1994 a programme of restoration began. The following videos show some of the actions taken by China to restore the plateau ecosystem, with help from the World Bank. As a result of the restoration programme millions of people benefited, although the costs were high – US$500 million.

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China’s Loess Plateau

JOHN D LIU

This is China's Loess Plateau. Until recently, this was one of the poorest regions in the country, a land renowned for floods, mud slides, and famine. But with the fanfare comes the hope of change for the better. My name is John D. Liu. I've been documenting the changes on the plateau for 15 years. I first came here in 1995 to film an ambitious project where local people were constructing a new landscape on a vast scale, transforming a barren land into a green and fertile one. The project certainly changed my life, convincing me to become a soil scientist. The lessons I've learned in the last few years have made me realise that many of the human tragedies that we regularly witness around the world - the floods, mud slides, droughts, and famines - are not inevitable. Here on the Loess Plateau, I've witnessed that people can lift themselves out of poverty. They can radically improve their environment, and by doing so, reduce the threat of climate change. When I first came to the Loess Plateau, I was astounded by the degree of poverty and degradation. And I wondered, how could the Chinese people, the largest ethnic group on the planet, and my father's and my own ancestors, come from a place that was this barren? China's Loess Plateau is a region that stretches for 640,000 square kilometres across North Central China. Unspoiled valleys in neighbouring Sichuan show us how it might once have looked. It's the sort of natural abundance that is necessary to support an emerging civilisation. How could a landscape with such potential have been reduced to this? When Chinese scientists and civil engineers began to survey the area, they realised that several thousand years of agricultural exploitation had denuded the hills and valleys of vegetation. The relentless grazing of domestic animals on the slopes meant that there was no chance for young trees and shrubs to grow. The rainfall no longer seeped into the earth, but simply washed down the hillsides, taking the soil with it. Over millennia, this progressively destroyed the region's fertility. When this happens over an area as extensive as the Plateau, millions of tonnes of silt are swept down into the Yellow River, which gets its name from the colour of the fine Loess soil. The mounting quantities of silt clog up the river, impeding its flow, contributing to the floods that give the river another name, China's Sorrow. In some areas, creating floating mud mattresses that attract passing tourists. A local problem becomes a national problem. In the dry season, the light, unprotected soil is swept up in the winds, causing the dust storms that are blown over China's cities and beyond its borders. On the Plateau, the researchers realised that progressive degradation of the environment trapped the local population into a life of subsistence farming. It's a process that has occurred throughout the world, where poor agricultural communities find themselves overusing their land in order to survive, depleting its fertility, and further impoverishing themselves. One thing that became apparent early on is the connection between damaged environments and human poverty. In many parts of the world, there's been a vicious cycle. Continuous use of the land has led to subsistence agriculture. And generation by generation, this has further degraded the soils. The vital question we have to ask is, can this destructive process be reversed? 15 years ago, Chinese and international experts were confident it could be. They decided that to prevent further erosion, it was necessary to cease farming on certain key areas to allow the trees and shrubs to grow back. But this could not happen without the consent of the farmers themselves. They took some persuading.

MR. TAFUYUAN

[SPEAKING FOREIGN LANGUAGE]

TRANSLATOR:

Of course, a lot of people didn't understand the project. They weren't thinking in the long term.

VILLAGER

[SPEAKING FOREIGN LANGUAGE]

TRANSLATOR

They want us to plant trees everywhere. Even in the good land. What about the next generation? They can't eat trees.

JOHN D LIU

What eventually convinced the local people was the assurance that they would have tenure of their land, that they would directly benefit from the effort they invested in the new project.

MR. TAFUYUAN

[SPEAKING FOREIGN LANGUAGE]

TRANSLATOR

The goal was to give a hat to the hilltops, give a belt to the hills, as well as shoes at the base. The hats meant that the top of these hills had to be replanted with trees. The belt meant that terraces had to be built, to be used for crop planting and also for trees. The shoes were the dams, which we had to build so that the hills could grow back to life, and our economy as well as our lives could improve.

JOHN D LIU

Hills and gullies were designated as ecological zones to be protected. Farmers were given financial compensation for not farming on them and keeping their livestock penned up. When I first filmed Mr. Tafuyuan and his colleagues back in 1995, I had no idea this initiative could achieve such dramatic results. The effort that people put into converting their slopes into terraces has resulted in a marked increase in agricultural productivity. The higher yields are directly related to the return of natural vegetation and the surrounding ecological land. Now when it rains, the water no longer runs straight off the slopes. Trapped by the vegetation, it sinks into the ground, where it is retained in the soil, taking weeks and months to gently seep down and irrigate the fields and terraces below. Restoration has occurred over an area of 35,000 square kilometres. The impact of such an enormous addition of vegetation goes far beyond the plateau itself. There's been a significant reduction in the soil rushing down into the Yellow River. As I've been travelling around the Loess Plateau, I've seen extensive changes. The vegetation cover on the hillsides, on the tops of the hills, and down in the valley, everything has changed. It's changed the lives of the people. And in fact, the people themselves have done this because they were the ones who changed their behaviours, terraced the fields, improved the soils, learned to protect the marginal areas. The changes are not simply on the hillsides. On the plains, you can see greenhouses that are filled with vegetables. This extends the growing season. It's very high value produce. The abundance and variety of new produce can be seen in the local markets. Follow up studies have shown that incomes have risen threefold. And scientists point to a more global benefit. Plants, through photosynthesis, remove carbon from the air, countering the effect of human greenhouse gas emissions on the climate.

PROF. CAI MANTANG

[SPEAKING FOREIGN LANGUAGE]

TRANSLATOR

In terms of climate change, we can say that the project made a double contribution. Firstly, the project was successful in restoring vegetation on a large scale. So many trees and so much vegetation grew up, and this definitely helped take carbon out of the atmosphere. Secondly, because the health of the Loess Plateau's ecosystem has been so much improved, the region will be better able to resist the negative impacts of climate change.

JOHN D LIU

As a result of its success, the lessons learned from the Loess Plateau rehabilitation are now being applied all over China. But could such projects work elsewhere in less centrally controlled societies with fewer resources and different soils?

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Contributors to this video include John D Liu.

Video: ©co-produced by The Open University and EEMP for BBC World, with support from the International Union for the Conservation of Nature (IUCN), The Open University, The Rockefeller Foundation, and the Syngenta Foundation for Sustainable Agriculture and The World Bank. © Environmental Educational Media Project (EEMP) 2009

The hills and valleys of China’s Loess Plateau eroded because grazing domestic animals denuded them of vegetation. Valuable soil was washed away into the nearby Yellow River, leaving the plateau unfertile.

The rehabilitation of the plateau has been a slow and arduous task. As you watch the next video think about the following questions:

• What were the activities that resulted in the destruction of the Loess Plateau?
• What actions were taken to restore the plateau?

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Loess Plateau’s success

SPEAKER

I remember when I was a kid, the water would run terribly off the slopes. Now that the trees have grown this doesn’t happen any more. Before the soil was very poor. It was difficult to grown anything on it. The land we used to cultivate was large, but it produced little. Now we have less land, but it produces more. So things have improved. In the beginning, I didn’t think much of the project. I was only a few years old, so I didn’t think that much. I was a bit afraid.

VILLAGER 1

Now we eat noodles and rice. Life has improved. Before, the best we had was millet. When conditions were bad, we did not even have millet.

VILLAGER 2

Before we hardly had anything to eat or wear. Life was really difficult. It’s much better now. Now we eat well and dress better. Conditions have really improved.

SPEAKER

Our standard of living has clearly increased. Our revenues are much higher than before. Now everything is much greener than before. It’s much better. Before everything was so barren, there was nothing. Now, it’s green.

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Video: ©co-produced by The Open University and EEMP for BBC World, with support from the International Union for the Conservation of Nature (IUCN), The Open University, The Rockefeller Foundation, and the Syngenta Foundation for Sustainable Agriculture and The World Bank. © Environmental Educational Media Project (EEMP) 2009

3 Galápagos

Figure 6 Peninsula and sea stack on Bartolome island

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Peninsula and sea stack on Bartolome island in the Galápagos archipelago.

Figure 6 Peninsula and sea stack on Bartolome island

The Galápagos archipelago is a unique ecosystem with a diverse collection of island habitats. It is a World Heritage Site and many of the plant and animal species are found nowhere else. The islands also have historical significance in the development of biological science, following the visit by Charles Darwin in 1835. The islands had a profound influence on his ideas about species formation, which culminated in his book On the origin of species by means of natural selection (1857).

The islands have been the focus of scientific research for many years, but the conservation problems are substantial. This week the course will feature a series of video portraits about the archipelago. This series of portraits of the islands highlights the biodiversity found there, the problems of invasive species, the value of the islands for research and the problems of maintaining a flourishing ecosystem. As you watch the videos, think about these questions and take notes that will help you to answer them.

• Bearing in mind the definition of an ecosystem that you encountered at the start of this journey, is it reasonable to regard the whole archipelago as an ecosystem?
• What tensions arise between keeping the islands pristine, allowing visitors and allowing colonisation from the mainland?
• What major threats to the integrity of the habitats on Galápagos can you identify? Are they peculiar to the islands or applicable to ecosystems in general?

3.1 Darwin’s arrival on the Galápagos Islands

Although it is possible to follow in Darwin’s footsteps, as Dr David Robinson demonstrates in this video, the habitat has changed substantially as a consequence of the introduction of alien animals in the past. There are very few of the larger islands where you can see ecosystems unaffected by alien introductions and thus see them as Darwin saw them.

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Darwin’s arrival on the Galápagos Islands

DR. DAVID ROBINSON

On the 8th of October, 1835, the survey ship, HMS Beagle, anchored in this bay. On board was Charles Darwin. And he and four companions were put ashore on this island for a week - an island that he described as both picturesque and curious. In Darwin's day it was called James Island. Today it's known as Santiago. At almost 600 square kilometres, it's one of the larger islands in the Galapagos. Its highest point is 900 metres above sea level. On Santiago, Darwin met two Spaniards who were hard at work butchering tortoises for their meat. Together, they had an uncomfortable walk across this lava field. Eventually they arrived at this volcanic lake where the Spaniards collected salt to use as a preservative. Darwin was fascinated by local flora and fauna. He described the Galápagos as a world within itself - full of creatures that were both curious and remarkable. The islands were teeming with wildlife. There were so many land iguanas, for instance, that Darwin found it difficult to pitch his tent without covering their burrows. Today, there are none left on Santiago. In total, Darwin spent five weeks on the Galápagos - experimenting, observing, and collecting specimens. As for tortoise meat, he noted that it tasted particularly good when roasted in its shell.

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The finches that Darwin brought back from the Galápagos hold a special place in the history of the development of the theory of evolution by means of natural selection. There are 13 species and they occupy different niches in the habitats on the islands.

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Finches on Galápagos

DR. DAVID ROBINSON

Although he didn't realise it at the time, the most important specimens that Charles Darwin brought back from the Galápagos were finches. Initially, he wasn't sure how they were related. But when back in England, they were examined by the ornithologist John Gould, he reported that, in fact, Darwin had brought back 13 different species of finch all of which were unique to the Galápagos. This realisation played a significant role in Darwin's formulation of his theory of evolution. The most important differences between the finches came in their beaks. Some were large, some were small. Each one was suited to the availability of particular foodstuffs. Eventually, Darwin theorised that different species of finch had evolved on different islands, their distinctive beaks being an adaptation to distinct natural habitats or environmental niches. In the years since Darwin's visit, many other scientists and ornithologists have come to the Galápagos to study its finches. In this experiment, researchers are observing the woodpecker finch using this wooden box to stand in for a tree. The woodpecker finch is one of the only birds to use tools to help it find food. A stick or small twig enables it to dig deeper into tree bark for insect larvae. This skill enables it to survive in conditions which other birds would find difficult. In the dry season, it can gather up to 50% of its food in this way. Woodpecker finches are hungry birds, which in the wild need to eat every three hours, so they never turn down the chance of a free meal.

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3.2 Darwin’s thoughts on the iguanas

The marine iguanas of the Galápagos are the only marine lizards and occur nowhere else. They occupy a fragile ecosystem that is very vulnerable to changes in sea temperature. There is also a species of land iguana on the islands.

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Darwin’s thoughts on the iguanas

DR. DAVID ROBINSON

Some of the most remarkable creatures encountered by Darwin on the Galápagos were its iguanas. He was particularly fascinated by the marine variety though he was far from flattering. Darwin wrote that they were hideous-looking creatures of a dirty black colour, stupid, and sluggish in their movements. He did concede, however, that they were strong, graceful swimmers. Bearing in mind how much time they spent in the water, Darwin was surprised to find that marine iguanas didn't eat fish. He dissected several creatures and found that their stomachs were full of seaweed. Darwin noticed that the water was too cold for marine iguanas to stay in for a long time. When they weren't feeding, he observed them clinging to the rocks above the shoreline, basking in the sun. After the cold sea, these reptiles craved warmth. Darwin was also interested in their terrestrial cousins, although again, he wasn't very complimentary about their appearance. He called them small, ugly animals with a singularly stupid appearance and lazy, half-torpid movements. Today they're still plentiful on some islands. But marine iguanas are particularly vulnerable to changes in sea temperature, which can have a dramatic effect on the availability of seaweed.

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3.3 Invasive alien species

Alien species represent a major threat to ecosystems and this is particularly significant for oceanic island groups. The tortoises that gave the Galápagos islands their name are now threatened by alien introductions. Goats have been a particular problem, but slowly the populations have been brought under control. The habitat, the wariness of goats and remoteness of the islands make eradicating goats a very expensive proposition.

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Goats compete with tortoises

DR. DAVID ROBINSON

When Darwin visited the Galápagos, almost every island was crowded with wildlife. Most large islands had their own species of tortoise, which could be identified by the distinctive shape of its shell. Today, some of these species are extinct, and on some islands, the tortoises are limited to nature reserves. The problem is people. Settlers to the islands have brought in farm animals and other nonnative species, which have had a devastating effect on native habitats. The tortoises, which gave the Galápagos Islands their name, have found themselves sharing their food with wild goats, the descendants of animals brought into the Galápagos by Ecuadorian fisherman and British pirates. The tortoises don't have the same reach as the goats. They're happy with handouts in the tortoise sanctuary, but find it harder to compete in the wild. On the island of Isabela, for example, at one stage, the goat population reached a staggering 50,000, and the national park authorities had to begin an eradication programme.

MICHAEL BLIEMSRIEDER

Eradication programme, in this case, means just get out and shoot these goats either by foot or by helicopter, or who knows, but we have to kill them so the vegetation can have a chance to recover.

DR. DAVID ROBINSON

By 2002, Isabela was cleared of its goat problem, and scientists were cautiously optimistic that the tortoises might be able to reclaim their territory.

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Like the animals on the Galápagos, much of the flora of the islands is also vulnerable to the impacts of introduced alien species. Up to 2017, 821 terrestrial plants had been introduced. Among the most devastating has been the red quinine tree.

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Eradicating the red quinine plant

DR. DAVID ROBINSON

The Galápagos are famous for their reptiles and birds. But much of the islands' flora is equally interesting, and it's just as vulnerable to the impact of humans. Over the last centuries, almost 500 species of plant have been imported into the Galápagos, some for agriculture, some for gardens, and some by accident. Like the wild goats who compete with indigenous tortoises for food, so these newcomers compete with local plants for sunlight, soil, and water. Santa Cruz, for example, is home to a unique species of plant called Miconia, which is only found on one other island. Today, it is under threat from the red quinine tree, first brought onto the islands in the late 1940s. The red quinine tree is very hardy, and it reproduces so rapidly that there were worries that it might wipe out the whole of the Miconia zone. Today, the National Park Service are actively engaged in a programme to eradicate the red quinine; injecting any seed-bearing trees with cartridges filled with herbicide. It's expensive, time-consuming work, and there are many trees to kill. But scientists are optimistic that they may eventually eradicate the most damaging newcomers.

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3.4 How do invasive alien species reach the Galápagos islands

The impact of an invasive alien species can be dramatic. The islands will only retain their unique biodiversity if the routes by which aliens can enter the islands can be identified and managed. The Galápagos Conservation Trust produced a summary diagram in 2019 which shows the extent of the problem of alien species. The diagram is based on figures published in 2017.

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Figure 7 Invasive species

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A chart produced by then Galápagos Conservation Trust showing the alien species in the islands. There are 1579 alien species, of which 50 are vertebrates, 821 are terrestrial plants, 77 are terrestrial invertebrates, 63 are pathogens, 545 are terrestrial insects, 2 are marine plants and 21 are marine invertebrates. 76% of these species have arrived in the islands since 1970. They have mostly been introduced by accident but many of the plants were introduced intentionally. There are continued threats, such as the 107 flights a week and the 4310 tourists arriving every day.

Figure 7 Invasive species

The vermillion flycatcher provides an example of an endangered species that is rapidly declining. The species is endemic to the Galápagos. It lives in the native Scalesia forest, but that forest is disappearing as an introduced plant, the hill raspberry spreads and prevents the Scalesia forest from regenerating. An alien parasitic fly that lays it’s eggs in the nests of small birds may also contribute to the decline in the flycatcher population. The larvae that hatch then feed on the blood of the nestlings. Mortality is often 100%.

Areas of land are now being cleared of invasive plants to allow the native plants to recover and thus provide a habitat for the insect populations that the flycatcher feeds on.

Figure 8 vermillion flycatcher

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An image of a vermillion flycatcher.

Figure 8 vermillion flycatcher

3.5 Galápagos research and human effects

Most of the animals and birds on the islands have no fear of humans, which is one of the reasons why the islands are such an attractive place to carry out research.

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Galápagos research

DR. DAVID ROBINSON

We're in the Pacific, about 1000 kilometres west of South America on the equator. Martin Wikelski is heading for his research site. It's an island called Santa Fe, part of the Galápagos archipelago. Santa Fe, like all the Galápagos Islands, is the tip of a volcano that became land only a few million years ago. Many of the animals and plants that now live there are found nowhere else on Earth. These island species have long fascinated biologists interested in evolution, but this is also a good place for animal physiologists to study. Like all animals found in isolated oceanic island groups, the species found in Galápagos are astonishingly unafraid of people because of the absence of predators. And even on an inhabited island on a hotel patio, marine iguanas, a Galápagos species, lounge in the shade of the chairs. With few natural predators, they don't see people as a threat. They're easy to observe and study, and a source of fascination.

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This video highlights the pressures of increasing tourism and increasing population. Since the video was made, an area of land close to Puerto Ayora, the main town on Santa Cruz, has been set aside for 1200 new houses, which will double the size of the town. The Prince’s Foundation for Building Community has been working with local people and the Galápagos Conservation Trust to produce building codes for sustainable housing.

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Managing tourism in the Galápagos Islands

DR. DAVID ROBINSON

When Charles Darwin landed on the Galápagos Islands in 1835, they were barely inhabited. But today things are very different. Over the last quarter century, the permanent population has grown rapidly from 5,000 in 1980 to over 25,000 today. This has caused problems for the National Park Service who want to preserve the unique character of the islands.

MICHAEL BLIEMSRIEDER

An increasing population size is a problem. For example, here in Santa Cruz and Puerta Ayora where we are now, there's no more space. The last areas were given away already to immigrants during the last four or five months, so people is living already at the borderline of the park.

DR. DAVID ROBINSON

In addition to the local population, over 150,000 tourists visit the Galápagos every year. The numbers keep on growing. Tourism on the Galápagos is tightly controlled by the Park Service. Some islands are totally closed off. Wardens supervise visitors at all times within the park zone, but there's such interest in these islands that the tourists keep on coming.

CHANTAL BLANTON

I think Galápagos should be important as a tourist area because one of the major purposes of protection in Galápagos is for conservation and for education. And it's very difficult for people to understand the problems that occur in Galápagos or in protected areas such as if they can't actually come here and see it with their own eyes. The problem from tourism isn't so much the tourist interaction with the organisms. What is more of a concern is all the people that tourism, as an ancillary activity, bring to the islands. And that is a concern because the islands cannot support large numbers of people.

DR. DAVID ROBINSON

So far, the Park Service and its supporters have managed to keep the big hotel chains and the huge cruise ships at bay. But the competing pressures of maintaining the islands' unique heritage and simultaneously allowing the local population to develop economically will always require delicate handling. Life on the Galápagos can be difficult, but nevertheless, scientists and conservationists regard it as a privilege to work there.

MICHAEL BLIEMSRIEDER

There are plenty of problems, and plenty of difficult situations, and plenty of frustrations, but they're also plenty of rewards and success. And things you can say, well, I helped to do this. I am getting an ulcer and things like that. I'm getting sick sometimes because of the problems, but well, that's part of the job. I mean, I prefer to be here instead of sitting at a desk at the main office in Quito.

CHANTAL BLANTON

Number one here is conservation. Number one here is this continuum to be, not a museum, not a vivarium. It's a living laboratory of evolution.

DR. DAVID ROBINSON

In the decades since Darwin's visit, the fame of the Galápagos has spread around the world. Much more is known about its natural history, but there's still much work to be done. Darwin's comment still holds true. It really is a remarkable and curious place.

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3.6 A fragile ecosystem

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Figure 9 The fragile ecosystem in the Galápagos archipelago

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The fragile ecosystem in the Galápagos archipelago is illustrated by these two photos. One shows a beach with a volcanic cone in the baqckground. The other shows a giant tortoise.

Figure 9 The fragile ecosystem in the Galápagos archipelago

Before you started watching this week’s videos about the Galápagos you were asked to consider three questions. You should now be able to answers them and set them in the context of your overall study of ecosystems.

4 End of course quiz

This is a longer quiz so you can check your understanding of the whole course.

5 Conclusion

Dr David Robinson, Lead Educator and Senior Lecturer in Biological Science at The Open University, discusses and summarises the contents of this course, and the skills and knowledge you will have gained from it.

Your journey has taken you to a variety of places, from Wicken Fen in Britain to the Bwindi Impenetrable National Park in Africa; from the Loess Plateau in China to the Pacific Islands of the Galápagos. These places have shown you a variety of different ecosystems, but there are two common themes: conservation and restoration. Neither of these activities can be undertaken without a very clear understanding of the ecosystems themselves.

At the start of this course three over-arching questions were posed. You should now be able to answer those questions.

‘What is the importance of understanding ecosystems, how do they work and how crucial is their conservation?’

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Conclusion

DR. DAVID ROBINSON

The natural world has been a continuing fascination for me throughout my professional life. And when I was a student, my ecology notes started with a quotation. "Ecological research of the most basic kind is vital to solving our environmental problems." And that's still very apposite today. Ecology, the scientific study of ecosystems, will be hugely important for the 21st century. Your journey has taken you to a variety of places, from Wicken Fen in Britain, to Africa to the Bwindi National Park, to the lowest plateau in China and finally, the Pacific Islands of the Galápagos. These places have shown you a variety of different ecosystems, but there are two common themes, conservation and restoration. Now, neither of these activities can be undertaken without a very clear understanding of the ecosystems themselves. You'll now appreciate the complex and beautiful relationships between the organisms in these ecosystems. The Galápagos Islands illustrate only too well how fragile ecosystems are. One change, such as the introduction of the alien red quinine tree can totally alter relationships within an ecosystem and hence, the whole system itself. Some events, like this one, are a result of human activities, but natural events can also potentially produce big changes. Every few years in Galápagos, the cool ocean currents from the south reverse and warm water from the north bathes the islands. The seaweed that the marine iguanas eat does not thrive in warm water and the plants die back. The result, no food for the iguanas and they die in large numbers. A prolonged reversal of the ocean currents might wipe out all the iguana populations. You might like to think about how this would affect the ecosystem as a whole. Unless we understand the links between species, we cannot limit damage, conserve, or restore, which emphasises that the study of ecosystems is a core part of biological science. This brings us back to the question that I posed for you at the start of your journey. What is the importance of understanding ecosystems, what they're comprised of, and how they work? Well, now you can answer that question.

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6 Beyond ecosystems

Figure 10

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An image of a mountain and clear stream at the bottom.

Figure 10

Well done for completing Introduction to ecosystems. If you have studied the full course and completed all the quizzes you will receive a Statement of Participation certificate as a record of your achievement. You can access and print it from your MyOpenLearn profile.

If you would like to learn more about natural history in general, here are some possibilities:

Explore OpenLearn further:

• Ecosystems: Taking it further
• Woodlands – in our Neighbourhood Nature course
• Polar regions – using our Frozen Planet interactive
• The Galápagos World Heritage Site – by listening to our podcasts

Continue your membership of the iSpot community and contribute your observations at www.ispotnature.org/.

Contribute to the UK national map of trees at treezilla.

Good luck with your learning.

Now you've completed the course we would again appreciate a few minutes of your time to tell us a bit about your experience of studying it and what you plan to do next. We will use this information to provide better online experiences for all our learners and to share our findings with others. If you’d like to help, please fill in this optional survey

Acknowledgements

Except for third party materials and otherwise stated (see terms and conditions), this content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 Licence.

The material acknowledged below is Proprietary and used under licence (not subject to Creative Commons Licence). Grateful acknowledgement is made to the following sources for permission to reproduce material in this course:

Course image: courtesy of Dr. David J. Robinson, The Open University

Figure 1: kemo1980/iStockphoto.com

Figure 2: guenterguni; iStockphoto.com

Figure 3: Steve Davey Photography; courtesy of Alamy

Figure 4: Paul Kapp/ University of Arizona Department of Geosciences

Figures 5 and 6: courtesy of Dr. David J. Robinson, The Open University

Figure 7: Galapagos Conservation Trust; http://creativecommons.org/licenses/by-nc-sa/3.0/

Audio/Video

China’s Loess Plateau: Environmental Educational Media Project 2009 (EEMP)

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