Arxiu d'etiquetes: deforestation

Madagascar: a paradise in danger

The country is suffering a great social, political and ecological crisis which is threatening the survival of much of its biodiversity, unique in the world. Selective logging of Madagascar rosewood is causing a biological crisis unprecedented in the country. Lemurs, one of the most affected groups, are treading on thin ice.

INTRODUCTION

When the French botanist Jean-Henri Humbert set foot on the massif of Marojejy for the first time, in 1948, he was so astonished of what he saw that 7 years later he published Une merveille de la nature à Madagascar, a book which exalted the incredible biodiversity and pristine forests present in the region1. The fact is that Marojejy is possibly the best example of the rich and varied fauna and flora that Madagascar holds and, hence, the best indicator to take notice when the island begins to show signs of collapse. Unfortunately, both the region and the whole of Madagascar live days of uncertainty, and the fear of the disappearance of this treasure is becoming more real day after day.

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A silky sifaka (Propithecus candidus) in Marojejy (Photo: Simponafotsy, Creative Commons).
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The fossa (Cryptoprocta ferox) is the largest carnivore in Madagascar, and endemic to the island (Photo: Becker1999).

Madagascar, the world’s fourth largest island, has an area of just over the Iberian Peninsula and contains a unique biological wealth. Despite its size and the relative proximity to the African continent, it has remained isolated from other continents since 80 million years ago, causing the local flora and wildlife have evolved independently from the rest. As a result, more than 90% of Madagascar’s species are considered unique in the world2. A 90% of reptiles3, 60% of birds4 and 80% of the island flora5 are endemic, as well as some unique lineages of mammals such as lemurs and fossas. However, all are at imminent risk of extinction due to the events experienced in the country in the recent years.

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Almost 80% of the original forest has already disappeared. A 90% of Madagascar’s endemic species live on the forest (Image: EOI).

CAUSES OF THE ECOLOGICAL CRISIS IN THE COUNTRY

Deforestation has been present on the island since its colonization by humans, approximately 2000 years ago. However, in recent years, the delicate political situation in the country has led to their forests to their limits. With an unprecedented population growth, an extreme poverty (one of the highest in the world 6, 7) and a pressing political crisis, the nature of the island is helpless and besieged by multiple fronts. In addition to the traditional system of slash and burn deforestation, which allows local people to open forests to cultivate, it has appeared an unexpected player led by international companies. Selective logging of species of the genus Dalbergia (rosewood), rare in the forests and precious in the developed world due to its characteristic color and the strength of its wood, has become the main threat for the biodiversity of the island. It must be added, to the direct impact that involves the extraction of specific species of forest, resulting threats that can be even more damaging for the biodiversity, such as poaching, opening roads, habitat alteration, introduction of invasive species or intimidation of local populations by criminal organizations that manage the illegal exploitation8.

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Rosewood illegal shipment in the Toamasina’s port, Madagascar (Photo: The Guardian).

Selective logging, present and endemic for decades, took a breather in 2000, thanks to its ban in National Parks. However, due to a deep political crisis occurred in 2009, which ended with a coup d’etat, the situation got out of hand, and criminal organizations took control, entering with impunity in the National Parks of the country9. Many of these National Parks are literally being swept away and looted, and they are nothing more than a mirage of what they were once. Despite the restoration of democracy in 201310 and the promises of the elected president to end the “plague” that selective logging of rosewood was causing to the country11, nothing is being done to fight against poaching.

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Masoala logging camp, storing timber from Masoala National Park (Photo by Toby Smith, National Geographic).

WHICH COUNTRIES ARE BEHIND POACHING?

China is by far, the major importer of illegal timber from Madagascar. The main reasons are the growth of its middle class, which demands new furniture in line with their new standard of living, and the facilities granted by China due to its lax legislation on illegal timber12. A considerable part of this wood is used to make furniture in the style of the Ming Dynasty, which can be sold for $ 20,000. As there is no control on the illegal timber entering to the country, it is impossible to trace their origin. That’s why, in many cases, furniture and musical instruments manufactured in Europe or North America have been made with some or all with illegal timber13.

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French transport company (CMA CMG Delmas) loading illegal timber in Madagascar (Photo: Mongabay).
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Factory processing rosewood timber (Photo by Erik Patel, National Geographic).

BIODIVERSITY IN DANGER

Due to the opening of roads to remove rosewood timber, lemurs and other native species have become the target of poachers. At the beginning of the political crisis of 2009, a huge amount of lemurs and other wildlife were hunted to feed the thousands of loggers who often live in the forest while carrying out the logging. However, later, a luxury market which involved lemurs emerged, supplying restaurants with its meal in the larger cities and selling them as a delicacy.

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Silky sifakas and white head lemurs (Eulemur albifrons) hunted to be sold as food (Photo: Simponafotsy, Creative Commons).
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Silky sifakas and white head lemurs (Eulemur albifrons) hunted to be sold as food (Photo: Marojejy Website).
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A red-ruffed lemur (Varecia rubra), critically endangered, lies dead victim of poaching (Photo: Mongabay).

Although the amount of death lemurs at the hands of poachers is unknown, there are many species that are suffering the impact, many of them in serious danger of extinction like the indri lemur -the largest lemur alive-, the Tattersall’s sifaka or the silky sifaka. The latter, has just a population estimated of 300 individuals. The situation of lemurs is so dramatic that a study of 2012 warned that 90% of the 103 species of lemurs should be on the Red List14. In addition, 23 of them should be qualified as Critically Endangered, the highest threat level.

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An indri (Indri indri). This specie is Critically Endangered (Photo: Erik Pattel).
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A Tattersall’s sifaka (Propithecus tattersalli). This specie is Critically Endangered (Photo: Jeff Gibbs).

During this time it has also been an increase of trade of wild animals to serve as exotic pets, mainly affecting chameleons and turtles15, but has also been intensified the smuggling of lemurs16. In fact, a study of 2015 estimated that the number of lemurs captured in freedom for the exotic pet market could reach the creepy number of 28,000 in the last 3 years17.

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A ring-tailed lemur (Lemur catta) in a pet cage. The smuggling to supply the exotic pet market is decimating its population (Photo: Importance of lemurs).

IS THERE ANY LONG TERM SOLUTION?

There is always a way to make things get better. Here there is some of them:

  • Avoid selective logging of rosewood should be the number one priority to reduce the collateral damage it generates. Since 2011 the Malagasy species of the genus Dalbergia belong to CITES Appendix 3, granting them a greater degree of protection and regulating their trade. However, the controls remain inefficient and wood is coming from Madagascar towards the ports of China. In 2013, CITES urged China to increase controls in ports, but nothing was done about it. As indicated in this 2015 article of The guardian18, illegal timber from Madagascar continues entering in large amounts, because Chinese law allows importing timber without requiring export permits.
  • Effective monitoring forest by independent observers could yield results. In fact, this system has already been implemented in countries such as Cambodia and Cameroon, achieving good results19.
  • DNA fingerprinting is another method that it has recently been used on confiscated ivory to determine which populations of African elephants are being hunted. DNA testing has already been applied recently to track limber in other countries20.
  • Finally, it is necessary that each and every one of us avoid purchasing exotic pets from Madagascar if there is no legal certification that tells us we are not damaging them.

With all these solutions, an increase of public awareness and a greater international responsability regarding environmental problems, it may still has a glimmer of hope for wildlife in Madagascar.

REFERENCES

  1. http://www.marojejy.com/Intro_e.htm
  2. Hobbes & Dolan (2008), p. 517
  3. Okajima, Yasuhisa; Kumazawa, Yoshinori (15 July 2009). “Mitogenomic perspectives into iguanid phylogeny and biogeography: Gondwanan vicariance for the origin of Madagascan oplurines”.Gene(Elsevier441 (1–2): 28–35. doi:1016/j.gene.2008.06.011.PMID 18598742.
  4. Conservation International (2007).“Madagascar and the Indian Ocean Islands”Biodiversity Hotspots. Conservation International. Archived from the original on 24 August 2011. Retrieved 24 August 2011.
  5. Callmander, Martin; et. al (2011). “The endemic and non-endemic vascular flora of Madagascar updated”. Plant Ecology and Evolution144 (2): 121–125. doi:5091/plecevo.2011.513. Archived from the original (PDF) on 11 February 2012. Retrieved 11 February 2012.
  6. http://www.wildmadagascar.org/overview/FAQs/why_is_Madagascar_poor.html
  7. http://allafrica.com/stories/201510070931.html
  8. http://www.marojejy.com/Breves_e.htm
  9. http://news.mongabay.com/2009/08/lessons-from-the-crisis-in-madagascar-an-interview-with-erik-patel/
  10. http://newafricanmagazine.com/madagascar-a-new-political-crisis/
  11. http://news.mongabay.com/2015/09/activist-arrested-while-illegal-loggers-chop-away-at-madagascars-forests/
  12. http://news.mongabay.com/2009/12/major-international-banks-shipping-companies-and-consumers-play-key-role-in-madagascars-logging-crisis/
  13. https://www.sciencedaily.com/releases/2010/05/100527141957.htm
  14. http://www.bbc.com/news/science-environment-18825901
  15. http://www.ecologiablog.com/post/4016/malasia-se-incauta-de-300-tortugas-en-peligro-de-extincion-procedentes-de-madagascar
  16. http://news.mongabay.com/2009/03/conservation-groups-condemn-open-and-organized-plundering-of-madagascars-natural-resources/
  17. http://journals.cambridge.org/action/displayAbstract;jsessionid=AC9F12B7B37BD27ED8538264F7A0B46B.journals?aid=10245472&fileId=S003060531400074X
  18. http://www.theguardian.com/environment/2015/feb/16/rosewood-madagascar-china-illegal-rainforest
  19. http://www.trocaire.org/sites/trocaire/files/resources/policy/2006-forest-monitoring.pdf
  20. http://voices.nationalgeographic.com/2010/05/20/madagascar_logging_crisis/
  21. Imagen de portada: Alexis Dittberner, n0mad.mu project.

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Migration in danger! The disappearance of the monarch butterfly

Generally, we tend to think of migration as an event exclusively linked to complex organisms (like mammals or birds). But there are always exceptions: the North American populations of the monarch butterfly (Danaus plexippus) cover a distance of almost 5000km (more than some complex animals!) in order to reach their hibernation areas, where there can be concentrated thousands of specimens during the winter. Unfortunately, the migration phenomenon depend on many factors that are being damaged by anthropogenic pressure nowadays, so that the future of these populations and also their migration are in danger.

Throughout this article, you will learn some of the most curious biology traits of these organisms, the main causes that could be endangering their populations and the consequences that this would entail.

INTRODUCTION

The monarch butterfly (Danaus plexippus) is a butterfly of the Nymphalidae family. It’s also probably one the most well-known butterflies of North America due to its long migration, that their specimens perform from the north of EEUU and Canada to California coast and Mexico, covering a distance of almost 5000km to reach their hibernation areas. It’s, by far, the insect that performs the widest and large migration of all.

Specimen of monarch butterfly (Danaus plexippus) with its typical color pattern: white, black and orange (Picture by Peter Miller on Flickr, Creative Commons).

Although the North American populations of this species are the most known worldwide due to their migration pattern, there are also monarch butterflies in some Atlantic islands (Canary islands, Azores and Madeira), and sometimes also as eventual migrators that reach the coasts of Western Europe (United Kingdom and Spain). Moreover, they were introduced in New Zealand and Australia during the XIX century.

LIFE CYCLE

The life cycle of this species is very unique. First of all, they’re considered specialist butterflies: they lay their eggs exclusively over plants of the Asclepias genus (also known as milkweeds), and their newborn caterpillars (which are black, white and yellow striped) feed only on these plants. This is a very interesting fact, because the plants of this genus contain cardiac glycosides that are progressively assimilated by the caterpillar tissues, which let them to acquire a disgusting taste that prevents them to be predated. This taste will last during their adult phase.

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Caterpillar of a monarch butterfly (Picture by Lisa Brown on Flickr, Creative Commons).

Once completed the larva phase, the metamorphosis take place so that the caterpillars become adult butterflies colored in black, white and orange. Both caterpillar and butterfly color patterns carry out a communicative function: it’s a mechanism to warn other animal of their toxicity, fact which is known as aposematic mimicry (this phenomenon is very frequent in a lot of group of animals, even in mammals).

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Phases of the metamorphosis of the monarch butterfly (Picture by Steve Greer Photography).

The adult phase also has some particularities: during the mating season (April-August) some generations of adults are generated, and each of them has a life expectancy of a few weeks, more or less. Then, an awesome event takes place: the butterflies of the generation born at the end of August (when temperatures get low and days became shorter) stops the maturing process of their reproductive organs (phenomenon known as diapause) so they can spend their energy on enlarging their life expectancy to 9 months. This generation is known as “Methuselah generation” due to its longevity.

The increase of their longevity allows this generation to cover the long distance required to reach the hibernation areas during the autumn (Mexico and California coast) and then to come back to the north of America at the end of the winter.

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Hundreds of monarch butterflies flying over the place called ‘El Santuario ‘El Rosario” (Mexico) (Picture by Luna sin estrellas on Flickr, Creative Commons).

A ROUND TRIP: THE GREAT MIGRATION

Although the monarch butterfly isn’t only located in North America, there is no evidence nowadays showing that the other populations of monarch butterflies do such a long migration. It’s believed that the fact that only these populations of butterflies go on a trip this long is due to the wide spreading of plants of the Asclepias genus over all North America that took place in the past. Scientists suggest this event allowed the monarch butterflies to spread progressively to the south.

WHICH PLACES DO THE BUTTERFLIES VISIT?

A migration is always a complex process. In this case, the migration to the south is divided into two simultaneous migrations:

  • The east migration: this trip is made by those butterflies that fly from the east of the Rocky Mountains, South of Canada and a big part of USA to the central part of Mexico (90% of all the monarch butterflies located in North America go on this trip).
  • The west migration: this trip is made by those butterflies that fly from the west of the Rocky Mountains, South of Canada and a little part of USA to the California coast (10% of all the monarch butterflies located in North America go on this trip).
Migratory patterns of the monarch butterfly in North America (round trip) (Sources: Monarchwatch.org y Monarch Alert).

Once in the winter habitats, the butterflies plunge into a lethargic state until the next spring, when they become sexually active and start mating before heading again to the north.

It’s a very surprising event seeing all the butterflies sleeping together and covering all the plants and trees of the winter habitats!

Thousands of butterflies gather over the vegetation (Picture by Carlos Adampol Galindo on Flickr, Creative Commons).

PROTECTED AREAS

There exists a lot of protected areas all over the places where the butterflies go through.

One of the most important protected areas is the Monarch Butterfly Biosphere Reserve (Mexico City), which is considered a World Heritage Site by the UNESCO since 2008.

Monarch Butterfly Biosphere Reserve (Picture by Michelle Tribe on Flickr, Creative Commons).

And why are these butterflies so protected? Besides the fact that their migration pattern is considered an incredible phenomenon, they are pollinators that contribute to the pollination of the wild flora and also of the crops of North America.

THE ‘QUEEN’ IS IN DANGER!

Although there exists a huge effort to protect them, the migratory phenomenon of the North American monarch butterflies is in danger nowadays due to the anthropic pressure, which could also put their populations at risk in the future.

According to the data generated by the WWF, the surface of the winter habitats occupied by these butterflies has decreased 94% in 10 years, going from 27,48 acres occupied in 2003 to only 1,65 acres in 2013. This is the lower value registered in the last 20 years.

Decresing of the surface occupied by the monarch butterflies in the winter habitats (Data form WWF website).

Even though the surface occupied by these organisms has been fluctuating over the years as a part of a natural process, this pronounced decreasing that has taken place in only a few years suggests that butterflies are stopping their annual migrations to the south.

Total occupied area by the butterflies in their winter habitats since 1993 to 2013 (WWF-Telcel-CONANP).

This recession has also been registered in other species of butterflies at different emplacements all over the world, so there must exist some kind of factor in common with the ones affecting the North American monarch butterfly populations.

WHAT COULD BE THE MAIN CAUSES OF THIS RECESSION?

According to the WWF, the main causes that could being putting in danger the migration process of the monarch butterflies are:

  • The reduction of the surface occupied by plants of the Asclepias genus: as we said above, the caterpillars feed exclusively on these plants. But the use of certain herbicides and the changes on the rain patterns could being limiting their dispersal over a big part of North America.
  • Deforestation: cutting down trees massively and the subsequent desertization could being reducing their winter habitats.
  • Extreme climate: the global change, which entails changes in temperature and rain patterns, could being putting at risk the survival of adult butterflies, preventing them to reach the longevity required to carry out complete migrations.

WHICH EFFORTS ARE MADE TO PROTECT THESE POPULATIONS?

As I said above, monarch butterflies are an essential part of the pollination net of North America and also iconic insects, so there exists a big interest on protecting them.

Nowadays, most of the protected areas of North America are making a big effort to improve the quality of their habitats. Among them, the Monarch Butterfly Biosphere Reserve (Mexico) along with the WWF are trying to restore the woods where butterflies hibernate and also promoting a sustainable tourism (enter this link to see more information).

 .            .            .

The case of the monarch butterfly is only one of a huge list of animals in danger. Nowadays, a lot of animals with complex migration patterns and wide spreading areas are suffering similar pressures, mostly of them with an anthropogenic origin. There’s still so much work to do, and it depends on all of us.

REFERENCES

Main picture by Carlos Adampol Galindo on Flickr.

Difusió-anglès

The plants and the climate change

Since a few years ago, we have heard about the climate change. Nowadays, it is already evident and also a concern. This not only affects to us, the humans, but to all kind of life. It has been talked enough about the global warming, but perhaps, what happens to the vegetation has not been much diffused. There are many things affected by climate change and vegetation is also one of them. In addition, the changes in this also affect us. But, what are these changes? how can the vegetation regulate them? And how we can help to mitigate them through plants?

CHANGES ON PLANTS

Biomes distribution

In general, due to climate change, an increase of precipitations in some parts of the world are expected, while in others a decrease is awaited. A global temperature increment is also denoted. This leads to an alteration in the location of the biomes, large units of vegetation (e.g.: savannas, tropical forests, tundras, etc.).

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Biome triangle classified by latitude, altitude and humidity (Author: Peter Halasaz).

On the other hand, there is an upward trend in the distribution of species in the high latitudes and a detriment in the lower latitudes. This has serious associated problems; the change in the species distribution affects their conservation and genetic diversity. Consequently, the marginal populations in lower latitudes, which have been considered very important for the long-term conservation of genetic diversity and due their evolutionary potential, are threatened by this diversity loss. And conversely, the populations in high latitudes would be affected by the arrival of other competing species that could displace those already present, being as invasive.

Species distribution

Within the scenario of climate change, species have some ability to adjust their distribution and to adapt to this.

But, what type of species may be responding more quickly to this change? It appears that those with a faster life cycle and a higher dispersion capacity will be showing more adaptability and a better response. This could lead to a loss of some plants with slower rates.

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The Purple milk Thistle (Galactites tomentosa) is a plant with a fast life cycle and high distribution capacity  (Author: Ghislain118).

One factor that facilitates adjustment in the distribution is the presence of wildlife corridors: these are parts of the geographical area that enable connectivity and movement of species from one population to another. They are important because they prevent that some species can remain isolated and because they can also allow the movement to new regions.

Another factor is the altitudinal gradient, which provides shelter for many species, facilitates the presence of wildlife corridors and permits redistribution of species along altitude. Therefore, in those territories where there is greater altitudinal range, the conservation is favored.

In short, the ability of species to cope with climate change depends on the plant characteristics and the territory attributes. And, conversely, the species vulnerability to climate change occurs when the speed to displace their distribution or adapt their lives is less than the climate change velocity.

At internal level

Climate change also affects the plant as an organism, as it causes changes in their metabolism and phenology (periodic or seasonal rhythms of the plant).

One of the effects that pushes the climate change is the carbon dioxide (CO2) concentration increase in the atmosphere. This could produce a fertilization phenomenon of vegetation. Due the COincrease in the atmosphere it also increases the uptake by plants, thus increasing the photosynthesis and allowing greater assimilation. But, this is not all advantages, because for this an important water loss occurs due that the stomata (structures that allow gas exchange and transpiration) remain open long time to incorporate CO2. So, there are opposing effects and fertilization will depend on the plant itself, but the local climate will also determine this process. Many studies have shown that various plants react differently to the COincrease, since the compound affects various physiological processes and therefore there are not unique responses. Then, we find a factor that alters the plant metabolism and we cannot predict what will be the effects. Furthermore, this fertilizer effect is limited by the nutrients amount and without them production slows.

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Photosynthesis process (Author: At09kg).

On the other hand, we must not forget that climate change also alters the weather and that this affects the vegetation growth and its phenology. This can have even an impact on a global scale; for example, could produce an imbalance in the production of cultivated plants for food.

PLANTS AS CLIMATE REGULATORS

Although one cannot speak of plants as regulators of global climate, it is clear that there is a relationship between climate and vegetation. However, this relationship is somewhat complicated because the vegetation has both effects of cooling and heating the weather.

The vegetation decreases the albedo; dark colours absorb more solar radiation and, in consequence, less sunlight is reflected outward. And besides, as the plants surface is usually rough, the absorption is increased. Consequently, if there is more vegetation, local temperature (transmitted heat) intensifies.

But, on the other hand, by increasing vegetation there is more evapotranspiration (set of water evaporation from a surface and transpiration through the plant). So, the heat is spent on passing the liquid water to gas, leading to a cooling effect. In addition, evapotranspiration also helps increase local rainfall.

Biophysical effects of landcover
Biophysical effects of different land uses and its consequences on the local climate. (From Jackson et al. 2008. Environmental Research Letters.3: article 0440066).

Therefore, it is an ambiguous process and in certain environments the cooling effect outweighs, while in others the heating effect has more relevance.

MITIGATION

Nowadays, there are several proposals to reduce climate change, but, in which way can the plants cooperate?

Plant communities can act as a sinks, carbon reservoirs, because through CO2 assimilation, they help to offset carbon emissions. Proper management of agricultural and forest ecosystems can stimulate capture and storage of carbon. On the other hand, if deforestation were reduced and protection of natural habitats and forests increased, emissions would be diminished and this would stimulate the sink effect. Still, there is a risk that these carbon sinks may become emission sources; for example, due to fire.

Finally, we must introduce biofuels: these, unlike fossil fuels (e.g. petroleum), are renewable resources, since they are cultivated plants for use as fuels. Although they fail to remove CO2 from the atmosphere or reduce carbon emissions, they get to avoid this increase in the atmosphere. For this reason, they may not become a strict mitigation measure, but they can keep neutral balance of uptake and release. The problem is that they can lead to side effects on social and environmental level, such as increased prices for other crops or stimulate deforestation to establish these biofuel crops, what should not happen.

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Sugarcane crop (Saccharum officinarum) in Brazil to produce biofuel (Author: Mariordo).

Difusió-anglès

REFERENCES